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Sample records for rapid resolution liquid

  1. Identification of the Related Substances in Ampicillin Capsule by Rapid Resolution Liquid Chromatography Coupled with Electrospray Ionization Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2014-01-01

    Full Text Available Rapid Resolution Liquid Chromatography coupled with Electrospray Ionization Tandem Mass Spectrometry (RRLC-ESI-MSn was used to separate and identify related substances in ampicillin capsule. The fragmentation behaviors of related substances were used to identify their chemical structures. Finally, a total of 13 related substances in ampicillin capsule were identified, including four identified components for the first time and three groups of isomers on the basis of the exact mass, fragmentation behaviors, retention time, and chemical structures in the literature. This study avoided time-consuming and complex chemosynthesis of related substances of ampicillin and the results could be useful for the quality control of ampicillin capsule to guarantee its safety in clinic. In the meantime, it provided a good example for the rapid identification of chemical structures of related substances of drugs.

  2. Qualitative and Quantitative Analysis of Andrographis paniculata by Rapid Resolution Liquid Chromatography/Time-of-Flight Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Jian-Fei Qin

    2013-09-01

    Full Text Available A rapid resolution liquid chromatography/time-of-flight tandem mass spectrometry (RRLC-TOF/MS method was developed for qualitative and quantitative analysis of the major chemical constituents in Andrographis paniculata. Fifteen compounds, including flavonoids and diterpenoid lactones, were unambiguously or tentatively identified in 10 min by comparing their retention times and accurate masses with standards or literature data. The characteristic fragmentation patterns of flavonoids and diterpenoid lactones were summarized, and the structures of the unknown compounds were predicted. Andrographolide, dehydroandrographolide and neoandrographolide were further quantified as marker substances. It was found that the calibration curves for all analytes showed good linearity (R2 > 0.9995 within the test ranges. The overall limits of detection (LODs and limits of quantification (LOQs were 0.02 μg/mL to 0.06 μg/mL and 0.06 μg/mL to 0.2 μg/mL, respectively. The relative standard deviations (RSDs for intra- and inter-day precisions were below 3.3% and 4.2%, respectively. The mean recovery rates ranged from 96.7% to 104.5% with the relative standard deviations (RSDs less than 2.72%. It is concluded that RRLC-TOF/MS is powerful and practical in qualitative and quantitative analysis of complex plant samples due to time savings, sensitivity, precision, accuracy and lowering solvent consumption.

  3. Development and validation of a rapid resolution liquid chromatography method for the screening of dietary plant isoprenoids: carotenoids, tocopherols and chlorophylls.

    Science.gov (United States)

    Stinco, Carla M; Benítez-González, Ana M; Hernanz, Dolores; Vicario, Isabel M; Meléndez-Martínez, Antonio J

    2014-11-28

    A rapid resolution liquid chromatography (RRLC) method was developed and validated for the simultaneous determination of nine carotenoids compounds (violaxanthin, lutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene, lycopene, phytoene, phytofluene), four tocopherols and four chlorophylls and derivates (chlorophylls and pheophytins). The methodology consisted in a micro-extraction procedure with or without saponification and subsequent analysis by RRLC. The limits of detection were saponification step was performed. The recovery of the method without the saponification step ranged from 92% to 107%, whilst that when saponification was carried out ranged from 60% for α-tocopherol to 82% for β-carotene. Finally, the applicability of the method was demonstrated by the identification and quantification of isoprenoids in different samples. The methodology is appropriate for the high-throughput screening of dietary isoprenoids in fruits and vegetables. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Ultra trace determination of 31 pesticides in water samples by direct injection-rapid resolution liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Díaz, Laura; Llorca-Pórcel, Julio; Valor, Ignacio

    2008-08-22

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for the detection of pesticides in tap and treated wastewater was developed and validated according to the ISO/IEC 17025:1999. Key features of this method include direct injection of 100 microL of sample, an 11 min separation by means of a rapid resolution liquid chromatography system with a 4.6 mm x 50 mm, 1.8 microm particle size reverse phase column and detection by electrospray ionization (ESI) MS-MS. The limits of detection were below 15 ng L(-1) and correlation coefficients for the calibration curves in the range of 30-2000 ng L(-1) were higher than 0.99. Precision was always below 20% and accuracy was confirmed by external evaluation. The main advantages of this method are direct injection of sample without preparative procedures and low limits of detection that fulfill the requirements established by the current European regulations governing pesticide detection.

  5. Sequential determination of fat- and water-soluble vitamins in Rhodiola imbricata root from trans-Himalaya with rapid resolution liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Tayade, Amol B; Dhar, Priyanka; Kumar, Jatinder; Sharma, Manu; Chaurasia, Om P; Srivastava, Ravi B

    2013-07-30

    A rapid method was developed to determine both types of vitamins in Rhodiola imbricata root for the accurate quantification of free vitamin forms. Rapid resolution liquid chromatography/tandem mass spectrometry (RRLC-MS/MS) with electrospray ionization (ESI) source operating in multiple reactions monitoring (MRM) mode was optimized for the sequential analysis of nine water-soluble vitamins (B1, B2, two B3 vitamins, B5, B6, B7, B9, and B12) and six fat-soluble vitamins (A, E, D2, D3, K1, and K2). Both types of vitamins were separated by ion-suppression reversed-phase liquid chromatography with gradient elution within 30 min and detected in positive ion mode. Deviations in the intra- and inter-day precision were always below 0.6% and 0.3% for recoveries and retention time. Intra- and inter-day relative standard deviation (RSD) values of retention time for water- and fat-soluble vitamin were ranged between 0.02-0.20% and 0.01-0.15%, respectively. The mean recoveries were ranged between 88.95 and 107.07%. Sensitivity and specificity of this method allowed the limits of detection (LOD) and limits of quantitation (LOQ) of the analytes at ppb levels. The linear range was achieved for fat- and water-soluble vitamins at 100-1000 ppb and 10-100 ppb. Vitamin B-complex and vitamin E were detected as the principle vitamins in the root of this adaptogen which would be of great interest to develop novel foods from the Indian trans-Himalaya. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim

    2012-05-04

    RATIONALE To enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high-resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated. RESULTS Fourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2- to 10-fold for the tested PAHs compared to those obtained with pure chlorobenzene. CONCLUSIONS A novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high-resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/;μL levels within a 5 min run time with high mass accuracy a;circ4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.

  7. Rapid profiling of antimicrobial compounds characterising B. subtilis TR50 cell-free filtrate by high-performance liquid chromatography coupled to high-resolution Orbitrap™ mass spectrometry.

    Science.gov (United States)

    Monaci, Linda; Quintieri, Laura; Caputo, Leonardo; Visconti, Angelo; Baruzzi, Federico

    2016-01-15

    Several Bacillus strains, typically isolated from different food sources, represent renowned producers of a multitude of low and high molecular weight compounds, including lipopeptides and macrolactones, with an importance for their antimicrobial activity. The high homology shared by many of these compounds also occurring as closely related isoforms poses a challenge in their prompt detection. Identification and structural elucidation is generally achieved by matrix-assisted laser desorption/ionization (MALDI) or liquid chromatography (LC) coupled to mass spectrometry (MS) after a pre-fractionation and/or purification step of the extract. In this paper we report the application of a method based on LC separation and high-resolution Orbitrap™-based MS for the rapid screening of raw filtrate of the strain Bacillus subtilis TR50 endowed with antimicrobial activity, without requiring any sample pre-treatment. Upon direct analysis of the cell-free filtrate of Bacillus subtilis TR50 by high-resolution mass spectrometry (HRMS), different compounds families, that proved to exert a remarked antimicrobial activity against several foodborne pathogens, can be readily displayed along the chromatographic run. Among them, three different classes were identified and characterized belonging to the iturin, fengycin and surfactin groups. The high resolving power and accurate mass accuracy provided by the HRMS system in use ensured an enhanced selectivity compared to other mass spectrometers. In addition, after activation of the HCD cell, the HR-MS/MS spectra can provide insights in the structural elucidation of several compounds. The acquisition of HRMS spectra of raw filtrates of subtilis strains allows untargeted analysis of the major classes of compounds produced to be performed, thus facilitating identification of other unknown bioactive molecules after retrospective analysis. These features make this approach a fast tool applicable to the rapid screening and further

  8. Rapid resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry-based metabolomics approach to study the effects of jieduquyuziyin prescription on systemic lupus erythematosus.

    Science.gov (United States)

    Ding, Xinghong; Hu, Jinbo; Wen, Chengping; Ding, Zhishan; Yao, Li; Fan, Yongsheng

    2014-01-01

    Jieduquyuziyin prescription (JP), a traditional Chinese medicine (TCM) prescription, has been widely used for the clinical treatment of systemic lupus erythematosus (SLE). However, the complex chemical constituents of JP and the multifactorial pathogenesis of SLE make research on the therapeutic mechanism of JP in SLE challenging. In this paper, a serum metabolomics approach based on rapid resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (RRLC-Q-TOF/MS) was employed to acquire the metabolic characteristics of serum samples obtained from mice in the SLE model group, JP-treated group, prednisone acetate (PA)-treated group and control group. The orthogonal partial least squares (OPLS) was applied to recognize metabolic patterns, and an obvious separation of groups was obtained. Thirteen metabolites, namely, phosphatidylethanolamine (PE 20:3), hepoxilin B3, lyso- phosphatidylethanolamine (lyso-PE 22:6), 12S-hydroxypentaenoic acid (12S-HEPE), traumatic acid, serotonin, platelet-activating factor (PAF), phosphatidylcholine (PC 20:5),eicosapentaenoic acid (EPA), 12(S)-hydroxyei- cosatetraenoic acid (12S-HETE), 14-hydroxy docosahexaenoic acid (14-HDOHE), lyso-phosphatidylcholine (lyso-PC 20:4), and indole acetaldehyde, were identified and characterized as differential metabolites involved in the pathogenesis of SLE. After treatment with JP, the relative content of 12(S)-HETE, PAF, 12(S)-HEPE, EPA, PE (20:3), Lyso-PE(22:6), and 14-HDOHE were effectively regulated, which suggested that the therapeutic effects of JP on SLE may involve regulating disturbances to the metabolism of unsaturated fatty acid, tryptophan and phospholipid. This research also demonstrated that metabolomics is a powerful tool for researching complex disease mechanisms and evaluating the mechanism of action of TCM.

  9. Analysis of cocoa flavanols and procyanidins (DP 1-10) in cocoa-containing ingredients and products by rapid resolution liquid chromatography: single-laboratory validation.

    Science.gov (United States)

    Machonis, Philip R; Jones, Matthew A; Kwik-Uribe, Catherine

    2014-01-01

    Recently, a multilaboratory validation (MLV) of AOAC Official Method 2012.24 for the determination of cocoa flavanols and procyanidins (CF-CP) in cocoa-based ingredients and products determined that the method was robust, reliable, and transferrable. Due to the complexity of the CF-CP molecules, this method required a run time exceeding 1 h to achieve acceptable separations. To address this issue, a rapid resolution normal phase LC method was developed, and a single-laboratory validation (SLV) study conducted. Flavanols and procyanidins with a degree of polymerization (DP) up to 10 were eluted in 15 min using a binary gradient applied to a diol stationary phase, detected using fluorescence detection, and reported as a total sum of DP 1-10. Quantification was achieved using (-)-epicatechin-based relative response factors for DP 2-10. Spike recovery samples and seven different types of cocoa-based samples were analyzed to evaluate the accuracy, precision, LOD, LOQ, and linearity of the method. The within-day precision of the reported content for the samples was 1.15-5.08%, and overall precision was 3.97-13.61%. Spike-recovery experiments demonstrated recoveries of over 98%. The results of this SLV were compared to those previously obtained in the MLV and found to be consistent. The translation to rapid resolution LC allowed for an 80% reduction in analysis time and solvent usage, while retaining the accuracy and reliability of the original method. The savings in both cost and time of this rapid method make it well-suited for routine laboratory use.

  10. Time resolution research in liquid scintillating detection

    International Nuclear Information System (INIS)

    He Hongkun; Shi Haoshan

    2006-01-01

    The signal processing design method is introduced into liquid scintillating detection system design. By analyzing the signal of liquid scintillating detection, improving time resolution is propitious to upgrade efficiency of detecting. The scheme of realization and satisfactory experiment data is demonstrated. Besides other types of liquid scintillating detection is the same, just using more high speed data signal processing techniques and elements. (authors)

  11. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim; Amad, Maan H.; Al-Talla, Zeyad

    2012-01-01

    with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs

  12. Profile of phenolic compounds of Brazilian virgin olive oils by rapid resolution liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry (RRLC-ESI-TOF-MS).

    Science.gov (United States)

    Ballus, Cristiano Augusto; Quirantes-Piné, Rosa; Bakhouche, Abdelhakim; da Silva, Luiz Fernando de Oliveira; de Oliveira, Adelson Francisco; Coutinho, Enilton Fick; da Croce, Dorli Mario; Segura-Carretero, Antonio; Godoy, Helena Teixeira

    2015-03-01

    In recent years, agronomical researchers began to cultivate several olive varieties in different regions of Brazil to produce virgin olive oil (VOO). Because there has been no reported data regarding the phenolic profile of the first Brazilian VOO, the aim of this work was to determine phenolic contents of these samples using rapid-resolution liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry. 25 VOO samples from Arbequina, Koroneiki, Arbosana, Grappolo, Manzanilla, Coratina, Frantoio and MGS Mariense varieties from three different Brazilian states and two crops were analysed. It was possible to quantify 19 phenolic compounds belonging to different classes. The results indicated that Brazilian VOOs have high total phenolic content because the values were comparable with those from high-quality VOOs produced in other countries. VOOs from Coratina, Arbosana and Grappolo presented the highest total phenolic content. These data will be useful in the development and improvement of Brazilian VOO. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. The Profiling and Identification of the Absorbed Constituents and Metabolites of Guizhi Decoction in Rat Plasma and Urine by Rapid Resolution Liquid Chromatography Combined with Quadrupole-Time-of-Flight Mass Spectrometry

    Science.gov (United States)

    Xiang, Hongjun; Zhang, Lishi; Song, Jiannan; Fan, Bin; Nie, Yinglan; Bai, Dong; Lei, Haimin

    2016-01-01

    Guizhi decoction (GZD), a well-known traditional Chinese medicine (TCM) prescription consisting of Ramulus Cinnamomi, Radix Paeoniae Alba, Radix Glycyrrhizae, Fructus Jujubae and Rhizoma Zingiberis Recens, is usually used for the treatment of common colds, influenza, and other pyretic conditions in the clinic. However, the absorbed ingredients and metabolic compounds of GZD have not been reported. In this paper, a method incorporating rapid resolution liquid chromatography (RRLC) with quadrupole-time-of-flight mass spectrometry (Q-TOF-MS) was used to identify ingredients after oral administration of GZD. Identification of the primary components in GZD, drug-containing serum and urine samples was carried out in order to investigate the assimilation and metabolites of the decoction in vivo. By comparing the total ion chromatograms (TICs) of GZD, a total of 71 constituents were detected or characterized. By comparing TICs of blank and dosed rat plasma, a total of 15 constituents were detected and identified as prototypes according to their retention time (tR) and MS, MS/MS data. Based on this, neutral loss scans of 80 and 176 Da in samples of rat plasma and urine helped us to identify most of the metabolites. Results showed that the predominant metabolic pathways of (epi) catechin and gallic acid were sulfation, methylation, glucuronidation and dehydroxylation; the major metabolic pathways of flavone were hydrolysis, sulfation and glucuronidation. Furthermore, degradation, oxidation and ring fission were found to often occur in the metabolism process of GZD in vivo. PMID:27626411

  14. High Resolution Displays Using NCAP Liquid Crystals

    Science.gov (United States)

    Macknick, A. Brian; Jones, Phil; White, Larry

    1989-07-01

    Nematic curvilinear aligned phase (NCAP) liquid crystals have been found useful for high information content video displays. NCAP materials are liquid crystals which have been encapsulated in a polymer matrix and which have a light transmission which is variable with applied electric fields. Because NCAP materials do not require polarizers, their on-state transmission is substantially better than twisted nematic cells. All dimensional tolerances are locked in during the encapsulation process and hence there are no critical sealing or spacing issues. By controlling the polymer/liquid crystal morphology, switching speeds of NCAP materials have been significantly improved over twisted nematic systems. Recent work has combined active matrix addressing with NCAP materials. Active matrices, such as thin film transistors, have given displays of high resolution. The paper will discuss the advantages of NCAP materials specifically designed for operation at video rates on transistor arrays; applications for both backlit and projection displays will be discussed.

  15. Energy resolution in liquid argon doped with allene

    International Nuclear Information System (INIS)

    Ichinose, H.; Doke, T.; Masuda, K.; Shibamura, E.

    1989-01-01

    Studies have been made on liquid argon as detection medium with large volume and good energy and position resolution. It is advantageous to dope liquid argon with molecules with an ionization potential lower than the energy of scintillation light. In the present work, the energy resolution for 5.305MeV alpha particles is examined, and the effect of allene added to liquid argon is investigated. Some preliminary results for 976 KeV electrons are also presented. Allene is purified by two methods: (a) small-quantity purification and (b) mass purification. Three methods are tried for mixing allene with argon. Results concerning the allene purification methods, effect of allene concentration, and allene-argon mixing methods are presented. Discussion is made of the collected charge and energy resolution. It is concluded that the addition of allene to liquid argon greatly improves the energy resolution of 5.305 MeV alpha particles. The best intrinsic resolution is 1.4 percent FWHM obtained for 4 ppm allene doped liquid argon. In the case of 976 KeV electron radiation, energy resolution is not improved by adding allene to liquid argon. The best resolution is 31 KeV FWHM obtaiend for 65ppm allene doped liquid argon. (N.K.)

  16. Rapid spontaneous resolution of an acute subdural hematoma: Case report

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Won Kyong; Kim, Pyo Nyun; Kim, Il Young; Lee, Byoung Ho; Lee, Kyeong Seok; Bae, Hack Gun; Yun, Il Gyu [Soonchunhyang University, Chonan Hospital, Chonan (Korea, Republic of)

    1989-10-15

    We present a case of acute subdural hematoma which was rapidly resolved without surgical intervention. This 31 year old man had a hematoma of which thickness was 9 mm and was paraplegic due to fracture-dislocation of thoracic spine at the level of TII-12 Rapid recovery of consciousness despite of sizable hematoma made to take a serial CT scanning instead of immediate surgical interventions. The hematoma was resolved within 4 hours without surgery. Possible mechanism of this rapid spontaneous resolution is discussed with brief review of the related literature.

  17. Predictors of rapid spontaneous resolution of acute subdural hematoma.

    Science.gov (United States)

    Fujimoto, Kenji; Otsuka, Tadahiro; Yoshizato, Kimio; Kuratsu, Jun-ichi

    2014-03-01

    Acute subdural hematoma (ASDH) usually requires emergency surgical decompression, but rare cases exhibit rapid spontaneous resolution. The aim of this retrospective study was to identify factors predictive of spontaneous ASDH resolution. A total of 366 consecutive patients with ASDH treated between January 2006 and September 2012 were identified in our hospital database. Patients with ASDH clot thickness >10mm in the frontoparietotemporal region and showing a midline shift >10mm on the initial computed tomography (CT) scan were divided into two groups according to subsequent spontaneous resolution. Univariate and multivariate logistic regression analyses were used to identify factors predictive of rapid spontaneous ASDH resolution. Fifty-six ASDH patients met study criteria and 18 demonstrated rapid spontaneous resolution (32%). Majority of these patients were not operated because of poor prognosis/condition and in accordance to family wishes. Univariate analysis revealed significant differences in use of antiplatelet agents before head injury and in the incidence of a low-density band between the hematoma and inner wall of the skull bone on the initial CT. Use of antiplatelet agents before head injury (OR 19.6, 95% CI 1.5-260.1, p=0.02) and the low-density band on CT images (OR 40.3, 95% CI 3.1-520.2, p=0.005) were identified as independent predictive factors by multivariate analysis. Our analysis suggested that use of antiplatelet agents before head injury and a low-density band between the hematoma and inner skull bone on CT images (indicative of cerebrospinal fluid infusion into the subdural space) increase the probability of rapid spontaneous resolution. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Spontaneous Rapid Resolution of Acute Epidural Hematoma in Childhood

    Directory of Open Access Journals (Sweden)

    Ismail Gülşen

    2013-01-01

    Full Text Available Acute epidural hematoma is a critical emergency all around the world, and its aggressive diagnosis and treatment are of vital importance. Emergent surgical evacuation of the hematoma is known as standard management; however, conservative procedures are also used for small ones. Spontaneous rapid resolution of these hematomas has also been reported in eight pediatric cases. Various theories have been proposed to explain the underlying pathophysiology of this resolution. Herein, we are reporting a new pediatric case with spontaneously resolving acute epidural hematoma 12 hours after admission to the emergency room.

  19. Liquid Scintillation High Resolution Spectral Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    2010-08-06

    The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

  20. Liquid Scintillation High Resolution Spectral Analysis

    International Nuclear Information System (INIS)

    Grau Carles, A.; Grau Malonda, A.

    2010-01-01

    The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

  1. Rapid, facile synthesis of conjugated polymer zwitterions in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Page, Zachariah A. [Polymer Science & Engineering Department; Conte Center for Polymer Research; University of Massachusetts; Amherst, USA; Liu, Feng [Polymer Science & Engineering Department; Conte Center for Polymer Research; University of Massachusetts; Amherst, USA; Russell, Thomas P. [Polymer Science & Engineering Department; Conte Center for Polymer Research; University of Massachusetts; Amherst, USA; Emrick, Todd [Polymer Science & Engineering Department; Conte Center for Polymer Research; University of Massachusetts; Amherst, USA

    2014-01-01

    Ionic liquids (ILs) were utilized for the rapid air-stable Suzuki polymerization of polar zwitterionic thiophene monomers, precluding the need for volatile organic solvents, phosphine ligands and phase transfer catalysts typically used in conjugated polymer synthesis.

  2. Resolution of RNA using high-performance liquid chromatography

    NARCIS (Netherlands)

    Mclaughlin, L.W.; Bischoff, Rainer

    1987-01-01

    High-performance liquid chromatographic techniques can be very effective for the resolution and isolation of nucleic acids. The characteristic ionic (phosphodiesters) and hydrophobic (nucleobases) properties of RNAs can be exploited for their separation. In this respect anion-exchange and

  3. Rapid-action valve especially for liquid metal

    International Nuclear Information System (INIS)

    Velek, V.; Cejka, J.; Jakl, J.

    1976-01-01

    A rapid-action large-diameter valve and control fitting was designed for cooling circuits of nuclear power plants with fast liquid metal cooled reactors, namely sodium cooled. The design meets the requirements for axial symmetry about the flow axis and secures the equilibrium of hydraulic and hydrodynamic forces observing the uniformity of the thickness of the fitting walls which is a pre-requisite for good resistance to thermal shock. (F.M.)

  4. Rapid objective measurement of gamma camera resolution using statistical moments.

    Science.gov (United States)

    Hander, T A; Lancaster, J L; Kopp, D T; Lasher, J C; Blumhardt, R; Fox, P T

    1997-02-01

    An easy and rapid method for the measurement of the intrinsic spatial resolution of a gamma camera was developed. The measurement is based on the first and second statistical moments of regions of interest (ROIs) applied to bar phantom images. This leads to an estimate of the modulation transfer function (MTF) and the full-width-at-half-maximum (FWHM) of a line spread function (LSF). Bar phantom images were acquired using four large field-of-view (LFOV) gamma cameras (Scintronix, Picker, Searle, Siemens). The following factors important for routine measurements of gamma camera resolution with this method were tested: ROI placement and shape, phantom orientation, spatial sampling, and procedural consistency. A 0.2% coefficient of variation (CV) between repeat measurements of MTF was observed for a circular ROI. The CVs of less than 2% were observed for measured MTF values for bar orientations ranging from -10 degrees to +10 degrees with respect to the x and y axes of the camera acquisition matrix. A 256 x 256 matrix (1.6 mm pixel spacing) was judged sufficient for routine measurements, giving an estimate of the FWHM to within 0.1 mm of manufacturer-specified values (3% difference). Under simulated clinical conditions, the variation in measurements attributable to procedural effects yielded a CV of less than 2% in newer generation cameras. The moments method for determining MTF correlated well with a peak-valley method, with an average difference of 0.03 across the range of spatial frequencies tested (0.11-0.17 line pairs/mm, corresponding to 4.5-3.0 mm bars). When compared with the NEMA method for measuring intrinsic spatial resolution, the moments method was found to be within 4% of the expected FWHM.

  5. Signal yields, energy resolution, and recombination fluctuations in liquid xenon

    Science.gov (United States)

    Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bramante, R.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

    2017-01-01

    This work presents an analysis of monoenergetic electronic recoil peaks in the dark-matter-search and calibration data from the first underground science run of the Large Underground Xenon (LUX) detector. Liquid xenon charge and light yields for electronic recoil energies between 5.2 and 661.7 keV are measured, as well as the energy resolution for the LUX detector at those same energies. Additionally, there is an interpretation of existing measurements and descriptions of electron-ion recombination fluctuations in liquid xenon as limiting cases of a more general liquid xenon recombination fluctuation model. Measurements of the standard deviation of these fluctuations at monoenergetic electronic recoil peaks exhibit a linear dependence on the number of ions for energy deposits up to 661.7 keV, consistent with previous LUX measurements between 2 and 16 keV with 3H. We highlight similarities in liquid xenon recombination for electronic and nuclear recoils with a comparison of recombination fluctuations measured with low-energy calibration data.

  6. Stochastic Approaches Within a High Resolution Rapid Refresh Ensemble

    Science.gov (United States)

    Jankov, I.

    2017-12-01

    It is well known that global and regional numerical weather prediction (NWP) ensemble systems are under-dispersive, producing unreliable and overconfident ensemble forecasts. Typical approaches to alleviate this problem include the use of multiple dynamic cores, multiple physics suite configurations, or a combination of the two. While these approaches may produce desirable results, they have practical and theoretical deficiencies and are more difficult and costly to maintain. An active area of research that promotes a more unified and sustainable system is the use of stochastic physics. Stochastic approaches include Stochastic Parameter Perturbations (SPP), Stochastic Kinetic Energy Backscatter (SKEB), and Stochastic Perturbation of Physics Tendencies (SPPT). The focus of this study is to assess model performance within a convection-permitting ensemble at 3-km grid spacing across the Contiguous United States (CONUS) using a variety of stochastic approaches. A single physics suite configuration based on the operational High-Resolution Rapid Refresh (HRRR) model was utilized and ensemble members produced by employing stochastic methods. Parameter perturbations (using SPP) for select fields were employed in the Rapid Update Cycle (RUC) land surface model (LSM) and Mellor-Yamada-Nakanishi-Niino (MYNN) Planetary Boundary Layer (PBL) schemes. Within MYNN, SPP was applied to sub-grid cloud fraction, mixing length, roughness length, mass fluxes and Prandtl number. In the RUC LSM, SPP was applied to hydraulic conductivity and tested perturbing soil moisture at initial time. First iterative testing was conducted to assess the initial performance of several configuration settings (e.g. variety of spatial and temporal de-correlation lengths). Upon selection of the most promising candidate configurations using SPP, a 10-day time period was run and more robust statistics were gathered. SKEB and SPPT were included in additional retrospective tests to assess the impact of using

  7. High Resolution NMR Studies of Encapsulated Proteins In Liquid Ethane

    Science.gov (United States)

    Peterson, Ronald W.; Lefebvre, Brian G.; Wand, A. Joshua

    2005-01-01

    Many of the difficulties presented by large, aggregation-prone, and membrane proteins to modern solution NMR spectroscopy can be alleviated by actively seeking to increase the effective rate of molecular reorientation. An emerging approach involves encapsulating the protein of interest within the protective shell of a reverse micelle, and dissolving the resulting particle in a low viscosity fluid, such as the short chain alkanes. Here we present the encapsulation of proteins with high structural fidelity within reverse micelles dissolved in liquid ethane. The addition of appropriate co-surfactants can significantly reduce the pressure required for successful encapsulation. At these reduced pressures, the viscosity of the ethane solution is low enough to provide sufficiently rapid molecular reorientation to significantly lengthen the spin-spin NMR relaxation times of the encapsulated protein. PMID:16028922

  8. Capillary gel electrophoresis for rapid, high resolution DNA sequencing.

    OpenAIRE

    Swerdlow, H; Gesteland, R

    1990-01-01

    Capillary gel electrophoresis has been demonstrated for the separation and detection of DNA sequencing samples. Enzymatic dideoxy nucleotide chain termination was employed, using fluorescently tagged oligonucleotide primers and laser based on-column detection (limit of detection is 6,000 molecules per peak). Capillary gel separations were shown to be three times faster, with better resolution (2.4 x), and higher separation efficiency (5.4 x) than a conventional automated slab gel DNA sequenci...

  9. Rapid determination of octanol-water partition coefficient using vortex-assisted liquid-liquid microextraction.

    Science.gov (United States)

    Román, Iván P; Mastromichali, Anna; Tyrovola, Konstantina; Canals, Antonio; Psillakis, Elefteria

    2014-02-21

    Vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography (HPLC) is proposed here for the rapid determination of octanol-water partitioning coefficients (Kow). VALLME uses vortex agitation, a mild emulsification procedure, to disperse microvolumes of octanol in the aqueous phase thus increasing the interfacial contact area and ensuring faster partitioning rates. With VALLME, 2min were enough to achieve equilibrium conditions between the octanolic and aqueous phases. Upon equilibration, separation was achieved using centrifugation and the octanolic microdrop was collected and analyzed in a HPLC system. Six model compounds with logKow values ranging between ∼0.5 and 3.5 were used during the present investigations. The proposed method produced logKow values that were consistent with previously published values and the recorded uncertainty was well within the acceptable log unit range. Overall, the key features of the proposed Kow determination procedure comprised speed, reliability, simplicity, low cost and minimal solvent consumption. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Rapid determination of 226Ra in drinking water samples using dispersive liquid-liquid microextraction coupled with liquid scintillation counting

    International Nuclear Information System (INIS)

    Sadi, B.K.; Chunsheng Li; Kramer, G.H.; Johnson, C.L.; Queenie Ko; Lai, E.P.C.

    2011-01-01

    A new radioanalytical method was developed for rapid determination of 226 Ra in drinking water samples. The method is based on extraction and preconcentration of 226 Ra from a water sample to an organic solvent using a dispersive liquid-liquid microextraction (DLLME) technique followed by radiometric measurement using liquid scintillation counting. In DLLME for 226 Ra, a mixture of an organic extractant (toluene doped with dibenzo-21-crown-7 and 2-theonyltrifluoroacetone) and a disperser solvent (acetonitrile) is rapidly injected into the water sample resulting in the formation of an emulsion. Within the emulsion, 226 Ra reacts with dibenzo-21-crown-7 and 2-theonyltrifluoroacetone and partitions into the fine droplets of toluene. The water/toluene phases were separated by addition of acetonitrile as a de-emulsifier solvent. The toluene phase containing 226 Ra was then measured by liquid scintillation counting. Several parameters were studied to optimize the extraction efficiency of 226 Ra, including water immiscible organic solvent, disperser and de-emulsifier solvent type and their volume, chelating ligands for 226 Ra and their concentrations, inorganic salt additive and its concentration, and equilibrium pH. With the optimized DLLME conditions, the accuracy (expressed as relative bias, B r ) and method repeatability (expressed as relative precision, S B ) were determined by spiking 226 Ra at the maximum acceptable concentration level (0.5 Bq L -1 ) according to the Guidelines for Canadian Drinking Water Quality. Accuracy and repeatability were found to be less than -5% (B r ) and less than 6% (S B ), respectively, for both tap water and bottled natural spring water samples. The minimum detectable activity and sample turnaround time for determination of 226 Ra was 33 mBq L -1 and less than 3 h, respectively. The DLLME technique is selective for extraction of 226 Ra from its decay progenies. (author)

  11. Analytical method for high resolution liquid chromatography for quality control French Macaw

    International Nuclear Information System (INIS)

    Garcia Penna, Caridad M; Torres Amaro, Leonid; Menendez Castillo, Rosa; Sanchez, Esther; Martinez Espinosa, Vivian; Gonzalez, Maria Lidia; Rodriguez, Carlos

    2007-01-01

    Was developed and validated an analytical method for high resolution liquid chromatography applicable to quality control of drugs dry French Macaw (Senna alata L. Roxb.) With ultraviolet detection at 340 nm. The method for high resolution liquid chromatography used to quantify the sennosides A and B, main components, was validated and proved to be specific, linear, precise and accurate. (Author)

  12. Super-resolution with an optically-addressable liquid crystal spatial light modulator

    International Nuclear Information System (INIS)

    McOrist, J.; Sharma, M.D.; Sheppard, C.J.R.

    2002-01-01

    Full text: An optically-addressable liquid crystal spatial light modulator has been used to generate super-resolving masks. This approach avoids problems of low efficiency and coupling between amplitude and phase modulation, that occur when using conventional liquid crystal modulators. When addressed by a programmed light intensity distribution, it allows filters to be changed rapidly to modify the response of a system or permit the investigation of different filter designs. The device used is not pixellated, with a spatial resolution of 30 line pairs/mm over an area 18mm X 18mm, and can achieve continuously-variable phase modulation up to 1.5 wavelengths. The system consists of a write-beam that is collimated from a white-light source. An input mask was used in our experiments determines the modulation pattern of the read-beam. The read-beam from a HeNe laser reflects from the modulator and is focused by a microscope objective. The value of the phase change induced by the transparent regions of the mask can be altered continuously by adjusting the brightness of the write-beam. We have used this system to attain super-resolution by simple Toraldo filters, consisting of arrays of rings. Copyright (2002) Australian Society for Electron Microscopy Inc

  13. A rapid method to estimate uranium using ionic liquid as extracting agent from basic aqueous media

    International Nuclear Information System (INIS)

    Prabhath Ravi, K.; Sathyapriya, R.S.; Rao, D.D.; Ghosh, S.K.

    2016-01-01

    Room temperature ionic liquids, as their name suggests are salts with a low melting point typically less than 100 °C and exist as liquid at room temperature. The common cationic parts of ionic liquids are imidazolium, pyridinium, pyrrolidinium, quaternary ammonium, or phosphonium ions, and common anionic parts are chloride, bromide, boron tetrafluorate, phosphorous hexafluorate, triflimide etc. The physical properties of ionic liquids can be tuned by choosing appropriate cations with differing alkyl chain lengths and anions. Application of ionic liquids in organic synthesis, liquid-liquid extractions, electrochemistry, catalysis, speciation studies, nuclear reprocessing is being studied extensively in recent times. In this paper a rapid method to estimate the uranium content in aqueous media by extraction with room temperature ionic liquid tricaprylammoniumthiosalicylate ((A- 336)(TS)) followed by liquid scintillation analysis is described. Re-extraction of uranium from ionic liquid phase to aqueous phase was also studied

  14. Fabrication of thin TEM sample of ionic liquid for high-resolution ELNES measurements

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Tomohiro, E-mail: tomo-m@iis.u-tokyo.ac.jp; Mizoguchi, Teruyasu, E-mail: teru@iis.u-tokyo.ac.jp

    2017-07-15

    Investigation of the local structure, ionic and molecular behavior, and chemical reactions at high spatial resolutions in liquids has become increasingly important. Improvements in these areas help to develop efficient batteries and improve organic syntheses. Transmission electron microscopy (TEM) and scanning-TEM (STEM) have excellent spatial resolution, and the electron energy-loss near edge structure (ELNES) measured by the accompanied electron energy-loss spectroscopy (EELS) is effective to analyze the liquid local structure owing to reflecting the electronic density of states. In this study, we fabricate a liquid-layer-only sample with thickness of single to tens nanometers using an ionic liquid. Because the liquid film has a thickness much less than the inelastic mean free path (IMFP) of the electron beam, the fine structure of the C-K edge electron energy loss near edge structure (ELNES) can be measured with sufficient resolution to allow meaningful analysis. The ELNES spectrum from the thin liquid film has been interpreted using first principles ELNES calculations. - Highlights: • A fabrication method of thin liquid film samples for STEM-EELS observations is proposed. • The thickness of the fabricated thin liquid film is about 10 nm. • An ELNES is measured from the thin liquid with a high energy resolution. • The peaks of the ELNES are interpreted using first principles calculations.

  15. Rapid screening for drugs of abuse in biological fluids by ultra high performance liquid chromatography/Orbitrap mass spectrometry.

    Science.gov (United States)

    Jagerdeo, Eshwar; Schaff, Jason E

    2016-08-01

    We present a UPLC(®)-High Resolution Mass Spectrometric method to simultaneously screen for nineteen benzodiazepines, twelve opiates, cocaine and three metabolites, and three "Z-drug" hypnotic sedatives in both blood and urine specimens. Sample processing consists of a high-speed, high-temperature enzymatic hydrolysis for urine samples followed by a rapid supported liquid extraction (SLE). The combination of ultra-high resolution chromatography with high resolution mass spectrometry allows all 38 analytes to be uniquely detected with a ten minute analytical run. Limits of detection for all target analytes are 3ng/mL or better, with only 0.3mL of specimen used for analysis. The combination of low sample volume with fast processing and analysis makes this method a suitable replacement for immunoassay screening of the targeted drug classes, while providing far superior specificity and better limits of detection than can routinely be obtained by immunoassay. Published by Elsevier B.V.

  16. Rapid resolution of diffusion weighted MRI abnormality in a patient with a stuttering stroke

    Science.gov (United States)

    Peters, Jurriaan M; MacLean, Ainsley V; Young, Geoffrey S

    2010-01-01

    We report the unusually rapid and spontaneous normalisation of low diffusivity that accompanied resolution of acute neurological deficits in a stroke patient who underwent two magnetic resonance imaging examinations within 24 h of symptom onset. Diffusion weighted imaging obtained within hours of onset of left sided weakness demonstrated a focal right capsular area of low diffusivity that resolved within 24 h, coinciding with resolution of the patient’s symptoms. PMID:22315635

  17. Rapid spontaneous resolution of acute subdural haematoma in a patient with chronic alcoholism.

    Science.gov (United States)

    Hadjigeorgiou, Georgios; Chamilos, Christos; Petsanas, Adamantios; Vranos, Georgios; Foteas, Pavlos; Spiridakis, Filokypros

    2012-06-01

    Acute subdural haematoma (ASDH) constitutes one of the most critical emergencies in neurosurgery. There are only several reports that show the rapid disappearance of ASDH without surgical intervention. We report a case of a 64-year-old alcoholic man who had a traumatic subdural haematoma after a fall from a height of about eight meters on level ground. The computed tomography (CT) of the brain on admission demonstrated a left parietooccipital ASDH. A follow-up CT scan after 8 hours showed resolution of the hematoma. The patient was discharged 9 days later with no neurological deficit. We discuss the possible mechanisms of the rapid resolution of the ASDH.

  18. Rapid, cost-effective liquid chromatograghic method for the ...

    African Journals Online (AJOL)

    GRACE

    2006-07-03

    Jul 3, 2006 ... The method was validated and used for pharmacokinetic studies. Key words: Metronidazole ... by the intrinsic analytical properties of the drug molecule ... In addition, such factors as sample size ... account, since these affect the reliability of the quantitation. ... phase and ion-pair high–performance liquid.

  19. Sensitive rapid analysis of iodine-labelled protein mixture on flat substrates with high spatial resolution

    International Nuclear Information System (INIS)

    Zanevskij, Yu.V.; Ivanov, A.B.; Movchan, S.A.; Peshekhonov, V.D.; Chan Dyk Tkhan'; Chernenko, S.P.; Kaminir, L.B.; Krejndlin, Eh.Ya.; Chernyj, A.A.

    1983-01-01

    Usability of rapid analysis by electrophoresis of the admixture of I 125 -labelled proteins on flat samples by means of URAN type installation developed using a multiwire proportional chamber is studied. The sensitivity of the method is better than 200 cpm/cm 2 and the spatial resolution is approximately 1 mm. The procedure of the rapid analysis is no longer than several tens of minutes

  20. Resolution 49/013. Is adequate the quality control of liquid fuels Regulation, approved by Resolution of the URSEA 150/2008

    International Nuclear Information System (INIS)

    2013-01-01

    This Resolution is about the need to adapt the quality control regulation of liquid carburant approved by Resolution of the URSEA N. 150/2008. ANCAP has informed to URSEA the incorporation and reformularization of alcohol carburant in the gasoline

  1. Toward high-resolution NMR spectroscopy of microscopic liquid samples

    Energy Technology Data Exchange (ETDEWEB)

    Butler, Mark C.; Mehta, Hardeep S.; Chen, Ying; Reardon, Patrick N.; Renslow, Ryan S.; Khbeis, Michael; Irish, Duane; Mueller, Karl T.

    2017-01-01

    A longstanding limitation of high-resolution NMR spectroscopy is the requirement for samples to have macroscopic dimensions. Commercial probes, for example, are designed for volumes of at least 5 mL, in spite of decades of work directed toward the goal of miniaturization. Progress in miniaturizing inductive detectors has been limited by a perceived need to meet two technical requirements: (1) minimal separation between the sample and the detector, which is essential for sensitivity, and (2) near-perfect magnetic-field homogeneity at the sample, which is typically needed for spectral resolution. The first of these requirements is real, but the second can be relaxed, as we demonstrate here. By using pulse sequences that yield high-resolution spectra in an inhomogeneous field, we eliminate the need for near-perfect field homogeneity and the accompanying requirement for susceptibility matching of microfabricated detector components. With this requirement removed, typical imperfections in microfabricated components can be tolerated, and detector dimensions can be matched to those of the sample, even for samples of volume << 5 uL. Pulse sequences that are robust to field inhomogeneity thus enable small-volume detection with optimal sensitivity. We illustrate the potential of this approach to miniaturization by presenting spectra acquired with a flat-wire detector that can easily be scaled to subnanoliter volumes. In particular, we report high-resolution NMR spectroscopy of an alanine sample of volume 500 pL.

  2. Rapid increase of near atomic resolution virus capsid structures determined by cryo-electron microscopy.

    Science.gov (United States)

    Ho, Phuong T; Reddy, Vijay S

    2018-01-01

    The recent technological advances in electron microscopes, detectors, as well as image processing and reconstruction software have brought single particle cryo-electron microscopy (cryo-EM) into prominence for determining structures of bio-molecules at near atomic resolution. This has been particularly true for virus capsids, ribosomes, and other large assemblies, which have been the ideal specimens for structural studies by cryo-EM approaches. An analysis of time series metadata of virus structures on the methods of structure determination, resolution of the structures, and size of the virus particles revealed a rapid increase in the virus structures determined by cryo-EM at near atomic resolution since 2010. In addition, the data highlight the median resolution (∼3.0 Å) and size (∼310.0 Å in diameter) of the virus particles determined by X-ray crystallography while no such limits exist for cryo-EM structures, which have a median diameter of 508 Å. Notably, cryo-EM virus structures in the last four years have a median resolution of 3.9 Å. Taken together with minimal sample requirements, not needing diffraction quality crystals, and being able to achieve similar resolutions of the crystal structures makes cryo-EM the method of choice for current and future virus capsid structure determinations. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Vortex-assisted liquid-liquid microextraction for the rapid screening of short-chain chlorinated paraffins in water.

    Science.gov (United States)

    Chang, Chia-Yu; Chung, Wu-Hsun; Ding, Wang-Hsien

    2016-01-01

    The rapid screening of trace levels of short-chain chlorinated paraffins in various aqueous samples was performed by a simple and reliable procedure based on vortex-assisted liquid-liquid microextraction combined with gas chromatography and electron capture negative ionization mass spectrometry. The optimal vortex-assisted liquid-liquid microextraction conditions for 20 mL water sample were as follows: extractant 400 μL of dichloromethane; vortex extraction time of 1 min at 2500 × g; centrifugation of 3 min at 5000 × g; and no ionic strength adjustment. Under the optimum conditions, the limit of quantitation was 0.05 μg/L. Precision, as indicated by relative standard deviations, was less than 9% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was above 91%. The vortex-assisted liquid-liquid microextraction with gas chromatography and electron capture negative ionization mass spectrometry method was successfully applied to quantitatively extract short-chain chlorinated paraffins from samples of river water and the effluent of a wastewater treatment plant, and the concentrations ranged from 0.8 to 1.6 μg/L. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Rapid determination of human globin chains using reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Wan, Jun-Hui; Tian, Pei-Ling; Luo, Wei-Hao; Wu, Bing-Yi; Xiong, Fu; Zhou, Wan-Jun; Wei, Xiang-Cai; Xu, Xiang-Min

    2012-07-15

    Reversed-phase high-performance liquid chromatography (RP-HPLC) of human globin chains is an important tool for detecting thalassemias and hemoglobin variants. The challenges of this method that limit its clinical application are a long analytical time and complex sample preparation. The aim of this study was to establish a simple, rapid and high-resolution RP-HPLC method for the separation of globin chains in human blood. Red blood cells from newborns and adults were diluted in deionized water and injected directly onto a micro-jupiter C18 reversed-phase column (250 mm × 4.6 mm) with UV detection at 280 nm. Under the conditions of varying pH or the HPLC gradient, the globin chains (pre-β, β, δ, α, (G)γ and (A)γ) were denatured and separated from the heme groups in 12 min with a retention time coefficient of variation (CV) ranging from 0.11 to 1.29% and a peak area CV between 0.32% and 4.86%. Significant differences (P<0.05) among three groups (normal, Hb H and β thalassemia) were found in the area ratio of α/pre-β+β applying the rapid elution procedure, while P≥0.05 was obtained between the normal and α thalassemia silent/trait group. Based on the ANOVA results, receiver operating characteristic (ROC) curve analysis of the δ/β and α/pre-β+β area ratios showed a sensitivity of 100.0%, and a specificity of 100.0% for indicating β thalassemia carriers, and a sensitivity of 96.6% and a specificity of 89.6% for the prediction of hemoglobin H (Hb H) disease. The proposed cut-off was 0.026 of δ/β for β thalassemia carriers and 0.626 of α/pre-β+β for Hb H disease. In addition, abnormal hemoglobin hemoglobin E (Hb E) and Hb Westmead (Hb WS) were successfully identified using this RP-HPLC method. Our experience in developing this RP-HPLC method for the rapid separation of human globin chains could be of use for similar work. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Resolution in QCM Sensors for the Viscosity and Density of Liquids: Application to Lead Acid Batteries

    Directory of Open Access Journals (Sweden)

    Jorge Marcos-Acevedo

    2012-08-01

    Full Text Available In battery applications, particularly in automobiles, submarines and remote communications, the state of charge (SoC is needed in order to manage batteries efficiently. The most widely used physical parameter for this is electrolyte density. However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC. This paper presents a Quartz Crystal Microbalance (QCM sensor for electrolyte density-viscosity product measurements in lead acid batteries. The sensor is calibrated in H2SO4 solutions in the battery electrolyte range to obtain sensitivity, noise and resolution. Also, real-time tests of charge and discharge are conducted placing the quartz crystal inside the battery. At the same time, the present theoretical “resolution limit” to measure the square root of the density-viscosity product ( of a liquid medium or best resolution achievable with a QCM oscillator is determined. Findings show that the resolution limit only depends on the characteristics of the liquid to be studied and not on frequency. The QCM resolution limit for  measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

  6. Resolution in QCM sensors for the viscosity and density of liquids: application to lead acid batteries.

    Science.gov (United States)

    Cao-Paz, Ana María; Rodríguez-Pardo, Loreto; Fariña, José; Marcos-Acevedo, Jorge

    2012-01-01

    In battery applications, particularly in automobiles, submarines and remote communications, the state of charge (SoC) is needed in order to manage batteries efficiently. The most widely used physical parameter for this is electrolyte density. However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC. This paper presents a Quartz Crystal Microbalance (QCM) sensor for electrolyte density-viscosity product measurements in lead acid batteries. The sensor is calibrated in H(2)SO(4) solutions in the battery electrolyte range to obtain sensitivity, noise and resolution. Also, real-time tests of charge and discharge are conducted placing the quartz crystal inside the battery. At the same time, the present theoretical "resolution limit" to measure the square root of the density-viscosity product [Formula: see text] of a liquid medium or best resolution achievable with a QCM oscillator is determined. Findings show that the resolution limit only depends on the characteristics of the liquid to be studied and not on frequency. The QCM resolution limit for [Formula: see text] measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

  7. Homogeneous nucleation ahead of the solid-liquid interface during rapid solidification of binary alloys

    International Nuclear Information System (INIS)

    Smith, P.M.; Elmer, J.W.

    1996-01-01

    In recent rapid solidification experiments on Al-5%Be alloys, a Liquid Phase Nucleation (LPN) model was developed to explain the formation of periodic arrays of randomly-oriented Be-rich particles in an Al-rich matrix. In the LPN model, Be droplets were assumed to nucleate in the liquid ahead of the solid-liquid interface, but no justification for this was given. Here the authors present a model which considers the geometric constraints (imposed by proximity to the interface) on the number of solute atoms available to form a nucleus. Calculations based on this model predict that nucleation of second-phase particles can be most likely a short distance ahead of the interface in immiscible binary systems such as Al-Be. As part of the nucleation calculations, a semi-empirical method of calculating solid-liquid surface tensions in binary systems was developed, and is presented in the Appendix

  8. Rapid Spontaneous Resolution of Acute Epidural Hematoma: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Fatih Aydemir

    2016-06-01

    Full Text Available Background: Epidural hematomas (EDH are pathologies in which the early diagnosis and treatment are important. Resolution under 24 hours is very rare. Case Report: An 11-month-old male patient was brought to the emergency department with head trauma from falling out of bed onto his back. There were no neurological deficits, except for the patient being somnolent. Computed tomography (CT of the patient revealed subgaleal edema in the right parietal region, linear fracture and image consistent with EDH with a thickness of about 9 mm underneath fracture. A control CT was performed after 3 hours as somnolence continued in follow-up of the patient. Hematoma in the epidural region was observed to completely resolve and edema in the subgaleal region was observed to gain hemorrhagic characteristics. Conclusion: In total, 15 cases have been reported, including our case, in the literature with resolution less than 24 hours. Our case has the fourth fastest resolution ever reported in the English literature. We think that the most important factor in the rapid spontaneous resolution is the presence of a connection between the epidural and epicranial space, either through a fracture or cranial sutures.

  9. Analyse chronometrique intersexes de la resolution de la tache d'horizontalite des liquides

    Science.gov (United States)

    Berthiaume, Francois

    D'abondantes recherches ont demontre que la reussite a la tache d'horizontalite des liquides est en moyenne plus elevee chez les individus de sexe masculin que chez ceux de sexe feminin. Deux facteurs principaux ont ete proposes: il s'agit de la connaissance du principe physique de l'invariance de l'orientation des liquides et de certaines habiletes perceptives d'ordre visuel. Le but de la presente recherche est d'etablir la duree detaillee de la resolution de la tache d'horizontalite des liquides chez 185 filles et 180 garcons, ages de 15 a 19 ans et repartis en 8 groupes. Dans une version informatisee, le premier groupe trace la position de la surface de l'eau a l'interieur d'un contenant dans diverses inclinaisons et le deuxieme evalue si l'orientation d'une ligne y represente bien cette position; le troisieme groupe trace une horizontale dans un rectangle et le quatrieme juge si la ligne illustree y est bien horizontale. Quatre autres groupes executent respectivement les memes taches dans la version classique papier-crayon. Le temps accorde a la reflexion avant de commencer le trace, le temps de tracage comme tel et le temps de verification du trace complete sont calcules. Chez les groupes qui evaluent l'orientation d'une ligne sur support informatique, le temps requis pour y parvenir est note. Enfin, un questionnaire estime si les participants connaissent ou non le principe physique d'invariance de l'orientation de la surface d'un liquide. Les resultats revelent que cette connaissance est plus frequente chez les garcons dans l'ensemble des groupes. Dans le cas ou les sujets ont a tracer une ligne, les filles reussissent moins d'essais que les garcons s'il faut, sur support informatique, tracer la surface de l'eau dans un contenant incline ou a l'horizontale. Il en va de meme s'il faut, sur support papier, tracer une horizontale dans un contenant incline. Le trace de la surface de l'eau est plus exact chez les sujets connaissant le principe d'invariance et l

  10. Force scanning: a rapid, high-resolution approach for spatial mechanical property mapping

    International Nuclear Information System (INIS)

    Darling, E M

    2011-01-01

    Atomic force microscopy (AFM) can be used to co-localize mechanical properties and topographical features through property mapping techniques. The most common approach for testing biological materials at the microscale and nanoscale is force mapping, which involves taking individual force curves at discrete sites across a region of interest. The limitations of force mapping include long testing times and low resolution. While newer AFM methodologies, like modulated scanning and torsional oscillation, circumvent this problem, their adoption for biological materials has been limited. This could be due to their need for specialized software algorithms and/or hardware. The objective of this study is to develop a novel force scanning technique using AFM to rapidly capture high-resolution topographical images of soft biological materials while simultaneously quantifying their mechanical properties. Force scanning is a straightforward methodology applicable to a wide range of materials and testing environments, requiring no special modification to standard AFMs. Essentially, if a contact-mode image can be acquired, then force scanning can be used to produce a spatial modulus map. The current study first validates this technique using agarose gels, comparing results to ones achieved by the standard force mapping approach. Biologically relevant demonstrations are then presented for high-resolution modulus mapping of individual cells, cell-cell interfaces, and articular cartilage tissue.

  11. Experimental observations of flow instabilities and rapid mixing of two dissimilar viscoelastic liquids

    Directory of Open Access Journals (Sweden)

    Hiong Yap Gan

    2012-12-01

    Full Text Available Viscoelastically induced flow instabilities, via a simple planar microchannel, were previously used to produce rapid mixing of two dissimilar polymeric liquids (i.e. at least a hundredfold different in shear viscosity even at a small Reynolds number. The unique advantage of this mixing technology is that viscoelastic liquids are readily found in chemical and biological samples like organic and polymeric liquids, blood and crowded proteins samples; their viscoelastic properties could be exploited. As such, an understanding of the underlying interactions will be important especially in rapid microfluidic mixing involving multiple-stream flow of complex (viscoelastic fluids in biological assays. Here, we use the same planar device to experimentally show that the elasticity ratio (i.e. the ratio of stored elastic energy to be relaxed between two liquids indeed plays a crucial role in the entire flow kinematics and the enhanced mixing. We demonstrate here that the polymer stretching dynamics generated in the upstream converging flow and the polymer relaxation events occurring in the downstream channel are not exclusively responsible for the transverse flow mixing, but the elasticity ratio is also equally important. The role of elasticity ratio for transverse flow instability and the associated enhanced mixing were illustrated based on experimental observations. A new parameter Deratio = Deside / Demain (i.e. the ratio of the Deborah number (De of the sidestream to the mainstream liquids is introduced to correlate the magnitude of energy discontinuity between the two liquids. A new Deratio-Demain operating space diagram was constructed to present the observation of the effects of both elasticity and energy discontinuity in a compact manner, and for a general classification of the states of flow development.

  12. Triple-frequency GPS precise point positioning with rapid ambiguity resolution

    Science.gov (United States)

    Geng, Jianghui; Bock, Yehuda

    2013-05-01

    At present, reliable ambiguity resolution in real-time GPS precise point positioning (PPP) can only be achieved after an initial observation period of a few tens of minutes. In this study, we propose a method where the incoming triple-frequency GPS signals are exploited to enable rapid convergences to ambiguity-fixed solutions in real-time PPP. Specifically, extra-wide-lane ambiguity resolution can be first achieved almost instantaneously with the Melbourne-Wübbena combination observable on L2 and L5. Then the resultant unambiguous extra-wide-lane carrier-phase is combined with the wide-lane carrier-phase on L1 and L2 to form an ionosphere-free observable with a wavelength of about 3.4 m. Although the noise of this observable is around 100 times the raw carrier-phase noise, its wide-lane ambiguity can still be resolved very efficiently, and the resultant ambiguity-fixed observable can assist much better than pseudorange in speeding up succeeding narrow-lane ambiguity resolution. To validate this method, we use an advanced hardware simulator to generate triple-frequency signals and a high-grade receiver to collect 1-Hz data. When the carrier-phase precisions on L1, L2 and L5 are as poor as 1.5, 6.3 and 1.5 mm, respectively, wide-lane ambiguity resolution can still reach a correctness rate of over 99 % within 20 s. As a result, the correctness rate of narrow-lane ambiguity resolution achieves 99 % within 65 s, in contrast to only 64 % within 150 s in dual-frequency PPP. In addition, we also simulate a multipath-contaminated data set and introduce new ambiguities for all satellites every 120 s. We find that when multipath effects are strong, ambiguity-fixed solutions are achieved at 78 % of all epochs in triple-frequency PPP whilst almost no ambiguities are resolved in dual-frequency PPP. Therefore, we demonstrate that triple-frequency PPP has the potential to achieve ambiguity-fixed solutions within a few minutes, or even shorter if raw carrier-phase precisions are

  13. Resolution of the stereoisomers of baclofen by high performance liquid chromatography

    International Nuclear Information System (INIS)

    Weatherby, R.P.; Allan, R.D.; Johnston, G.A.R.

    1984-01-01

    The GABA analogue baclofen [3-(p-chlorophenyl)-4-aminobutanoic acid] has stereospecific actions on the peripheral and central nervous systems. This paper describes the resolution of tritium-labelled baclofen by high performance liquid chromatography on a reverse-phase C18 column using a chiral mobile phase. The method, which may have general application to certain other GABA analogues, affords optically pure (+)- and (-)-baclofen labelled with tritium to high specific activity suitable for ligand binding and other neurochemical studies. (Auth.)

  14. Quantification of steroid hormones in human serum by liquid chromatography-high resolution tandem mass spectrometry.

    Science.gov (United States)

    Matysik, Silke; Liebisch, Gerhard

    2017-12-01

    A limited specificity is inherent to immunoassays for steroid hormone analysis. To improve selectivity mass spectrometric analysis of steroid hormones by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been introduced in the clinical laboratory over the past years usually with low mass resolution triple-quadrupole instruments or more recently by high resolution mass spectrometry (HR-MS). Here we introduce liquid chromatography-high resolution tandem mass spectrometry (LC-MS/HR-MS) to further increase selectivity of steroid hormone quantification. Application of HR-MS demonstrates an enhanced selectivity compared to low mass resolution. Separation of isobaric interferences reduces background noise and avoids overestimation. Samples were prepared by automated liquid-liquid extraction with MTBE. The LC-MS/HR-MS method using a quadrupole-Orbitrap analyzer includes eight steroid hormones i.e. androstenedione, corticosterone, cortisol, cortisone, 11-deoxycortisol, 17-hydroxyprogesterone, progesterone, and testosterone. It has a run-time of 5.3min and was validated according to the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) guidelines. For most of the analytes coefficient of variation were 10% or lower and LOQs were determined significantly below 1ng/ml. Full product ion spectra including accurate masses substantiate compound identification by matching their masses and ratios with authentic standards. In summary, quantification of steroid hormones by LC-MS/HR-MS is applicable for clinical diagnostics and holds also promise for highly selective quantification of other small molecules. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Rapid determination of some psychotropic drugs in complex matrices by tandem dispersive liquid-liquid microextraction followed by high performance liquid chromatography.

    Science.gov (United States)

    Asghari, Alireza; Fahimi, Ebrahim; Bazregar, Mohammad; Rajabi, Maryam; Boutorabi, Leila

    2017-05-01

    Simple and rapid determinations of some psychotropic drugs in some pharmaceutical wastewater and human plasma samples were successfully accomplished via the tandem dispersive liquid-liquid microextraction combined with high performance liquid chromatography-ultraviolet detection (TDLLME-HPLC-UV). TDLLME of the three psychotropic drugs clozapine, chlorpromazine, and thioridazine was easily performed through two consecutive dispersive liquid-liquid microextractions. By performing this convenient method, proper sample preconcentrations and clean-ups were achieved in just about 7min. In order to achieve the best extraction efficiency, the effective parameters involved were optimized. The optimal experimental conditions consisted of 100μL of CCl 4 (as the extraction organic solvent), and the pH values of 13 and 2 for the donor and acceptor phases, respectively. Under these optimum experimental conditions, the proposed TDLLME-HPLC-UV technique provided a good linearity in the range of 5-3000ngmL -1 for the three psychotropic drugs with the correlation of determinations (R 2 s) higher than 0.996. The limits of quantification (LOQs) and limits of detection (LODs) obtained were 5.0ngmL -1 and 1.0-1.5ngmL -1 , respectively. Also the proper enrichment factors (EFs) of 96, 99, and 88 for clozapine, chlorpromazine, and thioridazine, respectively, and good extraction repeatabilities (relative standard deviations below 9.3%, n=5) were obtained. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Rapid screening for targeted genetic variants via high-resolution melting curve analysis.

    Science.gov (United States)

    Chambliss, Allison B; Resnick, Molly; Petrides, Athena K; Clarke, William A; Marzinke, Mark A

    2017-03-01

    Current methods for the detection of single nucleotide polymorphisms (SNPs) associated with aberrant drug-metabolizing enzyme function are hindered by long turnaround times and specialized techniques and instrumentation. In this study, we describe the development and validation of a high-resolution melting (HRM) curve assay for the rapid screening of variant genotypes for targeted genetic polymorphisms in the cytochrome P450 enzymes CYP2C9, CYP2C19, and CYP3A5. Sequence-specific primers were custom-designed to flank nine SNPs within the genetic regions of aforementioned drug metabolizing enzymes. PCR amplification was performed followed by amplicon denaturation by precise temperature ramping in order to distinguish genotypes by melting temperature (Tm). A standardized software algorithm was used to assign amplicons as 'reference' or 'variant' as compared to duplicate reference sequence DNA controls for each SNP. Intra-assay (n=5) precision of Tms for all SNPs was ≤0.19%, while inter-assay (n=20) precision ranged from 0.04% to 0.21%. When compared to a reference method of Sanger sequencing, the HRM assay produced no false negative results, and overcall frequency ranged from 0% to 26%, depending on the SNP. Furthermore, HRM genotyping displayed accuracy over input DNA concentrations ranging from 10 to 200 ng/μL. The presented assay provides a rapid method for the screening for genetic variants in targeted CYP450 regions with a result of 'reference' or 'variant' available within 2 h from receipt of extracted DNA. The method can serve as a screening approach to rapidly identify individuals with variant sequences who should be further investigated by reflexed confirmatory testing for aberrant cytochrome P450 enzymatic activity. Rapid knowledge of variant status may aid in the avoidance of adverse clinical events by allowing for dosing of normal metabolizer patients immediately while identifying the need to wait for confirmatory testing in those patients who are

  17. Correlative analysis of metabolite profiling of Danggui Buxue Tang in rat biological fluids by rapid resolution LC-TOF/MS.

    Science.gov (United States)

    Li, Chang-Yin; Qi, Lian-Wen; Li, Ping

    2011-04-28

    In this work, the metabolite profiles of Danggui Buxue Tang (DBT) in rat bile and plasma were qualitatively described, and the possible metabolic pathways of DBT were subsequently proposed. Emphasis was put on correlative analysis of metabolite profiling in different biological fluids. After oral administration of DBT, bile and plasma samples were collected and pretreated by solid phase extraction. Rapid resolution liquid chromatography coupled to time-of-flight mass spectrometry (RRLC-TOFMS) was used for characterization of DBT-related compounds (parent compounds and metabolites) in biological matrices. A total of 142 metabolites were detected and tentatively identified from the drug-containing bile and plasma samples. Metabolite profiling shows that rat bile contained relatively more glutathione-derived conjugates, more saponins compounds and more diverse forms of metabolites than urine. The metabolite profile in plasma revealed that glucuronide conjugates of isoflavonoids, dimmers, acetylcysteine conjugates and parent form of phthalides, as well as saponin aglycones were the major circulating forms of DBT. Collectively, the metabolite profile analysis of DBT in different biological matrices provided a comprehensive understanding of the in vivo metabolic fates of constituents in DBT. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Rapid hydrogen hydrate growth from non-stoichiometric tuning mixtures during liquid nitrogen quenching.

    Science.gov (United States)

    Grim, R Gary; Kerkar, Prasad B; Sloan, E Dendy; Koh, Carolyn A; Sum, Amadeu K

    2012-06-21

    In this study the rapid growth of sII H(2) hydrate within 20 min of post formation quenching towards liquid nitrogen (LN(2)) temperature is presented. Initially at 72 MPa and 258 K, hydrate samples would cool to the conditions of ~60 MPa and ~90 K after quenching. Although within the stability region for H(2) hydrate, new hydrate growth only occurred under LN(2) quenching of the samples when preformed hydrate "seeds" of THF + H(2) were in the presence of unconverted ice. The characterization of hydrate seeds and the post-quenched samples was performed with confocal Raman spectroscopy. These results suggest that quenching to LN(2) temperature, a common preservation technique for ex situ hydrate analysis, can lead to rapid unintended hydrate growth. Specifically, guest such as H(2) that may otherwise need sufficiently long induction periods to nucleate, may still experience rapid growth through an increased kinetic effect from a preformed hydrate template.

  19. High-Resolution Melt Analysis for Rapid Comparison of Bacterial Community Compositions

    DEFF Research Database (Denmark)

    Hjelmsø, Mathis Hjort; Hansen, Lars Hestbjerg; Bælum, Jacob

    2014-01-01

    In the study of bacterial community composition, 16S rRNA gene amplicon sequencing is today among the preferred methods of analysis. The cost of nucleotide sequence analysis, including requisite computational and bioinformatic steps, however, takes up a large part of many research budgets. High......-resolution melt (HRM) analysis is the study of the melt behavior of specific PCR products. Here we describe a novel high-throughput approach in which we used HRM analysis targeting the 16S rRNA gene to rapidly screen multiple complex samples for differences in bacterial community composition. We hypothesized...... that HRM analysis of amplified 16S rRNA genes from a soil ecosystem could be used as a screening tool to identify changes in bacterial community structure. This hypothesis was tested using a soil microcosm setup exposed to a total of six treatments representing different combinations of pesticide...

  20. High Resolution Tracking Devices Based on Capillaries Filled with Liquid Scintillator

    CERN Multimedia

    Bonekamper, D; Vassiltchenko, V; Wolff, T

    2002-01-01

    %RD46 %title\\\\ \\\\The aim of the project is to develop high resolution tracking devices based on thin glass capillary arrays filled with liquid scintillator. This technique provides high hit densities and a position resolution better than 20 $\\mu$m. Further, their radiation hardness makes them superior to other types of tracking devices with comparable performance. Therefore, the technique is attractive for inner tracking in collider experiments, microvertex devices, or active targets for short-lived particle detection. High integration levels in the read-out based on the use of multi-pixel photon detectors and the possibility of optical multiplexing allow to reduce considerably the number of output channels, and, thus, the cost for the detector.\\\\ \\\\New optoelectronic devices have been developed and tested: the megapixel Electron Bombarded CCD (EBCCD), a high resolution image-detector having an outstanding capability of single photo-electron detection; the Vacuum Image Pipeline (VIP), a high-speed gateable pi...

  1. Rapid Screening and Characterization of Acetylcholinesterase Inhibitors from Yinhuang Oral Liquid Using Ultrafiltration-liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry.

    Science.gov (United States)

    Zhang, Haomin; Guo, Yinan; Meng, Lingwen; Sun, Hui; Yang, Yinping; Gao, Ying; Sun, Jiaming

    2018-01-01

    At present, approximately 17-25 million people in the world suffer from Alzheimer's disease (AD). The most efficacious and acceptable therapeutic drug clinically are the acetylcholinesterase inhibitors (AChEIs). Yinhuang oral liquid is a Chinese medicine preparation which contains AChEIs according to the literatures. However, no strategy has been presented for rapid screening and identification of AChEIs from Yinhuang oral liquid. To develop a method for rapid screening and identification of AChEIs from Yinhuang oral liquid using ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry (UF-LC-ESI-MS/MS). In this study, UF incubation conditions such as enzyme concentration, incubation time, and incubation temperature were optimized so as to get better screening results. The AChEIs from Yinhuang oral liquid were identified by high-performance liquid chromatography-ESI-MS and the improved Ellman method was used for the AChE inhibitory activity test in vitro . The results showed that Yinhuang oral liquid can inhibit the activity of AChE. We screened and identified seven compounds with potential AChE inhibitory activity from Yinhuang oral liquid, which provided experimental basis for the treatment and prevention of AD. The current technique was used to directly screen the active ingredients with acetylcholinesterase inhibition from complex traditional Chinese medicine, which was simple, rapid, accurate, and suitable for high-throughput screening of AChEI from complex systems. A UF-LC-ESI-MS/MS method for rapid screening and identification of AChEIs from Yinhuang oral liquid was developedSeven compounds were screened and identified with potential AChE inhibitory activity from Yinhuang oral liquidIt provided experimental basis of Yinhuang oral liquid for the treating and preventing AD. Abbreviations used: (AD): Alzheimer's disease; (UF-LC-ESI-MS/MS): ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry; (ACh

  2. Rapid Screening and Characterization of Acetylcholinesterase Inhibitors from Yinhuang Oral Liquid Using Ultrafiltration-liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry

    Science.gov (United States)

    Zhang, Haomin; Guo, Yinan; Meng, Lingwen; Sun, Hui; Yang, Yinping; Gao, Ying; Sun, Jiaming

    2018-01-01

    Background: At present, approximately 17–25 million people in the world suffer from Alzheimer's disease (AD). The most efficacious and acceptable therapeutic drug clinically are the acetylcholinesterase inhibitors (AChEIs). Yinhuang oral liquid is a Chinese medicine preparation which contains AChEIs according to the literatures. However, no strategy has been presented for rapid screening and identification of AChEIs from Yinhuang oral liquid. Objective: To develop a method for rapid screening and identification of AChEIs from Yinhuang oral liquid using ultrafiltration–liquid chromatography–electrospray ionization tandem mass spectrometry (UF-LC-ESI-MS/MS). Materials and Methods: In this study, UF incubation conditions such as enzyme concentration, incubation time, and incubation temperature were optimized so as to get better screening results. The AChEIs from Yinhuang oral liquid were identified by high-performance liquid chromatography-ESI-MS and the improved Ellman method was used for the AChE inhibitory activity test in vitro. Results: The results showed that Yinhuang oral liquid can inhibit the activity of AChE. We screened and identified seven compounds with potential AChE inhibitory activity from Yinhuang oral liquid, which provided experimental basis for the treatment and prevention of AD. Conclusion: The current technique was used to directly screen the active ingredients with acetylcholinesterase inhibition from complex traditional Chinese medicine, which was simple, rapid, accurate, and suitable for high-throughput screening of AChEI from complex systems. SUMMARY A UF-LC-ESI-MS/MS method for rapid screening and identification of AChEIs from Yinhuang oral liquid was developedSeven compounds were screened and identified with potential AChE inhibitory activity from Yinhuang oral liquidIt provided experimental basis of Yinhuang oral liquid for the treating and preventing AD. Abbreviations used: (AD): Alzheimer's disease; (UF

  3. Eculizumab Therapy Leads to Rapid Resolution of Thrombocytopenia in Atypical Hemolytic Uremic Syndrome

    Directory of Open Access Journals (Sweden)

    Han-Mou Tsai

    2014-01-01

    Full Text Available Eculizumab is highly effective in controlling complement activation in patients with the atypical hemolytic uremic syndrome (aHUS. However, the course of responses to the treatment is not well understood. We reviewed the responses to eculizumab therapy for aHUS. The results show that, in patients with aHUS, eculizumab therapy, when not accompanied with concurrent plasma exchange therapy, led to steady increase in the platelet count and improvement in extra-renal complications within 3 days. By day 7, the platelet count was normal in 15 of 17 cases. The resolution of hemolytic anemia and improvement in renal function were less predictable and were not apparent for weeks to months in two patients. The swift response in the platelet counts was only observed in one of five cases who received concurrent plasma exchange therapy and was not observed in a case of TMA due to gemcitabine/carboplatin. In summary, eculizumab leads to rapid increase in the platelet counts and resolution of extrarenal symptoms in patients with aHUS. Concurrent plasma exchange greatly impedes the response of aHUS to eculizumab therapy. Eculizumab is ineffective for gemcitabine/carboplatin associated TMA.

  4. Rapid detection and identification of four major Schistosoma species by high-resolution melt (HRM) analysis.

    Science.gov (United States)

    Li, Juan; Zhao, Guang-Hui; Lin, RuiQing; Blair, David; Sugiyama, Hiromu; Zhu, Xing-Quan

    2015-11-01

    Schistosomiasis, caused by blood flukes belonging to several species of the genus Schistosoma, is a serious and widespread parasitic disease. Accurate and rapid differentiation of these etiological agents of animal and human schistosomiasis to species level can be difficult. We report a real-time PCR assay coupled with a high-resolution melt (HRM) assay targeting a portion of the nuclear 18S rDNA to detect, identify, and distinguish between four major blood fluke species (Schistosoma japonicum, Schistosoma mansoni, Schistosoma haematobium, and Schistosoma mekongi). Using this system, the Schistosoma spp. was accurately identified and could also be distinguished from all other trematode species with which they were compared. As little as 10(-5) ng genomic DNA from a Schistosoma sp. could be detected. This process is inexpensive, easy, and can be completed within 3 h. Examination of 21 representative Schistosoma samples from 15 geographical localities in seven endemic countries validated the value of the HRM detection assay and proved its reliability. The melting curves were characterized by peaks of 83.65 °C for S. japonicum and S. mekongi, 85.65 °C for S. mansoni, and 85.85 °C for S. haematobium. The present study developed a real-time PCR coupled with HRM analysis assay for detection and differential identification of S. mansoni, S. haematobium, S. japonicum, and S. mekongi. This method is rapid, sensitive, and inexpensive. It has important implications for epidemiological studies of Schistosoma.

  5. High resolution melting analysis: a rapid and accurate method to detect CALR mutations.

    Directory of Open Access Journals (Sweden)

    Cristina Bilbao-Sieyro

    Full Text Available The recent discovery of CALR mutations in essential thrombocythemia (ET and primary myelofibrosis (PMF patients without JAK2/MPL mutations has emerged as a relevant finding for the molecular diagnosis of these myeloproliferative neoplasms (MPN. We tested the feasibility of high-resolution melting (HRM as a screening method for rapid detection of CALR mutations.CALR was studied in wild-type JAK2/MPL patients including 34 ET, 21 persistent thrombocytosis suggestive of MPN and 98 suspected secondary thrombocytosis. CALR mutation analysis was performed through HRM and Sanger sequencing. We compared clinical features of CALR-mutated versus 45 JAK2/MPL-mutated subjects in ET.Nineteen samples showed distinct HRM patterns from wild-type. Of them, 18 were mutations and one a polymorphism as confirmed by direct sequencing. CALR mutations were present in 44% of ET (15/34, 14% of persistent thrombocytosis suggestive of MPN (3/21 and none of the secondary thrombocytosis (0/98. Of the 18 mutants, 9 were 52 bp deletions, 8 were 5 bp insertions and other was a complex mutation with insertion/deletion. No mutations were found after sequencing analysis of 45 samples displaying wild-type HRM curves. HRM technique was reproducible, no false positive or negative were detected and the limit of detection was of 3%.This study establishes a sensitive, reliable and rapid HRM method to screen for the presence of CALR mutations.

  6. Recent progress of task-specific ionic liquids in chiral resolution and extraction of biological samples and metal ions.

    Science.gov (United States)

    Wu, Datong; Cai, Pengfei; Zhao, Xiaoyong; Kong, Yong; Pan, Yuanjiang

    2018-01-01

    Ionic liquids have been functionalized for modern applications. The functional ionic liquids are also called task-specific ionic liquids. Various task-specific ionic liquids with certain groups have been constructed and exploited widely in the field of separation. To take advantage of their properties in separation science, task-specific ionic liquids are generally used in techniques such as liquid-liquid extraction, solid-phase extraction, gas chromatography, high-performance liquid chromatography, and capillary electrophoresis. This review mainly covers original research papers published in the last five years, and we will focus on task-specific ionic liquids as the chiral selectors in chiral resolution and as extractant or sensor for biological samples and metal ion purification. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Rapid Detection and Identification of Human Hookworm Infections through High Resolution Melting (HRM) Analysis

    Science.gov (United States)

    Ngui, Romano; Lim, Yvonne A. L.; Chua, Kek Heng

    2012-01-01

    Background Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. Methods Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus, 79.12±0.10°C for Ancylostoma duodenale, 79.40±0.10°C for Ancylostoma ceylanicum, 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma braziliense. An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species. PMID:22844538

  8. Rapid detection and identification of human hookworm infections through high resolution melting (HRM analysis.

    Directory of Open Access Journals (Sweden)

    Romano Ngui

    Full Text Available BACKGROUND: Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR coupled with high resolution melting-curve (HRM analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. METHODS: Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2 of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus, 79.12±0.10°C for Ancylostoma duodenale, 79.40±0.10°C for Ancylostoma ceylanicum, 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma braziliense. An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. CONCLUSION: The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species.

  9. Ultra-performance liquid chromatography tandem mass-spectrometry (uplc-ms/ms) for the rapid, simultaneous analysis of thiamin, riboflavin, flavin adenine dinucleotide, nicotinamide and pyridoxal in human milk

    Science.gov (United States)

    A novel, rapid and sensitive Ultra Performance Liquid-Chromatography tandem Mass-Spectrometry (UPLC-MS/MS) method for the simultaneous determination of several B-vitamins in human milk was developed. Resolution by retention time or multiple reaction monitoring (MRM) for thiamin, riboflavin, flavin a...

  10. High-resolution tracking using large capillary bundles filled with liquid scintillator

    CERN Document Server

    Annis, P; Benussi, L; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Van Dantzig, R; Dupraz, J P; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Feyt, J; Frekers, D; Frenkel, A; Galeazzi, F; Garufi, F; Goldberg, J; Golovkin, S V; Gorin, A M; Grégoire, G; Harrison, K; Höpfner, K; Holtz, K; Konijn, J; Kozarenko, E N; Kreslo, I E; Kushnirenko, A E; Liberti, B; Martellotti, G; Medvedkov, A M; Michel, L; Migliozzi, P; Mommaert, C; Mondardini, M R; Panman, J; Penso, G; Petukhov, Yu P; Rondeshagen, D; Siegmund, W P; Tyukov, V E; Van Beek, G; Vasilchenko, V G; Vilain, P; Visschers, J L; Wilquet, G; Winter, Klaus; Wolff, T; Wörtche, H J; Wong, H; Zimyn, K V

    2000-01-01

    We have developed large high-resolution tracking detectors based on glass capillaries filled with organic liquid scintillator of high refractive index. These liquid-core scintillating optical fibres act simultaneously as detectors of charged particles and as image guides. Track images projected onto the readout end of a capillary bundle are visualized by an optoelectronic chain consisting of a set of image-intensifier tubes followed by a photosensitive CCD or by an EBCCD camera. Two prototype detectors, each composed of \\hbox{$\\approx 10^6$} capillaries with \\hbox{20$-$25 $\\mu$m} diameter and \\hbox{0.9$-$1.8 m} length, have been tested, and a spatial resolution of the order of \\hbox{20$-$40 $\\mu$m} has been attained. A high scintillation efficiency and a large light-attenuation length, in excess of 3 m, was achieved through special purification of the liquid scintillator. Along the tracks of minimum-ionizing particles, the hit densities obtained were $\\sim$ 8 hits/mm at the readout window, and \\hbox{$\\sim$ 3 ...

  11. Rapid determination of some beta-blockers in complicated matrices by tandem dispersive liquid-liquid microextraction followed by high performance liquid chromatography.

    Science.gov (United States)

    Hemmati, Maryam; Asghari, Alireza; Bazregar, Mohammad; Rajabi, Maryam

    2016-11-01

    In this research work, an efficient tandem dispersive liquid-liquid microextraction (TDLLME) procedure coupled with high performance liquid chromatography-ultraviolet detection (HPLC-UV) was successfully applied for the determination of beta-blockers in human plasma and pharmaceutical wastewater samples. High clean-up and preconcentration factor are easily and rapidly feasible via this novel, cheap, and safe microextraction method, leading to high quality experimental data. It consists of two sequential dispersive liquid-liquid microextraction methods, accomplished via air/ultrasonic agitation and air agitation, respectively. In order to enrich the optimal values for the mentioned procedures, the Box-Behnken design (BBD) combined with the desirability function (DF) was used. The optimum values were found to be 11.0 % (w/v) of the salt amount, an initial pH value of 12.0, 103 μL of organic extractant phase, and 45 μL of aqueous extractant phase with pH value of 2.0, resulted in reasonable recovery percentages with a logical desirability. Under optimal experimental conditions, good linear ranges (3-2000 ng mL -1 for metoprolol and 2.5-2500 ng mL -1 for propranolol with the correlation of determinations (R 2 s) higher than 0.99) and low limits of detection (0.8 and 1.0 ng mL -1 for propranolol and metoprolol, respectively) were obtainable. Also, TDLLME-HPLC-UV provided good proper repeatabilities (relative standard deviations (RSDs) below 5.7 %, n = 3) and high enrichment factors (EFs) of 75-100. Graphical abstract TDLLME of beta-blockers from complicated matrices.

  12. Rapid determination of ampicillin in bovine milk by liquid chromatography with fluorescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Ang, C.Y.W.; Luo, Wenhong [National Center for Toxicological Research, Jefferson, AR (United States)

    1997-01-01

    A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of ampicillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deproteinized with trichloroacetic acid (TCA) and acetonictrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5, 10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb. 16 refs., 4 figs., 3 tabs.

  13. Development of high performance liquid chromatography for rapid determination of burn-up of nuclear fuels

    International Nuclear Information System (INIS)

    Joseph, M.; Karunasagar, D.; Saha, B.

    1996-01-01

    Burn-up an important parameter during evaluation of the performance of any nuclear fuel. Among the various techniques available, the preferred one for its determination is based on accurate measurement of a suitable fission product monitor and the residual heavy elements. Since isotopes of rare earth elements are generally used as burn-up monitors, conditions were standardized for rapid separation (within 15 minutes) of light rare earths using high performance liquid chromatography based on either anion exchange (Partisil 10 SAX) in methanol-nitric acid medium or by cation exchange on a reverse phase column (Spherisorb 5-ODS-2 or Supelcosil LC-18) dynamically modified with 1-octane sulfonate or camphor-10-sulfonic acid (β). Both these methods were assessed for separation of individual fission product rare earths from their mixtures. A new approach has been examined in detail for rapid assay of neodymium, which appears promising for faster and accurate measurement of burn-up. (author)

  14. Rapid high resolution MR neurography with a diffusion-weighted pre-pulse

    International Nuclear Information System (INIS)

    Yoneyama, Masami; Nakamura, Masanobu; Tabuchi, Takashi; Takahara, Taro; Kwee, T.C.

    2013-01-01

    The purpose of this study was to introduce, optimize, and assess the feasibility of a new scheme to rapidly acquire high-resolution volumetric neurographic images using a three-dimensional turbo spin-echo sequence combined with a diffusion-weighted pre-pulse called improved motion-sensitized driven equilibrium (iMSDE): Diffusion-prepared magnetic resonance (MR) Neurography (D-prep MRN). In order to optimize the signal suppression of blood vessels and muscle at D-prep MRN, coronal lumbosacral plexus images were acquired in five volunteers at 3T, and the following parameters were examined: iMSDE gradient-strength (b-value) of 0, 2 and 10 s/mm 2 (with the aim to suppress blood vessels) and iMSDE preparation duration (iMSDE prep-time ) of 18, 50 and 100 ms (with the aim to suppress muscle signal). Subsequently, the feasibility of the optimized D-prep MRN sequence in visualizing the brachial plexus, lumbosacral plexus, and cranial nerves was evaluated in 5 healthy volunteers. A higher b-value of 10 s/mm 2 was better in signal suppression of blood vessels, whereas an intermediate iMSDE prep-time of 50 ms provided the best compromise between suppression of muscle signal and minimization of signal loss of nerves. With these parameters, the normal nerve structures showed high signal intensity, while the blood vessels and muscles were effectively suppressed. The optimized D-prep MRN sequence clearly showed the three-dimensional trajectory of the brachial plexus, lumbosacral plexus, and cranial nerves. D-prep MRN was introduced and optimized, and clearly showed detailed anatomy of the brachial plexus, lumbosacral plexus, and cranial nerves. These results suggest that the D-prep MRN can be used for fast, high-resolution, volumetric imaging of the peripheral nervous system. (author)

  15. High-resolution liquid patterns via three-dimensional droplet shape control.

    Science.gov (United States)

    Raj, Rishi; Adera, Solomon; Enright, Ryan; Wang, Evelyn N

    2014-09-25

    Understanding liquid dynamics on surfaces can provide insight into nature's design and enable fine manipulation capability in biological, manufacturing, microfluidic and thermal management applications. Of particular interest is the ability to control the shape of the droplet contact area on the surface, which is typically circular on a smooth homogeneous surface. Here, we show the ability to tailor various droplet contact area shapes ranging from squares, rectangles, hexagons, octagons, to dodecagons via the design of the structure or chemical heterogeneity on the surface. We simultaneously obtain the necessary physical insights to develop a universal model for the three-dimensional droplet shape by characterizing the droplet side and top profiles. Furthermore, arrays of droplets with controlled shapes and high spatial resolution can be achieved using this approach. This liquid-based patterning strategy promises low-cost fabrication of integrated circuits, conductive patterns and bio-microarrays for high-density information storage and miniaturized biochips and biosensors, among others.

  16. Rapid detection of SMARCB1 sequence variation using high resolution melting

    Directory of Open Access Journals (Sweden)

    Ashley David M

    2009-12-01

    Full Text Available Abstract Background Rhabdoid tumors are rare cancers of early childhood arising in the kidney, central nervous system and other organs. The majority are caused by somatic inactivating mutations or deletions affecting the tumor suppressor locus SMARCB1 [OMIM 601607]. Germ-line SMARCB1 inactivation has been reported in association with rhabdoid tumor, epitheloid sarcoma and familial schwannomatosis, underscoring the importance of accurate mutation screening to ascertain recurrence and transmission risks. We describe a rapid and sensitive diagnostic screening method, using high resolution melting (HRM, for detecting sequence variations in SMARCB1. Methods Amplicons, encompassing the nine coding exons of SMARCB1, flanking splice site sequences and the 5' and 3' UTR, were screened by both HRM and direct DNA sequencing to establish the reliability of HRM as a primary mutation screening tool. Reaction conditions were optimized with commercially available HRM mixes. Results The false negative rate for detecting sequence variants by HRM in our sample series was zero. Nine amplicons out of a total of 140 (6.4% showed variant melt profiles that were subsequently shown to be false positive. Overall nine distinct pathogenic SMARCB1 mutations were identified in a total of 19 possible rhabdoid tumors. Two tumors had two distinct mutations and two harbored SMARCB1 deletion. Other mutations were nonsense or frame-shifts. The detection sensitivity of the HRM screening method was influenced by both sequence context and specific nucleotide change and varied from 1: 4 to 1:1000 (variant to wild-type DNA. A novel method involving digital HRM, followed by re-sequencing, was used to confirm mutations in tumor specimens containing associated normal tissue. Conclusions This is the first report describing SMARCB1 mutation screening using HRM. HRM is a rapid, sensitive and inexpensive screening technology that is likely to be widely adopted in diagnostic laboratories to

  17. Rapid detection of SMARCB1 sequence variation using high resolution melting

    International Nuclear Information System (INIS)

    Dagar, Vinod; Chow, Chung-Wo; Ashley, David M; Algar, Elizabeth M

    2009-01-01

    Rhabdoid tumors are rare cancers of early childhood arising in the kidney, central nervous system and other organs. The majority are caused by somatic inactivating mutations or deletions affecting the tumor suppressor locus SMARCB1 [OMIM 601607]. Germ-line SMARCB1 inactivation has been reported in association with rhabdoid tumor, epitheloid sarcoma and familial schwannomatosis, underscoring the importance of accurate mutation screening to ascertain recurrence and transmission risks. We describe a rapid and sensitive diagnostic screening method, using high resolution melting (HRM), for detecting sequence variations in SMARCB1. Amplicons, encompassing the nine coding exons of SMARCB1, flanking splice site sequences and the 5' and 3' UTR, were screened by both HRM and direct DNA sequencing to establish the reliability of HRM as a primary mutation screening tool. Reaction conditions were optimized with commercially available HRM mixes. The false negative rate for detecting sequence variants by HRM in our sample series was zero. Nine amplicons out of a total of 140 (6.4%) showed variant melt profiles that were subsequently shown to be false positive. Overall nine distinct pathogenic SMARCB1 mutations were identified in a total of 19 possible rhabdoid tumors. Two tumors had two distinct mutations and two harbored SMARCB1 deletion. Other mutations were nonsense or frame-shifts. The detection sensitivity of the HRM screening method was influenced by both sequence context and specific nucleotide change and varied from 1: 4 to 1:1000 (variant to wild-type DNA). A novel method involving digital HRM, followed by re-sequencing, was used to confirm mutations in tumor specimens containing associated normal tissue. This is the first report describing SMARCB1 mutation screening using HRM. HRM is a rapid, sensitive and inexpensive screening technology that is likely to be widely adopted in diagnostic laboratories to facilitate whole gene mutation screening

  18. High Resolution Temperature Measurement of Liquid Stainless Steel Using Hyperspectral Imaging

    Directory of Open Access Journals (Sweden)

    Wim Devesse

    2017-01-01

    Full Text Available A contactless temperature measurement system is presented based on a hyperspectral line camera that captures the spectra in the visible and near infrared (VNIR region of a large set of closely spaced points. The measured spectra are used in a nonlinear least squares optimization routine to calculate a one-dimensional temperature profile with high spatial resolution. Measurements of a liquid melt pool of AISI 316L stainless steel show that the system is able to determine the absolute temperatures with an accuracy of 10%. The measurements are made with a spatial resolution of 12 µm/pixel, justifying its use in applications where high temperature measurements with high spatial detail are desired, such as in the laser material processing and additive manufacturing fields.

  19. [Application of liquid chromatography-high resolution mass spectrometry in toxicological screening].

    Science.gov (United States)

    Li, Xiao-Wen; Shen, Bao-Hua; Zhuo, Xian-Yi

    2011-10-01

    Due to the diversity of toxicologically relevant substances, the uncertainty of target compounds and the specificity of samples, toxicological screening techniques have always been valued by the forensic toxicologists. Depending on its powerful separation ability, superhigh resolution and accurate mass measurement, combined with the two levels spectrum database matching and abundance ratio of isotope ion, the liquid chromatography-high resolution mass spectrometry (LC-HRMS) analyzers have increasingly advantage in screening and identification of chemical compound. This review focuses on the applications of LC-HRMS in screening and identification of drug-of-abuse, prescription drugs, pesticide and stimulant. The prospect of LC-HRMS in forensic toxicology analysis is also included.

  20. Rapid determination of 9 aromatic amines in mainstream cigarette smoke by modified dispersive liquid liquid microextraction and ultraperformance convergence chromatography tandem mass spectrometry.

    Science.gov (United States)

    Deng, Huimin; Yang, Fei; Li, Zhonghao; Bian, Zhaoyang; Fan, Ziyan; Wang, Ying; Liu, Shanshan; Tang, Gangling

    2017-07-21

    Aromatic amines in mainstream cigarette smoke have long been monitored due to their carcinogenic toxicity. In this work, a reliable and rapid method was developed for the simultaneous determination of 9 aromatic amines in mainstream cigarette smoke by modified dispersive liquid liquid microextraction (DLLME) and ultraperformance convergence chromatography tandem mass spectrometry (UPC 2 -MS/MS). Briefly, the particulate phase of the cigarette smoke was captured by a Cambridge filter pad, and diluted hydrogen chloride aqueous solution is employed to extract the aromatic amines under mechanical shaking. After alkalization with sodium hydroxide solution, small amount of toluene was introduced to further extract and enrich aromatic amines by modified DLLME under vortexing. After centrifugation, toluene phase was purified by a universal QuEChERS cleanup kit and was finally analyzed by UPC 2 -MS/MS. Attributing to the superior performance of UPC 2 -MS/MS, this novel approach allowed the separation and determination of 9 aromatic amines within 5.0min with satisfactory resolution and sensitivity. The proposed method was finally validated using Kentucky reference cigarette 3R4F, and emission levels of targeted aromatic amines determined were comparable to previously reported methods At three different spiked levels, the recoveries of most analytes were ranged from 74.01% to 120.50% with relative standard deviation (RSD) less than 12%, except that the recovery of p-toluidine at low spiked level and 3-aminobiphenyl at medium spiked level was 62.77% and 69.37% respectively. Thus, this work provides a novel alternative method for the simultaneous analysis of 9 aromatic amines in mainstream cigarette smoke. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Cloud archiving and data mining of High-Resolution Rapid Refresh forecast model output

    Science.gov (United States)

    Blaylock, Brian K.; Horel, John D.; Liston, Samuel T.

    2017-12-01

    Weather-related research often requires synthesizing vast amounts of data that need archival solutions that are both economical and viable during and past the lifetime of the project. Public cloud computing services (e.g., from Amazon, Microsoft, or Google) or private clouds managed by research institutions are providing object data storage systems potentially appropriate for long-term archives of such large geophysical data sets. We illustrate the use of a private cloud object store developed by the Center for High Performance Computing (CHPC) at the University of Utah. Since early 2015, we have been archiving thousands of two-dimensional gridded fields (each one containing over 1.9 million values over the contiguous United States) from the High-Resolution Rapid Refresh (HRRR) data assimilation and forecast modeling system. The archive is being used for retrospective analyses of meteorological conditions during high-impact weather events, assessing the accuracy of the HRRR forecasts, and providing initial and boundary conditions for research simulations. The archive is accessible interactively and through automated download procedures for researchers at other institutions that can be tailored by the user to extract individual two-dimensional grids from within the highly compressed files. Characteristics of the CHPC object storage system are summarized relative to network file system storage or tape storage solutions. The CHPC storage system is proving to be a scalable, reliable, extensible, affordable, and usable archive solution for our research.

  2. The rapid use of gender information: evidence of the time course of pronoun resolution from eyetracking.

    Science.gov (United States)

    Arnold, J E; Eisenband, J G; Brown-Schmidt, S; Trueswell, J C

    2000-07-14

    Eye movements of listeners were monitored to investigate how gender information and accessibility influence the initial processes of pronoun interpretation. Previous studies on this issue have produced mixed results, and several studies have concluded that gender cues are not automatically used during the early processes of pronoun interpretation (e.g. Garnham, A., Oakhill, J. & Cruttenden, H. (1992). The role of implicit causality and gender cue in the interpretation of pronouns. Language and Cognitive Processes, 73 (4), 231-255; Greene, S. B., McKoon, G. & Ratcliff, R. (1992). Pronoun resolution and discourse models. Journal of Experimental Psychology: Learning, Memory, and Cognition, 182, 266-283). In the two experiments presented here, participants viewed a picture with two familiar cartoon characters of either same or different gender. They listened to a text describing the picture, in which a pronoun referred to either the first, more accessible, character, or the second. (For example, Donald is bringing some mail to ¿Mickey/Minnie¿ while a violent storm is beginning. He's carrying an umbrellaellipsis.) The results of both experiments show rapid use of both gender and accessibility at approximately 200 ms after the pronoun offset.

  3. Parameterizing Subgrid-Scale Orographic Drag in the High-Resolution Rapid Refresh (HRRR) Atmospheric Model

    Science.gov (United States)

    Toy, M. D.; Olson, J.; Kenyon, J.; Smirnova, T. G.; Brown, J. M.

    2017-12-01

    The accuracy of wind forecasts in numerical weather prediction (NWP) models is improved when the drag forces imparted on atmospheric flow by subgrid-scale orography are included. Without such parameterizations, only the terrain resolved by the model grid, along with the small-scale obstacles parameterized by the roughness lengths can have an effect on the flow. This neglects the impacts of subgrid-scale terrain variations, which typically leads to wind speeds that are too strong. Using statistical information about the subgrid-scale orography, such as the mean and variance of the topographic height within a grid cell, the drag forces due to flow blocking, gravity wave drag, and turbulent form drag are estimated and distributed vertically throughout the grid cell column. We recently implemented the small-scale gravity wave drag paramterization of Steeneveld et al. (2008) and Tsiringakis et al. (2017) for stable planetary boundary layers, and the turbulent form drag parameterization of Beljaars et al. (2004) in the High-Resolution Rapid Refresh (HRRR) NWP model developed at the National Oceanic and Atmospheric Administration (NOAA). As a result, a high surface wind speed bias in the model has been reduced and small improvement to the maintenance of stable layers has also been found. We present the results of experiments with the subgrid-scale orographic drag parameterization for the regional HRRR model, as well as for a global model in development at NOAA, showing the direct and indirect impacts.

  4. A Liquid-Cryogen-Free Cryostat for Ultrahigh Resolution Gamma-Ray Spectrometers

    International Nuclear Information System (INIS)

    Dreyer, J.G.; Hertrich, T.; Drury, O.B.; Hohne, J.; Friedrich, S.

    2008-01-01

    We are developing ultra-high energy resolution gamma-ray detectors based on superconducting transition edge sensors (TESs) for nuclear non-proliferation and fundamental science applications. They use bulk tin absorbers attached to molybdenum-copper multilayer TESs, and have achieved an energy resolution between 50 and 90 eV FWHM for gamma-ray energies below 122 keV. For increased user-friendliness, we have built a cryostat that attains the required detector operating temperature of 0.1 K at the push of a button without the use of cryogenic liquids. It uses a two-stage mechanical pulse tube refrigerator for precooling to ∼3 K, and a two-stage adiabatic demagnetization refrigerator for cooling to the base temperature. The cryostat is fully automated, attains a base temperature below 30 mK without the use of cryogenic liquids, and has a hold time of ∼2 days at 0.1 K between 1-hour demagnetization cycles. Here we discuss the performance of the cryostat for operation in a Gamma-spectrometer with 112-pixel arrays of superconducting TES detectors

  5. Rapid-resolution HPLC with specgtrometric detection for the determination and identification of isoflavones in soy preparations and plant extracts

    Czech Academy of Sciences Publication Activity Database

    Klejdus, B.; Vacek, J.; Benešová, L.; Kopecký, Jiří; Lapčík, O.; Kubáň, V.

    2007-01-01

    Roč. 389, - (2007), s. 2277-2285 ISSN 1618-2642 R&D Projects: GA ČR GA525/07/0338; GA ČR GA525/06/0864 Institutional research plan: CEZ:AV0Z50200510 Keywords : rapid resolution * fast chromatography * hplc Subject RIV: EE - Microbiology, Virology Impact factor: 2.867, year: 2007

  6. Transmission and selection of macrolide resistant Mycoplasma genitalium infections detected by rapid high resolution melt analysis.

    Directory of Open Access Journals (Sweden)

    Jimmy Twin

    Full Text Available BACKGROUND: Mycoplasma genitalium (MG causes urethritis, cervicitis and pelvic inflammatory disease. The MG treatment failure rate using 1 g azithromycin at an Australian Sexual Health clinic in 2007-9 was 31% (95%CI 23-40%. We developed a rapid high resolution melt analysis (HRMA assay targeting resistance mutations in the MG 23S rRNA gene, and validated it against DNA sequencing by examining pre- and post-treatment archived samples from MG-infected patients. METHODOLOGY/PRINCIPAL FINDINGS: Available MG-positive pre-treatment (n = 82 and post-treatment samples from individuals with clinical treatment failure (n = 20 were screened for 23S rRNA gene mutations. Sixteen (20% pre-treatment samples possessed resistance mutations (A2058G, A2059G, A2059C, which were significantly more common in patients with symptomatic azithromycin-treatment failure (12/26; 44% than in those clinically cured (4/56; 7%, p<0.001. All 20 patients experiencing azithromycin-failure had detectable mutations in their post-treatment samples. In 9 of these cases, the same mutational types were present in both pre- and post-treatment samples indicating transmitted resistance, whilst in 11 of these cases (55%, mutations were absent in pre-treatment samples indicating likely selection of resistant isolates have occurred. HRMA was able to detect all mutational changes determined in this study by DNA sequencing. An additional HRMA assay incorporating an unlabelled probe was also developed to detect type 4 single-nucleotide polymorphisms found in other populations, with a slightly lower sensitivity of 90%. CONCLUSIONS/SIGNIFICANCE: Treatment failure is associated with the detection of macrolide resistance mutations, which appear to be almost equally due to selection of resistant isolates following exposure to 1 g azithromycin and pre-existing transmitted resistance. The application of a rapid molecular assay to detect resistance at the time of initial detection of infection allows

  7. Multiple Rapid Swallow Responses During Esophageal High-Resolution Manometry Reflect Esophageal Body Peristaltic Reserve

    Science.gov (United States)

    Shaker, Anisa; Stoikes, Nathaniel; Drapekin, Jesse; Kushnir, Vladimir; Brunt, L. Michael; Gyawali, C. Prakash

    2014-01-01

    OBJECTIVES Dysphagia may develop following antireflux surgery as a consequence of poor esophageal peristaltic reserve. We hypothesized that suboptimal contraction response following multiple rapid swallows (MRS) could be associated with chronic transit symptoms following antireflux surgery. METHODS Wet swallow and MRS responses on esophageal high-resolution manometry (HRM) were characterized collectively in the esophageal body (distal contractile integral (DCI)), and individually in each smooth muscle contraction segment (S2 and S3 amplitudes) in 63 patients undergoing antireflux surgery and in 18 healthy controls. Dysphagia was assessed using symptom questionnaires. The MRS/wet swallow ratios were calculated for S2 and S3 peak amplitudes and DCI. MRS responses were compared in patients with and without late postoperative dysphagia following antireflux surgery. RESULTS Augmentation of smooth muscle contraction (MRS/wet swallow ratios > 1.0) as measured collectively by DCI was seen in only 11.1% with late postoperative dysphagia, compared with 63.6% in those with no dysphagia and 78.1% in controls (P≤0.02 for each comparison). Similar results were seen with S3 but not S2 peak amplitude ratios. Receiver operating characteristics identified a DCI MRS/wet swallow ratio threshold of 0.85 in segregating patients with late postoperative dysphagia from those with no postoperative dysphagia with a sensitivity of 0.67 and specificity of 0.64. CONCLUSIONS Lack of augmentation of smooth muscle contraction following MRS is associated with late postoperative dysphagia following antireflux surgery, suggesting that MRS responses could assess esophageal smooth muscle peristaltic reserve. Further research is warranted to determine if antireflux surgery needs to be tailored to the MRS response. PMID:24019081

  8. Rapid Determination of Bile Acids in Bile from Various Mammals by Reversed-Phase Ultra-Fast Liquid Chromatography.

    Science.gov (United States)

    Si, Gu Leng Ri; Yao, Peng; Shi, Luwen

    2015-08-01

    A valid and efficient reversed-phase ultra-fast liquid chromatography method was developed for the simultaneous determination of 13 bile acids in the bile of three mammal species, including rat, pig and human gallstone patients. Chromatographic separation was performed with a Shim-pack XR-ODS column, and the mobile phase consisted of acetonitrile and potassium phosphate buffer (pH 2.6) at a flow rate of 0.5 mL min(-1). The linear detection range of most bile acids ranged from 2 to 600 ng µL(-1) with a good correlation coefficient (>0.9995). The precision of each bile acid was bile acids were separated in 15 min with satisfactory resolution, and the total analysis time was 18 min, including equilibration. The method was successfully applied in rapid screening of bile samples from the three mammals. Significant metabolic frameworks of bile acids among various species were observed, whereas considerable quantitative variations in both inter- and intraspecies were also observed, especially for gallstone patients. Our results suggest that detecting the change of bile acid profiles could be applied for the diagnosis of gallstone disease. © Crown copyright 2014.

  9. Novel strategy for the determination of illegal adulterants in health foods and herbal medicines using high-performance liquid chromatography with high-resolution mass spectrometry.

    Science.gov (United States)

    Wang, Zhe; Wu, Caisheng; Wang, Gangli; Zhang, Qingsheng; Zhang, Jinlan

    2015-03-01

    The detection, confirmation, and quantification of multiple illegal adulterants in health foods and herbal medicines by using a single analytical method are a challenge. This paper reports on a new strategy to meet this challenge by employing high-performance liquid chromatography coupled with high-resolution mass spectrometry and a mass spectral tree similarity filter technique. This analytical method can rapidly collect high-resolution, high-accuracy, optionally multistage mass data for compounds in samples. After a preliminary screening by retention time and high-resolution mass spectral data, known illegal adulterants can be detected. The mass spectral tree similarity filter technique has been applied to rapidly confirm these adulterants and simultaneously discover unknown ones. By using full-scan mass spectra as stem and data-dependent subsequent stage mass spectra to form branches, mass spectrometry data from detected compounds are converted into mass spectral trees. The known or unknown illegal adulterants in the samples are confirmed or discovered based on the similarity between their mass spectral trees and those of the references in a library, and they are finally quantified against standard curves. This new strategy has been tested by using 50 samples, and the illegal adulterants were rapidly and effectively detected, confirmed and quantified. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Miniaturized Planar Room Temperature Ionic Liquid Electrochemical Gas Sensor for Rapid Multiple Gas Pollutants Monitoring.

    Science.gov (United States)

    Wan, Hao; Yin, Heyu; Lin, Lu; Zeng, Xiangqun; Mason, Andrew J

    2018-02-01

    The growing impact of airborne pollutants and explosive gases on human health and occupational safety has escalated the demand of sensors to monitor hazardous gases. This paper presents a new miniaturized planar electrochemical gas sensor for rapid measurement of multiple gaseous hazards. The gas sensor features a porous polytetrafluoroethylene substrate that enables fast gas diffusion and room temperature ionic liquid as the electrolyte. Metal sputtering was utilized for platinum electrodes fabrication to enhance adhesion between the electrodes and the substrate. Together with carefully selected electrochemical methods, the miniaturized gas sensor is capable of measuring multiple gases including oxygen, methane, ozone and sulfur dioxide that are important to human health and safety. Compared to its manually-assembled Clark-cell predecessor, this sensor provides better sensitivity, linearity and repeatability, as validated for oxygen monitoring. With solid performance, fast response and miniaturized size, this sensor is promising for deployment in wearable devices for real-time point-of-exposure gas pollutant monitoring.

  11. Rapid bioassay method for estimation of 90Sr in urine samples by liquid scintillation counting

    International Nuclear Information System (INIS)

    Wankhede, Sonal; Chaudhary, Seema; Sawant, Pramilla D.

    2018-01-01

    Radiostrontium (Sr) is a by-product of the nuclear fission of uranium and plutonium in nuclear reactors and is an important radionuclide in spent nuclear fuel and radioactive waste. Rapid bioassay methods are required for estimating Sr in urine following internal contamination. Decision regarding medical intervention, if any can be based upon the results of urinalysis. The present method used at Bioassay Laboratory, Trombay is by Solid Extraction Chromatography (SEC) technique. The Sr separated from urine sample is precipitated as SrCO 3 and analyzed gravimetrically. However, gravimetric procedure is time consuming and therefore, in the present study, feasibility of Liquid Scintillation Counting for direct detection of radiostrontium in effluent was explored. The results obtained in the present study were compared with those obtained using gravimetric method

  12. Diffusion-stress coupling in liquid phase during rapid solidification of binary mixtures

    International Nuclear Information System (INIS)

    Sobolev, S.L.

    2014-01-01

    An analytical model has been developed to describe the diffusion-viscous stress coupling in the liquid phase during rapid solidification of binary mixtures. The model starts with a set of evolution equations for diffusion flux and viscous pressure tensor, based on extended irreversible thermodynamics. It has been demonstrated that the diffusion-stress coupling leads to non-Fickian diffusion effects in the liquid phase. With only diffusive dynamics, the model results in the nonlocal diffusion equations of parabolic type, which imply the transition to complete solute trapping only asymptotically at an infinite interface velocity. With the wavelike dynamics, the model leads to the nonlocal diffusion equations of hyperbolic type and describes the transition to complete solute trapping and diffusionless solidification at a finite interface velocity in accordance with experimental data and molecular dynamic simulation. -- Highlights: •We propose the diffusion-stress coupling model for binary solidification. •The coupling arises at deep undercooling. •With diffusive dynamics, the models result in parabolic transfer equations. •With the wavelike dynamics, the models lead to hyperbolic transfer equations. •The coupling strongly affects the solute partition coefficient

  13. Subcritical thermal convection of liquid metals in a rapidly rotating sphere

    Science.gov (United States)

    Cardin, P.; Schaeffer, N.; Guervilly, C.; Kaplan, E.

    2017-12-01

    Planetary cores consist of liquid metals (low Prandtl number Pr) that convect as the core cools. Here we study nonlinear convection in a rotating (low Ekman number Ek) planetary core using a fully 3D direct (down to Ek=10-7) and a quasi geostrophic (down to Ek=10-10) numerical simulations. Near the critical thermal forcing (Rayleigh number Ra), convection onsets as thermal Rossby waves, but as Ra increases, this state is superceded by one dominated by advection. At moderate rotation, these states (here called the weak branch and strong branch, respectively) are continuously connected. As the planetary core rotates faster, the continuous transition is replaced by hysteresis cycles and subcriticality until the weak branch disappears entirely and the strong branch onsets in a turbulent state at Ekforcing decreases well below the linear onset of convection (Ra 0.4Racrit in this study for Ek=10-10 and Pr=0.01). We highlight the importance of the Reynolds stress, which is required for convection to persist below the linear onset. We further note the presence of a strong zonal flow that is nonetheless unimportant to the convective subcritical state. Our study suggests that, in the asymptotic regime of rapid rotation relevant for planetary interiors, thermal convection of liquid metals in a sphere onsets and shuts down through a subcritical bifurcation. This scenario may be relevant to explain the lunar and martian dynamo extinctions.

  14. A rapid hydrophilic interaction liquid chromatographic determination of glimepiride in pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    Si Zhou

    2017-09-01

    Full Text Available Glimepiride is one of the most widely prescribed antidiabetic drugs and contains both hydrophobic and hydrophilic functional groups in its molecules, and thus could be analyzed by either reversed-phase high performance liquid chromatography (HPLC or hydrophilic interaction liquid chromatography (HILIC. In the literature, however, only reversed-phase HPLC has been reported. In this study, a simple, rapid and accurate hydrophilic interaction liquid chromatographic method was developed for the determination of glimepiride in pharmaceutical formulations. The analytical method comprised a fast ultrasound-assisted extraction with acetonitrile as a solvent followed by HILIC separation and quantification using a Waters Spherisorb S5NH2 hydrophilic column with a mobile phase consisting of acetonitrile and aqueous acetate buffer (5.0 mM. The retention time of glimepiride increased slightly with decrease of mobile phase pH value from 6.8 to 5.8 and of acetonitrile content from 60% to 40%, indicating that both hydrophilic, ionic, and hydrophobic interactions were involved in the HILIC retention and elution mechanisms. Quantitation was carried out with a mobile phase of 40% acetonitrile and 60% aqueous acetate buffer (5.0 mM at pH 6.3, by relating the peak area of glimepiride to that of the internal standard, with a detection limit of 15.0 μg/L. UV light absorption responses at 228 nm were linear over a wide concentration range from 50.0 μg/L to 6.00 mg/L. The recoveries of the standard added to pharmaceutical tablet samples were 99.4–103.0% for glimepiride, and the relative standard deviation for the analyte was less than 1.0%. This method has been successfully applied to determine the glimepiride contents in pharmaceutical formulations.

  15. Resolution 197/012. It replaces the wording of Annex III of the Regulation of Technical Specifications for Quality of Liquid Fuels, approved by Resolution of the URSEA 150/008

    International Nuclear Information System (INIS)

    2012-01-01

    This resolution is about modifications made in the regulation of technical specifications in the quality of liquid fuels, approved by Resolution of the URSEA 150/008. These modifications concern to the Especial Oil gas

  16. Assessment of disintegration of rapidly disintegrating tablets by a visiometric liquid jet-mediated disintegration apparatus.

    Science.gov (United States)

    Desai, Parind M; Liew, Celine V; Heng, Paul W S

    2013-02-14

    The aim of this study was to develop a responsive disintegration test apparatus that is particularly suitable for rapidly disintegrating tablets (RDTs). The designed RDT disintegration apparatus consisted of disintegration compartment, stereomicroscope and high speed video camera. Computational fluid dynamics (CFD) was used to simulate 3 different designs of the compartment and to predict velocity and pressure patterns inside the compartment. The CFD preprocessor established the compartment models and the CFD solver determined the numerical solutions of the governing equations that described disintegration medium flow. Simulation was validated by good agreement between CFD and experimental results. Based on the results, the most suitable disintegration compartment was selected. Six types of commercial RDTs were used and disintegration times of these tablets were determined using the designed RDT disintegration apparatus and the USP disintegration apparatus. The results obtained using the designed apparatus correlated well to those obtained by the USP apparatus. Thus, the applied CFD approach had the potential to predict the fluid hydrodynamics for the design of optimal disintegration apparatus. The designed visiometric liquid jet-mediated disintegration apparatus for RDT provided efficient and precise determination of very short disintegration times of rapidly disintegrating dosage forms. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Rapid Quantitation of Furanocoumarins and Flavonoids in Grapefruit Juice using Ultra-Performance Liquid Chromatography.

    Science.gov (United States)

    Vandermolen, Karen M; Cech, Nadja B; Paine, Mary F; Oberlies, Nicholas H

    2013-01-01

    Grapefruit juice can increase or decrease the systemic exposure of myriad oral medications, leading to untoward effects or reduced efficacy. Furanocoumarins in grapefruit juice have been established as inhibitors of cytochrome P450 3A (CYP3A)-mediated metabolism and P-glycoprotein (P-gp)-mediated efflux, while flavonoids have been implicated as inhibitors of organic anion transporting polypeptide (OATP)-mediated absorptive uptake in the intestine. The potential for drug interactions with a food product necessitates an understanding of the expected concentrations of a suite of structurally diverse and potentially bioactive compounds. Develop methods for the rapid quantitation of two furanocoumarins (bergamottin and 6',7'-dihydroxybergamottin) and four flavonoids (naringin, naringenin, narirutin and hesperidin) in five grapefruit juice products using ultra-performance liquid chromatography (UPLC). Grapefruit juice products were extracted with ethyl acetate; the concentrated extract was analysed by UPLC using acetonitrile:water gradients and a C18 -column. Analytes were detected using a photodiode array detector, set at 250 nm (furanocoumarins) and 310 nm (flavonoids). Intraday and interday precision and accuracy and limits of detection and quantitation were determined. Rapid (0.999. Considerable between-juice variation in the concentrations of these compounds was observed, and the quantities measured were in agreement with the concentrations published in HPLC studies. These analytical methods provide an expedient means to quantitate key furanocoumarins and flavonoids in grapefruit juice and other foods used in dietary substance-drug interaction studies. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Novel approaches in analysis of Fusarium mycotoxins in cereals employing ultra performance liquid chromatography coupled with high resolution mass spectrometry

    International Nuclear Information System (INIS)

    Zachariasova, M.; Lacina, O.; Malachova, A.; Kostelanska, M.; Poustka, J.; Godula, M.; Hajslova, J.

    2010-01-01

    Rapid, simple and cost-effective analytical methods with performance characteristics matching regulatory requirements are needed for effective control of occurrence of Fusarium toxins in cereals and cereal-based products to which they might be transferred during processing. Within this study, two alternative approaches enabling retrospective data analysis and identification of unknown signals in sample extracts have been implemented and validated for determination of 11 major Fusarium toxins. In both cases, ultra-high performance liquid chromatography (U-HPLC) coupled with high resolution mass spectrometry (HR MS) was employed. 13 C isotopically labeled surrogates as well as matrix-matched standards were employed for quantification. As far as time of flight mass analyzer (TOF-MS) was a detection tool, the use of modified QuEChERS (quick easy cheap effective rugged and safe) sample preparation procedure, widely employed in multi-pesticides residue analysis, was shown as an optimal approach to obtain low detection limits. The second challenging alternative, enabling direct analysis of crude extract, was the use of mass analyzer based on Orbitrap technology. In addition to demonstration of full compliance of the new methods with Commission Regulation (EC) No. 401/2006, also their potential to be used for confirmatory purposes according to Commission Decision 2002/657/EC has been critically assessed.

  19. Liquid chromatography with diode array detection and multivariate curve resolution for the selective and sensitive quantification of estrogens in natural waters.

    Science.gov (United States)

    Pérez, Rocío L; Escandar, Graciela M

    2014-07-04

    Following the green analytical chemistry principles, an efficient strategy involving second-order data provided by liquid chromatography (LC) with diode array detection (DAD) was applied for the simultaneous determination of estriol, 17β-estradiol, 17α-ethinylestradiol and estrone in natural water samples. After a simple pre-concentration step, LC-DAD matrix data were rapidly obtained (in less than 5 min) with a chromatographic system operating isocratically. Applying a second-order calibration algorithm based on multivariate curve resolution with alternating least-squares (MCR-ALS), successful resolution was achieved in the presence of sample constituents that strongly coelute with the analytes. The flexibility of this multivariate model allowed the quantification of the four estrogens in tap, mineral, underground and river water samples. Limits of detection in the range between 3 and 13 ng L(-1), and relative prediction errors from 2 to 11% were achieved. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Probing spatial locality in ionic liquids with the grand canonical adaptive resolution molecular dynamics technique

    Science.gov (United States)

    Shadrack Jabes, B.; Krekeler, C.; Klein, R.; Delle Site, L.

    2018-05-01

    We employ the Grand Canonical Adaptive Resolution Simulation (GC-AdResS) molecular dynamics technique to test the spatial locality of the 1-ethyl 3-methyl imidazolium chloride liquid. In GC-AdResS, atomistic details are kept only in an open sub-region of the system while the environment is treated at coarse-grained level; thus, if spatial quantities calculated in such a sub-region agree with the equivalent quantities calculated in a full atomistic simulation, then the atomistic degrees of freedom outside the sub-region play a negligible role. The size of the sub-region fixes the degree of spatial locality of a certain quantity. We show that even for sub-regions whose radius corresponds to the size of a few molecules, spatial properties are reasonably reproduced thus suggesting a higher degree of spatial locality, a hypothesis put forward also by other researchers and that seems to play an important role for the characterization of fundamental properties of a large class of ionic liquids.

  1. Some rules to improve the energy resolution in alpha liquid scintillation with beta rejection

    CERN Document Server

    Aupiais, J; Dacheux, N

    2003-01-01

    Two common scintillating mixtures dedicated to alpha measurements by means of alpha liquid scintillation with pulse shape discrimination were tested: the di-isopropylnaphthalene - based and the toluene-based solvents containing the commercial cocktails Ultima Gold AB trademark and Alphaex trademark. We show the possibility to enhance the resolution up to 200% by using no-water miscible cocktails and by reducing the optical path. Under these conditions, the resolution of about 200 keV can be obtained either by the Tri Carb sup T sup M or by the Perals sup T sup M spectrometers. The time responses, e.g., the time required for a complete energy transfer between the initial interaction alpha particle-solvent and the final fluorescence of the organic scintillator, have been compared. Both cocktails present similar behavior. According to the Foerster theory, about 6-10 ns are required to complete the energy transfer. For both apparatus, the detection limits were determined for alpha emitters. The sensitivity of the...

  2. Rapid Detection and Differentiation of Clonorchis sinensis and Opisthorchis viverrini Using Real-Time PCR and High Resolution Melting Analysis

    OpenAIRE

    Cai, Xian-Quan; Yu, Hai-Qiong; Li, Rong; Yue, Qiao-Yun; Liu, Guo-Hua; Bai, Jian-Shan; Deng, Yan; Qiu, De-Yi; Zhu, Xing-Quan

    2014-01-01

    Clonorchis sinensis and Opisthorchis viverrini are both important fish-borne pathogens, causing serious public health problem in Asia. The present study developed an assay integrating real-time PCR and high resolution melting (HRM) analysis for the specific detection and rapid identification of C. sinensis and O. viverrini. Primers targeting COX1 gene were highly specific for these liver flukes, as evidenced by the negative amplification of closely related trematodes. Assays using genomic DNA...

  3. Rapid screening of oxytetracycline residue in catfish muscle by dispersive liquid-liquid microextraction and europium-sensitized luminescence

    Science.gov (United States)

    Oxytetracycline (OTC) residue in catfish muscle was screened by dispersive liquid-liquid microextraction (DLLME) and europium-sensitized luminescence (ESL). After extraction in EDTA, HCl, and acetonitrile, cleanup was carried out by DLLME, and ESL was measured at microgram = 385 nm and wavelength = ...

  4. Identification of dominant flow structures in rapidly rotating convection of liquid metals using Dynamic Mode Decomposition

    Science.gov (United States)

    Horn, S.; Schmid, P. J.; Aurnou, J. M.

    2016-12-01

    The Earth's metal core acts as a dynamo whose efficiency in generating and maintaining the magnetic field is essentially determined by the rotation rate and the convective motions occurring in its outer liquid part. For the description of the primary physics in the outer core the idealized system of rotating Rayleigh-Bénard convection is often invoked, with the majority of studies considering only working fluids with Prandtl numbers of Pr ≳ 1. However, liquid metals are characterized by distinctly smaller Prandtl numbers which in turn result in an inherently different type of convection. Here, we will present results from direct numerical simulations of rapidly rotating convection in a fluid with Pr ≈ 0.025 in cylindrical containers and Ekman numbers as low as 5 × 10-6. In this system, the Coriolis force is the source of two types of inertial modes, the so-called wall modes, that also exist at moderate Prandtl numbers, and cylinder-filling oscillatory modes, that are a unique feature of small Prandtl number convection. The obtained flow fields were analyzed using the Dynamic Mode Decomposition (DMD). This technique allows to extract and identify the structures that govern the dynamics of the system as well as their corresponding frequencies. We have investigated both the regime where the flow is purely oscillatory and the regime where wall modes and oscillatory modes co-exist. In the purely oscillatory regime, high and low frequency oscillatory modes characterize the flow. When both types of modes are present, the DMD reveals that the wall-attached modes dominate the flow dynamics. They precess with a relatively low frequency in retrograde direction. Nonetheless, also in this case, high frequency oscillations have a significant contribution.

  5. Rapid Quantitation of Furanocoumarins and Flavonoids in Grapefruit Juice using Ultra Performance Liquid Chromatography

    Science.gov (United States)

    VanderMolen, Karen M.; Cech, Nadja B.; Paine, Mary F.

    2013-01-01

    Introduction Grapefruit juice can increase or decrease the systemic exposure of myriad oral medications, leading to untoward effects or reduced efficacy. Furanocoumarins in grapefruit juice have been established as inhibitors of cytochrome P450 3A (CYP3A)-mediated metabolism and P-glycoprotein (P-gp)-mediated efflux, while flavonoids have been implicated as inhibitors of organic anion transporting polypeptide (OATP)-mediated absorptive uptake in the intestine. The potential for drug interactions with a food product necessitates an understanding of the expected concentrations of a suite of structurally diverse and potentially bioactive compounds. Objective Develop methods for the rapid quantitation of two furanocoumarins (bergamottin and 6′,7′-dihydroxybergamottin) and four flavonoids (naringin, naringenin, narirutin, and hesperidin) in five grapefruit juice products using ultra performance liquid chromatography (UPLC). Methodology Grapefruit juice products were extracted with ethyl acetate; the concentrated extract was analyzed by UPLC using acetonitrile:water gradients and a C18 column. Analytes were detected using a photodiode array detector, set at 250 nm (furanocoumarins) and 310 nm (flavonoids). Intraday and interday precision and accuracy and limits of detection and quantitation were determined. Results Rapid (flavonoids. R2 values for the calibration curves of all analytes were >0.999. Considerable between-juice variation in the concentrations of these compounds was observed, and the quantities measured were in agreement with the concentrations published in HPLC studies. Conclusion These analytical methods provide an expedient means to quantitate key furanocoumarins and flavonoids in grapefruit juice and other foods used in dietary substance-drug interaction studies. PMID:23780830

  6. Rapid response sensor to monitor the temperature and flow of liquid metals

    International Nuclear Information System (INIS)

    McCann, J.D.

    1980-01-01

    Two forms of a sensor capable of simultaneously monitoring the temperature and flow of liquid metal coolants within a reactor are described. They operate by measuring the coupling impedances between the sensor and the surrounding electrically conductive coolant. Since the system utilises electrical rather than thermal properties, the response to perturbations is rapid, typically displaying the changed conditions within a few milliseconds. The first form of the sensor was designed to operate whilst protected by a thick walled service tube positioned in the reactor coolant. Providing bends in the tube had a radius greater than 70 cm, the sensor could be removed for inspection and maintenance if necessary. The second sensor was fitted inside a streamlined NaK proof capsule. This was inserted directly into the coolant outlet stream of a fuel pin assembly in the Dounreay Fast Reactor. In this form the sensor successfully monitored flow, entrained gas and temperature excursions during the final operating cycle of D.F.R. (author)

  7. Rapid calibrated high-resolution hyperspectral imaging using tunable laser source

    Science.gov (United States)

    Nguyen, Lam K.; Margalith, Eli

    2009-05-01

    We present a novel hyperspectral imaging technique based on tunable laser technology. By replacing the broadband source and tunable filters of a typical NIR imaging instrument, several advantages are realized, including: high spectral resolution, highly variable field-of-views, fast scan-rates, high signal-to-noise ratio, and the ability to use optical fiber for efficient and flexible sample illumination. With this technique, high-resolution, calibrated hyperspectral images over the NIR range can be acquired in seconds. The performance of system features will be demonstrated on two example applications: detecting melamine contamination in wheat gluten and separating bovine protein from wheat protein in cattle feed.

  8. Analytical method by high resolution liquid chromatography for the determination of carbamazepine in human plasma

    International Nuclear Information System (INIS)

    Jimenez Aleman, Narda M; Calero Carbonell, Jorge E; Padron Yaquis, Alejandro S; Izquierdo Lozano, Julio C

    2007-01-01

    One of the requirements to develop the studies of bioavailability and bioequivalence is to have analytic methodologies validated for the work with samples in biological fluids. A method was developed by high resolution liquid chromatography for the determination of carbamazepine in human plasma. A mixture of hydrogen phosphate of sodium: acetonitrile (65:35) adjusted to pH= 3.3 with phosphoric acid, flow of 1.2 mL/min and ultraviolet detection at 210 nm, was used as mobile phase. Propylparabene was used as an internal standard. According to the established regulations for the validation of the methods in biological fluids, the following parameters were studied: stability of the samples, lineality, specificity, precision, accuracy and limit of detection and quantification. The method proved to be specific and sensitive with a detection and quantification limit of 0.9 and 1.0 ng, respectively. The method was lineal, precise and exact in the range of concentrations of 1. 07 at 12.67 μg/mL. The mean recovery was not statistically different from 100.0 %. The analito in the proposed biological matrix remained in the studied period. The methodology described in this work is applied in our case to the study that evaluates the bioavailability and bioequivalence of a Cuban formulation of carbamazepine in healthy volunteers. (Author)

  9. A high-resolution tracking hodoscope based on capillary layers filled with liquid scintillator

    CERN Document Server

    Bay, A; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Ekimov, A V; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Frekers, D; Frenkel, A; Golovkin, S V; Govorun, V N; Harrison, K; Koppenburg, P; Kozarenko, E N; Kreslo, I E; Liberti, B; Martellotti, G; Medvedkov, A M; Mondardini, M R; Penso, G; Siegmund, W P; Vasilchenko, V G; Vilain, P; Wilquet, G; Winter, Klaus; Wörtche, H J

    2001-01-01

    Results are given on tests of a high-resolution tracking hodoscope based on layers of \\hbox{26-$\\mu$m-bore} glass capillaries filled with organic liquid scintillator (1-methylnaphthalene doped with R39). The detector prototype consisted of three 2-mm-thick parallel layers, with surface areas of $2.1 \\times 21$~cm$^2$. The layers had a centre-to-centre spacing of 6~mm, and were read by an optoelectronic chain comprising two electrostatically focused image intensifiers and an Electron-Bombarded Charge-Coupled Device (EBCCD). Tracks of cosmic-ray particles were recorded and analysed. The observed hit density was 6.6~hits/mm for particles crossing the layers perpendicularly, at a distance of 1~cm from the capillaries' readout end, and 4.2~hits/mm for particles at a distance of 20~cm. A track segment reconstructed in a single layer had an rms residual of $\\sim$~20~$\\mu$m, and allowed determination of the track position in a neighbouring layer with a precision of $\\sim$~170~$\\mu$m. This latter value corresponded to...

  10. Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

    Science.gov (United States)

    Chung, Philip; Heller, J. Alex; Etemadi, Mozziyar; Ottoson, Paige E.; Liu, Jonathan A.; Rand, Larry; Roy, Shuvo

    2014-01-01

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications. PMID:24998993

  11. [Rapid resolution of acute subdural haematoma with significant impact on clinical outcome].

    Science.gov (United States)

    Capion, Tenna; Lilja-Cyron, Alexander; Kelsen, Jesper

    2017-09-04

    A 73-year-old woman was admitted to hospital due to anaemia. She suffered a minor head trauma and deteriorated to deep unconsciousness. A CT revealed an acute subdural haematoma (ASDH). Initially, she was not found to be a candidate for neurosurgical intervention, but within 24 hours her level of consciousness improved dramatically, and a renewed CT showed resolution of the ASDH. She underwent acute craniotomy with good outcome. This illustrates the importance of re-evaluation of patients with intracranial haemorrhage.

  12. Rapid resolution of cellulitis in patients managed with combination antibiotic and anti-inflammatory therapy.

    Science.gov (United States)

    Dall, Lawrence; Peterson, Sandford; Simmons, Tom; Dall, Amy

    2005-03-01

    There is some evidence to suggest that host inflammatory response has some effect on the clinical manifestations of cellulitis. The objective of this pilot study was to investigate whether the addition of oral nonsteroidal anti-inflammatory (NSAI) therapy to antibiotic treatment hastens resolution of cellulitis-related inflammation. Patients presenting in the emergency department with signs and symptoms of class II cellulitis were assigned to receive treatment with either antibiotic therapy alone (intravenous, supplemented with oral cephalexin or an equivalent) for 10 days (n = 33) or antibiotic therapy for 10 days plus an oral anti-inflammatory (ibuprofen 400 mg every 6 hours) for 5 days (n = 31). Patients were discharged as soon as possible to complete their therapy on an outpatient basis. The addition of an oral anti-inflammatory agent significantly (P < .05) shortened the time to regression of inflammation and complete resolution of cellulitis. Twenty-four of 29 evaluable patients (82.8%) who received supplemental anti-inflammatory treatment showed regression of inflammation within 1 to 2 days compared with only 3 of 33 patients (9.1%) treated without an anti-inflammatory in the same time frame. All patients receiving adjunctive anti-inflammatory treatment experienced complete resolution of cellulitis in 4 to 5 days or less, while 24.2% (8/33) of patients treated with antibiotic alone required 6 to 7 days, and 6.1% (2/33) required 7 days or more (P < .05). This small preliminary study provides some promising data, suggesting that the supplemental use of anti-inflammatory therapy may hasten the time to regression of inflammation and complete resolution of cellulitis.

  13. Toward Rapid Unattended X-ray Tomography of Large Planar Samples at 50-nm Resolution

    International Nuclear Information System (INIS)

    Rudati, J.; Tkachuk, A.; Gelb, J.; Hsu, G.; Feng, Y.; Pastrick, R.; Lyon, A.; Trapp, D.; Beetz, T.; Chen, S.; Hornberger, B.; Seshadri, S.; Kamath, S.; Zeng, X.; Feser, M.; Yun, W.; Pianetta, P.; Andrews, J.; Brennan, S.; Chu, Y. S.

    2009-01-01

    X-ray tomography at sub-50 nm resolution of small areas (∼15 μmx15 μm) are routinely performed with both laboratory and synchrotron sources. Optics and detectors for laboratory systems have been optimized to approach the theoretical efficiency limit. Limited by the availability of relatively low-brightness laboratory X-ray sources, exposure times for 3-D data sets at 50 nm resolution are still many hours up to a full day. However, for bright synchrotron sources, the use of these optimized imaging systems results in extremely short exposure times, approaching live-camera speeds at the Advanced Photon Source at Argonne National Laboratory near Chicago in the US These speeds make it possible to acquire a full tomographic dataset at 50 nm resolution in less than a minute of true X-ray exposure time. However, limits in the control and positioning system lead to large overhead that results in typical exposure times of ∼15 min currently.We present our work on the reduction and elimination of system overhead and toward complete automation of the data acquisition process. The enhancements underway are primarily to boost the scanning rate, sample positioning speed, and illumination homogeneity to performance levels necessary for unattended tomography of large areas (many mm 2 in size). We present first results on this ongoing project.

  14. Rapid analysis of ethanol and water in commercial products using ionic liquid capillary gas chromatography with thermal conductivity detection and/or barrier discharge ionization detection.

    Science.gov (United States)

    Weatherly, Choyce A; Woods, Ross M; Armstrong, Daniel W

    2014-02-26

    Analysis of ethanol and water in consumer products is important in a variety of processes and often is mandated by regulating agencies. A method for the simultaneous quantitation of ethanol and water that is simple, accurate, precise, rapid, and cost-effective is demonstrated. This approach requires no internal standard for the quantitation of both ethanol and water at any/all levels in commercial products. Ionic liquid based gas chromatography (GC) capillary columns are used to obtain a fast analysis with high selectivity and resolution of water and ethanol. Typical run times are just over 3 min. Examination of the response range of water and ethanol with GC, thermal conductivity detection (TCD), and barrier ionization detection (BID) is performed. Quantitation of both ethanol and water in consumer products is accomplished with both TCD and BID GC detectors using a nonlinear calibration. Validation of method accuracy is accomplished by using standard reference materials.

  15. Tsunami Rapid Assessment Using High Resolution Images and Field Surveys: the 2010 , Central Chile, and the 2011, Tohoku Tsunamis

    Science.gov (United States)

    Ramirez-Herrera, M.; Navarrete-Pacheco, J.; Lagos, M.; Arcas, D.

    2013-12-01

    Recent extreme tsunamis have shown their major socioeconomic impact and imprint in the coastal landscape. Extensive destruction, erosion, sediment transport and deposition resculpted coastal landscape within few minutes along hundreds of kilometers of the Central Chile, in 2010, and the Northeast coast of Japan, in 2011. In the central coast of Chile, we performed a post-tsunami survey a week after the tsunami due to access restrictions. Our observations focus on the inundation and geomorphic effects of the 2010 tsunami and included an air reconnaissance flight, analysis of pre- and post-event low fly air-photographs and Google Earth satellite images, together with ground reconnaissance and mapping in the field, including topographic transects, during a period of 13 days. Eyewitness accounts enabled us to confirm our observations on effects produced by the tsunami along ~ 500km along the coastline landscape in central Chile For the Tohoku case study, we assessed in a day tsunami inundation distances and runup heights using satellite data (very high resolution satellite images from the GeoEye1 satellite and from the DigitalGlobe worldview through the Google crisis response project, SRTM and ASTER GDEM) of the Tohoku region, Northeast Japan. Field survey data by Japanese, other international scientists and us validated our results. The rapid assessment of damage using high-resolution images has proven to be an excellent tool neccessary for effcient postsunami surveys as well as for rapid assessment of areas with access restrictions. All countries, in particular those with less access to technology and infrastructure, can benefit from the use of freely available satellite imagery and DEMs for an initial, pre-field survey, rapid estimate of inundated areas, distances and runup, tsunami effects in the coastal geomorphology and for assisting in hazard management and mitigation after a natural disaster. These data provide unprecedented opportunities for rapid assessment

  16. High-Resolution Liquid Chromatography Tandem Mass Spectrometry Enables Large Scale Molecular Characterization of Dissolved Organic Matter

    Directory of Open Access Journals (Sweden)

    Daniel Petras

    2017-12-01

    Full Text Available Dissolved organic matter (DOM is arguably one of the most complex exometabolomes on earth, and is comprised of thousands of compounds, that together contribute more than 600 × 1015 g carbon. This reservoir is primarily the product of interactions between the upper ocean's microbial food web, yet abiotic processes that occur over millennia have also modified many of its molecules. The compounds within this reservoir play important roles in determining the rate and extent of element exchange between inorganic reservoirs and the marine biosphere, while also mediating microbe-microbe interactions. As such, there has been a widespread effort to characterize DOM using high-resolution analytical methods including nuclear magnetic resonance spectroscopy (NMR and mass spectrometry (MS. To date, molecular information in DOM has been primarily obtained through calculated molecular formulas from exact mass. This approach has the advantage of being non-targeted, accessing the inherent complexity of DOM. Molecular structures are however still elusive and the most commonly used instruments are costly. More recently, tandem mass spectrometry has been employed to more precisely identify DOM components through comparison to library mass spectra. Here we describe a data acquisition and analysis workflow that expands the repertoire of high-resolution analytical approaches available to access the complexity of DOM molecules that are amenable to electrospray ionization (ESI MS. We couple liquid chromatographic separation with tandem MS (LC-MS/MS and a data analysis pipeline, that integrates peak extraction from extracted ion chromatograms (XIC, molecular formula calculation and molecular networking. This provides more precise structural characterization. Although only around 1% of detectable DOM compounds can be annotated through publicly available spectral libraries, community-wide participation in populating and annotating DOM datasets could rapidly increase the

  17. Supported liquid membrane stability in chiral resolution by chemically and physically modified membranes

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, R.; Argurio, P. [Arcavata di Rende Univ. of Calabria, Arcavata di Rende, CS (Italy). Dept. of Chemical and Materials Engineering

    2001-04-01

    In the present work some stability studies on Supported Liquid Membranes (SLMs) to be used for chiral separations were realized. In particular, primary aim was to determine how a modification of the support surface influences the SLM stability. First, the procedure for support modification was optimised, making a screening of various compounds (sulphuric acid, nitric acid, chromic acid, sodium dodecyl sulphate (SDS), glycerol, oleic alcohol, propylene glycol (PPG), bovine serum albumin (BSA)) and testing their performance by means of contact angle measurements. Next, a second screening was realized by permeation tests in a stirred cell. Finally, to compare the stability of modified with unmodified support in a process of interest for chemical and/or biochemical industries, some permeation tests for resolution of DNB-DL-Leucine were realized in a re-circulation system. Results showed a better surface hydrophilization of chemically modified support and better stability of the sulphonated support. However, in operating conditions a little high stability of the unmodified support was obtained. [Italian] Nel presente lavoro sono stati realizzati degli studi di stabilita' di Membrane Liquide Supportate (SLMs) da impiegare in separazioni chirali. In particolare, obiettivo principale e' stato quello di determinare l'influenza che una modifica della superficie del supporto ha sulla stabilita' della SLM. Cosi', in un primo momento, e' stata ottimizzata le procedura di modifica del supporto, facendo una selezione tra vari composti (acido solforico, acido nitrico, acido cromico, sodio dodecil solfato (SDS), glicerolo, alcool oleico, glicole propilenico (PPG), siero di albumina bovina (BSA)) basata su misure dell'angolo di contatto. Successivamente, e' stata realizzata una seconda selezione mediante prove di permeazione in una cella agitata. Infine, con lo scopo di confrontare la stabilita' della SLM con supporto modificato rispetto

  18. Rapid Target Detection in High Resolution Remote Sensing Images Using Yolo Model

    Science.gov (United States)

    Wu, Z.; Chen, X.; Gao, Y.; Li, Y.

    2018-04-01

    Object detection in high resolution remote sensing images is a fundamental and challenging problem in the field of remote sensing imagery analysis for civil and military application due to the complex neighboring environments, which can cause the recognition algorithms to mistake irrelevant ground objects for target objects. Deep Convolution Neural Network(DCNN) is the hotspot in object detection for its powerful ability of feature extraction and has achieved state-of-the-art results in Computer Vision. Common pipeline of object detection based on DCNN consists of region proposal, CNN feature extraction, region classification and post processing. YOLO model frames object detection as a regression problem, using a single CNN predicts bounding boxes and class probabilities in an end-to-end way and make the predict faster. In this paper, a YOLO based model is used for object detection in high resolution sensing images. The experiments on NWPU VHR-10 dataset and our airport/airplane dataset gain from GoogleEarth show that, compare with the common pipeline, the proposed model speeds up the detection process and have good accuracy.

  19. A simple and rapid method for high-resolution visualization of single-ion tracks

    Directory of Open Access Journals (Sweden)

    Masaaki Omichi

    2014-11-01

    Full Text Available Prompt determination of spatial points of single-ion tracks plays a key role in high-energy particle induced-cancer therapy and gene/plant mutations. In this study, a simple method for the high-resolution visualization of single-ion tracks without etching was developed through the use of polyacrylic acid (PAA-N, N’-methylene bisacrylamide (MBAAm blend films. One of the steps of the proposed method includes exposure of the irradiated films to water vapor for several minutes. Water vapor was found to promote the cross-linking reaction of PAA and MBAAm to form a bulky cross-linked structure; the ion-track scars were detectable at a nanometer scale by atomic force microscopy. This study demonstrated that each scar is easily distinguishable, and the amount of generated radicals of the ion tracks can be estimated by measuring the height of the scars, even in highly dense ion tracks. This method is suitable for the visualization of the penumbra region in a single-ion track with a high spatial resolution of 50 nm, which is sufficiently small to confirm that a single ion hits a cell nucleus with a size ranging between 5 and 20 μm.

  20. A simple and rapid method for high-resolution visualization of single-ion tracks

    Energy Technology Data Exchange (ETDEWEB)

    Omichi, Masaaki [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Center for Collaborative Research, Anan National College of Technology, Anan, Tokushima 774-0017 (Japan); Choi, Wookjin; Sakamaki, Daisuke; Seki, Shu, E-mail: seki@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Tsukuda, Satoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Sugimoto, Masaki [Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, Gunma, Gunma 370-1292 (Japan)

    2014-11-15

    Prompt determination of spatial points of single-ion tracks plays a key role in high-energy particle induced-cancer therapy and gene/plant mutations. In this study, a simple method for the high-resolution visualization of single-ion tracks without etching was developed through the use of polyacrylic acid (PAA)-N, N’-methylene bisacrylamide (MBAAm) blend films. One of the steps of the proposed method includes exposure of the irradiated films to water vapor for several minutes. Water vapor was found to promote the cross-linking reaction of PAA and MBAAm to form a bulky cross-linked structure; the ion-track scars were detectable at a nanometer scale by atomic force microscopy. This study demonstrated that each scar is easily distinguishable, and the amount of generated radicals of the ion tracks can be estimated by measuring the height of the scars, even in highly dense ion tracks. This method is suitable for the visualization of the penumbra region in a single-ion track with a high spatial resolution of 50 nm, which is sufficiently small to confirm that a single ion hits a cell nucleus with a size ranging between 5 and 20 μm.

  1. Droplet deposition measurement with high-speed camera and novel high-speed liquid film sensor with high spatial resolution

    International Nuclear Information System (INIS)

    Damsohn, M.; Prasser, H.-M.

    2011-01-01

    Highlights: → Development of a sensor for time- and space-resolved droplet deposition in annular flow. → Experimental measurement of droplet deposition in horizontal annular flow to compare readings of the sensor with images of a high-speed camera when droplets are depositing unto the liquid film. → Self-adaptive signal filter based on autoregression to separate droplet impacts in the sensor signal from waves of liquid films. - Abstract: A sensor based on the electrical conductance method is presented for the measurement of dynamic liquid films in two-phase flow. The so called liquid film sensor consists of a matrix with 64 x 16 measuring points, a spatial resolution of 3.12 mm and a time resolution of 10 kHz. Experiments in a horizontal co-current air-water film flow were conducted to test the capability of the sensor to detect droplet deposition from the gas core onto the liquid film. The experimental setup is equipped with the liquid film sensor and a high speed camera (HSC) recording the droplet deposition with a sampling rate of 10 kHz simultaneously. In some experiments the recognition of droplet deposition on the sensor is enhanced by marking the droplets with higher electrical conductivity. The comparison between the HSC and the sensor shows, that the sensor captures the droplet deposition above a certain droplet diameter. The impacts of droplet deposition can be filtered from the wavy structures respectively conductivity changes of the liquid film using a filter algorithm based on autoregression. The results will be used to locally measure droplet deposition e.g. in the proximity of spacers in a subchannel geometry.

  2. A microfluidic platform for the rapid determination of distribution coefficients by gravity assisted droplet-based liquid-liquid extraction

    DEFF Research Database (Denmark)

    Poulsen, Carl Esben; Wootton, Robert C. R.; Wolff, Anders

    2015-01-01

    The determination of pharmacokinetic properties of drugs, such as the distribution coefficient, D, is a crucial measurement in pharmaceutical research. Surprisingly, the conventional (gold standard) technique used for D measurements, the shake-flask method, is antiquated and unsuitable...... for the testing of valuable and scarce drug candidates. Herein we present a simple micro fluidic platform for the determination of distribution coefficients using droplet-based liquid-liquid extraction. For simplicity, this platform makes use of gravity to enable phase separation for analysis and is 48 times...... the apparent acid dissociation constant, pK', as a proxy for inter-system comparison. Our platform determines a pK' value of 7.24 ± 0.15, compared to 7.25 ± 0.58 for the shake-flask method in our hands and 7.21 for the shake-flask method in literature. Devices are fabricated using injection moulding, the batch...

  3. Introducing a new and rapid microextraction approach based on magnetic ionic liquids: Stir bar dispersive liquid microextraction.

    Science.gov (United States)

    Chisvert, Alberto; Benedé, Juan L; Anderson, Jared L; Pierson, Stephen A; Salvador, Amparo

    2017-08-29

    With the aim of contributing to the development and improvement of microextraction techniques, a novel approach combining the principles and advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) is presented. This new approach, termed stir bar dispersive liquid microextraction (SBDLME), involves the addition of a magnetic ionic liquid (MIL) and a neodymium-core magnetic stir bar into the sample allowing the MIL coat the stir bar due to physical forces (i.e., magnetism). As long as the stirring rate is maintained at low speed, the MIL resists rotational (centrifugal) forces and remains on the stir bar surface in a manner closely resembling SBSE. By increasing the stirring rate, the rotational forces surpass the magnetic field and the MIL disperses into the sample solution in a similar manner to DLLME. After extraction, the stirring is stopped and the MIL returns to the stir bar without the requirement of an additional external magnetic field. The MIL-coated stir bar containing the preconcentrated analytes is thermally desorbed directly into a gas chromatographic system coupled to a mass spectrometric detector (TD-GC-MS). This novel approach opens new insights into the microextraction field, by using the benefits provided by SBSE and DLLME simultaneously, such as automated thermal desorption and high surface contact area, respectively, but most importantly, it enables the use of tailor-made solvents (i.e., MILs). To prove its utility, SBDLME has been used in the extraction of lipophilic organic UV filters from environmental water samples as model analytical application with excellent analytical features in terms of linearity, enrichment factors (67-791), limits of detection (low ng L -1 ), intra- and inter-day repeatability (RSD<15%) and relative recoveries (87-113%, 91-117% and 89-115% for river, sea and swimming pool water samples, respectively). Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Characterization of Fumonisin A-Series by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Masayoshi Tamura

    2014-08-01

    Full Text Available Fumonisin A-series (FAs in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS. Peaks for fumonisin B1 (FB1, fumonisin B2 (FB2, and fumonisin B3 (FB3, in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200–800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50–200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I–III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1 synthesized from FB1 standards, compounds I–III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1, A2 (FA2, and A3 (FA3. The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

  5. Characterization of fumonisin A-series by high-resolution liquid chromatography-orbitrap mass spectrometry.

    Science.gov (United States)

    Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Toriba, Akira; Hayakawa, Kazuichi

    2014-08-21

    Fumonisin A-series (FAs) in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS). Peaks for fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3), in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200-800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50-200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I-III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1) synthesized from FB1 standards, compounds I-III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1), A2 (FA2), and A3 (FA3). The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

  6. Introducing a new and rapid microextraction approach based on magnetic ionic liquids: Stir bar dispersive liquid microextraction

    International Nuclear Information System (INIS)

    Chisvert, Alberto; Benedé, Juan L.; Anderson, Jared L.; Pierson, Stephen A.; Salvador, Amparo

    2017-01-01

    With the aim of contributing to the development and improvement of microextraction techniques, a novel approach combining the principles and advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) is presented. This new approach, termed stir bar dispersive liquid microextraction (SBDLME), involves the addition of a magnetic ionic liquid (MIL) and a neodymium-core magnetic stir bar into the sample allowing the MIL coat the stir bar due to physical forces (i.e., magnetism). As long as the stirring rate is maintained at low speed, the MIL resists rotational (centrifugal) forces and remains on the stir bar surface in a manner closely resembling SBSE. By increasing the stirring rate, the rotational forces surpass the magnetic field and the MIL disperses into the sample solution in a similar manner to DLLME. After extraction, the stirring is stopped and the MIL returns to the stir bar without the requirement of an additional external magnetic field. The MIL-coated stir bar containing the preconcentrated analytes is thermally desorbed directly into a gas chromatographic system coupled to a mass spectrometric detector (TD-GC-MS). This novel approach opens new insights into the microextraction field, by using the benefits provided by SBSE and DLLME simultaneously, such as automated thermal desorption and high surface contact area, respectively, but most importantly, it enables the use of tailor-made solvents (i.e., MILs). To prove its utility, SBDLME has been used in the extraction of lipophilic organic UV filters from environmental water samples as model analytical application with excellent analytical features in terms of linearity, enrichment factors (67–791), limits of detection (low ng L −1 ), intra- and inter-day repeatability (RSD<15%) and relative recoveries (87–113%, 91–117% and 89–115% for river, sea and swimming pool water samples, respectively). - Highlights: • A new microextraction method combining the

  7. Rapid determination of gross alpha and beta activity in seafood utilizing microwave digestion and liquid scintillation counting

    International Nuclear Information System (INIS)

    Daniel Sas; Jiri Janda; Alena Tokarova

    2015-01-01

    This paper describes a method for rapid determination of gross alpha and beta activity in seafood using liquid scintillation counting and microwave digestion for fast sample decomposition. The general group of seafood was divided into two groups based on its structure, whether it has shell or not. The selected group of radionuclides was chosen with respect to military significance, radiotoxicity, and possibility of potential misuse. 90 Sr and 239 Pu were selected as model radionuclides. (author)

  8. Rapid high resolution genotyping of Francisella tularensis by whole genome sequence comparison of annotated genes ("MLST+".

    Directory of Open Access Journals (Sweden)

    Markus H Antwerpen

    Full Text Available The zoonotic disease tularemia is caused by the bacterium Francisella tularensis. This pathogen is considered as a category A select agent with potential to be misused in bioterrorism. Molecular typing based on DNA-sequence like canSNP-typing or MLVA has become the accepted standard for this organism. Due to the organism's highly clonal nature, the current typing methods have reached their limit of discrimination for classifying closely related subpopulations within the subspecies F. tularensis ssp. holarctica. We introduce a new gene-by-gene approach, MLST+, based on whole genome data of 15 sequenced F. tularensis ssp. holarctica strains and apply this approach to investigate an epidemic of lethal tularemia among non-human primates in two animal facilities in Germany. Due to the high resolution of MLST+ we are able to demonstrate that three independent clones of this highly infectious pathogen were responsible for these spatially and temporally restricted outbreaks.

  9. Optimization of the detector and associated electronics used for high-resolution liquid-scintillation alpha spectroscopy

    International Nuclear Information System (INIS)

    Thorngate, J.H.; Christian, D.J.

    1977-01-01

    The performance of various reflector geometries, light coupling liquids, photomultiplier tubes, preamplifiers and linear amplifiers were compared and the configuration found that optimized the combination of pulse-height resolution and pulse-shape discrimination. The best combination used a hemispherical reflector, filled with distilled water, coupled to an 8575 photomultiplier tube, the output of which was conditioned by a special integrating preamplifier and a double-delay-line linear amplifier. Careful choice of the scintillator, sample preparation procedures, and electronic apparatus can produce liquid-scintillation alpha spectroscopy with a pulse-height resolution of 300 keV, or less, and, by using pulse-shape discrimination, background levels as low as 0.01 counts/min. (author)

  10. Synchrotron-based radioscopy employing spatio-temporal micro-resolution for studying fast phenomena in liquid metal foams

    International Nuclear Information System (INIS)

    Rack, A.; García-Moreno, F.; Baumbach, T.; Banhart, J.

    2009-01-01

    High-speed synchrotron-based radioscopy is applied to study a coalescence event (which lasts ∼2 ms) in situ in a liquid metal foam. Investigations of pore coalescence and individual cell wall collapse in an expanding liquid metal foam by means of X-ray radioscopy with spatio-temporal micro-resolution are reported. By using white synchrotron radiation for imaging, the rupture of a film and the subsequent merger of two neighbouring bubbles could be recorded with a time sampling rate of 40000 frames s −1 (25 µs exposure time) and a spatial sampling rate of 20 µm. The rupture time of a cell wall was found to be in the range of 300 µs. This value is in agreement with theoretical considerations which assume an inertia-dominated rupture time of cell walls in liquid metal foams

  11. Rapid pretreatment and determination of bisphenol A in water samples based on vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Yang, Xiao; Diao, Chun-Peng; Sun, Ai-Ling; Liu, Ren-Min

    2014-10-01

    A method for the rapid pretreatment and determination of bisphenol A in water samples based on vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with fluorescence detection was proposed in this paper. A simple apparatus consisting of a test tube and a cut-glass dropper was designed and applied to collect the floating extraction drop in liquid-liquid microextraction when low-density organic solvent was used as the extraction solvent. Solidification and melting steps that were tedious but necessary once the low-density organic solvent used as extraction solvent could be avoided by using this apparatus. Bisphenol A was selected as model pollutant and vortex-assisted liquid-liquid microextraction was employed to investigate the usefulness of the apparatus. High-performance liquid chromatography with fluorescence detection was selected as the analytical tool for the detection of bisphenol A. The linear dynamic range was from 0.10 to 100 μg/L for bisphenol A, with good squared regression coefficient (r(2) = 0.9990). The relative standard deviation (n = 7) was 4.7% and the limit of detection was 0.02 μg/L. The proposed method had been applied to the determination of bisphenol A in natural water samples and was shown to be economical, fast, and convenient. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Massively parallel digital high resolution melt for rapid and absolutely quantitative sequence profiling

    Science.gov (United States)

    Velez, Daniel Ortiz; Mack, Hannah; Jupe, Julietta; Hawker, Sinead; Kulkarni, Ninad; Hedayatnia, Behnam; Zhang, Yang; Lawrence, Shelley; Fraley, Stephanie I.

    2017-02-01

    In clinical diagnostics and pathogen detection, profiling of complex samples for low-level genotypes represents a significant challenge. Advances in speed, sensitivity, and extent of multiplexing of molecular pathogen detection assays are needed to improve patient care. We report the development of an integrated platform enabling the identification of bacterial pathogen DNA sequences in complex samples in less than four hours. The system incorporates a microfluidic chip and instrumentation to accomplish universal PCR amplification, High Resolution Melting (HRM), and machine learning within 20,000 picoliter scale reactions, simultaneously. Clinically relevant concentrations of bacterial DNA molecules are separated by digitization across 20,000 reactions and amplified with universal primers targeting the bacterial 16S gene. Amplification is followed by HRM sequence fingerprinting in all reactions, simultaneously. The resulting bacteria-specific melt curves are identified by Support Vector Machine learning, and individual pathogen loads are quantified. The platform reduces reaction volumes by 99.995% and achieves a greater than 200-fold increase in dynamic range of detection compared to traditional PCR HRM approaches. Type I and II error rates are reduced by 99% and 100% respectively, compared to intercalating dye-based digital PCR (dPCR) methods. This technology could impact a number of quantitative profiling applications, especially infectious disease diagnostics.

  13. Scanning, Multibeam, Single Photon Lidars for Rapid, Large Scale, High Resolution, Topographic and Bathymetric Mapping

    Directory of Open Access Journals (Sweden)

    John J. Degnan

    2016-11-01

    Full Text Available Several scanning, single photon sensitive, 3D imaging lidars are herein described that operate at aircraft above ground levels (AGLs between 1 and 11 km, and speeds in excess of 200 knots. With 100 beamlets and laser fire rates up to 60 kHz, we, at the Sigma Space Corporation (Lanham, MD, USA, have interrogated up to 6 million ground pixels per second, all of which can record multiple returns from volumetric scatterers such as tree canopies. High range resolution has been achieved through the use of subnanosecond laser pulsewidths, detectors and timing receivers. The systems are presently being deployed on a variety of aircraft to demonstrate their utility in multiple applications including large scale surveying, bathymetry, forestry, etc. Efficient noise filters, suitable for near realtime imaging, have been shown to effectively eliminate the solar background during daytime operations. Geolocation elevation errors measured to date are at the subdecimeter level. Key differences between our Single Photon Lidars, and competing Geiger Mode lidars are also discussed.

  14. Rapid resolution of fetal goiter associated with maternal Grave's disease: a case report.

    Science.gov (United States)

    Friedland, D R; Rothschild, M A

    2000-08-11

    The incidence of abnormal fetal thyroid function with maternal Grave's disease is about 2-12%. The development of larger fetal goiters can complicate labor and precipitate life-threatening airway obstruction at delivery. A case is presented of a large stable goiter confirmed by sonography, which unexpectedly resolved by the time of parturition. A 3 x 6 cm fetal goiter was detected at 34 weeks gestation in a mother treated with propylthiouracil for Grave's disease. A repeat sonogram at 36 weeks showed no change in goiter size. Umbilical blood sampling showed the fetus to be markedly hyperthyroid. Planned Cesarean section took place 11 days after the final sonogram. A multi-disciplinary operative team was present including the Otolaryngology service with equipment for emergency intubation, bronchoscopy and tracheotomy. Upon delivery, the infant had no evidence of goiter and no airway compromise. Fetal goiter is a rare entity, and recent advances in the field of maternal-fetal medicine have enabled intra-uterine diagnosis and treatment of such conditions. A review of published case reports demonstrates two trends in treated fetuses: preterm progressive resolution of the goiter, or delivery with gross evidence of goiter. This reported case is unique, as a persistent goiter resolved completely in less than 2 weeks. Otolaryngologic response to and management of potential congenital airway compromise is discussed.

  15. Rapid resolution of hyperammonemia in neonates using extracorporeal membrane oxygenation as a platform to drive hemodialysis.

    Science.gov (United States)

    Robinson, Jamie R; Conroy, Patricia C; Hardison, Daphne; Hamid, Rizwan; Grubb, Peter H; Pietsch, John B; Lovvorn, Harold N

    2018-02-21

    We aimed to clarify the impact of extracorporeal membrane oxygenation (ECMO) as a platform to drive hemodialysis (HD) for ammonia clearance on outcomes of neonates with severe hyperammonemia. All neonates treated for hyperammonemia at a single children's hospital between 1992 and 2016 were identified. Patient characteristics and outcomes were compared between those receiving medical management or ECMO/HD. Twenty-five neonates were treated for hyperammonemia, of which 13 (52%) received ECMO/HD. Peak ammonia levels among neonates treated with ECMO/HD were significantly higher than those medically managed (1041 [IQR 902-1581] μmol/L versus 212 [IQR 110-410] μmol/L; p = 0.009). Serum ammonia levels in the ECMO/HD cohort declined to the median of medically managed within 4.5 (IQR 2.9-7.0) hours and normalized within 7.3 (IQR 3.6-13.5) hours. All neonates survived ECMO/HD, and nine (69.2%) survived to discharge. ECMO/HD is an effective adjunct to rapidly clear severe hyperammonemia in newborns, reducing potential neurodevelopmental morbidity.

  16. Rapid detection of Echinococcus species by a high-resolution melting (HRM) approach.

    Science.gov (United States)

    Santos, Guilherme Brzoskowski; Espínola, Sergio Martín; Ferreira, Henrique Bunselmeyer; Margis, Rogerio; Zaha, Arnaldo

    2013-11-14

    High-resolution melting (HRM) provides a low-cost, fast and sensitive scanning method that allows the detection of DNA sequence variations in a single step, which makes it appropriate for application in parasite identification and genotyping. The aim of this work was to implement an HRM-PCR assay targeting part of the mitochondrial cox1 gene to achieve an accurate and fast method for Echinococcus spp. differentiation. For melting analysis, a total of 107 samples from seven species were used in this study. The species analyzed included Echinococcus granulosus (n = 41) and Echinococcus ortleppi (n = 50) from bovine, Echinococcus vogeli (n = 2) from paca, Echinococcus oligarthra (n = 3) from agouti, Echinococcus multilocularis (n = 6) from monkey and Echinococcus canadensis (n = 2) and Taenia hydatigena (n = 3) from pig. DNA extraction was performed, and a 444-bp fragment of the cox1 gene was amplified. Two approaches were used, one based on HRM analysis, and a second using SYBR Green Tm-based. In the HRM analysis, a specific profile for each species was observed. Although some species exhibited almost the same melting temperature (Tm) value, the HRM profiles could be clearly discriminated. The SYBR Green Tm-based analysis showed differences between E. granulosus and E. ortleppi and between E. vogeli and E. oligarthra. In this work, we report the implementation of HRM analysis to differentiate species of the genus Echinococcus using part of the mitochondrial gene cox1. This method may be also potentially applied to identify other species belonging to the Taeniidae family.

  17. High Resolution Topography of Age-Related Changes in Non-Rapid Eye Movement Sleep Electroencephalography.

    Directory of Open Access Journals (Sweden)

    Kate E Sprecher

    Full Text Available Sleeping brain activity reflects brain anatomy and physiology. The aim of this study was to use high density (256 channel electroencephalography (EEG during sleep to characterize topographic changes in sleep EEG power across normal aging, with high spatial resolution. Sleep was evaluated in 92 healthy adults aged 18-65 years old using full polysomnography and high density EEG. After artifact removal, spectral power density was calculated for standard frequency bands for all channels, averaged across the NREM periods of the first 3 sleep cycles. To quantify topographic changes with age, maps were generated of the Pearson's coefficient of the correlation between power and age at each electrode. Significant correlations were determined by statistical non-parametric mapping. Absolute slow wave power declined significantly with increasing age across the entire scalp, whereas declines in theta and sigma power were significant only in frontal regions. Power in fast spindle frequencies declined significantly with increasing age frontally, whereas absolute power of slow spindle frequencies showed no significant change with age. When EEG power was normalized across the scalp, a left centro-parietal region showed significantly less age-related decline in power than the rest of the scalp. This partial preservation was particularly significant in the slow wave and sigma bands. The effect of age on sleep EEG varies substantially by region and frequency band. This non-uniformity should inform the design of future investigations of aging and sleep. This study provides normative data on the effect of age on sleep EEG topography, and provides a basis from which to explore the mechanisms of normal aging as well as neurodegenerative disorders for which age is a risk factor.

  18. High-resolution melting curve analysis for rapid detection of mutations in a Medaka TILLING library

    Directory of Open Access Journals (Sweden)

    Deguchi Tomonori

    2010-09-01

    Full Text Available Abstract Background During the last two decades, DNA sequencing has led to the identification of numerous genes in key species; however, in most cases, their functions are still unknown. In this situation, reverse genetics is the most suitable method to assign function to a gene. TILLING (Targeting Induced Local Lesions IN Genomes is a reverse-genetic strategy that combines random chemical mutagenesis with high-throughput discovery of the induced mutations in target genes. The method has been applied to a variety of plant and animal species. Screening of the induced mutations is the most important step in TILLING. Currently, direct sequencing or nuclease-mediated screening of heteroduplexes is widely used for detection of mutations in TILLING. Both methods are useful, but the costs are substantial and turnaround times are relatively long. Thus, there is a need for an alternative method that is of higher throughput and more cost effective. Results In this study, we developed a high resolution melting (HRM assay and evaluated its effectiveness for screening ENU-induced mutations in a medaka TILLING library. We had previously screened mutations in the p53 gene by direct sequencing. Therefore, we first tested the efficiency of the HRM assay by screening mutations in p53, which indicated that the HRM assay is as useful as direct sequencing. Next, we screened mutations in the atr and atm genes with the HRM assay. Nonsense mutations were identified in each gene, and the phenotypes of these nonsense mutants confirmed their loss-of-function nature. Conclusions These results demonstrate that the HRM assay is useful for screening mutations in TILLING. Furthermore, the phenotype of the obtained mutants indicates that medaka is an excellent animal model for investigating genome stability and gene function, especially when combined with TILLING.

  19. Airborne LIDAR and high resolution satellite data for rapid 3D feature extraction

    Science.gov (United States)

    Jawak, S. D.; Panditrao, S. N.; Luis, A. J.

    2014-11-01

    This work uses the canopy height model (CHM) based workflow for individual tree crown delineation and 3D feature extraction approach (Overwatch Geospatial's proprietary algorithm) for building feature delineation from high-density light detection and ranging (LiDAR) point cloud data in an urban environment and evaluates its accuracy by using very high-resolution panchromatic (PAN) (spatial) and 8-band (multispectral) WorldView-2 (WV-2) imagery. LiDAR point cloud data over San Francisco, California, USA, recorded in June 2010, was used to detect tree and building features by classifying point elevation values. The workflow employed includes resampling of LiDAR point cloud to generate a raster surface or digital terrain model (DTM), generation of a hill-shade image and an intensity image, extraction of digital surface model, generation of bare earth digital elevation model (DEM) and extraction of tree and building features. First, the optical WV-2 data and the LiDAR intensity image were co-registered using ground control points (GCPs). The WV-2 rational polynomial coefficients model (RPC) was executed in ERDAS Leica Photogrammetry Suite (LPS) using supplementary *.RPB file. In the second stage, ortho-rectification was carried out using ERDAS LPS by incorporating well-distributed GCPs. The root mean square error (RMSE) for the WV-2 was estimated to be 0.25 m by using more than 10 well-distributed GCPs. In the second stage, we generated the bare earth DEM from LiDAR point cloud data. In most of the cases, bare earth DEM does not represent true ground elevation. Hence, the model was edited to get the most accurate DEM/ DTM possible and normalized the LiDAR point cloud data based on DTM in order to reduce the effect of undulating terrain. We normalized the vegetation point cloud values by subtracting the ground points (DEM) from the LiDAR point cloud. A normalized digital surface model (nDSM) or CHM was calculated from the LiDAR data by subtracting the DEM from the DSM

  20. Interface for the rapid analysis of liquid samples by accelerator mass spectrometry

    Science.gov (United States)

    Turteltaub, Kenneth; Ognibene, Ted; Thomas, Avi; Daley, Paul F; Salazar Quintero, Gary A; Bench, Graham

    2014-02-04

    An interface for the analysis of liquid sample having carbon content by an accelerator mass spectrometer including a wire, defects on the wire, a system for moving the wire, a droplet maker for producing droplets of the liquid sample and placing the droplets of the liquid sample on the wire in the defects, a system that converts the carbon content of the droplets of the liquid sample to carbon dioxide gas in a helium stream, and a gas-accepting ion source connected to the accelerator mass spectrometer that receives the carbon dioxide gas of the sample in a helium stream and introduces the carbon dioxide gas of the sample into the accelerator mass spectrometer.

  1. Rapid multiplex high resolution melting method to analyze inflammatory related SNPs in preterm birth

    Directory of Open Access Journals (Sweden)

    Pereyra Silvana

    2012-01-01

    Full Text Available Abstract Background Complex traits like cancer, diabetes, obesity or schizophrenia arise from an intricate interaction between genetic and environmental factors. Complex disorders often cluster in families without a clear-cut pattern of inheritance. Genomic wide association studies focus on the detection of tens or hundreds individual markers contributing to complex diseases. In order to test if a subset of single nucleotide polymorphisms (SNPs from candidate genes are associated to a condition of interest in a particular individual or group of people, new techniques are needed. High-resolution melting (HRM analysis is a new method in which polymerase chain reaction (PCR and mutations scanning are carried out simultaneously in a closed tube, making the procedure fast, inexpensive and easy. Preterm birth (PTB is considered a complex disease, where genetic and environmental factors interact to carry out the delivery of a newborn before 37 weeks of gestation. It is accepted that inflammation plays an important role in pregnancy and PTB. Methods Here, we used real time-PCR followed by HRM analysis to simultaneously identify several gene variations involved in inflammatory pathways on preterm labor. SNPs from TLR4, IL6, IL1 beta and IL12RB genes were analyzed in a case-control study. The results were confirmed either by sequencing or by PCR followed by restriction fragment length polymorphism. Results We were able to simultaneously recognize the variations of four genes with similar accuracy than other methods. In order to obtain non-overlapping melting temperatures, the key step in this strategy was primer design. Genotypic frequencies found for each SNP are in concordance with those previously described in similar populations. None of the studied SNPs were associated with PTB. Conclusions Several gene variations related to the same inflammatory pathway were screened through a new flexible, fast and non expensive method with the purpose of analyzing

  2. Rapid determination of 18 glucocorticoids in serum using reusable on-line SPE polymeric monolithic column coupled with LC-quadrupole/orbitrap high-resolution mass spectrometer.

    Science.gov (United States)

    Li, Hui; Ai, Lianfeng; Fan, Sufang; Wang, Yan; Sun, Dianxing

    2017-10-15

    A simple, rapid and sensitive method for the simultaneous determination of 18 glucocorticoids in serum was developed by coupling on-line solid-phase extraction (SPE) polymeric monolithic column to a liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometer. A simple poly(ethylene glycol dimethacrylate) monolith column (10mm×2.1mm i.d.) was fabricated, and the morphology, surface area and extraction performance of the monolithic column were characterized. Serum samples were extracted by acetonitrile (ACN). Then, online SPE was achieved on the synthesized monolithic column using a 10mmol/L ammonium acetate solution as the loading solvent. After the transfer from the monolith into analytical column (Capcell Pak ADME column) using ACN, the adsorbed analytes were separated on the analytical column and detected with a high-resolution hybrid quadrupole/orbitrap mass spectrometer with full scan/ddMS 2 scan mode Under optimized conditions, the method was linear with target linear correlation coefficient (R 2 ) higher than 0.995. Detection limits were in range of 0.1-0.6ng/mL, and the quantification limits were 0.3-1.5ng/mL. The recovery was between 71.9% and 89.2% in three spike levels with precision (n=5) of 5.40-12.1%. The serum sample was directly analyzed after a simple extraction procedure, and the on-line SPE and determination were achieved within only 16min. The method was used to analyze the dynamic contents variation of cortisone and hydrocortisone in serum before and after the surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Rapid screening and identification of chemical hazards in surface and drinking water using high resolution mass spectrometry and a case-control filter.

    Science.gov (United States)

    Kaserzon, Sarit L; Heffernan, Amy L; Thompson, Kristie; Mueller, Jochen F; Gomez Ramos, Maria Jose

    2017-09-01

    Access to clean, safe drinking water poses a serious challenge to regulators, and requires analytical strategies capable of rapid screening and identification of potentially hazardous chemicals, specifically in situations when threats to water quality or security require rapid investigations and potential response. This study describes a fast and efficient chemical hazard screening strategy for characterising trace levels of polar organic contaminants in water matrices, based on liquid chromatography high resolution mass spectrometry with post-acquisition 'case-control' data processing. This method allowed for a rapid response time of less than 24 h for the screening of target, suspect and non-target unknown chemicals via direct injection analysis, and a second, more sensitive analysis option requiring sample pre-concentration. The method was validated by fortifying samples with a range of pesticides, pharmaceuticals and personal care products (n = 46); with >90% of target compounds positively screened in samples at 1 ng mL -1 , and 46% at 0.1 ng mL -1 when analysed via direct injection. To simulate a contamination event samples were fortified with compounds not present in the commercial library (designated 'non-target compounds'; fipronil and fenitrothion), tentatively identified at 0.2 and 1 ng mL -1 , respectively; and a compound not included in any known commercial library or public database (designated 'unknown' compounds; 8Cl - perfluorooctanesulfonic acid), at 0.8 ng mL -1 . The method was applied to two 'real-case' scenarios: (1) the assessment of drinking water safety during a high-profile event in Brisbane, Australia; and (2) to screen treated, re-circulated drinking water and pre-treated (raw) water. The validated workflow was effective for rapid prioritisation and screening of suspect and non-target potential hazards at trace levels, and could be applied to a wide range of matrices and investigations where comparison of organic contaminants

  4. Deformation and instabilities at a free surface of liquid subject to a local rapid evaporation

    International Nuclear Information System (INIS)

    Marechal, Anne

    1993-01-01

    This research thesis first addresses theoretical aspects related to the study of stationary system (the deformation of the liquid-vapour interface) and to the study of the linear stability of this interface, and more particularly the study of the liquid-vapour interface of a fluid heated by electron bombardment in a vacuum enclosure. The author reports the analysis of Landau and Palmer systems, reports the study of the marginal stability of a simplified SILVA (isotopic separation by laser on atomic vapour) system which allows the identification of destabilizing mechanisms, and the comparison between a liquid system heated from underneath with liquid system heated from above. Results are then validated by experimental results. In the next part, the author sets the equations of a SILVA system closer to reality by addressing vapour in a more realistic way. Results of conventional kinetic theory are studied again by analysing sonic evaporation of a liquid. The author reports a study of the linear stability of this system, and reports an attempt to analyse the obtained results [fr

  5. Electrokinetic migration across artificial liquid membranes. New concept for rapid sample preparation of biological fluids.

    Science.gov (United States)

    Pedersen-Bjergaard, Stig; Rasmussen, Knut Einar

    2006-03-24

    Basic drug substances were transported across a thin artificial organic liquid membrane by the application of 300 V d.c. From a 300 microl aqueous donor compartment (containing 10 mM HCl), the drugs migrated through a 200 microm artificial liquid membrane of 2-nitrophenyl octyl ether immobilized in the pores of a polypropylene hollow fiber, and into a 30 microl aqueous acceptor solution of 10 mM HCl inside the lumen of the hollow fiber. The transport was forced by an electrical potential difference sustained over the liquid membrane, resulting in electrokinetic migration of drug substances from the donor compartment to the acceptor solution. Within 5 min of operation at 300 V, pethidine, nortriptyline, methadone, haloperidol, and loperamide were extracted with recoveries in the range 70-79%, which corresponded to enrichments in the range 7.0-7.9. The chemical composition of the organic liquid membrane strongly affected the permeability, and may serve as an efficient tool for controlling the transport selectivity. Water samples, human plasma, and human urine were successfully processed, and in light of the present report, electrokinetic migration across thin artificial liquid membranes may be an interesting tool for future isolation within chemical analysis.

  6. [Rapid determination of theophylline, theobromine and caffeine in dietary supplements containing guarana by ultra-performance liquid chromatography].

    Science.gov (United States)

    Hasegawa, Takashi; Takahashi, Kazunaga; Saijo, Masaaki; Ishii, Toshiyasu; Nagata, Tomoko

    2009-12-01

    A rapid and simple method for determination of theophylline, theobromine and caffeine in dietary supplements containing guarana by ultra-performance liquid chromatography (UPLC) has been developed. Theophylline, theobromine and caffeine were extracted from finely powdered samples with water in a boiling water bath for 20 min, then the extracts were filtered and the filtrates were subjected to UPLC. Liquid samples were diluted with water and filteres, and the filtrates were subjected to UPLC. UPLC separation was performed on an AQUITY UPLC BEH C18 column (2.1 mm i.d.x50 mm, 1.7 microm, Waters) with 10 mmol/L ammonium acetate buffer (pH 4.0)-acetonitrile gradient and eluates were monitored at 275 nm. The recoveries of theophylline (spiked at 200 microg/g [tablet] and 50 microg/mL [liquid]), theobromine (spiked at 200 microg/g [tablet] and 50 microg/mL [liquid]) and caffeine (spiked at 1,000 microg/g [tablet] and 250 microg/mL [liquid]) were 97.6-98.7%, 97.3-99.7%, 97.1-105.4%, respectively. The quantitation limits of theophylline, theobromine and caffeine were 10 microg/g (seed, seed powder, tablet and capsule) and 2.0 microg/mL (liquid) each. When this analytical method was applied to commercial dietary supplements, theophylline, theobromine and caffeine were found at concentrations of 4.45 mg/tablet, 5.48 mg/tablet, 139 mg/tablet, respectively. Taking 4 tablets of this product according to the directions on the package could be dangerous to consumers because of possible overdosing of these ingredients.

  7. Rapid detection and differentiation of Clonorchis sinensis and Opisthorchis viverrini using real-time PCR and high resolution melting analysis.

    Science.gov (United States)

    Cai, Xian-Quan; Yu, Hai-Qiong; Li, Rong; Yue, Qiao-Yun; Liu, Guo-Hua; Bai, Jian-Shan; Deng, Yan; Qiu, De-Yi; Zhu, Xing-Quan

    2014-01-01

    Clonorchis sinensis and Opisthorchis viverrini are both important fish-borne pathogens, causing serious public health problem in Asia. The present study developed an assay integrating real-time PCR and high resolution melting (HRM) analysis for the specific detection and rapid identification of C. sinensis and O. viverrini. Primers targeting COX1 gene were highly specific for these liver flukes, as evidenced by the negative amplification of closely related trematodes. Assays using genomic DNA extracted from the two flukes yielded specific amplification and their identity was confirmed by sequencing, having the accuracy of 100% in reference to conventional methods. The assay was proved to be highly sensitive with a detection limit below 1 pg of purified genomic DNA, 5 EPG, or 1 metacercaria of C. sinensis. Moreover, C. sinensis and O. viverrini were able to be differentiated by their HRM profiles. The method can reduce labor of microscopic examination and the contamination of agarose electrophoresis. Moreover, it can differentiate these two flukes which are difficult to be distinguished using other methods. The established method provides an alternative tool for rapid, simple, and duplex detection of C. sinensis and O. viverrini.

  8. Rapid Detection and Differentiation of Clonorchis sinensis and Opisthorchis viverrini Using Real-Time PCR and High Resolution Melting Analysis

    Directory of Open Access Journals (Sweden)

    Xian-Quan Cai

    2014-01-01

    Full Text Available Clonorchis sinensis and Opisthorchis viverrini are both important fish-borne pathogens, causing serious public health problem in Asia. The present study developed an assay integrating real-time PCR and high resolution melting (HRM analysis for the specific detection and rapid identification of C. sinensis and O. viverrini. Primers targeting COX1 gene were highly specific for these liver flukes, as evidenced by the negative amplification of closely related trematodes. Assays using genomic DNA extracted from the two flukes yielded specific amplification and their identity was confirmed by sequencing, having the accuracy of 100% in reference to conventional methods. The assay was proved to be highly sensitive with a detection limit below 1 pg of purified genomic DNA, 5 EPG, or 1 metacercaria of C. sinensis. Moreover, C. sinensis and O. viverrini were able to be differentiated by their HRM profiles. The method can reduce labor of microscopic examination and the contamination of agarose electrophoresis. Moreover, it can differentiate these two flukes which are difficult to be distinguished using other methods. The established method provides an alternative tool for rapid, simple, and duplex detection of C. sinensis and O. viverrini.

  9. High resolution melting curve analysis, a rapid and affordable method for mutation analysis in childhood acute myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Yin eLiu

    2014-09-01

    Full Text Available Background: Molecular genetic alterations with prognostic significance have been described in childhood acute myeloid leukemia (AML. The aim of this study was to establish cost-effective techniques to detect mutations of FMS-like tyrosine kinase 3 (FLT3, Nucleophosmin 1 (NPM1, and a partial tandem duplication within the mixed lineage leukemia (MLL-PTD genes in childhood AML. Procedure: Ninety-nine children with newly diagnosed AML were included in this study. We developed a fluoresent dye SYTO-82 based high resolution melting curve (HRM anaylsis to detect FLT3 internal tandem duplication (FLT3-ITD, FLT3 tyrosine kinase domain (FLT3-TKD and NPM1 mutations. MLL-PTD was screened by real-time quantitative PCR. Results: The HRM methodology correlated well with gold standard Sanger sequencing with less cost. Among the 99 patients studied, the FLT3-ITD mutation was associated with significantly worse event free survival (EFS. Patients with the NPM1 mutation had significantly better EFS and overall survival. However, HRM was not sensitive enough for minimal residual disease monitoring. Conclusions: HRM was a rapid and efficient method for screening of FLT3 and NPM1 gene mutations. It was both affordable and accurate, especially in resource underprivileged regions. Our results indicated that HRM could be a useful clinical tool for rapid and cost effective screening of the FLT3 and NPM1 mutations in AML patients.

  10. Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering

    International Nuclear Information System (INIS)

    Wang, Y.P.; Zhou, L.; Zhang, M.F.; Chen, X.Y.; Liu, J.-M.; Liu, Z.G.

    2004-01-01

    Single-phased ferroelectromagnet BiFeO 3 ceramics with high resistivity were synthesized by a rapid liquid phase sintering technique. Saturated ferroelectric hysteresis loops were observed at room temperature in the ceramics sintered at 880 deg. C for 450 s. The spontaneous polarization, remnant polarization, and the coercive field are 8.9 μC/cm 2 , 4.0 μC/cm 2 , and 39 kV/cm, respectively, under an applied field of 100 kV/cm. It is proposed that the formation of Fe 2+ and an oxygen deficiency leading to the higher leakage can be greatly suppressed by the very high heating rate, short sintering period, and liquid phase sintering technique. The latter was also found effective in increasing the density of the ceramics. The sintering technique developed in this work is expected to be useful in synthesizing other ceramics from multivalent or volatile starting materials

  11. Use of ultra-high pressure liquid chromatography coupled to high resolution mass spectrometry for fast screening in high throughput doping control.

    Science.gov (United States)

    Musenga, Alessandro; Cowan, David A

    2013-05-03

    We describe a sensitive, comprehensive and fast screening method based on liquid chromatography-high resolution mass spectrometry for the detection of a large number of analytes in sports samples. UHPLC coupled to high resolution mass spectrometry with polarity switching capability is applied for the rapid screening of a large number of analytes in human urine samples. Full scan data are acquired alternating both positive and negative ionisation. Collision-induced dissociation with positive ionisation is also performed to produce fragment ions to improve selectivity for some analytes. Data are reviewed as extracted ion chromatograms based on narrow mass/charge windows (±5ppm). A simple sample preparation method was developed, using direct enzymatic hydrolysis of glucuronide conjugates, followed by solid phase extraction with mixed mode ion-exchange cartridges. Within a 10min run time (including re-equilibration) the method presented allows for the analysis of a large number of analytes from most of the classes in the World Anti-Doping Agency (WADA) Prohibited List, including anabolic agents, β2-agonists, hormone antagonists and modulators, diuretics, stimulants, narcotics, glucocorticoids and β-blockers, and does so while meeting the WADA sensitivity requirements. The high throughput of the method and the fast sample pre-treatment reduces analysis cost and increases productivity. The method presented has been used for the analysis of over 5000 samples in about one month and proved to be reliable. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Synthesis and electroplating of high resolution insulated carbon nanotube scanning probes for imaging in liquid solutions.

    Science.gov (United States)

    Roberts, N A; Noh, J H; Lassiter, M G; Guo, S; Kalinin, S V; Rack, P D

    2012-04-13

    High resolution and isolated scanning probe microscopy (SPM) is in demand for continued development of energy storage and conversion systems involving chemical reactions at the nanoscale as well as an improved understanding of biological systems. Carbon nanotubes (CNTs) have large aspect ratios and, if leveraged properly, can be used to develop high resolution SPM probes. Isolation of SPM probes can be achieved by depositing a dielectric film and selectively etching at the apex of the probe. In this paper the fabrication of a high resolution and isolated SPM tip is demonstrated using electron beam induced etching of a dielectric film deposited onto an SPM tip with an attached CNT at the apex.

  13. Urinary detection of conjugated and unconjugated anabolic steroids by dilute-and-shoot liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Tudela, Eva; Deventer, Koen; Geldof, Lore; Van Eenoo, Peter

    2015-02-01

    Anabolic androgenic steroids (AAS) are an important class of doping agents. The metabolism of these substances is generally very extensive and includes phase-I and phase-II pathways. In this work, a comprehensive detection of these metabolites is described using a 2-fold dilution of urine and subsequent analysis by liquid chromatography-high resolution mass spectrometry (LC-HRMS). The method was applied to study 32 different metabolites, excreted free or conjugated (glucuronide or sulfate), which permit the detection of misuse of at least 21 anabolic steroids. The method has been fully validated for 21 target compounds (8 glucuronide, 1 sulfate and 12 free steroids) and 18 out of 21 compounds had detection limits in the range of 1-10 ng mL(-1) in urine. For the conjugated compounds, for which no reference standards are available, metabolites were synthesized in vitro or excretion studies were investigated. The detection limits for these compounds ranged between 0.5 and 18 ng mL(-1) in urine. The simple and straightforward methodology complements the traditional methods based on hydrolysis, liquid-liquid extraction, derivatization and analysis by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Copyright © 2014 John Wiley & Sons, Ltd.

  14. Quantitative assessment of liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography

    International Nuclear Information System (INIS)

    Ohgaki, T.; Toda, H.; Sinclair, I.; Buffiere, J.-Y.; Ludwig, W.; Kobayashi, T.; Niinomi, M.; Akahori, T.

    2005-01-01

    We have evaluated the liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography. The 3D visualization of a crack together with its surrounding grain structure was performed with the help of the Ga penetration technique. It is found that the advance directions of the crack-tip were strongly influenced by the grain microstructure and the branching of the crack is affected by grain distribution. In this study, the liquid Ga not only acts as a contrast agent for grain boundaries, but also expands the volume of the Al alloy due to Ga diffusion and associated processes. The 3D strain between the grains has been determined by microstructural gauging technique, which uses micropores as marker points. The 3D expansion of the sample volume, the volume reduction of micropores and the brittle fracture were evidently observed

  15. Multi-detection of corticosteroids in sports doping and veterinary control using high-resolution liquid chromatography/time-of-flight mass spectrometry

    NARCIS (Netherlands)

    Touber, M.E.; Engelen, M.C.; Georgakopoulus, C.; Rhijn, van J.A.; Nielen, M.W.F.

    2007-01-01

    A liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) method was developed using the latest high-resolution LC column technology, the ultra performance liquid chromatography (UPLC (TM)), and electrospray ionization (ESI) in the positive ion mode. Gradient UPLC separation conditions

  16. [Screening and confirmation of 24 hormones in cosmetics by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

    Science.gov (United States)

    Li, Zhaoyong; Wang, Fengmei; Niu, Zengyuan; Luo, Xin; Zhang, Gang; Chen, Junhui

    2014-05-01

    A method of ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS) was established to screen and confirm 24 hormones in cosmetics. Various cosmetic samples were extracted with methanol. The extract was loaded onto a Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm) using a gradient elution of acetonitrile/water containing 0.1% (v/v) formic acid for the separation. The accurate mass of quasi-molecular ion was acquired by full scanning of electrostatic field orbitrap. The rapid screening was carried out by the accurate mass of quasi-molecular ion. The confirmation analysis for targeted compounds was performed with the retention time and qualitative fragments obtained by data dependent scan mode. Under the optimal conditions, the 24 hormones were routinely detected with mass accuracy error below 3 x 10(-6) (3 ppm), and good linearities were obtained in their respective linear ranges with correlation coefficients higher than 0.99. The LODs (S/N = 3) of the 24 compounds were hormones in 50 cosmetic samples. The results demonstrate that the method is a useful tool for the rapid screening and identification of the hormones in cosmetics.

  17. Real time, high resolution studies of protein adsorption and structure at the solid-liquid interface using dual polarization interferometry

    International Nuclear Information System (INIS)

    Freeman, Neville J; Peel, Louise L; Swann, Marcus J; Cross, Graham H; Reeves, Andrew; Brand, Stuart; Lu, Jian R

    2004-01-01

    A novel method for the analysis of thin biological films, called dual polarization interferometry (DPI), is described. This high resolution (<1 A), laboratory-based technique allows the thickness and refractive index (density) of biological molecules adsorbing or reacting at the solid-liquid interface to be measured in real time (up to 10 measurements per second). Results from the adsorption of bovine serum albumin (BSA) on to a silicon oxynitride chip surface are presented to demonstrate how time dependent molecular behaviour can be examined using DPI. Mechanistic and structural information relating to the adsorption process is obtained as a function of the solution pH

  18. Expanding the linear dynamic range for quantitative liquid chromatography-high resolution mass spectrometry utilizing natural isotopologue signals

    International Nuclear Information System (INIS)

    Liu, Hanghui; Lam, Lily; Yan, Lin; Chi, Bert; Dasgupta, Purnendu K.

    2014-01-01

    Highlights: • Less abundant isotopologue ions were utilized to decrease detector saturation. • A 25–50 fold increase in the upper limit of dynamic range was demonstrated. • Linear dynamic range was expanded without compromising mass resolution. - Abstract: The linear dynamic range (LDR) for quantitative liquid chromatography–mass spectrometry can be extended until ionization saturation is reached by using a number of target isotopologue ions in addition to the normally used target ion that provides the highest sensitivity. Less abundant isotopologue ions extend the LDR: the lower ion abundance decreases the probability of ion detector saturation. Effectively the sensitivity decreases and the upper limit of the LDR increases. We show in this paper that the technique is particularly powerful with a high resolution time of flight mass spectrometer because the data for all ions are automatically acquired, and we demonstrated this for four small organic molecules; the upper limits of LDRs increased by 25–50 times

  19. High-resolution lipidomics coupled with rapid fixation reveals novel ischemia-induced signaling in the rat neurolipidome.

    Science.gov (United States)

    Trépanier, Marc-Olivier; Eiden, Michael; Morin-Rivron, Delphine; Bazinet, Richard P; Masoodi, Mojgan

    2017-03-01

    The field of lipidomics has evolved vastly since its creation 15 years ago. Advancements in mass spectrometry have allowed for the identification of hundreds of intact lipids and lipid mediators. However, because of the release of fatty acids from the phospholipid membrane in the brain caused by ischemia, identifying the neurolipidome has been challenging. Microwave fixation has been shown to reduce the ischemia-induced release of several lipid mediators. Therefore, this study aimed to develop a method combining high-resolution tandem mass spectrometry (MS/MS), high-energy head-focused microwave fixation and statistical modeling, allowing for the measurement of intact lipids and lipid mediators in order to eliminate the ischemia-induced release of fatty acids and identify the rat neurolipidome. In this study, we demonstrated the ischemia-induced production of bioactive lipid mediators, and the reduction in variability using microwave fixation in combination with liquid chromatography (LC)-MS/MS. We have also illustrated for the first time that microwave fixation eliminates the alterations in intact lipid species following ischemia. While many phospholipid species were unchanged by ischemia, other intact lipid classes, such as diacylglycerol, were lower in concentration following microwave fixation compared to ischemia. © 2016 International Society for Neurochemistry.

  20. Rapid conversion of sorbitol to isosorbide in hydrophobic ionic liquids under microwave irradiation.

    Science.gov (United States)

    Kamimura, Akio; Murata, Kengo; Tanaka, Yoshiki; Okagawa, Tomoki; Matsumoto, Hiroshi; Kaiso, Kouji; Yoshimoto, Makoto

    2014-12-01

    Sorbitol was effectively converted to isosorbide by treatment with [TMPA][NTf2 ] in the presence of catalytic amounts of TsOH under microwave heating at 180 °C. The reaction completed within 10 min and isosorbide was isolated to about 60%. Ionic liquids were readily recovered by an extraction treatment and reused several times. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Resolution 127/012. It approve the fuel quality 50-S Oil Gas characteristics within the framework of Technical Quality Specifications Rules for liquid fuel

    International Nuclear Information System (INIS)

    2012-01-01

    This resolution approves the initiative of Ancap fuel quality 50-S Oil Gas characteristics within the framework of Technical Quality Specifications Rules for liquid fuel. This resolution is according to the opinion of the National Energy Regulatory Unit and the Energy and Water Services in relation with the requirements of the current rule.

  2. Centrifuge-less dispersive liquid-liquid microextraction base on the solidification of switchable solvent for rapid on-site extraction of four pyrethroid insecticides in water samples.

    Science.gov (United States)

    Hu, Lu; Wang, Huazi; Qian, Heng; Liu, Chaoran; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang; Xu, Donghui

    2016-11-11

    An on-site dispersive liquid liquid microextraction base on the solidification of switchable solvent has been developed as a simple, rapid and eco-friendly sample extraction method for the fast determination of pyrethroid insecticides in aqueous samples using high-performance liquid chromatography with ultraviolet detection. In this extraction method, medium-chain saturated fatty acids (n≥10), which can rapidly solidify at low temperatures (centrifugation. The microextraction process was performed in a 10mL syringe and the pretreatment process could thus be finished in 5min. No external energy resources were required in this method, which makes it a potential method for on-site extraction. The optimal experimental parameters were as follows: 350μL of decanoic acid (1mol/L) was used as the extraction solvent, 150μL of sulfuric acid (2mol/L) was used to decrease the pH of the samples, no salt was added, and the temperature of the samples was in the range of 20-40°C. Finally, the sample was cooled in an ice bath for three minutes. Under these optimal conditions, good responses for four pyrethroid insecticides were obtained in the concentration ranges of 1-500μg/L, with coefficients of determination greater than 0.9993. The recoveries of the four pyrethroid insecticides ranged from 84.7 to 95.3%, with relative standard deviations ranging from 1.6 to 4.6%. The limits of detection based on a signal-to-noise ratio of 3 were in the range of 0.24-0.68μg/L, and the enrichment factors were in the range of 121-136. The results demonstrate that this method was successfully applied to determine pyrethroid insecticides in real water samples. No centrifugation or any special apparatus are required, make this a promising method for rapid field-sampling procedures. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Microwave-assisted ionic liquid-mediated rapid catalytic conversion of non-edible lignocellulosic Sunn hemp fibres to biofuels.

    Science.gov (United States)

    Paul, Souvik Kumar; Chakraborty, Saikat

    2018-04-01

    Sunn hemp fibre - a cellulose-rich crystalline non-food energy crop, containing 75.6% cellulose, 10.05% hemicellulose, 10.32% lignin, with high crystallinity (80.17%) and degree of polymerization (650) - is identified as a new non-food substrate for lignocellulosic biofuel production. Microwave irradiation is employed to rapidly rupture the cellulose's glycosidic bonds and enhance glucose yield to 78.7% at 160 °C in only 46 min. The reactants - long-chain cellulose, ionic liquid, transition metal catalyst, and water - form a polar supramolecular complex that rotates under the microwave's alternating polarity and rapidly dissipates the electromagnetic energy through molecular collisions, thus accelerating glycosidic bond breakage. In 46 min, 1 kg of Sunn hemp fibres containing 756 g of cellulose produces 595 g of glucose at 160 °C, and 203 g of hydroxymethyl furfural (furanic biofuel precursor) at 180 °C. Yeast mediated glucose fermentation produces 75.6% bioethanol yield at 30 °C, and the ionic liquid is recycled for cost-effectiveness. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Perfect Composition Depth Profiling of Ionic Liquid Surfaces Using High-Resolution RBS/ERDA.

    Czech Academy of Sciences Publication Activity Database

    Nakajima, K.; Zolboo, E.; Ohashi, T.; Lísal, Martin; Kimura, K.

    2016-01-01

    Roč. 32, č. 10 (2016), s. 1089-1094 ISSN 0910-6340 R&D Projects: GA ČR(CZ) GA16-12291S Institutional support: RVO:67985858 Keywords : surface structure * ionic liquid * hydrogen Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.228, year: 2016

  5. Molecular dynamics study of dynamic and structural properties of supercooled liquid and glassy iron in the rapid-cooling processes

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Qi-Long; Huang, Duo-Hui; Yang, Jun-Sheng; Wan, Min-Jie; Wang, Fan-Hou, E-mail: eatonch@gmail.com

    2014-10-01

    Molecular dynamics simulations were applied to study the dynamic and structural properties of supercooled liquid and glassy iron in the rapid-cooling processes. The mean-square displacement and the non-Gaussian parameter were used to describe the dynamic properties. The evolution of structural properties was investigated using the pair distribution functions and bond-angle distribution functions. Results for dynamic and structural relaxations indicate that the dynamic features are consistently correlated with the structure evolution, and there are three temperature regions as the temperature decreases: (1) at higher temperatures (1500 K, 1300 K, and 1100 K), the system remains in the liquid characteristics during the overall relaxation process. (2) At medial temperatures (1050 K, 900 K, and 700 K), a fast β-relaxation is followed by a much slower α-relaxation. There is a little change in the structural properties in the β-relaxation region, while major configuration rearrangements occurred in the α-relaxation range and the crystallization process was completed at the end of α-relaxation region. (3) At lower temperature (500 K), the system shows glassy characteristics during the overall relaxation process. In addition, the melting temperature, glass transition temperature and diffusion coefficients of supercooled liquid iron are also computed.

  6. Development of large-volume, high-resolution tracking detectors based on capillaries filled with liquid scintillator

    International Nuclear Information System (INIS)

    Buontempo, S.; Fabre, J.P.; Frenkel, A.; Gregoire, G.; Hoepfner, K.; Konijn, J.; Kozarenko, E.; Kreslo, I.; Kushnirenko, A.; Martellotti, G.; Michel, L.; Mondardini, M.R.; Penso, G.; Siegmund, W.P.; Strack, R.; Tyukov, V.; Vasilchenko, V.; Vilain, P.; Wilquet, G.; Winter, K.; Wong, H.; Zymin, K.

    1995-01-01

    Searches for the decay of short-lived particles require real time, high-resolution tracking in active targets, which in the case of neutrino physics should be of large volume. The possibility of achieving this by using glass capillaries filled with organic liquid scintillator is being investigated in the framework of the CHORUS experiment at CERN. In this paper, after outlining the application foreseen, advances in the tracking technique are discussed and results from tests are reported. An active target of dimensions 180x2x2 cm 3 has been assembled from capillaries with 20 μm diameter pores. The readout scheme currently in operation allows the reading of similar 5x10 5 channels using a single chain of image intensifiers having a resolution of σ similar 20 μm. Following the development of new liquid scintillators and purification methods an attenuation length of similar 3 m has been obtained. This translates into a hit density of 3.5 per mm for a minimum-ionizing particle that crosses the active target at a distance of 1 m from the readout end. (orig.)

  7. [Rapid determination of 8 urinary carbamate pesticides by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Liu, Hualiang; Wang, Yuan; Zhu, Baoli

    2015-11-01

    To establish a method for simultaneously determining the urinary concentrations of 8 carbamate pesticides. After being purified by acetonitrile precipitation, urine samples were transferred to a liquid chromatography-tandem mass spectrometry system, and the concentrations of 8 carbamate pesticides were determined by external standard method. A C18 column was used for ultra-high-performance liquid chromatography; methanol/ammonium acetate solution was used as the mobile phase for gradient elution; the mass spectrometer was operated in a multi-reaction monitoring mode. The calibration curves were linear when the urinary concentrations of these carbamate pesticides were 20~800 µg/L, and the recovery rates were 61.0%~121% at spiked levels of 20, 200 and 800 µg/L, with a relative standard deviation of 1.7%~5.5%. This determination method meets the Guide for establishing occupational health standards-part 5: Determination methods of chemicals in biological materials, and can be used for simultaneous determination of 8 carbamate pesticides in the urine of poisoning patients.

  8. High-resolution bistable nematic liquid crystal device realized on orientational surface patterns

    International Nuclear Information System (INIS)

    Kim, Jong-Hyun; Yoneya, Makoto; Yokoyama, Hiroshi

    2003-01-01

    The four-fold symmetry of a checkerboard-like surface alignment consisted of square domains arrived at the macroscopic orientational bistability of nematic liquid crystals. Switching between the two orientations took place with an appropriate electric field. Here the threshold field of bistable switching decreased as temperature increased, and the light could heat only the selected region in the cell including a light-absorbing medium. Irradiating the laser concurrently with an electric field, we addressed a selected region in the alignment pattern without the disturbance of neighboring regions. Extending this process, we realized an extremely fine bistable device of nematic liquid crystal with a pixel size down to about 2 μm

  9. Rapid characterisation of Klebsiella oxytoca isolates from contaminated liquid hand soap using mass spectrometry, FTIR and Raman spectroscopy.

    Science.gov (United States)

    Dieckmann, Ralf; Hammerl, Jens Andre; Hahmann, Hartmut; Wicke, Amal; Kleta, Sylvia; Dabrowski, Piotr Wojciech; Nitsche, Andreas; Stämmler, Maren; Al Dahouk, Sascha; Lasch, Peter

    2016-06-23

    Microbiological monitoring of consumer products and the efficiency of early warning systems and outbreak investigations depend on the rapid identification and strain characterisation of pathogens posing risks to the health and safety of consumers. This study evaluates the potential of three rapid analytical techniques for identification and subtyping of bacterial isolates obtained from a liquid hand soap product, which has been recalled and reported through the EU RAPEX system due to its severe bacterial contamination. Ten isolates recovered from two bottles of the product were identified as Klebsiella oxytoca and subtyped using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI TOF MS), near-infrared Fourier transform (NIR FT) Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Comparison of the classification results obtained by these phenotype-based techniques with outcomes of the DNA-based methods pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis of whole-genome sequencing (WGS) data revealed a high level of concordance. In conclusion, a set of analytical techniques might be useful for rapid, reliable and cost-effective microbial typing to ensure safe consumer products and allow source tracking.

  10. A new immersion sensor for rapid electrochemical determination of dissolved oxygen in liquid metals

    International Nuclear Information System (INIS)

    Janke, D.; Schwerdtfeger, K.

    1978-01-01

    Development of a new solid electrolyte 'needle sensor' with ZrO 2 or ThO 2 electrolyte and metal-metal oxide reference mixture for the rapid determination of oxygen in steel melts. Details of the manufacture of the layer-structured, miniaturized probe. Test results of simultaneous measurements performed with the newly developed ZrO 2 needle sensor and the hitherto usual tubular sensor in iron melts at oxygen activities between 0.00005 and 0.030. (orig.) [de

  11. Disorder trapping by rapidly moving phase interface in an undercooled liquid

    Science.gov (United States)

    Galenko, Peter; Danilov, Denis; Nizovtseva, Irina; Reuther, Klemens; Rettenmayr, Markus

    2017-08-01

    Non-equilibrium phenomena such as the disappearance of solute drag, the origin of solute trapping and evolution of disorder trapping occur during fast transformations with originating metastable phases [D.M. Herlach, P.K. Galenko, D. Holland-Moritz, Metastable solids from undrercooled melts (Elsevier, Amsterdam, 2007)]. In the present work, a theoretical investigation of disorder trapping by a rapidly moving phase interface is presented. Using a model of fast phase transformations, a system of governing equations for the diffusion of atoms, and the evolution of both long-range order parameter and phase field variable is formulated. First numerical solutions are carried out for a congruently melting binary alloy system.

  12. Three rapid methods for determination 90Sr in milk samples using liquid scintillation spectrometry

    International Nuclear Information System (INIS)

    Abbasisiara, F.; Attarilar, N.; Afshar, N.

    2006-01-01

    Strontium radionuclide 90 Sr is one of the main long-lived components of the radioactive fallout which occurred as a result of previous atmospheric nuclear tests and also nuclear accidents such as Chernobyl accident. Due to chemical and biochemical similarities between strontium and calcium, more than 99% of strontium is efficiently incorporated into bone tissue and teeth and Characterized by along physical and biological half-life, it may cause damage to bone marrow. Since determination of this radionuclide often is a time consuming process, rapid determination methods specially in emergency situations is always desirable. In this work, three rapid methods for determination of this radionuclide in milk samples will be evaluated. All of the methods include two major steps: 1- strontium separation from fats and proteins which can be performed by drying (in case of the fresh milk samples), ashing and leaching by nitric acids or by using exchange or chelating resins which have strong affinity for alkaline earth cations such as Dowex 50W-X8. And 2- Separation of Sr-90 or its daughter product, Y-90. In two methods separation of 90 Sr is performed by extraction of the daughter nuclide, 90 Y, by aid of organic extracting agent, Tributylphosphate or T.B.P., and then Cherenkov counting of the Y-90 extracted. The third method is based on separation of this radionuclide using Crown Ether or Sr -Spec resin. The detailed radiochemical procedures and evaluation of each method advantages or disadvantages will explained in full text paper. (authors)

  13. Rapid analysis of charge variants of monoclonal antibodies using non-linear salt gradient in cation-exchange high performance liquid chromatography.

    Science.gov (United States)

    Joshi, Varsha; Kumar, Vijesh; Rathore, Anurag S

    2015-08-07

    A method is proposed for rapid development of a short, analytical cation exchange high performance liquid chromatography method for analysis of charge heterogeneity in monoclonal antibody products. The parameters investigated and optimized include pH, shape of elution gradient and length of the column. It is found that the most important parameter for development of a shorter method is the choice of the shape of elution gradient. In this paper, we propose a step by step approach to develop a non-linear sigmoidal shape gradient for analysis of charge heterogeneity for two different monoclonal antibody products. The use of this gradient not only decreases the run time of the method to 4min against the conventional method that takes more than 40min but also the resolution is retained. Superiority of the phosphate gradient over sodium chloride gradient for elution of mAbs is also observed. The method has been successfully evaluated for specificity, sensitivity, linearity, limit of detection, and limit of quantification. Application of this method as a potential at-line process analytical technology tool has been suggested. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Rapid Identification of Steroidal Saponins in Trillium tschonoskii Maxim by Ultraperformance Liquid Chromatography Coupled to Electrospray Ionisation Quadrupole Time-of-Flight Tandem Mass Spectrometry.

    Science.gov (United States)

    Gao, Xin; Sun, Wenjun; Fu, Qiang; Niu, Xiaofeng

    2015-01-01

    Steroidal saponins in Trillium tschonoskii Maxim have many biological activities, including immunological regulation and anti-tumour. Comprehensive ingredient identification is critical for understanding its pharmacological mechanism and establishing quality control protocols. However, it is a challenging problem because of the complexity of steroidal saponins. To develop a UPLC-MS method for identifying and characterising steroidal saponins in the root and rhizome of T. tschonoskii. Methanolic extracts of T. tschonoskii were analysed by using ultraperformance liquid chromatography coupled to electrospray ionisation quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI/QTOF/MS). The UPLC experiments were performed by means of a reversed-phase C18 -column and a binary mobile phase system consisting of water and acetonitrile with formic acid under gradient elution conditions. For the UPLC-MS measurements, positive and negative ion modes were used in order to obtain better tandem mass spectra and high-resolution mass spectra. Based on retention times, accurate mass and mass spectrometric fragmentation, a total of 31 saponins distributed over eight steroidal aglycone skeletons were identified or tentatively elucidated from T. tschonoskii. The UPLC-ESI/QTOF/MS method has proven to be a powerful tool for rapid identification of steroidal saponins in T. tschonoskii without tedious and time-consuming isolation of pure constituents. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Rapid and sensitive determination of carbohydrates in foods using high temperature liquid chromatography with evaporative light scattering detection.

    Science.gov (United States)

    Terol, Amanda; Paredes, Eduardo; Maestre, Salvador E; Prats, Soledad; Todolí, José L

    2012-04-01

    In the present work, an evaporative light scattering detector was used as a high-temperature liquid chromatography detector for the determination of carbohydrates. The compounds studied were glucose, fructose, galactose, sucrose, maltose, and lactose. The effect of column temperature on the retention times and detectability of these compounds was investigated. Column heating temperatures ranged from 25 to 175°C. The optimum temperature in terms of peak resolution and detectability with pure water as mobile phase and a liquid flow rate of 1 mL/min was 150°C as it allowed the separation of glucose and the three disaccharides here considered in less than 3 min. These conditions were employed for lactose determination in milk samples. Limits of quantification were between 2 and 4.7 mg/L. On the other hand, a temperature gradient was developed for the simultaneous determination of glucose, fructose, and sucrose in orange juices, due to coelution of monosaccharides at temperatures higher than 70°C, being limits of quantifications between 8.5 and 12 mg/L. The proposed hyphenation was successfully applied to different types of milk and different varieties of oranges and mandarins. Recoveries for spiked samples were close to 100% for all the studied analytes. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Analysis of complete mitochondrial genome sequences increases phylogenetic resolution of bears (Ursidae, a mammalian family that experienced rapid speciation

    Directory of Open Access Journals (Sweden)

    Ryder Oliver A

    2007-10-01

    Full Text Available Abstract Background Despite the small number of ursid species, bear phylogeny has long been a focus of study due to their conservation value, as all bear genera have been classified as endangered at either the species or subspecies level. The Ursidae family represents a typical example of rapid evolutionary radiation. Previous analyses with a single mitochondrial (mt gene or a small number of mt genes either provide weak support or a large unresolved polytomy for ursids. We revisit the contentious relationships within Ursidae by analyzing complete mt genome sequences and evaluating the performance of both entire mt genomes and constituent mtDNA genes in recovering a phylogeny of extremely recent speciation events. Results This mitochondrial genome-based phylogeny provides strong evidence that the spectacled bear diverged first, while within the genus Ursus, the sloth bear is the sister taxon of all the other five ursines. The latter group is divided into the brown bear/polar bear and the two black bears/sun bear assemblages. These findings resolve the previous conflicts between trees using partial mt genes. The ability of different categories of mt protein coding genes to recover the correct phylogeny is concordant with previous analyses for taxa with deep divergence times. This study provides a robust Ursidae phylogenetic framework for future validation by additional independent evidence, and also has significant implications for assisting in the resolution of other similarly difficult phylogenetic investigations. Conclusion Identification of base composition bias and utilization of the combined data of whole mitochondrial genome sequences has allowed recovery of a strongly supported phylogeny that is upheld when using multiple alternative outgroups for the Ursidae, a mammalian family that underwent a rapid radiation since the mid- to late Pliocene. It remains to be seen if the reliability of mt genome analysis will hold up in studies of other

  17. Employing high resolution satellite imagery to document a rapid glacier surge in the Karakoram - risks and opportunities for hazard assessment

    Science.gov (United States)

    Steiner, J. F.; Kraaijenbrink, P. D. A.; Jiduc, S. G.; Immerzeel, W. W.

    2017-12-01

    Glacier surges occur regularly in the Karakoram but their driving mechanisms, recurrence and its relation to climatic change remain unclear. Since many glacier tongues in the region reach to very low elevations, local populations are often exposed to glacial hazards. While the scientific interpretation of hazard is one challenge, adequately communicating results to possibly affected stakeholders poses a different set of hurdles. Using DEMs as well as Landsat imagery in combination with high-resolution Planet imagery we quantify surface elevation changes and flow velocities to document a glacier surge of the Khurdopin glacier, located in a remote valley in Pakistan, in the first half of 2017. Results reveal that an accumulation of ice mass leads to a rapid surge in peaking with velocities above 5000 m a-1 or 0.5 m h-1 during a few days. Velocities increase steadily during a four-year build-up phase prior to the actual surge, while the remaining 15 years of the recurring cycle the glacier is quiescent. It is hypothesized that the surge is mainly initiated as a result of increased pressure melting caused by ice accumulation. However, surface observations show increased crevassing and disappearance of supra glacial ponds, which could have led to increased lubrication of the glacier bed. As a consequence of the surging tongue blocking the main valley a lake has formed and grown continuously in size over two months at a rate of up to 3000 m2 per day. Using satellite imagery with a frequent overpass rate we are able to (a) characterize the nature of glacier surges in the region with greater detail and (b) monitor the surge as well as the formation of the lake as it develops. Having developed a connection to local stakeholders we were able to provide rapid hazard assessments to affected communities, which can be employed to define possible actions. We show the potential of satellite imagery - freely available Landsat in combination with commercial Planet imagery -, which

  18. Rapid radiometric detection of microbial contamination using 14C-glucose and standard liquid scintillation counting system

    International Nuclear Information System (INIS)

    Joshi, S.H.; Kamble, S.B.; Pilkhwal, N.S.; Ramamoorthy, N.

    1998-01-01

    A simple and rapid method for detection of microbial contamination based on quantitation of 14 CO 2 released during metabolism of 14 C-Glucose by microorganisms is reported. Liquid scintillation counting system (LSCS) with a modified sample preparation method was utilised. The scintillator was impregnated on Whatman-1 paper on which 14 CO 2 evolved during metabolism could be absorbed. The important parameters of counting such as efficiency, position sensitivity and geometry as well as effect of NaOH quantity and of microbial load on detection period were studied. The efficiency of radioactivity assay was 18±2.8 %. Contamination of the order of 5-10 organism/ml of product could be detected in about 24 hours. (author)

  19. Rapid determination of vitamin D₃ in milk-based infant formulas by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kwak, Byung-Man; Jeong, In-Seek; Lee, Moon-Seok; Ahn, Jang-Hyuk; Park, Jong-Su

    2014-12-15

    A rapid and simple sample preparation method for vitamin D3 (cholecalciferol) was developed for emulsified dairy products such as milk-based infant formulas. A sample was mixed in a 50 mL centrifuge tube with the same amount of water and isopropyl alcohol to achieve chemical extraction. Ammonium sulfate was used to induce phase separation. No-heating saponification was performed in the sample tube by adding KOH, NaCl, and NH3. Vitamin D3 was then separated and quantified using liquid chromatography-tandem mass spectrometry. The results for added recovery tests were in the range 93.11-110.65%, with relative standard deviations between 2.66% and 2.93%. The results, compared to those obtained using a certified reference material (SRM 1849a), were within the range of the certificated values. This method could be implemented in many laboratories that require time and labour saving. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Rapid liquid phase sintered Mn doped BiFeO3 ceramics with enhanced polarization and weak magnetization

    Science.gov (United States)

    Kumar, Manoj; Yadav, K. L.

    2007-12-01

    Single-phase BiFe1-xMnxO3 multiferroic ceramics have been synthesized by rapid liquid phase sintering method to study the influence of Mn substitution on their crystal structure, dielectric, magnetic, and ferroelectric behaviors. From XRD analysis it is seen that Mn substitution does not affect the crystal structure of the BiFe1-xMnxO3 system. An enhancement in magnetization was observed for BiFe1-xMnxO3 ceramics. However, the ferooelectric hysteresis loops were not really saturated, we observed a spontaneous polarization of 10.23μC /cm2 under the applied field of 42kV/cm and remanent polarization of 3.99μC/cm2 for x =0.3 ceramic.

  1. Enantioselective determination of (R)-zopiclone and (S)-zopiclone (eszopiclone) in human hair by micropulverized extraction and chiral liquid chromatography/high resolution mass spectrometry.

    Science.gov (United States)

    Miyaguchi, Hajime; Kuwayama, Kenji

    2017-10-13

    Zopiclone and its (S)-enantiomer (eszopiclone) are commonly prescribed for insomnia. Despite the high demand for enantioselective differentiation, the chiral analysis of zopiclone in hair has not been reported. In this study, a method for the enantioselective quantification of zopiclone in human hair was developed. The extraction medium and duration were optimized using real eszopiclone-positive hair samples. Specifically, micropulverized extraction with 3.0M ammonium phosphate buffer (pH 8.4) involving salting-out assisted liquid-liquid extraction with acetonitrile was utilized to minimize the degradation of zopiclone and for rapid and facile operation. On the other hand, recovery of the conventional solid-liquid extraction involved overnight soaking in 3.0M ammonium phosphate buffer (pH 8.4) was only 0.58±0.12% of the maximum recovery achieved by the present method due to the decomposition in the phosphate buffer. An excellent chiral separation (Rs=5.0) was achieved using a chiral stationary phase comprising cellulose tris(3,5-dichlorophenylcarbamate) and a volatile mobile phase of 10mM ammonium carbonate (pH 8.0)-acetonitrile (25:75, v/v). Detection was carried out using liquid chromatography/high resolution mass spectrometry (LC/HRMS) with electrospray ionization. A Q Exactive mass spectrometer equipped with a quadrupole-Orbitrap analyzer was used for detection. The concentration of 0.50pg/mg was defined as the lowest limit of quantification using 5mg of hair sample. Using the developed approach, the concentration of eszopiclone in hair after a single 2-mg dose was found to be 441pg/mg, which was higher than all the reported values regarding a single administration of zopiclone. After daily administration of racemic zopiclone (3.75mg/day), the concentrations of (R)-enantiomer and (S)-enantiomer in the black hair were 5.30-8.31ng/mg and 7.96-12.8ng/mg, respectively, and the concentration of the (S)-enantiomer was always higher than that of the (R

  2. Three rapid methods for determination {sup 90}Sr in milk samples using liquid scintillation spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Abbasisiara, F.; Attarilar, N. [Iranian Nuclear Regulatory Authority (INRA), Atomic Energy Organization of Iran (AEOI), Environmental Radiation Protection Div., National Radiation Protection Dept. (Iran, Islamic Republic of); Afshar, N. [Tarbiat Modarres Univ. (Iran, Islamic Republic of)

    2006-07-01

    Strontium radionuclide {sup 90}Sr is one of the main long-lived components of the radioactive fallout which occurred as a result of previous atmospheric nuclear tests and also nuclear accidents such as Chernobyl accident. Due to chemical and biochemical similarities between strontium and calcium, more than 99% of strontium is efficiently incorporated into bone tissue and teeth and Characterized by along physical and biological half-life, it may cause damage to bone marrow. Since determination of this radionuclide often is a time consuming process, rapid determination methods specially in emergency situations is always desirable. In this work, three rapid methods for determination of this radionuclide in milk samples will be evaluated. All of the methods include two major steps: 1- strontium separation from fats and proteins which can be performed by drying (in case of the fresh milk samples), ashing and leaching by nitric acids or by using exchange or chelating resins which have strong affinity for alkaline earth cations such as Dowex 50W-X8. And 2- Separation of Sr-90 or its daughter product, Y-90. In two methods separation of {sup 90}Sr is performed by extraction of the daughter nuclide, {sup 90}Y, by aid of organic extracting agent, Tributylphosphate or T.B.P., and then Cherenkov counting of the Y-90 extracted. The third method is based on separation of this radionuclide using Crown Ether or Sr -Spec resin. The detailed radiochemical procedures and evaluation of each method advantages or disadvantages will explained in full text paper. (authors)

  3. Rapid and inexpensive body fluid identification by RNA profiling-based multiplex High Resolution Melt (HRM) analysis.

    Science.gov (United States)

    Hanson, Erin K; Ballantyne, Jack

    2013-01-01

    Positive identification of the nature of biological material present on evidentiary items can be crucial for understanding the circumstances surrounding a crime. However, traditional protein-based methods do not permit the identification of all body fluids and tissues, and thus molecular based strategies for the conclusive identification of all forensically relevant biological fluids and tissues need to be developed. Messenger RNA (mRNA) profiling is an example of such a molecular-based approach. Current mRNA body fluid identification assays involve capillary electrophoresis (CE) or quantitative RT-PCR (qRT-PCR) platforms, each with its own limitations. Both platforms require the use of expensive fluorescently labeled primers or probes. CE-based assays require separate amplification and detection steps thus increasing the analysis time. For qRT-PCR assays, only 3-4 markers can be included in a single reaction since each requires a different fluorescent dye. To simplify mRNA profiling assays, and reduce the time and cost of analysis, we have developed single- and multiplex body fluid High Resolution Melt (HRM) assays for the identification of common forensically relevant biological fluids and tissues. The incorporated biomarkers include IL19 (vaginal secretions), IL1F7 (skin), ALAS2 (blood), MMP10 (menstrual blood), HTN3 (saliva) and TGM4 (semen).  The HRM assays require only unlabeled PCR primers and a single saturating intercalating fluorescent dye (Eva Green). Each body-fluid-specific marker can easily be identified by the presence of a distinct melt peak. Usually, HRM assays are used to detect variants or isoforms for a single gene target. However, we have uniquely developed duplex and triplex HRM assays to permit the simultaneous detection of multiple targets per reaction. Here we describe the development and initial performance evaluation of the developed HRM assays. The results demonstrate the potential use of HRM assays for rapid, and relatively inexpensive

  4. Soft nanomaterials analysed by in situ liquid TEM: Towards high resolution characterisation of nanoparticles in motion

    Directory of Open Access Journals (Sweden)

    Joseph P. Patterson

    2015-12-01

    Full Text Available In this article we present in situ transmission electron microscopy (TEM of soft, synthetic nanoparticles with a comparative analysis using conventional TEM methods. This comparison is made with the simple aim of describing what is an unprecedented example of in situ imaging by TEM. However, we contend the technique will quickly become essential in the characterisation of analogous systems, especially where dynamics are of interest in the solvated state. In this case, particles were studied which were obtained from the direct polymerisation of an oxaliplatin analogue, designed for an ongoing programme in novel chemotherapeutic delivery systems. The resulting nanoparticles provided sufficient contrast for facile imaging in situ, and point towards key design parameters that enable this new characterisation approach for organic nanomaterials. We describe the preparation of the synthetic nanoparticles together with their characterisation in liquid water. Finally, we provide a future perspective of this technique for the analysis of soft and dynamic nanomaterials and discussion the progress which needs to be made in order to bring in situ liquid TEM to its full potential.

  5. Rapid determination of fumonisins in corn-based products by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Li, Wei; Herrman, Timothy J; Dai, Susie Y

    2010-01-01

    A simple, fast, and robust method was developed for the determination of fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3) in corn-based human food and animal feed (cornmeal). The method involves a single extraction step followed by centrifugation and filtration before analysis by ultra-performance liquid chromatographylelectrospray ionization (UPLC/ESI)-MS/MS. The LC/MS/MS method developed here represents the fastest and simplest procedure (<30 min) among both conventional HPLC methods and other LC/MS methods using SPE cleanup. The potential for high throughput analysis makes the method particularly beneficial for regulatory agencies and analytical laboratories with a high sample volume. A single-laboratory validation was conducted by testing three different spiking levels (200, 500, and 1000 ng/g for FB1 and FB2; 100, 250, and 500 ng/g for FB3) for accuracy and precision. Recoveries of FB1 ranged from 93 to 98% with RSD values of 3-8%. Recoveries of FB2 ranged from 104 to 108%, with RSD values of 2-6%. Recoveries of FB3 ranged from 94 to 108%, with RSD values of 2-5%.

  6. Rapid production of Candida albicans chlamydospores in liquid media under various incubation conditions.

    Science.gov (United States)

    Alicia, Zavalza-Stiker; Blanca, Ortiz-Saldivar; Mariana, García-Hernández; Magdalena, Castillo-Casanova; Alexandro, Bonifaz

    2006-01-01

    The production of chlamydospores is a diagnostic tool used to identify Candida albicans; these structures also represent a model for morphogenetic research. The time required to produce them with standard methods is 48-72 hours in rice meal agar and tensoactive agents. This time can be shorted using liquid media such as cornmeal broth (CMB) and dairy supplements. Five media were tested: CMB plus 1% Tween-80, CMB plus 5% milk, CMB plus 5% milk serum, milk serum, and milk serum plus 1% Tween-80, under different incubation conditions: at 28 degrees C and 37 degrees C in a metabolic bath stirring at 150 rpm, and at 28 degrees C in a culture stove. The reading time points were established at 8 and 16 hours. The best results were obtained at 16 hours with CMB plus 5% milk under incubation at 28 degrees C and stirring at 150 rpm. The next most efficient methods were CMB plus 5% milk serum and CMB plus 1% Tween-80, under the same incubation conditions. The other media were ineffective in producing chlamydospores. The absence of stirring at 28 degrees C prevented the formation of chlamydospores within the set time points, and incubation at 37 degrees C decreased their production. This paper reports that the time to form C. albicans chlamydospores can be reduced.

  7. Rapid determination of triclosan in personal care products using new in-tube based ultrasound-assisted salt-induced liquid-liquid microextraction coupled with high performance liquid chromatography-ultraviolet detection.

    Science.gov (United States)

    Chen, Ming-Jen; Liu, Ya-Ting; Lin, Chiao-Wen; Ponnusamy, Vinoth Kumar; Jen, Jen-Fon

    2013-03-12

    This paper describes the development of a novel, simple and efficient in-tube based ultrasound-assisted salt-induced liquid-liquid microextraction (IT-USA-SI-LLME) technique for the rapid determination of triclosan (TCS) in personal care products by high performance liquid chromatography-ultraviolet (HPLC-UV) detection. IT-USA-SI-LLME method is based on the rapid phase separation of water-miscible organic solvent from the aqueous phase in the presence of high concentration of salt (salting-out phenomena) under ultrasonication. In the present work, an indigenously fabricated home-made glass extraction device (8-mL glass tube inbuilt with a self-scaled capillary tip) was utilized as the phase separation device for USA-SI-LLME. After the extraction, the upper extractant layer was narrowed into the self-scaled capillary tip by pushing the plunger plug; thus, the collection and measurement of the upper organic solvent layer was simple and convenient. The effects of various parameters on the extraction efficiency were thoroughly evaluated and optimized. Under optimal conditions, detection was linear in the concentration range of 0.4-100ngmL(-1) with correlation coefficient of 0.9968. The limit of detection was 0.09ngmL(-1) and the relative standard deviations ranged between 0.8 and 5.3% (n=5). The applicability of the developed method was demonstrated for the analysis of TCS in different commercial personal care products and the relative recoveries ranged from 90.4 to 98.5%. The present method was proven to be a simple, sensitive, less organic solvent consuming, inexpensive and rapid procedure for analysis of TCS in a variety of commercially available personal care products or cosmetic preparations. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. A Rough Guide to Metabolite Identification Using High Resolution Liquid Chromatography Mass Spectrometry in Metabolomic Profiling in Metazoans

    Directory of Open Access Journals (Sweden)

    David G Watson

    2013-01-01

    Full Text Available Compound identification in mass spectrometry based metabolomics can be a problem but sometimes the problem seems to be presented in an over complicated way. The current review focuses on metazoans where the range of metabolites is more restricted than for example in plants. The focus is on liquid chromatography with high resolution mass spectrometry where it is proposed that most of the problems in compound identification relate to structural isomers rather than to isobaric compounds. Thus many of the problems faced relate to separation of isomers, which is usually required even if fragmentation is used to support structural identification. Many papers report the use of MS/MS or MS2 as an adjunct to the identification of known metabolites but there a few examples in metabolomics studies of metazoans of complete structure elucidation of novel metabolites or metabolites where no authentic standards are available for comparison.

  9. Deducing 2D Crystal Structure at the Solid/Liquid Interface with Atomic Resolution by Combined STM and SFG Study

    Science.gov (United States)

    McClelland, Arthur; Ahn, Seokhoon; Matzger, Adam J.; Chen, Zhan

    2009-03-01

    Supplemented by computed models, Scanning Tunneling Microscopy (STM) can provide detailed structure of 2D crystals formed at the liquid/solid interface with atomic resolution. However, some structural information such as functional group orientations in such 2D crystals needs to be tested experimentally to ensure the accuracy of the deduced structures. Due to the limited sensitivity, many other experimental techniques such as Raman and infrared spectroscopy have not been allowed to provide such structural information of 2D crystals. Here we showed that Sum Frequency Generation Vibrational Spectroscopy (SFG) can measure average orientation of functional groups in such 2D crystals, or physisorbed monolayers, providing key experimental data to aid in the modeling and interpretation of the STM images. The usefulness of combining these two techniques is demonstrated with a phthalate diesters monolayer formed at the 1-phenyloctane/ highly oriented pyrolytic graphite (HOPG) interface. The spatial orientation of the ester C=O of the monolayer was successfully determined using SFG.

  10. Analytical method by high resolution liquid chromatography for the stability study of cloratidine syrup 0.1 %

    International Nuclear Information System (INIS)

    Torres Amaro, Leonid; Garcia Penna, Caridad M; Pardo Ruiz, Zenia

    2007-01-01

    A high resolution liquid chromatography method was validated to study the stability of cloratidine syrup 0.1 %. The calibration curve in the range from 13.6 to 3.36 μg/mL was lineal, with a coefficient of correlation equal to 0.99975. The intercept and slope statistical test was not significant. The recovery obtained was 100.2 % in the concentration range studied, and the Cochran and Student (t) tests results were not important. The variation coefficient in the repeatability study was equal to 0.41 % for 10 replications assayed, whereas in the reproducibility Fischer and Student tests were not remarkable. The method proved to be specific, lineal, accurate, and exact. (Author)

  11. Rapid Solid-Liquid Dynamic Extraction (RSLDE): a New Rapid and Greener Method for Extracting Two Steviol Glycosides (Stevioside and Rebaudioside A) from Stevia Leaves.

    Science.gov (United States)

    Gallo, Monica; Vitulano, Manuela; Andolfi, Anna; DellaGreca, Marina; Conte, Esterina; Ciaravolo, Martina; Naviglio, Daniele

    2017-06-01

    Stevioside and rebaudioside A are the main diterpene glycosides present in the leaves of the Stevia rebaudiana plant, which is used in the production of foods and low-calorie beverages. The difficulties associated with their extraction and purification are currently a problem for the food processing industries. The objective of this study was to develop an effective and economically viable method to obtain a high-quality product while trying to overcome the disadvantages derived from the conventional transformation processes. For this reason, extractions were carried out using a conventional maceration (CM) and a cyclically pressurized extraction known as rapid solid-liquid dynamic extraction (RSLDE) by the Naviglio extractor (NE). After only 20 min of extraction using the NE, a quantity of rebaudioside A and stevioside equal to 1197.8 and 413.6 mg/L was obtained, respectively, while for the CM, the optimum time was 90 min. From the results, it can be stated that the extraction process by NE and its subsequent purification developed in this study is a simple, economical, environmentally friendly method for producing steviol glycosides. Therefore, this method constitutes a valid alternative to conventional extraction by reducing the extraction time and the consumption of toxic solvents and favouring the use of the extracted metabolites as food additives and/or nutraceuticals. As an added value and of local interest, the experiment was carried out on stevia leaves from the Benevento area (Italy), where a high content of rebaudioside A was observed, which exhibits a sweet taste compared to stevioside, which has a significant bitter aftertaste.

  12. Rapid analysis of pharmaceuticals and personal care products in fish plasma micro-aliquots using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Chen, Fangfang; Gong, Zhiyuan; Kelly, Barry C

    2015-02-27

    A sensitive analytical method based on liquid-liquid extraction (LLE) and liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for rapid analysis of 11 pharmaceuticals and personal care products (PPCPs) in fish plasma micro-aliquots (∼20μL). Target PPCPs included, bisphenol A, carbamazepine, diclofenac, fluoxetine, gemfibrozil, ibuprofen, naproxen, risperidone, sertraline, simvastatin and triclosan. A relatively quicker and cheaper LLE procedure exhibited comparable analyte recoveries with solid-phase extraction. Rapid separation and analysis of target compounds in fish plasma extracts was achieved by employing a high efficiency C-18 HPLC column (Agilent Poroshell 120 SB-C18, 2.1mm×50mm, 2.7μm) and fast polarity switching, enabling effective monitoring of positive and negative ions in a single 9min run. With the exception of bisphenol A, which exhibited relatively high background contamination, method detection limits of individual PPCPs ranged between 0.15 and 0.69pg/μL, while method quantification limits were between 0.05 and 2.3pg/μL. Mean matrix effect (ME) values ranged between 65 and 156% for the various target analytes. Isotope dilution quantification using isotopically labelled internal surrogates was utilized to correct for signal suppression or enhancement and analyte losses during sample preparation. The method was evaluated by analysis of 20μL plasma micro-aliquots collected from zebrafish (Danio rerio) from a laboratory bioaccumulation study, which included control group fish (no exposure), as well as fish exposed to environmentally relevant concentrations of PPCPs. Using the developed LC-MS/MS based method, concentrations of the studied PPCPs were consistently detected in the low pg/μL (ppb) range. The method may be useful for investigations requiring fast, reliable concentration measurements of PPCPs in fish plasma. In particular, the method may be applicable for in situ contaminant biomonitoring, as well as

  13. Path integral molecular dynamics within the grand canonical-like adaptive resolution technique: Simulation of liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Animesh, E-mail: animesh@zedat.fu-berlin.de; Delle Site, Luigi, E-mail: dellesite@fu-berlin.de [Institute for Mathematics, Freie Universität Berlin, Berlin (Germany)

    2015-09-07

    Quantum effects due to the spatial delocalization of light atoms are treated in molecular simulation via the path integral technique. Among several methods, Path Integral (PI) Molecular Dynamics (MD) is nowadays a powerful tool to investigate properties induced by spatial delocalization of atoms; however, computationally this technique is very demanding. The above mentioned limitation implies the restriction of PIMD applications to relatively small systems and short time scales. One of the possible solutions to overcome size and time limitation is to introduce PIMD algorithms into the Adaptive Resolution Simulation Scheme (AdResS). AdResS requires a relatively small region treated at path integral level and embeds it into a large molecular reservoir consisting of generic spherical coarse grained molecules. It was previously shown that the realization of the idea above, at a simple level, produced reasonable results for toy systems or simple/test systems like liquid parahydrogen. Encouraged by previous results, in this paper, we show the simulation of liquid water at room conditions where AdResS, in its latest and more accurate Grand-Canonical-like version (GC-AdResS), is merged with two of the most relevant PIMD techniques available in the literature. The comparison of our results with those reported in the literature and/or with those obtained from full PIMD simulations shows a highly satisfactory agreement.

  14. A sediment extraction and cleanup method for wide-scope multitarget screening by liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Massei, Riccardo; Byers, Harry; Beckers, Liza-Marie; Prothmann, Jens; Brack, Werner; Schulze, Tobias; Krauss, Martin

    2018-01-01

    Previous studies on organic sediment contaminants focused mainly on a limited number of highly hydrophobic micropollutants accessible to gas chromatography using nonpolar, aprotic extraction solvents. The development of liquid chromatography-high-resolution mass spectrometry (LC-HRMS) permits the spectrum of analysis to be expanded to a wider range of more polar and ionic compounds present in sediments and allows target, suspect, and nontarget screening to be conducted with high sensitivity and selectivity. In this study, we propose a comprehensive multitarget extraction and sample preparation method for characterization of sediment pollution covering a broad range of physicochemical properties that is suitable for LC-HRMS screening analysis. We optimized pressurized liquid extraction, cleanup, and sample dilution for a target list of 310 compounds. Finally, the method was tested on sediment samples from a small river and its tributaries. The results show that the combination of 100 °C for ethyl acetate-acetone (50:50, neutral extract) followed by 80 °C for acetone-formic acid (100:1, acidic extract) and methanol-10 mM sodium tetraborate in water (90:10, basic extract) offered the best extraction recoveries for 287 of 310 compounds. At a spiking level of 1 μg mL -1 , we obtained satisfactory cleanup recoveries for the neutral extract-(93 ± 23)%-and for the combined acidic/basic extracts-(42 ± 16)%-after solvent exchange. Among the 69 compounds detected in environmental samples, we successfully quantified several pharmaceuticals and polar pesticides.

  15. Application of an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum.

    Science.gov (United States)

    Chen, Tao; Liu, Yongling; Zou, Denglang; Chen, Chen; You, Jinmao; Zhou, Guoying; Sun, Jing; Li, Yulin

    2014-01-01

    This study presents an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum. A new solvent system composed of petroleum ether/ethyl acetate/water (4:2:1, v/v/v) was developed for the liquid-liquid extraction of the crude extract from R. tanguticum. As a result, emodin, aloe-emodin, physcion, and chrysophanol were greatly enriched in the organic layer. In addition, an efficient method was successfully established to separate and purify the above anthraquinones by high-speed counter-current chromatography and preparative HPLC. This study supplies a new alternative method for the rapid enrichment, separation, and purification of emodin, aloe-emodin, physcione, and chrysophanol. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Redistribution of hematoma to spinal subdural space as a mechanism for the rapid spontaneous resolution of posttraumatic intracranial acute subdural hematoma: case report.

    Science.gov (United States)

    Wong, Sui To; Yuen, Ming Keung; Fok, Kam Fuk; Yuen, Shing Chau; Yam, Kwong Yui; Fong, Dawson

    2009-01-01

    Rapid spontaneous resolution of posttraumatic intracranial ASDH has been reported in the literature since 1986. We report a case to demonstrate that redistribution of hematoma to the spinal subdural space is a mechanism for the rapid spontaneous resolution of posttraumatic intracranial ASDH. A 73-year-old woman with a slipped-and-fell injury had a worst GCS score of 8/15. Computerized tomography of the brain demonstrated a large intracranial ASDH with mass effect. Conservative management was decided because of her poor premorbid general condition. Rapid clinical improvement was observed within 5 hours after the CT. Progress CT of the brain at 45 hours postinjury showed that the size of the intracranial ASDH was markedly diminished. The CT findings apparently demonstrated a caudal distribution of the intracranial ASDH over the tentorium and then into the posterior fossa. To investigate this further, an MRI of the spine was performed, which showed that there was spinal SDH in the cervical and thoracic spine. This is the first report demonstrating that redistribution of posttraumatic intracranial ASDH to the spinal subdural space is one of the mechanisms behind the rapid spontaneous resolution of posttraumatic intracranial ASDH in the acute phase.

  17. DETECTING LOW-LEVEL SYNTHESIS IMPURITIES IN MODIFIED PHOSPHOROTHIOATE OLIGONUCLEOTIDES USING LIQUID CHROMATOGRAPHY – HIGH RESOLUTION MASS SPECTROMETRY

    Science.gov (United States)

    Nikcevic, Irena; Wyrzykiewicz, Tadeusz K.; Limbach, Patrick A.

    2010-01-01

    Summary An LC-MS method based on the use of high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS) for profiling oligonucleotides synthesis impurities is described. Oligonucleotide phosphorothioatediesters (phosphorothioate oligonucleotides), in which one of the non-bridging oxygen atoms at each phosphorus center is replaced by a sulfur atom, are now one of the most popular oligonucleotide modifications due to their ease of chemical synthesis and advantageous pharmacokinetic properties. Despite significant progress in the solid-phase oligomerization chemistry used in the manufacturing of these oligonucleotides, multiple classes of low-level impurities always accompany synthetic oligonucleotides. Liquid chromatography-mass spectrometry has emerged as a powerful technique for the identification of these synthesis impurities. However, impurity profiling, where the entire complement of low-level synthetic impurities is identified in a single analysis, is more challenging. Here we present an LC-MS method based the use of high resolution-mass spectrometry, specifically Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS or FTMS). The optimal LC-FTMS conditions, including the stationary phase and mobile phases for the separation and identification of phosphorothioate oligonucleotides, were found. The characteristics of FTMS enable charge state determination from single m/z values of low-level impurities. Charge state information then enables more accurate modeling of the detected isotopic distribution for identification of the chemical composition of the detected impurity. Using this approach, a number of phosphorothioate impurities can be detected by LC-FTMS including failure sequences carrying 3′-terminal phosphate monoester and 3′-terminal phosphorothioate monoester, incomplete backbone sulfurization and desulfurization products, high molecular weight impurities, and chloral, isobutyryl, and N3 (2-cyanoethyl) adducts

  18. Triacylglycerol profiling of microalgae strains for biofuel feedstock by liquid chromatography-high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, Karen M.; McNichol, Jesse; McGinn, Patrick J.; O' Leary, Stephen J.B.; Melanson, Jeremy E. [Institute for Marine Biosciences, National Research Council of Canada, Halifax, NS (Canada)

    2011-11-15

    Biofuels from photosynthetic microalgae are quickly gaining interest as a viable carbon-neutral energy source. Typically, characterization of algal feedstock involves breaking down triacylglycerols (TAG) and other intact lipids, followed by derivatization of the fatty acids to fatty acid methyl esters prior to analysis by gas chromatography (GC). However, knowledge of the intact lipid profile could offer significant advantages for discovery stage biofuel research such as the selection of an algal strain or the optimization of growth and extraction conditions. Herein, lipid extracts from microalgae were directly analyzed by ultra-high pressure liquid chromatography-mass spectrometry (UHPLC-MS) using a benchtop Orbitrap mass spectrometer. Phospholipids, glycolipids, and TAGs were analyzed in the same chromatographic run, using a combination of accurate mass and diagnostic fragment ions for identification. Using this approach, greater than 100 unique TAGs were identified over the six algal strains studied and TAG profiles were obtained to assess their potential for biofuel applications. Under the growth conditions employed, Botryococcus braunii and Scenedesmus obliquus yielded the most comprehensive TAG profile with a high abundance of TAGs containing oleic acid. (orig.)

  19. Liquid chromatography-high resolution mass spectrometric methods for the surveillance monitoring of cyanotoxins in freshwaters.

    Science.gov (United States)

    Bogialli, Sara; Bortolini, Claudio; Di Gangi, Iole Maria; Di Gregorio, Federica Nigro; Lucentini, Luca; Favaro, Gabriella; Pastore, Paolo

    2017-08-01

    A comprehensive risk management on human exposure to cyanotoxins, whose production is actually unpredictable, is limited by reliable analytical tools for monitoring as many toxic algal metabolites as possible. Two analytical approaches based on a LC-QTOF system for target analysis and suspect screening of cyanotoxins in freshwater were presented. A database with 369 compounds belonging to cyanobacterial metabolites was developed and used for a retrospective data analysis based on high resolution mass spectrometry (HRMS). HRMS fragmentation of the suspect cyanotoxin precursor ions was subsequently performed for correctly identifying the specific variants. Alternatively, an automatic tandem HRMS analysis tailored for cyanotoxins was performed in a single chromatographic run, using the developed database as a preferred precursor ions list. Twenty-five extracts of surface and drinking waters contaminated by cyanobacteria were processed. The identification of seven uncommon microcystins (M(O)R, MC-FR, MSer 7 -YR, D-Asp 3 MSer 7 -LR, MSer 7 -LR, dmAdda-LR and dmAdda-YR) and 6 anabaenopeptins (A, B, F, MM850, MM864, oscyllamide Y) was reported. Several isobaric variants, fully separated by chromatography, were pointed out. The developed methods are proposed to be used by environmental and health agencies for strengthening the surveillance monitoring of cyanotoxins in water. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Rapid and sensitive analysis of polychlorinated biphenyls and acrylamide in food samples using ionic liquid-based in situ dispersive liquid-liquid microextraction coupled to headspace gas chromatography.

    Science.gov (United States)

    Zhang, Cheng; Cagliero, Cecilia; Pierson, Stephen A; Anderson, Jared L

    2017-01-20

    A simple and rapid ionic liquid (IL)-based in situ dispersive liquid-liquid microextraction (DLLME) method was developed and coupled to headspace gas chromatography (HS-GC) employing electron capture (ECD) and mass spectrometry (MS) detection for the analysis of polychlorinated biphenyls (PCBs) and acrylamide at trace levels from milk and coffee samples. The chemical structures of the halide-based ILs were tailored by introducing various functional groups to the cations to evaluate the effect of different structural features on the extraction efficiency of the target analytes. Extraction parameters including the molar ratio of IL to metathesis reagent and IL mass were optimized. The effects of HS oven temperature and the HS sample vial volume on the analyte response were also evaluated. The optimized in situ DLLME method exhibited good analytical precision, good linearity, and provided detection limits down to the low ppt level for PCBs and the low ppb level for acrylamide in aqueous samples. The matrix-compatibility of the developed method was also established by quantifying acrylamide in brewed coffee samples. This method is much simpler and faster compared to previously reported GC-MS methods using solid-phase microextraction (SPME) for the extraction/preconcentration of PCBs and acrylamide from complex food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Fast and sensitive analysis of beta blockers by ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry.

    Science.gov (United States)

    Tomková, Jana; Ondra, Peter; Kocianová, Eva; Václavík, Jan

    2017-07-01

    This paper presents a method for the determination of acebutolol, betaxolol, bisoprolol, metoprolol, nebivolol and sotalol in human serum by liquid-liquid extraction and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. After liquid-liquid extraction, beta blockers were separated on a reverse-phase analytical column (Acclaim RS 120; 100 × 2.1 mm, 2.2 μm). The total run time was 6 min for each sample. Linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery and sample stability were evaluated. The method was successfully applied to the therapeutic drug monitoring of 108 patients with hypertension. This method was also used for determination of beta blockers in 33 intoxicated patients. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Rapid methods to determine procyanidins, anthocyanins, theobromine and caffeine in rat tissues by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Serra, Aida; Macià, Alba; Romero, Maria-Paz; Piñol, Carme; Motilva, Maria-José

    2011-06-01

    Rapid, selective and sensitive methods were developed and validated to determine procyanidins, anthocyanins and alkaloids in different biological tissues, such as liver, brain, the aorta vein and adipose tissue. For this purpose, standards of procyanidins (catechin, epicatechin, and dimer B(2)), anthocyanins (cyanidin-3-glucoside and malvidin-3-glucoside) and alkaloids (theobromine, caffeine and theophylline) were used. The methods included the extraction of homogenized tissues by off-line liquid-solid extraction, and then solid-phase extraction to analyze alkaloids, or microelution solid-phase extraction plate for the analysis of procyanidins and anthocyanins. The eluted extracts were then analyzed by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, using a triple quadrupole as the analyzer. The optimum extraction solution was water/methanol/phosphoric acid 4% (94/4.5/1.5, v/v/v). The extraction recoveries were higher than 81% for all the studied compounds in all the tissues, except the anthocyanins, which were between 50 and 65% in the liver and brain. In order to show the applicability of the developed methods, different rat tissues were analyzed to determine the procyanidins, anthocyanins and alkaloids and their generated metabolites. The rats had previously consumed 1g of a grape pomace extract (to analyze procyanidins and anthocyanins) or a cocoa extract (to analyze alkaloids) per kilogram of body weight. Different tissues were extracted 4h after administration of the respective extracts. The analysis of the metabolites revealed a hepatic metabolism of procyanidins. The liver was the tissue which produced a greater accumulation of these metabolites. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Non-invasive transdermal two-dimensional mapping of cutaneous oxygenation with a rapid-drying liquid bandage.

    Science.gov (United States)

    Li, Zongxi; Roussakis, Emmanuel; Koolen, Pieter G L; Ibrahim, Ahmed M S; Kim, Kuylhee; Rose, Lloyd F; Wu, Jesse; Nichols, Alexander J; Baek, Yunjung; Birngruber, Reginald; Apiou-Sbirlea, Gabriela; Matyal, Robina; Huang, Thomas; Chan, Rodney; Lin, Samuel J; Evans, Conor L

    2014-11-01

    Oxygen plays an important role in wound healing, as it is essential to biological functions such as cell proliferation, immune responses and collagen synthesis. Poor oxygenation is directly associated with the development of chronic ischemic wounds, which affect more than 6 million people each year in the United States alone at an estimated cost of $25 billion. Knowledge of oxygenation status is also important in the management of burns and skin grafts, as well as in a wide range of skin conditions. Despite the importance of the clinical determination of tissue oxygenation, there is a lack of rapid, user-friendly and quantitative diagnostic tools that allow for non-disruptive, continuous monitoring of oxygen content across large areas of skin and wounds to guide care and therapeutic decisions. In this work, we describe a sensitive, colorimetric, oxygen-sensing paint-on bandage for two-dimensional mapping of tissue oxygenation in skin, burns, and skin grafts. By embedding both an oxygen-sensing porphyrin-dendrimer phosphor and a reference dye in a liquid bandage matrix, we have created a liquid bandage that can be painted onto the skin surface and dries into a thin film that adheres tightly to the skin or wound topology. When captured by a camera-based imaging device, the oxygen-dependent phosphorescence emission of the bandage can be used to quantify and map both the pO2 and oxygen consumption of the underlying tissue. In this proof-of-principle study, we first demonstrate our system on a rat ischemic limb model to show its capabilities in sensing tissue ischemia. It is then tested on both ex vivo and in vivo porcine burn models to monitor the progression of burn injuries. Lastly, the bandage is applied to an in vivo porcine graft model for monitoring the integration of full- and partial-thickness skin grafts.

  4. The coupling of supercritical fluid chromatography and field ionization time-of-flight high-resolution mass spectrometry for rapid and quantitative analysis of petroleum middle distillates.

    Science.gov (United States)

    Qian, Kuangnan; Diehl, John W; Dechert, Gary J; DiSanzo, Frank P

    2004-01-01

    We report the first coupling of supercritical fluid chromatography (SFC) with field ionization time-of-flight high-resolution mass spectrometry (FI-ToF HRMS), in parallel with ultraviolet (UV) detection and flame ionization detection (FID), for rapid and quantitative analysis of petroleum middle distillates. SFC separates petroleum middle distillates into saturates and 1- to 3-ring aromatics. FI generates molecular ions for hydrocarbon species eluted from the SFC. The high resolution and exact mass measurements by ToF mass spectrometry provide elemental compositions of the molecules in the petroleum product. The amounts of saturates and aromatic ring types were quantified using the parallel SFC-FID assisted by SFC-UV. With a proper carbon-number calibration, the detailed composition of the petroleum middle distillate was rapidly determined.

  5. Rapid non-destructive quantitative estimation of urania/ thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Shriwastwa, B.B.; Kumar, Anil; Raghunath, B.; Nair, M.R.; Abani, M.C.; Ramachandran, R.; Majumdar, S.; Ghosh, J.K.

    2001-01-01

    A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO 2 -UO 2 ) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign

  6. A gas/liquid chromatographic-mass spectrometric method for the rapid screening of 250 pesticides in aqueous matrices

    Energy Technology Data Exchange (ETDEWEB)

    Chandramouli, B.; Harvan, D.; Brittain, S.; Hass, R. [Eno River Labs, LLC. Durham, NC (United States)

    2004-09-15

    Pesticide residues in food present a potentially serious and significant cause for concern. Many pesticides have been associated with significant health effects to the nervous and endocrine systems and some have been deemed carcinogenic. There are many well-established techniques for pesticide analysis. However, commercial pesticide methods have traditionally only been available for specific pesticide families, such as chlorinated pesticides or herbicides, and at detection limits ranging from 0.05 ppb to 1 ppm in aqueous matrices. Techniques that can quickly screen for the presence/absence of pesticide residues in food matrices are critical in ensuring the safety of food and water. This paper outlines a combined Gas Chromatographic-High Resolution Mass Spectrometric (GC-HRMS) and Liquid Chromatographic Tandem Mass Spectrometric (LC-MS/MS) screening assay for 250 pesticides that was developed for use in water, and soda samples at screening levels ranging from 0.1-5 ppb. The pesticides selected have been identified by the European Union as being of concern and the target of possible legislation. The list encompasses a variety of pesticide classes and compound groupings.

  7. Comprehensive Two-dimensional Liquid Chromatography coupled to High Resolution Time of Flight Mass Spectrometry for Chemical Characterization of Sewage Treatment Plant Effluents

    NARCIS (Netherlands)

    Ouyang, X.; Leonards, P.E.G.; Legler, J.; van der Oost, R.; de Boer, J.; Lamoree, M.H.

    2015-01-01

    For the first time a comprehensive two-dimensional liquid chromatography (LC. ×. LC) system coupled with a high resolution time-of-flight mass spectrometer (HR-ToF MS) was developed and applied for analysis of emerging toxicants in wastewater effluent. The system was optimized and validated using

  8. Isocratic Solid Phase Extraction-Liquid Chromatography (SPE-LC) Interfaced to High-Performance Tandem Mass Spectrometry for Rapid Protein Identification

    DEFF Research Database (Denmark)

    Hørning, Ole B; Kjeldsen, Frank; Theodorsen, Søren

    2008-01-01

    the isocratic solid phase extraction-liquid chromatography (SPE-LC) technology for rapid separation ( approximately 8 min) of simple peptide samples. We now extend these studies to demonstrate the potential of SPE-LC separation in combination with a hybrid linear ion trap-Orbitrap tandem mass spectrometer...

  9. Development of an automated on-line pepsin digestion-liquid chromatography-tandem mass spectrometry configuration for the rapid analysis of protein adducts of chemical warfare agents

    NARCIS (Netherlands)

    Carol-Visser, J.; van der Schans, M.; Fidder, A.; Huist, A.G.; van Baar, B.L.M.; Irth, H.; Noort, D.

    2008-01-01

    Rapid monitoring and retrospective verification are key issues in protection against and non-proliferation of chemical warfare agents (CWA). Such monitoring and verification are adequately accomplished by the analysis of persistent protein adducts of these agents. Liquid chromatography-mass

  10. Comparative analysis of native and permethylated human milk oligosaccharides by liquid chromatography coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Oursel, Stéphanie; Cholet, Sophie; Junot, Christophe; Fenaille, François

    2017-12-15

    Human milk oligosaccharides (HMOs) represent the third most abundant components of milk after lactose and lipids. HMOs are indigestible by the suckling infant but can act as prebiotics and have significant biological functions regarding the organism defense against pathogens (such as bacteria or viruses) by preventing interactions with their receptors. Although constituted of only five distinct monosaccharide building blocks, HMOs are highly structurally diverse compounds with many co-existing structural isomers. Here we report the development and comparison of two distinct glycomic platforms based on liquid chromatography coupled to high resolution mass spectrometry (LC-MS) for analyzing HMOs. We have implemented and thoroughly compared the LC-MS of permethylated and native HMOs on reversed phase (RP) and porous graphitic carbon (PGC) columns for their ability to resolve the natural heterogeneity of milk oligosaccharides at the highest sensitivity. Our data essentially underlines the usefulness of analyzing HMOs as permethylated derivatives especially for getting more precise structural information at high sensitivity. For instance, permethylation annihilates gas-phase fucose migration during MS/MS experiments, thus facilitating spectra interpretation and giving access to relevant information regarding oligosaccharide branching and isomer distinction. At the opposite, LC-MS profiling of native HMOs (using PGC) in milk performed best in terms of detected species, while also being much faster in terms of sample preparation. Although less efficient than PGC chromatography, RPLC proved successful for separating pairs of permethylated isomeric HMOs. A key advantage of RP over PGC liquid chromatography is that retention times can be correlated to molecular weights, which can greatly facilitate further HMO identification using retention time prediction. Altogether these data lead us to think that LC-MS analysis of native HMOs (using PGC) can be used as first

  11. Hydrophilic interaction liquid chromatography coupled to high-resolution mass spectrometry to determine artificial sweeteners in environmental waters.

    Science.gov (United States)

    Salas, Daniela; Borrull, Francesc; Fontanals, Núria; Marcé, Rosa Maria

    2015-06-01

    Artificial sweeteners are food additives employed as sugar substitutes which are now considered to be emerging organic contaminants. In the present study, a method is developed for the determination of a group of artificial sweeteners in environmental waters. Considering the polar and hydrophilic character of these compounds, hydrophilic interaction liquid chromatography is proposed for their separation as an alternative to traditional reversed-phase liquid chromatography. Two stationary phases with different chemistry were compared for this purpose. For the detection of the analytes, high-resolution mass spectrometry (Orbitrap) was employed to take advantage of its benefits in terms of reliable quantification and confirmation for the measurement of accurate masses. Solid-phase extraction was chosen as the sample treatment, in which the extract in a mixture of NH4OH:MeOH:ACN (1:4:15) was directly injected into the chromatographic system, simplifying the analytical procedure. The optimized method was validated on river and waste water samples. For example, in the case of effluent water samples, limits of detection ranged from 0.002 to 0.7 μg/L and limits of quantification ranged from 0.004 to 1.5 μg/L. Apparent (whole method) recoveries ranged from 57 to 74% with intra-day precision (%RSD, n = 5) ranging from 6 to 25%. The method was successfully applied to water samples from different rivers in Catalonia and different waste water treatment plants in Tarragona. Acesulfame, cyclamate, saccharine and sucralose were found in several samples.

  12. Rapid quantification of underivatized amino acids in plasma by hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass-spectrometry.

    Science.gov (United States)

    Prinsen, Hubertus C M T; Schiebergen-Bronkhorst, B G M; Roeleveld, M W; Jans, J J M; de Sain-van der Velden, M G M; Visser, G; van Hasselt, P M; Verhoeven-Duif, N M

    2016-09-01

    Amino acidopathies are a class of inborn errors of metabolism (IEM) that can be diagnosed by analysis of amino acids (AA) in plasma. Current strategies for AA analysis include cation exchange HPLC with post-column ninhydrin derivatization, GC-MS, and LC-MS/MS-related methods. Major drawbacks of the current methods are time-consuming procedures, derivative problems, problems with retention, and MS-sensitivity. The use of hydrophilic interaction liquid chromatography (HILIC) columns is an ideal separation mode for hydrophilic compounds like AA. Here we report a HILIC-method for analysis of 36 underivatized AA in plasma to detect defects in AA metabolism that overcomes the major drawbacks of other methods. A rapid, sensitive, and specific method was developed for the analysis of AA in plasma without derivatization using HILIC coupled with tandem mass-spectrometry (Xevo TQ, Waters). Excellent separation of 36 AA (24 quantitative/12 qualitative) in plasma was achieved on an Acquity BEH Amide column (2.1×100 mm, 1.7 μm) in a single MS run of 18 min. Plasma of patients with a known IEM in AA metabolism was analyzed and all patients were correctly identified. The reported method analyzes 36 AA in plasma within 18 min and provides baseline separation of isomeric AA such as leucine and isoleucine. No separation was obtained for isoleucine and allo-isoleucine. The method is applicable to study defects in AA metabolism in plasma.

  13. Rapid ion-pair liquid chromatographic method for the determination of fenbendazole marker residue in fermented dairy products.

    Science.gov (United States)

    Vousdouka, Venetia I; Papapanagiotou, Elias P; Angelidis, Apostolos S; Fletouris, Dimitrios J

    2017-04-15

    A simple, rapid and sensitive liquid chromatographic method that allows for the quantitative determination of fenbendazole residues in fermented dairy products is described. Samples were extracted with a mixture of acetonitrile-phosphoric acid and the extracts were defatted with hexane to be further partitioned into ethyl acetate. The organic layer was evaporated to dryness and the residue was reconstituted in mobile phase. Separation of fenbendazole and its sulphoxide, sulphone, and p-hydroxylated metabolites was carried out isocratically with a mobile phase containing both positively and negatively charged pairing ions. Overall recoveries ranged from 79.8 to 88.8%, while precision data, based on within and between days variations, suggested an overall relative standard deviation of 6.3-11.0%. The detection and quantification limits were lower than 9 and 21μg/kg, respectively. The method has been successfully applied to quantitate fenbendazole residues in Feta cheese and yoghurt made from spiked and incurred ovine milk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Simple and Rapid Dual-Dispersive Liquid-Liquid Microextraction as an Innovative Extraction Method for Uranium in Real Water Samples Prior to the Determination of Uranium by a Spectrophotometric Technique.

    Science.gov (United States)

    Khan, Naeemullah; Tuzen, Mustafa; Kazi, Tasneem Gul

    2017-11-01

    An innovative, rapid, and simple dual-dispersive liquid-liquid microextraction (DDLL-ME) approach was used to extract uranium from real samples for the first time. The main objective of this study was to disperse extraction solvent by using an air-agitated syringe system to overcome matrix effects and avoid dispersion of hazardous dispersive organic solvents by using heat. The DDLL-ME method consisted of two dispersive liquid-liquid extraction steps with chloroform as the extracting solvent. Uranium formed complexes with 4-(2-thiazolylazo) resorcinol in the aqueous phase and was extracted in extracting solvent (chloroform) after the first dispersive liquid-liquid process. Uranium was then back-extracted in the acidic aqueous phase in a second dispersive liquid-liquid process. Finally, uranium was determined by a spectrophotometric detection technique. The variables that played a key role in the proposed method were studied and optimized. The LOD and sensitivity enhancement factor for uranium were found to be 0.60 µg/L and 45, respectively, under optimized conditions. Calibration graphs were found to be linear in the range of 5.0-600 µg/L. The RSD was 2.5%. Reliability of the proposed method was verified by analyzing certified reference material TM-28.3.

  15. Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry.

    Science.gov (United States)

    Strano-Rossi, Sabina; Castrignanò, Erika; Anzillotti, Luca; Odoardi, Sara; De-Giorgio, Fabio; Bermejo, Ana; Pascali, Vincenzo L

    2013-09-02

    A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography-high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg(-1), and limits of quantitation were 0.5 ng mg(-1) for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg(-1), giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Liquid chromatography-high resolution mass spectrometry for the analysis of phytochemicals in vegetal-derived food and beverages.

    Science.gov (United States)

    La Barbera, Giorgia; Capriotti, Anna Laura; Cavaliere, Chiara; Montone, Carmela Maria; Piovesana, Susy; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2017-10-01

    The recent years witnessed a change in the perception of nutrition. Diet does not only provide nutrients to meet the metabolic requirements of the body, but it also constitutes an active way for the consumption of compounds beneficial for human health. Fruit and vegetables are an excellent source of such compounds, thus the growing interest in characterizing phytochemical sources, structures and activities. Given the interest for phytochemicals in food, the development of advanced and suitable analytical techniques for their identification is fundamental for the advancement of food research. In this review, the state of the art of phytochemical research in food plants is described, starting from sample preparation, throughout extract clean-up and compound separation techniques, to the final analysis, considering both qualitative and quantitative investigations. In this regard, from an analytical point of view, fruit and vegetable extracts are complex matrices, which greatly benefit from the use of modern hyphenated techniques, in particular from the combination of high performance liquid chromatography separation and high resolution mass spectrometry, powerful tools which are being increasingly used in the recent years. Therefore, selected applications to real samples are presented and discussed, in particular for the analysis of phenols, polyphenols and phenolic acids. Finally, some hot points are discussed, such as waste characterization for high value-compounds recovery and the untargeted metabolomics approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Analysis of volatile thiols in alcoholic beverages by simultaneous derivatization/extraction and liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Vichi, Stefania; Cortés-Francisco, Nuria; Caixach, Josep

    2015-05-15

    A simultaneous derivatization/extraction method followed by liquid chromatography-electrospray-high resolution mass spectrometry for the determination of volatile thiols in hydroalcoholic matrixes was optimized and used to identify and quantify volatile thiols in wine and beer samples. The method was evaluated in terms of sensitivity, precision, accuracy and selectivity. The experimental LOQs of eleven thiols tested ranged between 0.01 ng/L and 10 ng/L. Intra-day relative standard deviation (RSD) was in general lower than 10% and inter-day RSD ranged between 10% and 30%. Recovery in the model and real matrixes ranged from 45% to 129%. The method was then applied for the analysis of four white wines and six beers. Five out of the eleven reference thiols were identified and quantified in the samples analyzed. The non-target approach, carried out by monitoring the diagnostic ion at m/z 275.9922 [C13H10ONSe](+) in the fragmentation spectrum, allowed detecting, in the same samples, fourteen non-target thiols. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Ultra-high performance liquid chromatography tandem high-resolution mass spectrometry study of tricyclazole photodegradation products in water.

    Science.gov (United States)

    Gosetti, Fabio; Chiuminatto, Ugo; Mazzucco, Eleonora; Mastroianni, Rita; Bolfi, Bianca; Marengo, Emilio

    2015-06-01

    This paper reports the study of the photodegradation reactions that tricyclazole can naturally undergo, under the action of sunlight, in aqueous solutions of standard tricyclazole and of the commercial BEAM(TM) formulation. The analyses are carried out by ultra-high performance liquid chromatography technique coupled with high-resolution tandem mass spectrometry. Analysis of both tricyclazole and BEAM(TM) water solutions undergone to hydrolysis does not evidence new chromatographic peaks with respect to the not treated solutions. On the contrary, analysis of the same samples subjected to sunlight irradiation shows a decreased intensity of tricyclazole signal and the presence of new chromatographic peaks. Two photodegradation products of tricyclazole have been identified, one of which has been also quantified, being the commercial standard available. The pattern is similar for the solutions of the standard fungicide and of the BEAM(TM) formulation. The results obtained from eco-toxicological tests show that toxicity of tricyclazole standard solutions is greater than that of the irradiated ones, whereas toxicity levels of all the BEAM(TM) solutions investigated (non-irradiated, irradiated, and hydrolyzed) are comparable and lower than those shown by tricyclazole standard solutions. Experiments performed in paddy water solution show that there is no difference in the degradation products formed.

  19. Evaluation and optimization of high-performance liquid chromatography coupled with high-resolution mass spectrometry for phospholipid quantitation.

    Science.gov (United States)

    Fu, Mingkun; Xu, Wei; Lu, Qing; Pan, Guoyu; Varga, Csanad

    2014-04-15

    High-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC/HRMS) provides an attractive alternative to the traditional triple quadrupole mass spectrometry selected reaction monitoring (SRM) methodology in the field of quantitation. An LTQ Orbitrap Velos mass spectrometer coupled with a Shimadzu UHPLC system was used. A mass extraction window (MEW) was defined to mathematically correlate with mass resolving power (MRP). Five MRP measurement conditions at 7500, 15,000, 30,000, 60,000, and 100,000, and five MEW widths at 10%, 20%, 50%, and 100% of ±1000000/MRP, and were utilized as the experimental conditions. Comparison of profile and centroid algorithms was evaluated as well. Selection of pH 8.5 buffer, C4 column, 20% IPA, and 10 ppm H3 PO4 , minimized hydrophobic and silanol interactions to enhance separation. Narrowing the MEW minimized background noise, while over-narrowing the MEW gave signal loss due to mass accuracy deviation. The mass accuracy deviation was larger for lower MRP measurements especially with centriod data, and hence a profile algorithm was recommended. The post-ionization signal suppression was observed with low MRP and was further confirmed with the analysis of multi-level linearity. It was found that the HPLC/HRMS method with conditions of 20% ±1000000/MRP as MEW, 30,000 or 60,000 MRP, and profile algorithm, provide optimum results for quantitation of seven model phospholipids. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Nontargeted Screening Method for Illegal Additives Based on Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Fu, Yanqing; Zhou, Zhihui; Kong, Hongwei; Lu, Xin; Zhao, Xinjie; Chen, Yihui; Chen, Jia; Wu, Zeming; Xu, Zhiliang; Zhao, Chunxia; Xu, Guowang

    2016-09-06

    Identification of illegal additives in complex matrixes is important in the food safety field. In this study a nontargeted screening strategy was developed to find illegal additives based on ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). First, an analytical method for possible illegal additives in complex matrixes was established including fast sample pretreatment, accurate UHPLC separation, and HRMS detection. Second, efficient data processing and differential analysis workflow were suggested and applied to find potential risk compounds. Third, structure elucidation of risk compounds was performed by (1) searching online databases [Metlin and the Human Metabolome Database (HMDB)] and an in-house database which was established at the above-defined conditions of UHPLC-HRMS analysis and contains information on retention time, mass spectra (MS), and tandem mass spectra (MS/MS) of 475 illegal additives, (2) analyzing fragment ions, and (3) referring to fragmentation rules. Fish was taken as an example to show the usefulness of the nontargeted screening strategy, and six additives were found in suspected fish samples. Quantitative analysis was further carried out to determine the contents of these compounds. The satisfactory application of this strategy in fish samples means that it can also be used in the screening of illegal additives in other kinds of food samples.

  1. Multivariate curve-resolution analysis of pesticides in water samples from liquid chromatographic-diode array data.

    Science.gov (United States)

    Maggio, Rubén M; Damiani, Patricia C; Olivieri, Alejandro C

    2011-01-30

    Liquid chromatographic-diode array detection data recorded for aqueous mixtures of 11 pesticides show the combined presence of strongly coeluting peaks, distortions in the time dimension between experimental runs, and the presence of potential interferents not modeled by the calibration phase in certain test samples. Due to the complexity of these phenomena, data were processed by a second-order multivariate algorithm based on multivariate curve resolution and alternating least-squares, which allows one to successfully model both the spectral and retention time behavior for all sample constituents. This led to the accurate quantitation of all analytes in a set of validation samples: aldicarb sulfoxide, oxamyl, aldicarb sulfone, methomyl, 3-hydroxy-carbofuran, aldicarb, propoxur, carbofuran, carbaryl, 1-naphthol and methiocarb. Limits of detection in the range 0.1-2 μg mL(-1) were obtained. Additionally, the second-order advantage for several analytes was achieved in samples containing several uncalibrated interferences. The limits of detection for all analytes were decreased by solid phase pre-concentration to values compatible to those officially recommended, i.e., in the order of 5 ng mL(-1). Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Study of Grape Polyphenols by Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC/QTOF and Suspect Screening Analysis

    Directory of Open Access Journals (Sweden)

    Riccardo Flamini

    2015-01-01

    Full Text Available Suspect screening analysis is a targeted metabolomics method in which the identification of compounds relies on specific available information, such as their molecular formula and isotopic pattern. This method, coupled to liquid chromatography-high-resolution mass spectrometry, is effective in the study of grape metabolomics, in particular for characterization of flavonols, stilbene derivatives, and anthocyanins. For identification of compounds expected in the samples, a new database of putative compounds was expressly constructed by using the molecular information on potential metabolites of grape and wine from the literature and other electronic databases. Currently, this database contains around 1,100 compounds. The method allows identification of several hundred grape metabolites with two analyses (positive and negative ionization modes, and performing of data reprocessing using “untargeted” algorithms also provided the identification of some flavonols and resveratrol trimers and tetramers in grape for the first time. This approach can be potentially used in the study of metabolomics of varieties of other plant species.

  3. Targeting high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance analysis with high-resolution radical scavenging profiles - bioactive secondary metabolites from the endophytic fungus Penicillium namyslowskii

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Nyberg, Nils; Tejesvi, Mysore V.

    2013-01-01

    The high-resolution radical scavenging profile of an extract of the endophytic fungus Penicillium namyslowskii was used to target analysis by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy, i.e., HPLC...... NMR probe designed for 1.7-mm NMR tubes. To further explore the potential of the above HPLC-HRMS-SPE-NMR platform for analysis of endophytic extracts, six peaks displaying no radical scavenging activity were also analyzed. This allowed unambiguous identification of six metabolites, i...... and griseofulvin, directly from crude extract via HPLC-HRMS-SPE-NMR. Dechlorodehydrogriseofulvin was reported for the first time from nature....

  4. Prediction of collision cross section and retention time for broad scope screening in gradient reversed-phase liquid chromatography-ion mobility-high resolution accurate mass spectrometry.

    Science.gov (United States)

    Mollerup, Christian Brinch; Mardal, Marie; Dalsgaard, Petur Weihe; Linnet, Kristian; Barron, Leon Patrick

    2018-03-23

    Exact mass, retention time (RT), and collision cross section (CCS) are used as identification parameters in liquid chromatography coupled to ion mobility high resolution accurate mass spectrometry (LC-IM-HRMS). Targeted screening analyses are now more flexible and can be expanded for suspect and non-targeted screening. These allow for tentative identification of new compounds, and in-silico predicted reference values are used for improving confidence and filtering false-positive identifications. In this work, predictions of both RT and CCS values are performed with machine learning using artificial neural networks (ANNs). Prediction was based on molecular descriptors, 827 RTs, and 357 CCS values from pharmaceuticals, drugs of abuse, and their metabolites. ANN models for the prediction of RT or CCS separately were examined, and the potential to predict both from a single model was investigated for the first time. The optimized combined RT-CCS model was a four-layered multi-layer perceptron ANN, and the 95th prediction error percentiles were within 2 min RT error and 5% relative CCS error for the external validation set (n = 36) and the full RT-CCS dataset (n = 357). 88.6% (n = 733) of predicted RTs were within 2 min error for the full dataset. Overall, when using 2 min RT error and 5% relative CCS error, 91.9% (n = 328) of compounds were retained, while 99.4% (n = 355) were retained when using at least one of these thresholds. This combined prediction approach can therefore be useful for rapid suspect/non-targeted screening involving HRMS, and will support current workflows. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Rapid discrimination of Isaria javanica and Isaria poprawskii from Isaria spp. using high resolution DNA melting assays

    Science.gov (United States)

    The current study evaluates the potential of using high resolution DNA melting assays to discriminate species in the genus, Isaria. The study utilizes a previously identified 103 base pair PCR amplicon, which was reported to be selective for Isaria fumosorosea. Our study finds the amplicon selective...

  6. A case of acute spinal subdural hematoma with subarachnoid hemorrhage: Rapid spontaneous remission, relapse, and complete resolution

    Directory of Open Access Journals (Sweden)

    Michito Namekawa

    2017-06-01

    In addition to rostrocaudal spreading of bloody components in the subdural space, rupture of the hematoma into the subarachnoid space must have released pressure, compressing the spinal cord. In this case report, we also describe the serial MRI studies and note the limitations of the resolution of spinal MRI in the acute phase.

  7. Rapid Determination of Lymphogranuloma Venereum Serovars of Chlamydia trachomatis by Quantitative High-Resolution Melt Analysis (HRMA)

    Science.gov (United States)

    Stevens, Matthew P.; Garland, Suzanne M.; Zaia, Angelo M.; Tabrizi, Sepehr N.

    2012-01-01

    A quantitative high-resolution melt analysis assay was developed to differentiate lymphogranuloma venereum-causing serovars of Chlamydia trachomatis (L1 to L3) from other C. trachomatis serovars (D to K). The detection limit of this assay is approximately 10 copies per reaction, comparable to the limits of other quantitative-PCR-based methods. PMID:22933594

  8. A Procedure for the Rapid Determination of 226Ra and 228Ra in Drinking Water by Liquid Scintillation Counting

    International Nuclear Information System (INIS)

    2014-01-01

    Since 2004, the environment programme of the IAEA has included activities aimed at the development of a set of procedures for the determination of radionuclides in terrestrial environmental samples. Reliable, comparable and ‘fit for purpose’ results are essential requirements for any decision based on analytical measurements. For the analyst, tested and validated analytical procedures are extremely important tools for the production of such data. For maximum utility, such procedures should be comprehensive, clearly formulated and readily available to both the analyst and the customer. This publication describes a procedure for the rapid determination of 226 Ra and 228 Ra in drinking water. The determination of radium in drinking water is important for protecting human health, since the consumption of drinking water containing radium may lead to an accumulation in the body, contributing to the radiological dose. The method is based on the separation of 226 Ra and 228 Ra from interfering elements using PbSO 4 and Ba(Ra)SO 4 coprecipitation steps. The isotopes 226 Ra and 228 Ra are then determined by liquid scintillation counting. The procedure is expected to be of general use to a wide range of laboratories, including the laboratories of the Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) network, both in emergency situations and for routine environmental monitoring purposes. The method was established after an extensive review of papers from the scientific literature, and was tested and validated in terms of repeatability and trueness (relative bias) in accordance with International Organization for Standardization guidelines. Reproducibility tests were performed at expert laboratories. The calculation of massic activities, uncertainty budget, decision threshold and detection limit are also described

  9. High resolution and high sensitivity methods for oligosaccharide mapping and characterization by normal phase high performance liquid chromatography following derivatization with highly fluorescent anthranilic acid.

    Science.gov (United States)

    Anumula, K R; Dhume, S T

    1998-07-01

    Facile labeling of oligosaccharides (acidic and neutral) in a nonselective manner was achieved with highly fluorescent anthranilic acid (AA, 2-aminobenzoic acid) (more than twice the intensity of 2-aminobenzamide, AB) for specific detection at very high sensitivity. Quantitative labeling in acetate-borate buffered methanol (approximately pH 5.0) at 80 degreesC for 60 min resulted in negligible or no desialylation of the oligosaccharides. A high resolution high performance liquid chromatographic method was developed for quantitative oligosaccharide mapping on a polymeric-NH2bonded (Astec) column operating under normal phase and anion exchange (NP-HPAEC) conditions. For isolation of oligosaccharides from the map by simple evaporation, the chromatographic conditions developed use volatile acetic acid-triethylamine buffer (approximately pH 4.0) systems. The mapping and characterization technology was developed using well characterized standard glycoproteins. The fluorescent oligosaccharide maps were similar to the maps obtained by the high pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD), except that the fluorescent maps contained more defined peaks. In the map, the oligosaccharides separated into groups based on charge, size, linkage, and overall structure in a manner similar to HPAEC-PAD with contribution of -COOH function from the label, anthranilic acid. However, selectivity of the column for sialic acid linkages was different. A second dimension normal phase HPLC (NP-HPLC) method was developed on an amide column (TSK Gel amide-80) for separation of the AA labeled neutral complex type and isomeric structures of high mannose type oligosaccharides. The oligosaccharides labeled with AA are compatible with biochemical and biophysical techniques, and use of matrix assisted laser desorption mass spectrometry for rapid determination of oligosaccharide mass map of glycoproteins is demonstrated. High resolution of NP-HPAEC and NP-HPLC methods

  10. Application of High-Resolution Ultrasonic Spectroscopy for analysis of complex formulations. Compressibility of solutes and solute particles in liquid mixtures

    International Nuclear Information System (INIS)

    Buckin, V

    2012-01-01

    The paper describes key aspects of interpretation of compressibility of solutes in liquid mixtures obtained through high-resolution measurements of ultrasonic parameters. It examines the fundamental relationships between the characteristics of solutes and the contributions of solutes to compressibility of liquid mixtures expressed through apparent adiabatic compressibility of solutes, and adiabatic compressibility of solute particles. In addition, it analyses relationships between the adiabatic compressibility of solutes and the measured ultrasonic characteristics of mixtures. Especial attention is given to the effects of solvents on the measured adiabatic compressibility of solutes and on concentration increment of ultrasonic velocity of solutes in mixtures.

  11. Rapid spontaneous resolution and redistribution of acute subdural hematoma in a patient with chronic alcoholism: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, Edmund Yik Kong. E-mail: yktsui@hongkong.com; Fai Ma, Ka; Cheung, Yu Keung; Chan, Jimmy Hon Mo; Yuen, Ming Keung

    2000-10-01

    We report a case of a 54-year-old man who had documented traumatic acute subdural hematoma. He suffered from a transient episode of confusion and a follow-up CT scan of brain 6 h after the initial scan showed resolution and redistribution of the subdural hematoma. In this case report, we review the literature for the underlying pathophysiology of this uncommon phenomenon.

  12. Rapid spontaneous resolution and redistribution of acute subdural hematoma in a patient with chronic alcoholism: a case report

    International Nuclear Information System (INIS)

    Tsui, Edmund Yik Kong.; Fai Ma, Ka; Cheung, Yu Keung; Chan, Jimmy Hon Mo; Yuen, Ming Keung

    2000-01-01

    We report a case of a 54-year-old man who had documented traumatic acute subdural hematoma. He suffered from a transient episode of confusion and a follow-up CT scan of brain 6 h after the initial scan showed resolution and redistribution of the subdural hematoma. In this case report, we review the literature for the underlying pathophysiology of this uncommon phenomenon

  13. Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry

    International Nuclear Information System (INIS)

    Strano-Rossi, Sabina; Castrignanò, Erika; Anzillotti, Luca; Odoardi, Sara; De-Giorgio, Fabio; Bermejo, Ana; Pascali, Vincenzo L.

    2013-01-01

    Graphical abstract: -- Highlights: •LC–HRMS screening method for the detection of a variety of anabolics in hair. •Detection of unmetabolized anabolic steroids and their esters in hair matrix by simple keratin pretreatment. •Identification of target compounds by retention time, accurate mass and isotopic cluster. •Quantitative determination of detected compounds. •Possibility to a retrospective re-analysis of the acquired datafile in case a further analyte is to be screened. -- Abstract: A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography–high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg −1 , and limits of quantitation were 0.5 ng mg −1 for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg −1 , giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened

  14. Annotation of the human serum metabolome by coupling three liquid chromatography methods to high-resolution mass spectrometry.

    Science.gov (United States)

    Boudah, Samia; Olivier, Marie-Françoise; Aros-Calt, Sandrine; Oliveira, Lydie; Fenaille, François; Tabet, Jean-Claude; Junot, Christophe

    2014-09-01

    This work aims at evaluating the relevance and versatility of liquid chromatography coupled to high resolution mass spectrometry (LC/HRMS) for performing a qualitative and comprehensive study of the human serum metabolome. To this end, three different chromatographic systems based on a reversed phase (RP), hydrophilic interaction chromatography (HILIC) and a pentafluorophenylpropyl (PFPP) stationary phase were used, with detection in both positive and negative electrospray modes. LC/HRMS platforms were first assessed for their ability to detect, retain and separate 657 metabolite standards representative of the chemical families occurring in biological fluids. More than 75% were efficiently retained in either one LC-condition and less than 5% were exclusively retained by the RP column. These three LC/HRMS systems were then evaluated for their coverage of serum metabolome. The combination of RP, HILIC and PFPP based LC/HRMS methods resulted in the annotation of about 1328 features in the negative ionization mode, and 1358 in the positive ionization mode on the basis of their accurate mass and precise retention time in at least one chromatographic condition. Less than 12% of these annotations were shared by the three LC systems, which highlights their complementarity. HILIC column ensured the greatest metabolome coverage in the negative ionization mode, whereas PFPP column was the most effective in the positive ionization mode. Altogether, 192 annotations were confirmed using our spectral database and 74 others by performing MS/MS experiments. This resulted in the formal or putative identification of 266 metabolites, among which 59 are reported for the first time in human serum. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Strano-Rossi, Sabina, E-mail: sabina.stranorossi@rm.unicatt.it [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy); Castrignanò, Erika; Anzillotti, Luca; Odoardi, Sara; De-Giorgio, Fabio [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy); Bermejo, Ana [Institute of Legal Medicine, University of Santiago de Compostela, Av S. Francisco s/n, Santiago de Compostela (Spain); Pascali, Vincenzo L. [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy)

    2013-09-02

    Graphical abstract: -- Highlights: •LC–HRMS screening method for the detection of a variety of anabolics in hair. •Detection of unmetabolized anabolic steroids and their esters in hair matrix by simple keratin pretreatment. •Identification of target compounds by retention time, accurate mass and isotopic cluster. •Quantitative determination of detected compounds. •Possibility to a retrospective re-analysis of the acquired datafile in case a further analyte is to be screened. -- Abstract: A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography–high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg{sup −1}, and limits of quantitation were 0.5 ng mg{sup −1} for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg{sup −1}, giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened.

  16. Validation of the Mass-Extraction-Window for Quantitative Methods Using Liquid Chromatography High Resolution Mass Spectrometry.

    Science.gov (United States)

    Glauser, Gaétan; Grund, Baptiste; Gassner, Anne-Laure; Menin, Laure; Henry, Hugues; Bromirski, Maciej; Schütz, Frédéric; McMullen, Justin; Rochat, Bertrand

    2016-03-15

    A paradigm shift is underway in the field of quantitative liquid chromatography-mass spectrometry (LC-MS) analysis thanks to the arrival of recent high-resolution mass spectrometers (HRMS). The capability of HRMS to perform sensitive and reliable quantifications of a large variety of analytes in HR-full scan mode is showing that it is now realistic to perform quantitative and qualitative analysis with the same instrument. Moreover, HR-full scan acquisition offers a global view of sample extracts and allows retrospective investigations as virtually all ionized compounds are detected with a high sensitivity. In time, the versatility of HRMS together with the increasing need for relative quantification of hundreds of endogenous metabolites should promote a shift from triple-quadrupole MS to HRMS. However, a current "pitfall" in quantitative LC-HRMS analysis is the lack of HRMS-specific guidance for validated quantitative analyses. Indeed, false positive and false negative HRMS detections are rare, albeit possible, if inadequate parameters are used. Here, we investigated two key parameters for the validation of LC-HRMS quantitative analyses: the mass accuracy (MA) and the mass-extraction-window (MEW) that is used to construct the extracted-ion-chromatograms. We propose MA-parameters, graphs, and equations to calculate rational MEW width for the validation of quantitative LC-HRMS methods. MA measurements were performed on four different LC-HRMS platforms. Experimentally determined MEW values ranged between 5.6 and 16.5 ppm and depended on the HRMS platform, its working environment, the calibration procedure, and the analyte considered. The proposed procedure provides a fit-for-purpose MEW determination and prevents false detections.

  17. Rapid non-destructive quantitative estimation of urania/ thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shriwastwa, B.B.; Kumar, Anil; Raghunath, B.; Nair, M.R.; Abani, M.C.; Ramachandran, R.; Majumdar, S.; Ghosh, J.K

    2001-06-01

    A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO{sub 2}-UO{sub 2}) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign.

  18. A rapid method for measuring maximum density temperatures in water and aqueous solutions for the study of quantum zero point energy effects in these liquids

    International Nuclear Information System (INIS)

    Deeney, F A; O'Leary, J P

    2008-01-01

    The connection between quantum zero point fluctuations and a density maximum in water and in liquid He 4 has recently been established. Here we present a description of a simple and rapid method of determining the temperatures at which maximum densities in water and aqueous solutions occur. The technique is such as to allow experiments to be carried out in one session of an undergraduate laboratory thereby introducing students to the concept of quantum zero point energy

  19. Quantification of rifampicin in human plasma and cerebrospinal fluid by a highly sensitive and rapid liquid chromatographic–tandem mass spectrometric method

    OpenAIRE

    Srivastava, Abhishek; Waterhouse, David; Ardrey, Alison; Ward, Stephen A.

    2012-01-01

    A highly sensitive and rapid liquid chromatography tandem mass spectrometry (LC–MS/MS) method has been developed to measure the levels of the antitubercular drug rifampicin (RIF) in human plasma and cerebrospinal fluid (CSF). The analyte and internal standard (IS) were isolated from plasma and CSF by a simple organic solvent based precipitation of proteins followed by centrifugation. Detection was carried out by electrospray positive ionization mass spectrometry in the multiple-reaction monit...

  20. First application of liquid-metal-jet sources for small-animal imaging: High-resolution CT and phase-contrast tumor demarcation

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Daniel H.; Lundstroem, Ulf; Burvall, Anna; Hertz, Hans M. [Department of Applied Physics, KTH Royal Institute of Technology/Albanova, 10691 Stockholm (Sweden); Westermark, Ulrica K.; Arsenian Henriksson, Marie [Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, 17177 Stockholm (Sweden)

    2013-02-15

    Purpose: Small-animal studies require images with high spatial resolution and high contrast due to the small scale of the structures. X-ray imaging systems for small animals are often limited by the microfocus source. Here, the authors investigate the applicability of liquid-metal-jet x-ray sources for such high-resolution small-animal imaging, both in tomography based on absorption and in soft-tissue tumor imaging based on in-line phase contrast. Methods: The experimental arrangement consists of a liquid-metal-jet x-ray source, the small-animal object on a rotating stage, and an imaging detector. The source-to-object and object-to-detector distances are adjusted for the preferred contrast mechanism. Two different liquid-metal-jet sources are used, one circulating a Ga/In/Sn alloy and the other an In/Ga alloy for higher penetration through thick tissue. Both sources are operated at 40-50 W electron-beam power with {approx}7 {mu}m x-ray spots, providing high spatial resolution in absorption imaging and high spatial coherence for the phase-contrast imaging. Results: High-resolution absorption imaging is demonstrated on mice with CT, showing 50 {mu}m bone details in the reconstructed slices. High-resolution phase-contrast soft-tissue imaging shows clear demarcation of mm-sized tumors at much lower dose than is required in absorption. Conclusions: This is the first application of liquid-metal-jet x-ray sources for whole-body small-animal x-ray imaging. In absorption, the method allows high-resolution tomographic skeletal imaging with potential for significantly shorter exposure times due to the power scalability of liquid-metal-jet sources. In phase contrast, the authors use a simple in-line arrangement to show distinct tumor demarcation of few-mm-sized tumors. This is, to their knowledge, the first small-animal tumor visualization with a laboratory phase-contrast system.

  1. Rapid method for the analysis of itraconazole and hydroxyitraconazole in serum by high-performance liquid chromatography

    NARCIS (Netherlands)

    Compas, D; Touw, D J; de Goede, P N

    1996-01-01

    An assay for the determination of itraconazole and its active metabolite hydroxyitraconazole in serum has been developed, using ketoconazole as internal standard. The procedure involved a one-step liquid-liquid extraction of the drug, its metabolite and the internal standard, followed by their

  2. Rapid determination of benzodiazepines, zolpidem and their metabolites in urine using direct injection liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Jeong, Yu-Dong; Kim, Min Kyung; Suh, Sung Ill; In, Moon Kyo; Kim, Jin Young; Paeng, Ki-Jung

    2015-12-01

    Benzodiazepines and zolpidem are generally prescribed as sedative, hypnotics, anxiolytics or anticonvulsants. These drugs, however, are frequently misused in drug-facilitated crime. Therefore, a rapid and simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for identification and quantification of benzodiazepines, zolpidem and their metabolites in urine using deuterium labeled internal standards (IS). Urine samples (120 μL) mixed with 80 μL of the IS solution were centrifuged. An aliquot (5 μL) of the sample solution was directly injected into the LC-MS/MS system for analysis. The mobile phases consisted of water and acetonitrile containing 2mM ammonium trifluoroacetate and 0.2% acetic acid. The analytical column was a Zorbax SB-C18 (100 mm × 2.1 mm i.d., 3.5 μm, Agilent). The separation and detection of 18 analytes were achieved within 10 min. Calibration curves were linear over the concentration ranges of 0.5-20 ng/mL (zolpidem), 1.0-40 ng/mL (flurazepam and temazepam), 2.5-100 ng/mL (7-aminoclonazepam, 1-hydroxymidazolam, midazolam, flunitrazepam and alprazolam), 5.0-200 ng/mL (zolpidem phenyl-4-carboxylic acid, α-hydroxyalprazolam, oxazepam, nordiazepam, triazolam, diazepam and α-hydroxytriazolam), 10-400 ng/mL (lorazepam and desalkylflurazepam) and 10-100 ng/mL (N-desmethylflunitrazepam) with the coefficients of determination (r(2)) above 0.9971. The dilution integrity of the analytes was examined for supplementation of short linear range. Dilution precision and accuracy were tested using two, four and ten-folds dilutions and they ranged from 3.7 to 14.4% and -12.8 to 12.5%, respectively. The process efficiency for this method was 63.0-104.6%. Intra- and inter-day precisions were less than 11.8% and 9.1%, while intra- and inter-day accuracies were less than -10.0 to 8.2%, respectively. The lower limits of quantification were lower than 10 ng/mL for each analyte. The applicability of the developed method was successfully

  3. R&D proposal to DRDC fast EM calorimeter with excellent photon angular resolution and energy resolution using scintillating noble liquids

    CERN Document Server

    Chen, M; Sumorok, K; Zhang, X; Gaudreau, M P J; Akimov, D Y; Bolozdynya, A I; Churakov, D; Chernyshov, V; Koutchenkov, A; Kovalenko, A; Kuzichev, V F; Lamkov, V A; Lebedenko, V; Gusev, L; Safronov, G A; Sheinkman, V A; Smirnov, G; Krasnokutsky, R N; Shuvalov, R S; Fedyakin, N N; Sushkov, V V; Akopyan, M V; Gougas, Andreas; Pevsner, A; CERN. Geneva. Detector Research and Development Committee

    1993-01-01

    Recent test beam data have shown fast and large signals for LKr, mixed with >1% LXe. Excellent uniformity in LKr and LXe was achieved over a 37 cm long cell. CsI cathode works well inside LKr/LXe with O(1%) resolution at 5 MeV. Precision calibration in-situ has been demonstrated. Scintillating LKr/LXe detectors are sufficiently radiation hard for LHC environment. These new developments simplify the construction of prototype LKr calorimeter, to demonstrate the superior e/gamma energy resolution and the determination of photon direction using longitudinal and transverse segmentations, which are vital for the detection of the multi-photon states. The constant term in the energy resolution is small, the electronics noise is negligible due to the large signal size. The overall pion/electron suppression is expected to be better than 10-4.

  4. Rapid resolution of chronic shoulder pain classified as derangement using the McKenzie method: a case series

    Science.gov (United States)

    Aytona, Maria Corazon; Dudley, Karlene

    2013-01-01

    The McKenzie method, also known as Mechanical Diagnosis and Therapy (MDT), is primarily recognized as an evaluation and treatment method for the spine. However, McKenzie suggested that this method could also be applied to the extremities. Derangement is an MDT classification defined as an anatomical disturbance in the normal resting position of the joint, and McKenzie proposed that repeated movements could be applied to reduce internal joint displacement and rapidly reduce derangement symptoms. However, the current literature on MDT application to shoulder disorders is limited. Here, we present a case series involving four patients with chronic shoulder pain from a duration of 2–18 months classified as derangement and treated using MDT principles. Each patient underwent mechanical assessment and was treated with repeated movements based on their directional preference. All patients demonstrated rapid and clinically significant improvement in baseline measures and the disabilities of the arm, shoulder, and hand (QuickDASH) scores from an average of 38% at initial evaluation to 5% at discharge within 3–5 visits. Our findings suggest that MDT may be an effective treatment approach for shoulder pain. PMID:24421633

  5. Comparing the Dry Season In-Situ Leaf Area Index (LAI Derived from High-Resolution RapidEye Imagery with MODIS LAI in a Namibian Savanna

    Directory of Open Access Journals (Sweden)

    Manuel J. Mayr

    2015-04-01

    Full Text Available The Leaf Area Index (LAI is one of the most frequently applied measures to characterize vegetation and its dynamics and functions with remote sensing. Satellite missions, such as NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS operationally produce global datasets of LAI. Due to their role as an input to large-scale modeling activities, evaluation and verification of such datasets are of high importance. In this context, savannas appear to be underrepresented with regards to their heterogeneous appearance (e.g., tree/grass-ratio, seasonality. Here, we aim to examine the LAI in a heterogeneous savanna ecosystem located in Namibia’s Owamboland during the dry season. Ground measurements of LAI are used to derive a high-resolution LAI model with RapidEye satellite data. This model is related to the corresponding MODIS LAI/FPAR (Fraction of Absorbed Photosynthetically Active Radiation scene (MOD15A2 in order to evaluate its performance at the intended annual minimum during the dry season. Based on a field survey we first assessed vegetation patterns from species composition and elevation for 109 sites. Secondly, we measured in situ LAI to quantitatively estimate the available vegetation (mean = 0.28. Green LAI samples were then empirically modeled (LAImodel with high resolution RapidEye imagery derived Difference Vegetation Index (DVI using a linear regression (R2 = 0.71. As indicated by several measures of model performance, the comparison with MOD15A2 revealed moderate consistency mostly due to overestimation by the aggregated LAImodel. Model constraints aside, this study may point to important issues for MOD15A2 in savannas concerning the underlying MODIS Land Cover product (MCD12Q1 and a potential adjustment by means of the MODIS Burned Area product (MCD45A1.

  6. A Prototype Regional GSI-based EnKF-Variational Hybrid Data Assimilation System for the Rapid Refresh Forecasting System: Dual-Resolution Implementation and Testing Results

    Science.gov (United States)

    Pan, Yujie; Xue, Ming; Zhu, Kefeng; Wang, Mingjun

    2018-05-01

    A dual-resolution (DR) version of a regional ensemble Kalman filter (EnKF)-3D ensemble variational (3DEnVar) coupled hybrid data assimilation system is implemented as a prototype for the operational Rapid Refresh forecasting system. The DR 3DEnVar system combines a high-resolution (HR) deterministic background forecast with lower-resolution (LR) EnKF ensemble perturbations used for flow-dependent background error covariance to produce a HR analysis. The computational cost is substantially reduced by running the ensemble forecasts and EnKF analyses at LR. The DR 3DEnVar system is tested with 3-h cycles over a 9-day period using a 40/˜13-km grid spacing combination. The HR forecasts from the DR hybrid analyses are compared with forecasts launched from HR Gridpoint Statistical Interpolation (GSI) 3D variational (3DVar) analyses, and single LR hybrid analyses interpolated to the HR grid. With the DR 3DEnVar system, a 90% weight for the ensemble covariance yields the lowest forecast errors and the DR hybrid system clearly outperforms the HR GSI 3DVar. Humidity and wind forecasts are also better than those launched from interpolated LR hybrid analyses, but the temperature forecasts are slightly worse. The humidity forecasts are improved most. For precipitation forecasts, the DR 3DEnVar always outperforms HR GSI 3DVar. It also outperforms the LR 3DEnVar, except for the initial forecast period and lower thresholds.

  7. Rapid high-resolution spin- and angle-resolved photoemission spectroscopy with pulsed laser source and time-of-flight spectrometer

    Science.gov (United States)

    Gotlieb, K.; Hussain, Z.; Bostwick, A.; Lanzara, A.; Jozwiak, C.

    2013-09-01

    A high-efficiency spin- and angle-resolved photoemission spectroscopy (spin-ARPES) spectrometer is coupled with a laboratory-based laser for rapid high-resolution measurements. The spectrometer combines time-of-flight (TOF) energy measurements with low-energy exchange scattering spin polarimetry for high detection efficiencies. Samples are irradiated with fourth harmonic photons generated from a cavity-dumped Ti:sapphire laser that provides high photon flux in a narrow bandwidth, with a pulse timing structure ideally matched to the needs of the TOF spectrometer. The overall efficiency of the combined system results in near-EF spin-resolved ARPES measurements with an unprecedented combination of energy resolution and acquisition speed. This allows high-resolution spin measurements with a large number of data points spanning multiple dimensions of interest (energy, momentum, photon polarization, etc.) and thus enables experiments not otherwise possible. The system is demonstrated with spin-resolved energy and momentum mapping of the L-gap Au(111) surface states, a prototypical Rashba system. The successful integration of the spectrometer with the pulsed laser system demonstrates its potential for simultaneous spin- and time-resolved ARPES with pump-probe based measurements.

  8. Rapid, high-resolution measurement of leaf area and leaf orientation using terrestrial LiDAR scanning data

    International Nuclear Information System (INIS)

    Bailey, Brian N; Mahaffee, Walter F

    2017-01-01

    The rapid evolution of high performance computing technology has allowed for the development of extremely detailed models of the urban and natural environment. Although models can now represent sub-meter-scale variability in environmental geometry, model users are often unable to specify the geometry of real domains at this scale given available measurements. An emerging technology in this field has been the use of terrestrial LiDAR scanning data to rapidly measure the three-dimensional geometry of trees, such as the distribution of leaf area. However, current LiDAR methods suffer from the limitation that they require detailed knowledge of leaf orientation in order to translate projected leaf area into actual leaf area. Common methods for measuring leaf orientation are often tedious or inaccurate, which places constraints on the LiDAR measurement technique. This work presents a new method to simultaneously measure leaf orientation and leaf area within an arbitrarily defined volume using terrestrial LiDAR data. The novelty of the method lies in the direct measurement of the fraction of projected leaf area G from the LiDAR data which is required to relate projected leaf area to total leaf area, and in the new way in which radiation transfer theory is used to calculate leaf area from the LiDAR data. The method was validated by comparing LiDAR-measured leaf area to (1) ‘synthetic’ or computer-generated LiDAR data where the exact area was known, and (2) direct measurements of leaf area in the field using destructive sampling. Overall, agreement between the LiDAR and reference measurements was very good, showing a normalized root-mean-squared-error of about 15% for the synthetic tests, and 13% in the field. (paper)

  9. Handling time misalignment and rank deficiency in liquid chromatography by multivariate curve resolution: Quantitation of five biogenic amines in fish.

    Science.gov (United States)

    Pinto, Licarion; Díaz Nieto, César Horacio; Zón, María Alicia; Fernández, Héctor; de Araujo, Mario Cesar Ugulino

    2016-01-01

    Biogenic amines (BAs) are used for identifying spoilage in food. The most common are tryptamine (TRY), 2-phenylethylamine (PHE), putrescine (PUT), cadaverine (CAD) and histamine (HIS). Due to lack of chromophores, chemical derivatization with dansyl was employed to analyze these BAs using high performance liquid chromatography with a diode array detector (HPLC-DAD). However, the derivatization reaction occurs with any primary or secondary amine, leading to co-elution of analytes and interferents with identical spectral profiles, and thus causing rank deficiency. When the spectral profile is the same and peak misalignment is present on the chromatographic runs, it is not possible to handle the data only with Multivariate Curve Resolution and Alternative Least Square (MCR-ALS), by augmenting the time, or the spectral mode. A way to circumvent this drawback is to receive information from another detector that leads to a selective profile for the analyte. To overcome both problems, (tri-linearity break in time, and spectral mode), this paper proposes a new analytical methodology for fast quantitation of these BAs in fish with HPLC-DAD by using the icoshift algorithm for temporal misalignment correction before MCR-ALS spectral mode augmented treatment. Limits of detection, relative errors of prediction (REP) and average recoveries, ranging from 0.14 to 0.50 µg mL(-1), 3.5-8.8% and 88.08%-99.68%, respectively. These are outstanding results obtained, reaching quantification limits for the five BAs much lower than those established by the Food and Agriculture Organization of the United Nations and World Health Organization (FAO/WHO), and the European Food Safety Authority (EFSA), all without any pre-concentration steps. The concentrations of BAs in fish samples ranged from 7.82 to 29.41 µg g(-1), 8.68-25.95 µg g(-1), 4.76-28.54 µg g(-1), 5.18-39.95 µg g(-1) and 1.45-52.62 µg g(-1) for TRY, PHE, PUT, CAD, and HIS, respectively. In addition, the proposed method spends

  10. High-resolution two-dimensional liquid chromatography analysis of key linker drug intermediate used in antibody drug conjugates.

    Science.gov (United States)

    Venkatramani, C J; Huang, Shu Rong; Al-Sayah, Mohammad; Patel, Ila; Wigman, Larry

    2017-10-27

    In this manuscript, the application of high-resolution sampling (HRS) two-dimensional liquid chromatography (2D-LC) in the detailed analysis of key linker drug intermediate is presented. Using HRS, selected regions of the primary column eluent were transferred to a secondary column with fidelity enabling qualitative and quantitative analysis of linker drugs. The primary column purity of linker drug intermediate ranged from 88.9% to 94.5% and the secondary column purity ranged from 99.6% to 99.9%, showing lot-to-lot variability, significant differences between the three lots, and substantiating the synthetic and analytical challenges of ADCs. Over 15 impurities co-eluting with the linker drug intermediate in the primary dimension were resolved in the secondary dimension. The concentrations of most of these impurities were over three orders of magnitude lower than the linker drug. Effective peak focusing and high-speed secondary column analysis resulted in sharp peaks in the secondary dimension, improving the signal-to-noise ratios. The sensitivity of 2D-LC separation was over five fold better than conventional HPLC separation. The limit of quantitation (LOQ) was less than 0.01%. Many peaks originating from primary dimension were resolved into multiple components in the complementary secondary dimension, demonstrating the complexity of these samples. The 2D-LC was highly reproducible, showing good precision between runs with%RSD of peak areas less than 0.1 for the main component. The absolute difference in the peak areas of impurities less than 0.1% were within ±0.01% and for impurities in the range of 0.1%-0.3%, the absolute difference were ±0.02%, which are comparable to 1D-LC. The overall purity of the linker drug intermediate was determined from the product of primary and secondary column purity (HPLC Purity=%peak area of main component in the primary dimension×%peak area of main component in the secondary dimension). Additionally, the 2D-LC separation enables

  11. [Rapid detection of hot spot mutations of FGFR3 gene with PCR-high resolution melting assay].

    Science.gov (United States)

    Li, Shan; Wang, Han; Su, Hua; Gao, Jinsong; Zhao, Xiuli

    2017-08-10

    To identify the causative mutations in five individuals affected with dyschondroplasia and develop an efficient procedure for detecting hot spot mutations of the FGFR3 gene. Genomic DNA was extracted from peripheral blood samples with a standard phenol/chloroform method. PCR-Sanger sequencing was used to analyze the causative mutations in the five probands. PCR-high resolution melting (HRM) was developed to detect the identified mutations. A c.1138G>A mutation in exon 8 was found in 4 probands, while a c.1620C>G mutation was found in exon 11 of proband 5 whom had a mild phenotype. All patients were successfully distinguished from healthy controls with the PCR-HRM method. The results of HRM analysis were highly consistent with that of Sanger sequencing. The Gly380Arg and Asn540Lys are hot spot mutations of the FGFR3 gene among patients with ACH/HCH. PCR-HRM analysis is more efficient for detecting hot spot mutations of the FGFR3 gene.

  12. Nanobodies: site-specific labeling for super-resolution imaging, rapid epitope-mapping and native protein complex isolation

    Science.gov (United States)

    Pleiner, Tino; Bates, Mark; Trakhanov, Sergei; Lee, Chung-Tien; Schliep, Jan Erik; Chug, Hema; Böhning, Marc; Stark, Holger; Urlaub, Henning; Görlich, Dirk

    2015-01-01

    Nanobodies are single-domain antibodies of camelid origin. We generated nanobodies against the vertebrate nuclear pore complex (NPC) and used them in STORM imaging to locate individual NPC proteins with nanobody sequence and labeled the resulting proteins with fluorophore-maleimides. As nanobodies are normally stabilized by disulfide-bonded cysteines, this appears counterintuitive. Yet, our analysis showed that this caused no folding problems. Compared to traditional NHS ester-labeling of lysines, the cysteine-maleimide strategy resulted in far less background in fluorescence imaging, it better preserved epitope recognition and it is site-specific. We also devised a rapid epitope-mapping strategy, which relies on crosslinking mass spectrometry and the introduced ectopic cysteines. Finally, we used different anti-nucleoporin nanobodies to purify the major NPC building blocks – each in a single step, with native elution and, as demonstrated, in excellent quality for structural analysis by electron microscopy. The presented strategies are applicable to any nanobody and nanobody-target. DOI: http://dx.doi.org/10.7554/eLife.11349.001 PMID:26633879

  13. Rapid, topology-based particle tracking for high-resolution measurements of large complex 3D motion fields.

    Science.gov (United States)

    Patel, Mohak; Leggett, Susan E; Landauer, Alexander K; Wong, Ian Y; Franck, Christian

    2018-04-03

    Spatiotemporal tracking of tracer particles or objects of interest can reveal localized behaviors in biological and physical systems. However, existing tracking algorithms are most effective for relatively low numbers of particles that undergo displacements smaller than their typical interparticle separation distance. Here, we demonstrate a single particle tracking algorithm to reconstruct large complex motion fields with large particle numbers, orders of magnitude larger than previously tractably resolvable, thus opening the door for attaining very high Nyquist spatial frequency motion recovery in the images. Our key innovations are feature vectors that encode nearest neighbor positions, a rigorous outlier removal scheme, and an iterative deformation warping scheme. We test this technique for its accuracy and computational efficacy using synthetically and experimentally generated 3D particle images, including non-affine deformation fields in soft materials, complex fluid flows, and cell-generated deformations. We augment this algorithm with additional particle information (e.g., color, size, or shape) to further enhance tracking accuracy for high gradient and large displacement fields. These applications demonstrate that this versatile technique can rapidly track unprecedented numbers of particles to resolve large and complex motion fields in 2D and 3D images, particularly when spatial correlations exist.

  14. High resolution melting curve analysis as a new tool for rapid identification of canine parvovirus type 2 strains.

    Science.gov (United States)

    Bingga, Gali; Liu, Zhicheng; Zhang, Jianfeng; Zhu, Yujun; Lin, Lifeng; Ding, Shuangyang; Guo, Pengju

    2014-01-01

    A high resolution melting (HRM) curve method was developed to identify canine parvovirus type 2 (CPV-2) strains by nested PCR. Two sets of primers, CPV-426F/426R and CPV-87R/87F, were designed that amplified a 52 bp and 53 bp product from the viral VP2 capsid gene. The region amplified by CPV-426F/426R included the A4062G and T4064A mutations in CPV-2a, CPV-2b and CPV-2c. The region amplified by CPV-87F/87R included the A3045T mutation in the vaccine strains of CPV-2 and CPV-2a, CPV-2b and CPV-2c. Faecal samples were obtained from 30 dogs that were CPV antigen-positive. The DNA was isolated from the faecal samples and PCR-amplified using the two sets of primers, and genotyped by HRM curve analysis. The PCR-HRM assay was able to distinguish single nucleotide polymorphisms between CPV-2a, CPV-2b and CPV-2c using CPV-426F/426R. CPV-2a was distinguished from CPV-2b and CPV-2c by differences in the melting temperature. CPV-2b and CPV-2c could be distinguished based on the shape of the melting curve after generating heteroduplexes using a CPV-2b reference sample. The vaccine strains of CPV-2 were identified using CPV-87F/87R. Conventional methods for genotyping CPV strains are labor intensive, expensive or time consuming; the present PCR-based HRM assay might be an attractive alternative. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Rapid Classification and Identification of Multiple Microorganisms with Accurate Statistical Significance via High-Resolution Tandem Mass Spectrometry.

    Science.gov (United States)

    Alves, Gelio; Wang, Guanghui; Ogurtsov, Aleksey Y; Drake, Steven K; Gucek, Marjan; Sacks, David B; Yu, Yi-Kuo

    2018-06-05

    Rapid and accurate identification and classification of microorganisms is of paramount importance to public health and safety. With the advance of mass spectrometry (MS) technology, the speed of identification can be greatly improved. However, the increasing number of microbes sequenced is complicating correct microbial identification even in a simple sample due to the large number of candidates present. To properly untwine candidate microbes in samples containing one or more microbes, one needs to go beyond apparent morphology or simple "fingerprinting"; to correctly prioritize the candidate microbes, one needs to have accurate statistical significance in microbial identification. We meet these challenges by using peptide-centric representations of microbes to better separate them and by augmenting our earlier analysis method that yields accurate statistical significance. Here, we present an updated analysis workflow that uses tandem MS (MS/MS) spectra for microbial identification or classification. We have demonstrated, using 226 MS/MS publicly available data files (each containing from 2500 to nearly 100,000 MS/MS spectra) and 4000 additional MS/MS data files, that the updated workflow can correctly identify multiple microbes at the genus and often the species level for samples containing more than one microbe. We have also shown that the proposed workflow computes accurate statistical significances, i.e., E values for identified peptides and unified E values for identified microbes. Our updated analysis workflow MiCId, a freely available software for Microorganism Classification and Identification, is available for download at https://www.ncbi.nlm.nih.gov/CBBresearch/Yu/downloads.html . Graphical Abstract ᅟ.

  16. Modeling the Rapid Boil-Off of a Cryogenic Liquid When Injected into a Low Pressure Cavity

    Science.gov (United States)

    Lira, Eric

    2016-01-01

    Many launch vehicle cryogenic applications require the modeling of injecting a cryogenic liquid into a low pressure cavity. The difficulty of such analyses lies in accurately predicting the heat transfer coefficient between the cold liquid and a warm wall in a low pressure environment. The heat transfer coefficient and the behavior of the liquid is highly dependent on the mass flow rate into the cavity, the cavity wall temperature and the cavity volume. Testing was performed to correlate the modeling performed using Thermal Desktop and Sinda Fluint Thermal and Fluids Analysis Software. This presentation shall describe a methodology to model the cryogenic process using Sinda Fluint, a description of the cryogenic test set up, a description of the test procedure and how the model was correlated to match the test results.

  17. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A., E-mail: abazylak@mie.utoronto.ca [Dept. of Mechanical & Industrial Engineering, Faculty of Applied Science & Engineering, University of Toronto, Toronto, Ontario (Canada); Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N. [Canadian Light Source, Saskatoon, Saskatchewan (Canada); Tabuchi, Y.; Kotaka, T. [EV System Laboratory, Research Division 2, Nissan Motor Co., Ltd., Yokosuka, Kanagawa (Japan)

    2016-07-27

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  18. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    International Nuclear Information System (INIS)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A.; Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N.; Tabuchi, Y.; Kotaka, T.

    2016-01-01

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  19. Rapid Calibration of High Resolution Geologic Models to Dynamic Data Using Inverse Modeling: Field Application and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Akhil Datta-Gupta

    2008-03-31

    Streamline-based assisted and automatic history matching techniques have shown great potential in reconciling high resolution geologic models to production data. However, a major drawback of these approaches has been incompressibility or slight compressibility assumptions that have limited applications to two-phase water-oil displacements only. We propose an approach to history matching three-phase flow using a novel compressible streamline formulation and streamline-derived analytic sensitivities. First, we utilize a generalized streamline model to account for compressible flow by introducing an 'effective density' of total fluids along streamlines. Second, we analytically compute parameter sensitivities that define the relationship between the reservoir properties and the production response, viz. water-cut and gas/oil ratio (GOR). These sensitivities are an integral part of history matching, and streamline models permit efficient computation of these sensitivities through a single flow simulation. We calibrate geologic models to production data by matching the water-cut and gas/oil ratio using our previously proposed generalized travel time inversion (GTTI) technique. For field applications, however, the highly non-monotonic profile of the gas/oil ratio data often presents a challenge to this technique. In this work we present a transformation of the field production data that makes it more amenable to GTTI. Further, we generalize the approach to incorporate bottom-hole flowing pressure during three-phase history matching. We examine the practical feasibility of the method using a field-scale synthetic example (SPE-9 comparative study) and a field application. Recently Ensemble Kalman Filtering (EnKF) has gained increased attention for history matching and continuous reservoir model updating using data from permanent downhole sensors. It is a sequential Monte-Carlo approach that works with an ensemble of reservoir models. Specifically, the method

  20. Functional Durability of a Quartz Crystal Microbalance Sensor for the Rapid Detection of Salmonella in Liquids from Poultry Packaging

    National Research Council Canada - National Science Library

    Olsen, Eric

    2000-01-01

    .... A rapid, sensitive (350 +/- 150 cells ml/cm) quartz crystal microbalance biosensor, layered with heat-treated anti-Salmonella-phospholipid monolayers by the Langmuir-Blodgett technique, has been evaluated by immersion testing in chicken exudate...

  1. Handling time misalignment and rank deficiency in liquid chromatography by multivariate curve resolution: Quantitation of five biogenic amines in fish

    International Nuclear Information System (INIS)

    Pinto, Licarion; Díaz Nieto, César Horacio; Zón, María Alicia; Fernández, Héctor; Ugulino de Araujo, Mario Cesar

    2016-01-01

    Biogenic amines (BAs) are used for identifying spoilage in food. The most common are tryptamine (TRY), 2-phenylethylamine (PHE), putrescine (PUT), cadaverine (CAD) and histamine (HIS). Due to lack of chromophores, chemical derivatization with dansyl was employed to analyze these BAs using high performance liquid chromatography with a diode array detector (HPLC-DAD). However, the derivatization reaction occurs with any primary or secondary amine, leading to co-elution of analytes and interferents with identical spectral profiles, and thus causing rank deficiency. When the spectral profile is the same and peak misalignment is present on the chromatographic runs, it is not possible to handle the data only with Multivariate Curve Resolution and Alternative Least Square (MCR-ALS), by augmenting the time, or the spectral mode. A way to circumvent this drawback is to receive information from another detector that leads to a selective profile for the analyte. To overcome both problems, (tri-linearity break in time, and spectral mode), this paper proposes a new analytical methodology for fast quantitation of these BAs in fish with HPLC-DAD by using the icoshift algorithm for temporal misalignment correction before MCR-ALS spectral mode augmented treatment. Limits of detection, relative errors of prediction (REP) and average recoveries, ranging from 0.14 to 0.50 µg mL"−"1, 3.5–8.8% and 88.08%–99.68%, respectively. These are outstanding results obtained, reaching quantification limits for the five BAs much lower than those established by the Food and Agriculture Organization of the United Nations and World Health Organization (FAO/WHO), and the European Food Safety Authority (EFSA), all without any pre-concentration steps. The concentrations of BAs in fish samples ranged from 7.82 to 29.41 µg g"−"1, 8.68–25.95 µg g"−"1, 4.76–28.54 µg g"−"1, 5.18–39.95 µg g"−"1 and 1.45–52.62 µg g"−"1 for TRY, PHE, PUT, CAD, and HIS, respectively. In

  2. Handling time misalignment and rank deficiency in liquid chromatography by multivariate curve resolution: Quantitation of five biogenic amines in fish

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Licarion [Laboratório de Automação e Instrumentação em Química Analítica e Quimiometria (LAQA), Universidade Federal da Paraíba, CCEN, Departamento de Química, Caixa Postal 5093, CEP 58051-970, João Pessoa, PB (Brazil); Díaz Nieto, César Horacio; Zón, María Alicia; Fernández, Héctor [Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, 5800, Río Cuarto (Argentina); Ugulino de Araujo, Mario Cesar, E-mail: laqa@quimica.ufpb.br [Laboratório de Automação e Instrumentação em Química Analítica e Quimiometria (LAQA), Universidade Federal da Paraíba, CCEN, Departamento de Química, Caixa Postal 5093, CEP 58051-970, João Pessoa, PB (Brazil)

    2016-01-01

    Biogenic amines (BAs) are used for identifying spoilage in food. The most common are tryptamine (TRY), 2-phenylethylamine (PHE), putrescine (PUT), cadaverine (CAD) and histamine (HIS). Due to lack of chromophores, chemical derivatization with dansyl was employed to analyze these BAs using high performance liquid chromatography with a diode array detector (HPLC-DAD). However, the derivatization reaction occurs with any primary or secondary amine, leading to co-elution of analytes and interferents with identical spectral profiles, and thus causing rank deficiency. When the spectral profile is the same and peak misalignment is present on the chromatographic runs, it is not possible to handle the data only with Multivariate Curve Resolution and Alternative Least Square (MCR-ALS), by augmenting the time, or the spectral mode. A way to circumvent this drawback is to receive information from another detector that leads to a selective profile for the analyte. To overcome both problems, (tri-linearity break in time, and spectral mode), this paper proposes a new analytical methodology for fast quantitation of these BAs in fish with HPLC-DAD by using the icoshift algorithm for temporal misalignment correction before MCR-ALS spectral mode augmented treatment. Limits of detection, relative errors of prediction (REP) and average recoveries, ranging from 0.14 to 0.50 µg mL{sup −1}, 3.5–8.8% and 88.08%–99.68%, respectively. These are outstanding results obtained, reaching quantification limits for the five BAs much lower than those established by the Food and Agriculture Organization of the United Nations and World Health Organization (FAO/WHO), and the European Food Safety Authority (EFSA), all without any pre-concentration steps. The concentrations of BAs in fish samples ranged from 7.82 to 29.41 µg g{sup −1}, 8.68–25.95 µg g{sup −1}, 4.76–28.54 µg g{sup −1}, 5.18–39.95 µg g{sup −1} and 1.45–52.62 µg g{sup −1} for TRY, PHE, PUT, CAD, and

  3. Development of a new screening method for the detection of antibiotic residues in muscle tissues using liquid chromatography and high resolution mass spectrometry with a LC-LTQ-Orbitrap instrument.

    Science.gov (United States)

    Hurtaud-Pessel, D; Jagadeshwar-Reddy, T; Verdon, E

    2011-10-01

    A liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was developed for screening meat for a wide range of antibiotics used in veterinary medicine. Full-scan mode under high resolution mass spectral conditions using an LTQ-Orbitrap mass spectrometer with resolving power 60,000 full width at half maximum (FWHM) was applied for analysis of the samples. Samples were prepared using two extraction protocols prior to LC-HRMS analysis. The scope of the method focuses on screening the following main families of antibacterial veterinary drugs: penicillins, cephalosporins, sulfonamides, macrolides, tetracyclines, aminoglucosides and quinolones. Compounds were successfully identified in spiked samples from their accurate mass and LC retention times from the acquired full-scan chromatogram. Automated data processing using ToxId software allowed rapid treatment of the data. Analyses of muscle tissues from real samples collected from antibiotic-treated animals was carried out using the above methodology and antibiotic residues were identified unambiguously. Further analysis of the data for real samples allowed the identification of the targeted antibiotic residues but also non-targeted compounds, such as some of their metabolites.

  4. Rapid Analysis of Apolar Low Molecular Weight Constituents in Wood Using High Pressure Liquid Chromatography with Evaporative Light Scattering Detection

    NARCIS (Netherlands)

    Claassen, F.W.; Haar, van de C.; Beek, van T.A.; Dorado, J.; Martinez-Inigo, M.; Sierra-Alvarez, R.

    2000-01-01

    A new high pressure liquid chromatographic method with evaporative light scattering detection was developed for the qualitative and quantitative analysis of apolar, low molecular weight constituents in wood. The wood extractives were obtained by means of a 6 h Soxhlet extraction with acetone. The

  5. Simple, rapid, and sensitive liquid chromatography-fluorescence method for the quantification of tranexamic acid in blood

    NARCIS (Netherlands)

    Huertas-Pérez, José Fernando; Heger, Michal; Dekker, Henk; Krabbe, Hans; Lankelma, Jan; Ariese, Freek

    2007-01-01

    Tranexamic acid (TA) is a synthetic antifibrinolytic agent that is being considered as a candidate adjuvant drug for site-specific pharmaco-laser therapy of port wine stains. For drug utility studies, a high-performance liquid chromatography (HPLC)-fluorescence method was developed for the

  6. A multiple-dimension liquid chromatography coupled with mass spectrometry data strategy for the rapid discovery and identification of unknown compounds from a Chinese herbal formula (Er-xian decoction).

    Science.gov (United States)

    Wang, Caihong; Zhang, Jinlan; Wu, Caisheng; Wang, Zhe

    2017-10-06

    It is very important to rapidly discover and identify the multiple components of traditional Chinese medicine (TCM) formula. High performance liquid chromatography with high resolution tandem mass spectrometry (HPLC-HRMS/MS) has been widely used to analyze TCM formula and contains multiple-dimension data including retention time (RT), high resolution mass (HRMS), multiple-stage mass spectrometric (MS n ), and isotope intensity distribution (IID) data. So it is very necessary to exploit a useful strategy to utilize multiple-dimension data to rapidly probe structural information and identify chemical compounds. In this study, a new strategy to initiatively use the multiple-dimension LC-MS data has been developed to discover and identify unknown compounds of TCM in many styles. The strategy guarantees the fast discovery of candidate structural information and provides efficient structure clues for identification. The strategy contains four steps in sequence: (1) to discover potential compounds and obtain sub-structure information by the mass spectral tree similarity filter (MTSF) technique, based on HRMS and MS n data; (2) to classify potential compounds into known chemical classes by discriminant analysis (DA) on the basis of RT and HRMS data; (3) to hit the candidate structural information of compounds by intersection sub-structure between MTSF and DA (M,D-INSS); (4) to annotate and confirm candidate structures by IID data. This strategy allowed for the high exclusion efficiency (greater than 41%) of irrelevant ions in er-xian decoction (EXD) while providing accurate structural information of 553 potential compounds and identifying 66 candidates, therefore accelerating and simplifying the discovery and identification of unknown compounds in TCM formula. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Study of hadrons energy resolution in a liquid argon calorimeter for the H1 experiment and study of supersymmetric particles detection at Hera

    International Nuclear Information System (INIS)

    Besancon, M.

    1989-08-01

    Tests of liquid Argon calorimeters have been carried out at CERN in 1986 and 1987 in order to study the properties of the forthcoming H1 detector calorimeter installed at the HERA collider. In the first part of this work, from data analysis, several weighting methods of the measured charge for hadronic showers are proposed and discussed. These weighting methods allow to correct the non compensation of liquid Argon calorimeters and so to optimize the hadrons energy resolution. The problem of electrons and pions identification is also met. In the second part, selectron and squark production is considered in the electrons protons collisions of HERA. Signal extraction from standard background is studied with the help of a simulation of supersymmetric and deep inelastic scattering processes as well as a rough simulation of the H1 detector [fr

  8. Simple and rapid determination of 5-nitroimidazoles and metabolites in fish roe samples by salting-out assisted liquid-liquid extraction and UHPLC-MS/MS.

    Science.gov (United States)

    Hernández-Mesa, Maykel; Cruces-Blanco, Carmen; García-Campaña, Ana M

    2018-06-30

    A novel multiresidue method is proposed for the determination of 12 5-nitroimidazoles and their metabolites in fish roe samples using UHPLC-MS/MS. A salting-out assisted liquid-liquid extraction procedure was performed prior to sample analysis. The separation of compounds was accomplished using a C18 Zorbax Eclipse Plus column (50 mm × 2.1 mm, 1.8 µm) at 25 °C and a mobile phase consisting of 0.025% (v/v) aqueous formic acid and pure MeOH at a flow rate of 0.5 mL/min. Parameters involved in ionization and fragmentation were also optimized. The method was characterized in terms of linearity (R 2  ≥ 0.9992), extraction efficiency (≥68.9%), repeatability (RSD ≤ 9.8%), reproducibility (RSD ≤ 13.9%) and trueness (recoveries ≥81.4%). Decision limits (CCα) and detection capabilities (CCβ) were obtained in the ranges 0.1-1.0 and 0.2-1.7 µg/kg, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Simple and rapid determination of norethindrone in human plasma by supported liquid extraction and ultra performance liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Gong, Zhilong; Chandler, Kiresha; Webster, Stephen; Kerley, Remy; Buist, Susan; McCort-Tipton, Melanie

    2012-03-15

    We report for the first time an ultra performance liquid chromatographic method with tandem mass spectrometric detection (UPLC/MS/MS) for the determination of norethindrone alone in human plasma over the concentration range of 50.0-25000 pg mL(-1) using a sample volume of 0.250 mL. Norethindrone and its internal standard (ISTD), norethindrone-(13)C(2), were extracted from human plasma by supported liquid extraction (SLE). After evaporation of the organic solvent, samples were reconstituted and analyzed on an UPLC/MS/MS system. The UPLC system used a Waters BEH C18 (100 mm × 2.1mm, 1.7 μm) column with mobile phase A of 0.05% formic acid in water:acetonitrile (65:35, v/v) and mobile phase B of 0.05% formic acid in methanol:acetonitrile (50:50, v/v). The flow rate was 0.500 mL min(-1). The method was fully validated. The inter-run accuracy and precision at the lower limit of quantitation (LLOQ), low, mid and high quality control (QC) concentration levels were 99.2-108.4% with a <8.1% CV (coefficient of variation), respectively. The validated method has been successfully applied to analysis of thousands of pharmacokinetic samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Rapid quantification of imidazolium-based ionic liquids by hydrophilic interaction liquid chromatography: Methodology and an investigation of the retention mechanisms.

    Science.gov (United States)

    Hawkins, Cory A; Rud, Anna; Guthrie, Margaret L; Dietz, Mark L

    2015-06-26

    The separation of nine N,N'-dialkylimidazolium-based ionic liquids (ILs) by an isocratic hydrophilic interaction high-performance liquid chromatographic method using an unmodified silica column was investigated. The chosen analytical conditions using a 90:10 acetonitrile-ammonium formate buffer mobile phase on a high-purity, unmodified silica column were found to be efficient, robust, and sensitive for the determination of ILs in a variety of solutions. The retention window (k' = 2-11) was narrower than that of previous methods, resulting in a 7-min runtime for the nine IL homologues. The lower limit of quantification of the method, 2-3 μmol L(-1), was significantly lower than those reported previously for HPLC-UV methods. The effects of systematically modifying the IL cation alkyl chain length, column temperature, and mobile-phase water and buffer content on solute retention were examined. Cation exchange was identified as the dominant retention mechanism for most of the solutes, with a distinct (single methylene group) transition to a dominant partitioning mode at the highest solute polarity. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. RAPID AND SENSITIVE DETERMINATION OF PALLADIUM USING HOMOGENEOUS LIQUID-LIQUID MICROEXTRACTION VIA FLOTATION ASSISTANCE FOLLOWED BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaee

    2015-05-01

    Full Text Available A method for the determination of trace amounts of palladium was developed using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA followed by graphite furnace atomic absorption spectrometry (GFAAS. Ammonium pyrrolidine dithiocarbamate (APDC was used as a complexing agent. This was applied to determine palladium in three types of water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added to the extraction cell which contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. Parameters affecting extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration graph was linear in the range of 1.0-200 µg L-1 with a limit of detection of 0.3 µg L-1. The performance of the method was evaluated for the extraction and determination of palladium in water samples and satisfactory results were obtained. In order to verify the accuracy of the approach, the standard addition method was applied for the determination of palladium in spiked synthetic samples and satisfactory results were obtained.

  12. Liquid Phase Separation and the Aging Effect on Mechanical and Electrical Properties of Laser Rapidly Solidified Cu100−xCrx Alloys

    Directory of Open Access Journals (Sweden)

    Song-Hua Si

    2015-11-01

    Full Text Available Duplex structure Cu-Cr alloys are widely used as contact materials. They are generally designed by increasing the Cr content for the hardness improvement, which, however, leads to the unfavorable rapid increase of the electrical resistivity. The solidification behavior of Cu100−xCrx (x = 4.2, 25 and 50 in wt.% alloys prepared by laser rapid solidification is studied here, and their hardness and electrical conductivity after aging are measured. The results show that the Cu-4.2%Cr alloy has the most desirable combination of hardness and conductive properties after aging in comparison with Cu-25%Cr and Cu-50%Cr alloys. Very importantly, a 50% improvement in hardness is achieved with a simultaneous 70% reduction in electrical resistivity. The reason is mainly attributed to the liquid phase separation occurring in the Cu-4.2%Cr alloy, which introduces a large a

  13. Optimisation of pressurised liquid extraction (PLE) for rapid and efficient extraction of superficial and total mineral oil contamination from dry foods.

    Science.gov (United States)

    Moret, Sabrina; Scolaro, Marianna; Barp, Laura; Purcaro, Giorgia; Sander, Maren; Conte, Lanfranco S

    2014-08-15

    Pressurised liquid extraction (PLE) represents a powerful technique which can be conveniently used for rapid extraction of mineral oil saturated (MOSH) and aromatic hydrocarbons (MOAH) from dry foods with a low fat content, such as semolina pasta, rice, and other cereals. Two different PLE methods, one for rapid determination of superficial contamination mainly from the packaging, the other for efficient extraction of total contamination from different sources, have been developed and optimised. The two methods presented good performance characteristics in terms of repeatability (relative standard deviation lower than 5%) and recoveries (higher than 95%). To show their potentiality, the two methods have been applied in combination on semolina pasta and rice packaged in direct contact with recycled cardboard. In the case of semolina pasta it was possible to discriminate between superficial contamination coming from the packaging, and pre-existing contamination (firmly enclosed into the matrix). Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Rapid Characterization and Identification of Flavonoids in Radix Astragali by Ultra-High-Pressure Liquid Chromatography Coupled with Linear Ion Trap-Orbitrap Mass Spectrometry.

    Science.gov (United States)

    Zhang, Jing; Xu, Xiao-Jie; Xu, Wen; Huang, Juan; Zhu, Da-yuan; Qiu, Xiao-Hui

    2015-07-01

    A simple and effective method was established for separation and characterization of flavonoid constituents in Radix Astragali (RA) by combination of ultra-high-pressure liquid chromatography with LTQ-Orbitrap tandem mass spectrometry (u-HPLC-LTQ-Orbitrap-MS(n)). For three major structural types of flavonoids, the proposed fragmentation pathways and major diagnostic fragment ions of isoflavones, pterocarpans and isoflavans were investigated to trace isoflavonoid derivatives in crude plant extracts. Based on the systematic identification strategy, 48 constituents were rapidly detected and characterized or tentatively identified, many of which were first reported in RA. The u-PHLC-LTQ-Orbitrap MS(n) platform was proved as an effective tool for rapid qualitative analysis of secondary metabolite productions from natural resources. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. A rapid monitoring method for inorganic arsenic in rice flour using reversed phase-high performance liquid chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Narukawa, Tomohiro; Chiba, Koichi; Sinaviwat, Savarin; Feldmann, Jörg

    2017-01-06

    A new rapid monitoring method by means of high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) following the heat-assisted extraction was developed for measurement of total inorganic arsenic species in rice flour. As(III) and As(V) eluted at the same retention time and completely separated from organoarsenic species by an isocratic elution program on a reversed phase column. Therefore, neither ambiguous oxidation of arsenite to arsenate nor the integration of two peaks were necessary to determine directly the target analyte inorganic arsenic. Rapid injection allowed measuring 3 replicates within 6min and this combined with a quantitative extraction of all arsenic species from rice flour by a 15min HNO 3 -H 2 O 2 extraction makes this the fastest laboratory based method for inorganic arsenic in rice flour. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Prediction of collision cross section and retention time for broad scope screening in gradient reversed-phase liquid chromatography-ion mobility-high resolution accurate mass spectrometry

    DEFF Research Database (Denmark)

    Mollerup, Christian Brinch; Mardal, Marie; Dalsgaard, Petur Weihe

    2018-01-01

    artificial neural networks (ANNs). Prediction was based on molecular descriptors, 827 RTs, and 357 CCS values from pharmaceuticals, drugs of abuse, and their metabolites. ANN models for the prediction of RT or CCS separately were examined, and the potential to predict both from a single model......Exact mass, retention time (RT), and collision cross section (CCS) are used as identification parameters in liquid chromatography coupled to ion mobility high resolution accurate mass spectrometry (LC-IM-HRMS). Targeted screening analyses are now more flexible and can be expanded for suspect...

  17. Determination of crystal growth rates during rapid solidification of polycrystalline aluminum by nano-scale spatio-temporal resolution in situ transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zweiacker, K., E-mail: Kai@zweiacker.org; Liu, C.; Wiezorek, J. M. K. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 648 Benedum Hall, 3700 OHara Street, Pittsburgh, Pennsylvania 15261 (United States); McKeown, J. T.; LaGrange, T.; Reed, B. W.; Campbell, G. H. [Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States)

    2016-08-07

    In situ investigations of rapid solidification in polycrystalline Al thin films were conducted using nano-scale spatio-temporal resolution dynamic transmission electron microscopy. Differences in crystal growth rates and asymmetries in melt pool development were observed as the heat extraction geometry was varied by controlling the proximity of the laser-pulse irradiation and the associated induced melt pools to the edge of the transmission electron microscopy support grid, which acts as a large heat sink. Experimental parameters have been established to maximize the reproducibility of the material response to the laser-pulse-related heating and to ensure that observations of the dynamical behavior of the metal are free from artifacts, leading to accurate interpretations and quantifiable measurements with improved precision. Interface migration rate measurements revealed solidification velocities that increased consistently from ∼1.3 m s{sup −1} to ∼2.5 m s{sup −1} during the rapid solidification process of the Al thin films. Under the influence of an additional large heat sink, increased crystal growth rates as high as 3.3 m s{sup −1} have been measured. The in situ experiments also provided evidence for development of a partially melted, two-phase region prior to the onset of rapid solidification facilitated crystal growth. Using the experimental observations and associated measurements as benchmarks, finite-element modeling based calculations of the melt pool evolution after pulsed laser irradiation have been performed to obtain estimates of the temperature evolution in the thin films.

  18. Rapid determination of hydrophilic phenols in olive oil by vortex-assisted reversed-phase dispersive liquid-liquid microextraction and screen-printed carbon electrodes.

    Science.gov (United States)

    Fernández, Elena; Vidal, Lorena; Canals, Antonio

    2018-05-01

    A novel approach is presented to determine hydrophilic phenols in olive oil samples, employing vortex-assisted reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) for sample preparation and screen-printed carbon electrodes for voltammetric analysis. The oxidation of oleuropein, hydroxytyrosol, caffeic acid, ferulic acid and tyrosol was investigated, being caffeic acid and tyrosol selected for quantification. A matrix-matching calibration using sunflower oil as analyte-free sample diluted with hexane was employed to compensate matrix effects. Samples were analyzed under optimized RP-DLLME conditions, i.e., extractant phase, 1M HCl; extractant volume, 100µL; extraction time, 2min; centrifugation time, 10min; centrifugation speed, 4000rpm. The working range showed a good linearity between 0.075 and 2.5mgL -1 (r = 0.998, N = 7) for caffeic acid, and between 0.075 and 3mgL -1 (r = 0.999, N = 8) for tyrosol. The methodological limit of detection was empirically established at 0.022mgL -1 for both analytes, which is significantly lower than average contents found in olive oil samples. The repeatability was evaluated at two different spiking levels (i.e., 0.5mgL -1 and 2mgL -1 ) and coefficients of variation ranged from 8% to 11% (n = 5). The applicability of the proposed method was tested in olive oil samples of different quality (i.e., refined olive oil, virgin olive oil and extra virgin olive oil). Relative recoveries varied between 83% and 108% showing negligible matrix effects. Finally, fifteen samples were analyzed by the proposed method and a high correlation with the traditional Folin-Ciocalteu spectrophotometric method was obtained. Thereafter, the concentrations of the fifteen oil samples were employed as input variables in linear discriminant analysis in order to distinguish between olive oils of different quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Mid-infrared and near-infrared spectroscopy for rapid detection of Gardeniae Fructus by a liquid-liquid extraction process.

    Science.gov (United States)

    Tao, Lingyan; Lin, Zhonglin; Chen, Jiashan; Wu, Yongjiang; Liu, Xuesong

    2017-10-25

    Gardeniae Fructus is widely used in the pharmaceutical industry, and many studies have confirmed its medical and economic value. In this study, samples collected from different liquid-liquid extraction batches of Gardeniae Fructus were detected by mid-infrared (MIR) and near-infrared (NIR) spectroscopy. Seven analytes, neochlorogenic acid (5-CQA), cryptochlorogenic acid (4-CQA), chlorogenic acid (3-CQA), geniposidic acid (GEA), deacetyl-asperulosidic acid methyl ester (DAAME), genipin-gentiobioside (GGB), and gardenoside (GA), were chosen as quality property indexes of Gardeniae Fructus. The two kinds of spectra were each used to build models by single partial least squares (PLS). Additionally, both spectral data were combined and modeled by multiblock PLS. For single spectroscopy modeling results, NIR had a better prediction for high-concentration analytes (3-CQA, DAAME, GGB, and GA) whereas MIR performed better for low-concentration analytes (5-CQA, 4-CQA, and GEA). The multiblock methodology was found to be better compared to single spectroscopy models for all seven analytes. Specifically, the coefficients of determination (R 2 ) of the NIR, MIR, and multiblock PLS calibration models of all seven components were higher than 0.95. Relative standard errors of prediction (RSEP) were all less than 7%, except for models of GGB, which were 10.36%, 13.24%, and 8.15% for the NIR-PLS, MIR-PLS, and multiblock models, respectively. These results indicate that MIR and NIR spectrographic techniques could provide a new choice for quality control in industrial production of Gardeniae Fructus. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Elucidation and identification of amino acid containing membrane lipids using liquid chromatography/high-resolution mass spectrometry

    NARCIS (Netherlands)

    Moore, E.K.; Hopmans, E.C.; Rijpstra, W.I.C.; Villanueva, L.; Sinninghe Damsté, J.S.

    2016-01-01

    RATIONALE: Intact polar lipids (IPLs) are the building blocks of cell membranes, and amino acid containing IPLs havebeen observed to be involved in response to changing environmental conditions in various species of bacteri a. High-performance liquid chromatography/mass spectrometry (HPLC/MS) has

  1. Liquid Chromatography with Electrospray Ionization and Tandem Mass Spectrometry Applied in the Quantitative Analysis of Chitin-Derived Glucosamine for a Rapid Estimation of Fungal Biomass in Soil

    Directory of Open Access Journals (Sweden)

    Madelen A. Olofsson

    2016-01-01

    Full Text Available This method employs liquid chromatography-tandem mass spectrometry to rapidly quantify chitin-derived glucosamine for estimating fungal biomass. Analyte retention was achieved using hydrophilic interaction liquid chromatography, with a zwitter-ionic stationary phase (ZIC-HILIC, and isocratic elution using 60% 5 mM ammonium formate buffer (pH 3.0 and 40% ACN. Inclusion of muramic acid and its chromatographic separation from glucosamine enabled calculation of the bacterial contribution to the latter. Galactosamine, an isobaric isomer to glucosamine, found in significant amounts in soil samples, was also investigated. The two isomers form the same precursor and product ions and could not be chromatographically separated using this rapid method. Instead, glucosamine and galactosamine were distinguished mathematically, using the linear relationships describing the differences in product ion intensities for the two analytes. The m/z transitions of 180 → 72 and 180 → 84 were applied for the detection of glucosamine and galactosamine and that of 252 → 126 for muramic acid. Limits of detection were in the nanomolar range for all included analytes. The total analysis time was 6 min, providing a high sample throughput method.

  2. Rapid quantitative analysis of individual anthocyanin content based on high-performance liquid chromatography with diode array detection with the pH differential method.

    Science.gov (United States)

    Wang, Huayin

    2014-09-01

    A new quantitative technique for the simultaneous quantification of the individual anthocyanins based on the pH differential method and high-performance liquid chromatography with diode array detection is proposed in this paper. The six individual anthocyanins (cyanidin 3-glucoside, cyanidin 3-rutinoside, petunidin 3-glucoside, petunidin 3-rutinoside, and malvidin 3-rutinoside) from mulberry (Morus rubra) and Liriope platyphylla were used for demonstration and validation. The elution of anthocyanins was performed using a C18 column with stepwise gradient elution and individual anthocyanins were identified by high-performance liquid chromatography with tandem mass spectrometry. Based on the pH differential method, the high-performance liquid chromatography peak areas of maximum and reference absorption wavelengths of anthocyanin extracts were conducted to quantify individual anthocyanins. The calibration curves for these anthocyanins were linear within the range of 10-5500 mg/L. The correlation coefficients (r(2)) all exceeded 0.9972, and the limits of detection were in the range of 1-4 mg/L at a signal-to-noise ratio ≥5 for these anthocyanins. The proposed quantitative analysis was reproducible with good accuracy of all individual anthocyanins ranging from 96.3 to 104.2% and relative recoveries were in the range 98.4-103.2%. The proposed technique is performed without anthocyanin standards and is a simple, rapid, accurate, and economical method to determine individual anthocyanin contents. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Rapid ultrasound-induced transient-liquid-phase bonding of Al-50Si alloys with Zn interlayer in air for electrical packaging application.

    Science.gov (United States)

    Wang, Qian; Chen, Xiaoguang; Zhu, Lin; Yan, Jiuchun; Lai, Zhiwei; Zhao, Pizhi; Bao, Juncheng; Lv, Guicai; You, Chen; Zhou, Xiaoyu; Zhang, Jian; Li, Yuntao

    2017-01-01

    Al-50Si alloys were joined by rapid ultrasound-induced transient-liquid-phase bonding method using Zn foil as interlayer at 390°C in air, below the melt point of interlayer. The fracture of oxide films along the edge of Si particles led to contact and inter-diffusion between aluminum substrate and Zn interlayer, and liquefied Zn-Al alloys were developed. The width of Zn-Al alloys gradually decreased with increasing the ultrasonic vibration time due to liquid squeezing out and accelerated diffusion. A stage of isothermal solidification existed, and the completion time was significantly shortened. In the liquid metal, the acoustic streaming and ultrasonic cavitations were induced. As the process developed, much more Si particles, which were particulate-reinforced phases of Al-50Si, gradually migrated to the center of soldering seam. The highest average shear strength of joints reached to 94.2MPa, and the fracture mainly occurred at the base metal. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Liquid chromatography and supercritical fluid chromatography as alternative techniques to gas chromatography for the rapid screening of anabolic agents in urine.

    Science.gov (United States)

    Desfontaine, Vincent; Nováková, Lucie; Ponzetto, Federico; Nicoli, Raul; Saugy, Martial; Veuthey, Jean-Luc; Guillarme, Davy

    2016-06-17

    This work describes the development of two methods involving supported liquid extraction (SLE) sample treatment followed by ultra-high performance liquid chromatography or ultra-high performance supercritical fluid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS and UHPSFC-MS/MS) for the screening of 43 anabolic agents in human urine. After evaluating different stationary phases, a polar-embedded C18 and a diol columns were selected for UHPLC-MS/MS and UHPSFC-MS/MS, respectively. Sample preparation, mobile phases and MS conditions were also finely tuned to achieve highest selectivity, chromatographic resolution and sensitivity. Then, the performance of these two methods was compared to the reference routine procedure for steroid analyses in anti-doping laboratories, which combines liquid-liquid extraction (LLE) followed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). For this purpose, urine samples spiked with the compounds of interest at five different concentrations were analyzed using the three analytical platforms. The retention and selectivity of the three techniques were very different, ensuring a good complementarity. However, the two new methods displayed numerous advantages. The overall procedure was much faster thanks to high throughput SLE sample treatment using 48-well plates and faster chromatographic analysis. Moreover, the highest sensitivity was attained using UHPLC-MS/MS with 98% of the doping agents detected at the lowest concentration level (0.1ng/mL), against 76% for UHPSFC-MS/MS and only 14% for GC-MS/MS. Finally, the weakest matrix effects were obtained with UHPSFC-MS/MS with 76% of the analytes displaying relative matrix effect between -20 and 20%, while the GC-MS/MS reference method displayed very strong matrix effects (over 100%) for all of the anabolic agents. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Two-phase mixture level swell and liquid entrainment/off-take in a vessel during rapid depressurization

    International Nuclear Information System (INIS)

    Kim, Chang Hyun

    2004-02-01

    An experimental study has been performed to analyze the two-phase mixture level swell and the liquid entrainment/off-take through the break in a vessel, which are important phenomena to determine the bleed capacity of the Safety Depressurization System (SDS) of Korea Advanced Power Reactor 1400 (APR1400). Three separate experiments are performed in this study: (a) the depressurization and two-phase mixture level swell experiment: (b) the two-phase mixture level measurement experiment: (c) the liquid entrainment and off-take experiment. A series of experiments has been performed using a scaled pressurized vessel in various depressurization conditions to analyze the two-phase mixture level swell and the liquid entrainment/off-take phenomena from the two-phase mixture surface in the first experiment. The test parameters are the initial pressure (10 - 38.75bars), the initial water level (43.7% - 80.0% of full height), the orifice inner diameter (10mm, 17.5mm, and 20mm). The liquid off-take takes place in certain experimental conditions. The measured parameters in the present experiments are axial void fraction distributions, pressures, temperatures in the test vessel, and the mixture density and mass flowrate through the discharge pipe. An assessment of RELAP5/MOD3 code with the present experimental data has been performed. With appropriate nodalization and time step, RELAP5/MOD3 showed reasonable agreement with the present experimental data for the gradual depressurization without liquid off-take. In the case that the off-take takes place, however, RELAP5/MOD3 under-predicts the amount of liquid entrainment/off-take during depressurization. In the second experiment, an assessment of an ultrasonic sensor and a two-wire type capacitance probe for the two-phase mixture level measurement has been performed under the same experimental conditions to adopt an appropriate measurement method for the two-phase mixture level swell and to investigate pool void fraction by the

  6. Validated High Performance Liquid Chromatography Method for ...

    African Journals Online (AJOL)

    Purpose: To develop a simple, rapid and sensitive high performance liquid ... response, tailing factor and resolution of six replicate injections was < 3 %. ... Cefadroxil monohydrate, Human plasma, Pharmacokinetics Bioequivalence ... Drug-free plasma was obtained from the local .... Influence of probenicid on the renal.

  7. Rapid screening of ASXL1, IDH1, IDH2, and c-CBL mutations in de novo acute myeloid leukemia by high-resolution melting.

    Science.gov (United States)

    Ibáñez, Mariam; Such, Esperanza; Cervera, José; Luna, Irene; Gómez-Seguí, Inés; López-Pavía, María; Dolz, Sandra; Barragán, Eva; Fuster, Oscar; Llop, Marta; Rodríguez-Veiga, Rebeca; Avaria, Amparo; Oltra, Silvestre; Senent, M Leonor; Moscardó, Federico; Montesinos, Pau; Martínez-Cuadrón, David; Martín, Guillermo; Sanz, Miguel A

    2012-11-01

    Recently, many novel molecular abnormalities were found to be distinctly associated with acute myeloid leukemia (AML). However, their clinical relevance and prognostic implications are not well established. We developed a new combination of high-resolution melting assays on a LightCycler 480 and direct sequencing to detect somatic mutations of ASXL1 (exon 12), IDH1 (exon 4), IDH2 (exon 4), and c-CBL (exons 8 and 9) genes to know their incidence and prognostic effect in a cohort of 175 patients with de novo AML: 16 patients (9%) carried ASXL1 mutations, 16 patients had IDH variations (3% with IDH1(R132) and 6% with IDH2(R140)), and none had c-CBL mutations. Patients with ASXL1 mutations did not harbor IDH1, [corrected] or CEBPA mutations, and a combination of ASXL1 and IDH2 mutations was found only in one patient. In addition, we did not find IDH1 and FLT3 or CEBPA mutations concurrently or IDH2 with CEBPA. IDH1 and IDH2 mutations were mutually exclusive. Alternatively, NPM1 mutations were concurrently found with ASXL1, IDH1, or IDH2 with a variable incidence. Mutations were not significantly correlated with any of the clinical and biological features studied. High-resolution melting is a reliable, rapid, and efficient screening technique for mutation detection in AML. The incidence for the studied genes was in the range of those previously reported. We were unable to find an effect on the outcome. Copyright © 2012 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  8. [11C]-Flumazenil metabolites: Measurements of unchanged ligand in plasma using thin layer chromatography and rapid liquid chromatography

    International Nuclear Information System (INIS)

    Loc'h, C.; Hantraye, Ph.; Khalili-Varasteh, M.; Maziere, B.; Delforge, J.; Brouillet, E.; Syrota, A.; Maziere, M.

    1990-01-01

    To study in vivo benzodiazepine (BZ) receptors using PET, Flumazenil, an imidazobenzodiazepine with selective antagonistic actions, has been labeled with 11 C on its methyl group. The accurate determination of in vivo binding parameters using biomathematical models requires the knowledge of radioligand metabolism and the measurement of the plasmatic concentration of unchanged radioligand is mandatory. The present report describes and compares rapid and simple analytical procedures to measure unchanged [ 11 C]-Flumazenil in plasma

  9. If Frisch is true - impacts of varying beam width, resolution, frequency combinations and beam overlap when retrieving liquid water content profiles

    Science.gov (United States)

    Küchler, N.; Kneifel, S.; Kollias, P.; Loehnert, U.

    2017-12-01

    Cumulus and stratocumulus clouds strongly affect the Earth's radiation budget and are a major uncertainty source in weather and climate prediction models. To improve and evaluate models, a comprehensive understanding of cloud processes is necessary and references are needed. Therefore active and passive microwave remote sensing of clouds can be used to derive cloud properties such as liquid water path and liquid water content (LWC), which can serve as a reference for model evaluation. However, both the measurements and the assumptions when retrieving physical quantities from the measurements involve uncertainty sources. Frisch et al. (1998) combined radar and radiometer observations to derive LWC profiles. Assuming their assumptions are correct, there will be still uncertainties regarding the measurement setup. We investigate how varying beam width, temporal and vertical resolutions, frequency combinations, and beam overlap of and between the two instruments influence the retrieval of LWC profiles. Especially, we discuss the benefit of combining vertically, high resolved radar and radiometer measurements using the same antenna, i.e. having ideal beam overlap. Frisch, A. S., G. Feingold, C. W. Fairall, T. Uttal, and J. B. Snider, 1998: On cloud radar and microwave radiometer measurements of stratus cloud liquid water profiles. J. Geophys. Res.: Atmos., 103 (18), 23 195-23 197, doi:0148-0227/98/98JD-01827509.00.

  10. High-performance liquid chromatography with fluorescence detection for the rapid analysis of pheophytins and pyropheophytins in virgin olive oil.

    Science.gov (United States)

    Li, Xueqi; Woodman, Michael; Wang, Selina C

    2015-08-01

    Pheophytins and pyropheophytin are degradation products of chlorophyll pigments, and their ratios can be used as a sensitive indicator of stress during the manufacturing and storage of olive oil. They increase over time depending on the storage condition and if the oil is exposed to heat treatments during the refining process. The traditional analysis method includes solvent- and time-consuming steps of solid-phase extraction followed by analysis by high-performance liquid chromatography with ultraviolet detection. We developed an improved dilute/fluorescence method where multi-step sample preparation was replaced by a simple isopropanol dilution before the high-performance liquid chromatography injection. A quaternary solvent gradient method was used to include a fourth strong solvent wash on a quaternary gradient pump, which avoided the need to premix any solvents and greatly reduced the oil residues on the column from previous analysis. This new method not only reduces analysis cost and time but shows reliability, repeatability, and improved sensitivity, especially important for low-level samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Large-Scale Liquid Hydrogen Tank Rapid Chill and Fill Testing for the Advanced Shuttle Upper Stage Concept

    Science.gov (United States)

    Flachbart, R. H.; Hedayat, A.; Holt, K. A.; Sims, J.; Johnson, E. F.; Hastings, L. J.; Lak, T.

    2013-01-01

    Cryogenic upper stages in the Space Shuttle program were prohibited primarily due to a safety risk of a 'return to launch site' abort. An upper stage concept addressed this concern by proposing that the stage be launched empty and filled using shuttle external tank residuals after the atmospheric pressure could no longer sustain an explosion. However, only about 5 minutes was allowed for tank fill. Liquid hydrogen testing was conducted within a near-ambient environment using the multipurpose hydrogen test bed 638.5 ft3 (18m3) cylindrical tank with a spray bar mounted longitudinally inside. Although the tank was filled within 5 minutes, chilldown of the tank structure was incomplete, and excessive tank pressures occurred upon vent valve closure. Elevated tank wall temperatures below the liquid level were clearly characteristic of film boiling. The test results have substantial implications for on-orbit cryogen transfer since the formation of a vapor film would be much less inhibited due to the reduced gravity. However, the heavy tank walls could become an asset in normal gravity testing for on-orbit transfer, i.e., if film boiling in a nonflight weight tank can be inhibited in normal gravity, then analytical modeling anchored with the data could be applied to reduced gravity environments with increased confidence.

  12. Rapid screening of rpoB and katG mutations in Mycobacterium tuberculosis isolates by high-resolution melting curve analysis

    Directory of Open Access Journals (Sweden)

    M Haeili

    2014-01-01

    Full Text Available Background: Early detection of multidrug-resistant tuberculosis (MDR-TB is essential to prevent its transmission in the community and initiate effective anti-TB treatment regimen. Materials and Methods: High-resolution melting curve (HRM analysis was evaluated for rapid detection of resistance conferring mutations in rpoB and katG genes. We screened 95 Mycobacterium tuberculosis clinical isolates including 20 rifampin resistant (RIF-R, 21 isoniazid resistant (INH-R and 54 fully susceptible (S isolates determined by proportion method of drug susceptibility testing. Nineteen M. tuberculosis isolates with known drug susceptibility genotypes were used as references for the assay validation. The nucleotide sequences of the target regions rpoB and katG genes were determined to investigate the frequency and type of mutations and to confirm HRM results. Results: HRM analysis of a 129-bp fragment of rpoB allowed correct identification of 19 of the 20 phenotypically RIF-R and all RIF-S isolates. All INH-S isolates generated wild-type HRM curves and 18 out of 21 INH-R isolates harboured any mutation in 109-bp fragment of katG exhibited mutant type HRM curves. However, 1 RIF-R and 3 INH-R isolates were falsely identified as susceptible which were confirmed for having no mutation in their target regions by sequencing. The main mutations involved in RIF and INH resistance were found at codons rpoB531 (60% of RIF-R isolates and katG315 (85.7% of INH-R isolates, respectively. Conclusion: HRM was found to be a reliable, rapid and low cost method to characterise drug susceptibility of clinical TB isolates in resource-limited settings.

  13. Enantiomeric high-performance liquid chromatography resolution and absolute configuration of 6β-benzoyloxy-3α-tropanol.

    Science.gov (United States)

    Muñoz, Marcelo A; González, Natalia; Joseph-Nathan, Pedro

    2016-07-01

    The absolute configuration of the naturally occurring isomers of 6β-benzoyloxy-3α-tropanol (1) has been established by the combined use of chiral high-performance liquid chromatography with electronic circular dichroism detection and optical rotation detection. For this purpose (±)-1, prepared in two steps from racemic 6-hydroxytropinone (4), was subjected to chiral high-performance liquid chromatography with electronic circular dichroism and optical rotation detection allowing the online measurement of both chiroptical properties for each enantiomer, which in turn were compared with the corresponding values obtained from density functional theory calculations. In an independent approach, preparative high-performance liquid chromatography separation using an automatic fraction collector, yielded an enantiopure sample of OR (+)-1 whose vibrational circular dichroism spectrum allowed its absolute configuration assignment when the bands in the 1100-950 cm(-1) region were compared with those of the enantiomers of esters derived from 3α,6β-tropanediol. In addition, an enantiomerically enriched sample of 4, instead of OR (±)-4, was used for the same transformation sequence, whose high-performance liquid chromatography follow-up allowed their spectroscopic correlation. All evidences lead to the OR (+)-(1S,3R,5S,6R) and OR (-)-(1R,3S,5R,6S) absolute configurations, from where it follows that samples of 1 isolated from Knightia strobilina and Erythroxylum zambesiacum have the OR (+)-(1S,3R,5S,6R) absolute configuration, while the sample obtained from E. rotundifolium has the OR (-)-(1R,3S,5R,6S) absolute configuration. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Using JPSS VIIRS Fire Radiative Power Data to Forecast Biomass Burning Emissions and Smoke Transport by the High Resolution Rapid Refresh Model

    Science.gov (United States)

    Ahmadov, R.; Grell, G. A.; James, E.; Alexander, C.; Stewart, J.; Benjamin, S.; McKeen, S. A.; Csiszar, I. A.; Tsidulko, M.; Pierce, R. B.; Pereira, G.; Freitas, S. R.; Goldberg, M.

    2017-12-01

    We present a new real-time smoke modeling system, the High Resolution Rapid Refresh coupled with smoke (HRRR-Smoke), to simulate biomass burning (BB) emissions, plume rise and smoke transport in real time. The HRRR is the NOAA Earth System Research Laboratory's 3km grid spacing version of the Weather Research and Forecasting (WRF) model used for weather forecasting. Here we make use of WRF-Chem (the WRF model coupled with chemistry) and simulate fine particulate matter (smoke) emissions emitted by BB. The HRRR-Smoke modeling system ingests fire radiative power (FRP) data from the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the Suomi National Polar-orbiting Partnership (S-NPP) satellite to calculate BB emissions. The FRP product is based on processing 750m resolution "M" bands. The algorithms for fire detection and FRP retrieval are consistent with those used to generate the MODIS fire detection data. For the purpose of ingesting VIIRS fire data into the HRRR-Smoke model, text files are generated to provide the location and detection confidence of fire pixels, as well as FRP. The VIIRS FRP data from the text files are processed and remapped over the HRRR-Smoke model domains. We process the FRP data to calculate BB emissions (smoldering part) and fire size for the model input. In addition, HRRR-Smoke uses the FRP data to simulate the injection height for the flaming emissions using concurrently simulated meteorological fields by the model. Currently, there are two 3km resolution domains covering the contiguous US and Alaska which are used to simulate smoke in real time. In our presentation, we focus on the CONUS domain. HRRR-Smoke is initialized 4 times per day to forecast smoke concentrations for the next 36 hours. The VIIRS FRP data, as well as near-surface and vertically integrated smoke mass concentrations are visualized for every forecast hour. These plots are provided to the public via the HRRR-Smoke web-page: https

  15. Rapid Determination of Amino Acids in Beer, Red Wine, and Donkey-Hide Gelatin by Gradient Elution of HPLC: From Micellar Liquid Chromatography to High Submicellar Liquid Chromatography.

    Science.gov (United States)

    Xie, Yunfei; Luo, Tian; Yang, Jing; Dong, Yuming

    2018-01-01

    Amino acids (AAs) in beer, red wine, and donkey-hide gelatin were rapidly determined by gradient LC elution from micellar LC to high submicellar LC. Mobile phase A was a 0.075 M sodium dodecyl sulfate solution containing 20 mM ammonium acetate with a pH value adjusted to 3.5 with acetic acid solution, and mobile phase B was acetonitrile. Optimized chromatographic conditions were as follows: mobile phase B increased from 25 to 60% (v/v) in 30 min and the use of a Venusil XBP C18 column (5 µm, 250 × 4.6 mm) as the stationary phase, with a column temperature of 35°C, flow rate of 1.2 mL/min, and detection wavelength of 266 nm. The results indicated good linearity (r2 ≥ 0.9924). The intraday precision of the retention time was RSD ≤ 1.1%, whereas interday was RSD ≤ 3.2%; intraday precision of the peak area was RSD ≤ 3.3%, whereas interday was RSD ≤ 4.9%. The range of recovery was 94.6-102.4%. The RSDs of the retention time for the AAs for the different samples were 0.04-0.31%.

  16. Characterization of Mycobacterium paratuberculosis by gas-liquid and thin-layer chromatography and rapid demonstration of mycobactin dependence using radiometric methods

    International Nuclear Information System (INIS)

    Damato, J.J.; Knisley, C.; Collins, M.T.

    1987-01-01

    Thirty-six Mycobacterium paratuberculosis isolates of bovine, caprine, and ovine origins were evaluated by using gas-liquid chromatography (GLC), thin-layer chromatography (TLC), and BACTEC 7H12 Middlebrook TB medium in an effort to more rapidly differentiate this group of organisms from other mycobacteria. Bacterial suspensions (0.1 ml) were inoculated by syringe into 7H12 broth containing 2 micrograms of mycobactin P per ml and control broth without mycobactin P. Cultures were incubated at 37 0 C and read daily with a BACTEC Model 301. After 8 days of incubation, the growth index readings for the test broths containing mycobactin P were twice those of the control broths without mycobactin P. Sixty-five isolates of mycobacteria other than M. paratuberculosis were also examined. No difference was noted between the growth index readings of control and mycobactin-containing broths. Except for Mycobacterium avium-Mycobacterium intracellulare, TLC studies differentiated M. paratuberculosis from the other mycobacterial species tested. The GLC data reveal that all M. paratuberculosis isolates had a distinctive peak (14A) which was not found among M. avium-M. intracellulare complex organisms. These data indicate that 7H12 radiometric broth was able to rapidly demonstrate the mycobactin dependence of M. paratuberculosis and GLC and TLC procedures were capable of rapidly differentiating this organism from the other mycobacteria studied

  17. Rapid method for the sequential measurement of isotopes of Am and Pu in liquid matrices by alpha spectrometry

    International Nuclear Information System (INIS)

    Mantero Cabrera, J.

    2014-01-01

    : In radiological emergencies it's necessary a fast response from the laboratories in the quantification of certain radionuclides, in order to take decisions. In these cases, is the reaction time the key parameter to consider (without neglecting the quality of the measurement). In this work, it is shown a method for aqueous matrices that generates Pu and Am isotopes sources in one single day of work, to be measured subsequently by alpha spectrometry. The developed methodology has been validated through its application to reference samples and also taking part intercom- parison exercises, having in both cases, satisfactory results. This way, we check the validity of this fast method that let us generate in 24 hours (since the sample arrives our laboratory), one measurement with a Minimun Detectable Activity (MDA) of about 0.004Bq/L for Pu and Am isotopes in liquid matrices. [es

  18. Introducing AAA-MS, a rapid and sensitive method for amino acid analysis using isotope dilution and high-resolution mass spectrometry.

    Science.gov (United States)

    Louwagie, Mathilde; Kieffer-Jaquinod, Sylvie; Dupierris, Véronique; Couté, Yohann; Bruley, Christophe; Garin, Jérôme; Dupuis, Alain; Jaquinod, Michel; Brun, Virginie

    2012-07-06

    Accurate quantification of pure peptides and proteins is essential for biotechnology, clinical chemistry, proteomics, and systems biology. The reference method to quantify peptides and proteins is amino acid analysis (AAA). This consists of an acidic hydrolysis followed by chromatographic separation and spectrophotometric detection of amino acids. Although widely used, this method displays some limitations, in particular the need for large amounts of starting material. Driven by the need to quantify isotope-dilution standards used for absolute quantitative proteomics, particularly stable isotope-labeled (SIL) peptides and PSAQ proteins, we developed a new AAA assay (AAA-MS). This method requires neither derivatization nor chromatographic separation of amino acids. It is based on rapid microwave-assisted acidic hydrolysis followed by high-resolution mass spectrometry analysis of amino acids. Quantification is performed by comparing MS signals from labeled amino acids (SIL peptide- and PSAQ-derived) with those of unlabeled amino acids originating from co-hydrolyzed NIST standard reference materials. For both SIL peptides and PSAQ standards, AAA-MS quantification results were consistent with classical AAA measurements. Compared to AAA assay, AAA-MS was much faster and was 100-fold more sensitive for peptide and protein quantification. Finally, thanks to the development of a labeled protein standard, we also extended AAA-MS analysis to the quantification of unlabeled proteins.

  19. The Liquid State

    Indian Academy of Sciences (India)

    like iron, aluminium, lead, zinc, etc .. Metals are cast ... dropping molten liquid of the alloys on a rapidly spinning copper wheel. ... Ed. Computer simulation studies in ... liquids, modelling ofliquids and study of the dynamic behaviour of liquids ...

  20. Application of Fourier transform near-infrared spectroscopy combined with high-performance liquid chromatography in rapid and simultaneous determination of essential components in crude Radix Scrophulariae.

    Science.gov (United States)

    Li, Xiaomeng; Fang, Dansi; Cong, Xiaodong; Cao, Gang; Cai, Hao; Cai, Baochang

    2012-12-01

    A method is described using rapid and sensitive Fourier transform near-infrared spectroscopy combined with high-performance liquid chromatography-diode array detection for the simultaneous identification and determination of four bioactive compounds in crude Radix Scrophulariae samples. Partial least squares regression is selected as the analysis type and multiplicative scatter correction, second derivative, and Savitzky-Golay filter were adopted for the spectral pretreatment. The correlation coefficients (R) of the calibration models were above 0.96 and the root mean square error of predictions were under 0.028. The developed models were applied to unknown samples with satisfactory results. The established method was validated and can be applied to the intrinsic quality control of crude Radix Scrophulariae.

  1. Use of extraction chromatography, ion chromatography and liquid scintillation spectrometry for rapid determination of strontium-89 and strontium-90 in food in cases of increased release of radionuclides

    International Nuclear Information System (INIS)

    Heilgeist, M.

    2000-01-01

    For rapid determination of 89 Sr and 90 Sr in food, isocratic ion chromatography used for Sr isolation and purification is integrated in a complete analytical system comprising sample preparation, incineration, dissolution, phosphate precipitation for alkali/alkaline earth separation, and Sr specific extraction chromatography on crown ether basis for Ca/Sr separation. Strontium-89 and 90 Sr are determined by liquid scintillation spectrometry after carbonate precipitation. The components of the mixed spectra obtained are calculated by the computerized spectra subtraction method. Two days plus measuring time are required for single, three for double analysis. The limit of detection for 89 Sr and 90 Sr is ca. 0.1 Bq x kg -1 , related to the fresh produce. (author)

  2. A flowing liquid test system for assessing the linearity and time-response of rapid fibre optic oxygen partial pressure sensors.

    Science.gov (United States)

    Chen, R; Hahn, C E W; Farmery, A D

    2012-08-15

    The development of a methodology for testing the time response, linearity and performance characteristics of ultra fast fibre optic oxygen sensors in the liquid phase is presented. Two standard medical paediatric oxygenators are arranged to provide two independent extracorporeal circuits. Flow from either circuit can be diverted over the sensor under test by means of a system of rapid cross-over solenoid valves exposing the sensor to an abrupt change in oxygen partial pressure, P O2. The system is also capable of testing the oxygen sensor responses to changes in temperature, carbon dioxide partial pressure P CO2 and pH in situ. Results are presented for a miniature fibre optic oxygen sensor constructed in-house with a response time ≈ 50 ms and a commercial fibre optic sensor (Ocean Optics Foxy), when tested in flowing saline and stored blood. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. A Simple and Rapid Determination of ATP, ADP and AMP Concentrations in Pericarp Tissue of Litchi Fruit by High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Weibo Jiang

    2006-01-01

    Full Text Available A simple and rapid method using high performance liquid chromatography (HPLC was developed to determine levels of adenosine triphosphate (ATP, adenosine diphosphate (ADP and adenosine monophosphate (AMP in litchi fruit pericarp tissue. This HPLC method used acetonitrile gradient elution and shortened the time required for determinations of adenosine phosphates. This analysis exhibited good repeatability (coefficients of variation 1.28–1.80 % and recovery rate (94.7–97.1 %. The correlation coefficients of ATP, ADP and AMP with their peak areas at a range of 0–80 ng were 0.9946, 0.9994 and 0.9974, respectively. This method was applied to determine levels of adenosine phosphates in pericarp tissue of litchi fruit at harvest. There were 27.4 μg/g of ATP, 35.4 μg/g of ADP and 7.9 μg/g of AMP on a fresh mass basis.

  4. Quantification of rifampicin in human plasma and cerebrospinal fluid by a highly sensitive and rapid liquid chromatographic-tandem mass spectrometric method.

    Science.gov (United States)

    Srivastava, Abhishek; Waterhouse, David; Ardrey, Alison; Ward, Stephen A

    2012-11-01

    A highly sensitive and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed to measure the levels of the antitubercular drug rifampicin (RIF) in human plasma and cerebrospinal fluid (CSF). The analyte and internal standard (IS) were isolated from plasma and CSF by a simple organic solvent based precipitation of proteins followed by centrifugation. Detection was carried out by electrospray positive ionization mass spectrometry in the multiple-reaction monitoring (MRM) mode. The assay was linear in the concentration range 25-6400 ng/mL with intra- and inter-day precision of <7% and <8%, respectively. The validated method was applied to the study of RIF pharmacokinetics in human CSF and plasma over 25 h period after a 10 mg/kg oral dose. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Thin-film culturing technique allowing rapid gas-liquid equilibration (6 sec) with no toxicity to mammalian cells

    International Nuclear Information System (INIS)

    Koch, C.J.

    1984-01-01

    A method is described for inoculating mammalian cells onto the central area of glass petri dishes. The medium depth above the cells is only 100 μm for an added medium volume of 1 ml and increases linearly and rapidly with additional medium. The theoretical time constant for equilibration of the medium with the gas is related to the square of the medium depth. The experimental time constant was measured in two different ways for large and small medium depths, giving excellent agreement with the theoretical values. Although the time constant is only 6 sec for the case of 1 ml of added medium, there is no drying out of the medium or toxicity to the cells because of a large reservoir of medium in the meniscus at the periphery of the dish

  6. High-resolution ultrahigh-pressure long column reversed-phase liquid chromatography for top-down proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yufeng; Tolic, Nikola; Piehowski, Paul D.; Shukla, Anil K.; Kim, Sangtae; Zhao, Rui; Qu, Yi; Robinson, E. W.; Smith, Richard D.; Pasa-Tolic, Ljiljana

    2017-05-01

    We report development of an approach providing high-resolution RPLC of proteins and its utility for mass spectrometry-based top-down proteomics. A chromatographic peak capacity of ~450 was achieved for proteins and large polypeptides having MWs up to 43 kDa in the context of proteomics applications. RPLC column lengths from 20 to 200 cm, particle sizes from 1.5 to 5 m, bonding alkyl chains from C1 to C2, C4, C8, and C18, and particle surface structures that spanned porous, superficially porous (porous shell, core-shell), and nonporous were investigated at pressures up to14K psi. Column length was found as the most important factor for >20 kDa proteins in gradient RPLC, and shortening column length degraded RPLC resolution and sensitivity regardless of the size and surface structure of the packing particles used. The alkyl chains bonded to the silica particle surface significantly affected the RPLC recovery and efficiency, and short alkyl C1-C4 phases provided higher sensitivity and resolution than C8 and C18 phases. Long gradient separations (e.g., >10 hours) with long columns (e.g., 100 cm) were particularly effective in conjunction with use of high accuracy mass spectrometers (e.g., the Orbitrap Elite) for top-down proteomics with improved proteoform coverage by allowing multiple HCD, CID, and ETD dissociation modes. It was also found that HCD produced small fragments useful for proteoform identification, while low energy CID and ETD often complemented HCD by providing large fragments.

  7. A rapid liquid chromatography tandem mass spectrometry-based method for measuring propranolol on dried blood spots.

    Science.gov (United States)

    Della Bona, Maria Luisa; Malvagia, Sabrina; Villanelli, Fabio; Giocaliere, Elisa; Ombrone, Daniela; Funghini, Silvia; Filippi, Luca; Cavallaro, Giacomo; Bagnoli, Paola; Guerrini, Renzo; la Marca, Giancarlo

    2013-05-05

    Propranolol, a non-selective beta blocker drug, is used in young infants and newborns for treating several heart diseases; its pharmacokinetics has been extensively evaluated in adult patients using extrapolation to treat pediatric population. The purpose of the present study was to develop and validate a method to measure propranolol levels in dried blood spots. The analysis was performed by using liquid chromatography/tandem mass spectrometry operating in multiple reaction monitoring mode. The calibration curve in matrix was linear in the concentration range of 2.5-200 μg/L with correlation coefficient r=0.9996. Intra-day and inter-day precisions and biases were less than 8.0% (n=10) and 11.5% (n=10) respectively. The recoveries ranged from 94 to 100% and the matrix effect did not result in a severe signal suppression. Propranolol on dried blood spot showed a good stability at three different temperatures for one month. This paper describes a micromethod for measuring propranolol levels on dried blood spot, which determines a great advantage in neonates or young infants during pharmacokinetic studies because of less invasive sampling and small blood volume required. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Development of aquatic plant bioassays for rapid screening and interpretive risk assessments of metal mining liquid waste waters

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, H G [Saskatchewan Research Council, Saskatoon, SK (Canada); Nyholm, N [Technical Univ. of Denmark, Lyngby (Denmark). Lab. of Environmental Science and Ecology; Huang, P M [Saskatchewan Univ., Saskatoon (Canada). Saskatchewan Inst. of Pedology

    1996-12-31

    The use of non-photosynthetic organisms alone to describe environmental impact has been recognized by regulatory agencies, industry and academia as being totally inadequate both in Europe and North America. Lack of adequate testing methods for photosynthetic aquatic organisms has been recognized as a major impediment to the successful regulation and safe use of pesticides and waste water discharges and is of even more concern to the metal mining industry due to the non-biodegradable nature of its waste streams. This work shows that the chemical effluent limits set in the `Metal mining liquid effluent regulations and guidelines` provide variable protection of aquatic photosynthetic organisms and aquatic effects of the more toxic metals (e.g., copper, nickel, and zinc) may occur at levels that are one to two orders of magnitude lower than present limits. To establish adequate protection of receiving water bodies it may be necessary to establish site-specific criteria taking into consideration toxicity modifying factors of individual sites. If the establishment of such criteria is determined with a host of ecologically relevant organisms, it will be possible to design effective environmental protection at the least possible cost. (author). 17 refs., 2 tabs.

  9. Rapid Determination of Imatinib in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jeong Soo; Cho, Eun Gi; Huh, Wooseong; Ko, Jaewook; Jung, Jin Ah; Lee, Sooyoun [Samsung Medical Center, Seoul (Korea, Republic of)

    2013-08-15

    A simple, fast and robust analytical method was developed to determine imatinib in human plasma using liquid chromatography-tandem mass spectrometry with electrospray ionization in the positive ion mode. Imatinib and labeled internal standard were extracted from plasma with a simple protein precipitation. The chromatographic separation was performed using an isocratic elution of mobile phase involving 5.0 mM ammonium formate in water -5.0 mM ammonium formate in methanol (30:70, v/v) over 3.0 min on reversed-stationary phase. The detection was performed using a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring mode. The developed method was validated with lower limit of quantification of 10 ng/mL. The calibration curve was linear over 10-2000 ng/mL (R{sup 2} > 0.99). The method validation parameters met the acceptance criteria. The spiked samples and standard solutions were stable under conditions for storage and handling. The reliable method was successfully applied to real sample analyses and thus a pharmacokinetic study in 27 healthy Korean male volunteers.

  10. Rapid method for determination of glyphosate in groundwater using high performance liquid chromatography and solid-phase extraction after derivatization

    Directory of Open Access Journals (Sweden)

    Valdir Eduardo Olivo

    2015-04-01

    Full Text Available The intensive use of pesticides in agriculture has prompted researchers to develop new methods for identifying these pollutants in water. This study sought to validate a high performance liquid chromatography (HPLC method to determine the concentration of the pesticide glyphosate in groundwater samples by using solid-phase extraction (SPE filters after derivatization with chloroformate 9-fluorenylmethoxycarbonyl (FMOC-Cl. For the HPLC method, we evaluated the following main validation parameters: linearity, specificity, precision, accuracy, robustness, and limits of detection and quantification. After validation of the method, we determined the concentration of glyphosate in samples from thirteen deep, tubular wells distributed in urban and rural areas in Chapecó, SC, Brazil. The solvent used in the extraction of excess FMOC-Cl was dichloromethane and subsequently filtration was performed on C18 SPE, and injected into the chromatograph column in amino polymer with fluorescence detection. The analytical curve made in ultrapure water was linear, with a correlation coefficient of 0.99. The limits of detection and quantification were 0.24 and 0.07 µg L-1, respectively. Recovery tests in natural waters ranged from 90.37 to 101.70%. Glyphosate was detected in 5 of the thirteen wells evaluated. The highest concentration of glyphosate (6.80 µg L-1 was detected in a countryside well, near the municipal water supply. Despite the low levels of glyphosate detected in our study, any amount present in groundwater samples is worrisome, as these molecules have low ground mobility.

  11. Development of aquatic plant bioassays for rapid screening and interpretive risk assessments of metal mining liquid waste waters

    International Nuclear Information System (INIS)

    Peterson, H.G.; Nyholm, N.; Huang, P.M.

    1995-01-01

    The use of non-photosynthetic organisms alone to describe environmental impact has been recognized by regulatory agencies, industry and academia as being totally inadequate both in Europe and North America. Lack of adequate testing methods for photosynthetic aquatic organisms has been recognized as a major impediment to the successful regulation and safe use of pesticides and waste water discharges and is of even more concern to the metal mining industry due to the non-biodegradable nature of its waste streams. This work shows that the chemical effluent limits set in the 'Metal mining liquid effluent regulations and guidelines' provide variable protection of aquatic photosynthetic organisms and aquatic effects of the more toxic metals (e.g., copper, nickel, and zinc) may occur at levels that are one to two orders of magnitude lower than present limits. To establish adequate protection of receiving water bodies it may be necessary to establish site-specific criteria taking into consideration toxicity modifying factors of individual sites. If the establishment of such criteria is determined with a host of ecologically relevant organisms, it will be possible to design effective environmental protection at the least possible cost. (author). 17 refs., 2 tabs

  12. Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiangwei [Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101 (China); College of Science, China Agricultural University, Beijing 100193 (China); Xing, Zhuokan [College of Science, China Agricultural University, Beijing 100193 (China); Liu, Fengmao, E-mail: liufengmao@cau.edu.cn [College of Science, China Agricultural University, Beijing 100193 (China); Zhang, Xu [College of Science, China Agricultural University, Beijing 100193 (China)

    2015-05-22

    Highlights: • A novel AALLME-SFO method was firstly reported for pesticide residue analysis. • Solvent with low density and proper melting point was used as extraction solvent. • The formation of “cloudy solvent” with a syringe only. • The new method avoided the use of organic dispersive solvent. - Abstract: A novel air assisted liquid–liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μg L{sup −1}. The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3–13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.

  13. Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

    International Nuclear Information System (INIS)

    You, Xiangwei; Xing, Zhuokan; Liu, Fengmao; Zhang, Xu

    2015-01-01

    Highlights: • A novel AALLME-SFO method was firstly reported for pesticide residue analysis. • Solvent with low density and proper melting point was used as extraction solvent. • The formation of “cloudy solvent” with a syringe only. • The new method avoided the use of organic dispersive solvent. - Abstract: A novel air assisted liquid–liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μg L −1 . The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3–13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly

  14. Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of dextromethorphan in human plasma samples.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Javanbakht, Mehran; Akbari-Adergani, Behrouz

    2011-04-01

    In this paper, a novel method is described for automated determination of dextromethorphan in biological fluids using molecularly imprinted solid-phase extraction (MISPE) as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker, chloroform as porogen and dextromethorphan as template molecule. These imprinted polymers were used as solid-phase extraction sorbent for the extraction of dextromethorphan from human plasma samples. Various parameters affecting the extraction efficiency of the MIP cartridges were evaluated. The high selectivity of the sorbent coupled to the high performance liquid chromatographic system permitted a simple and rapid analysis of this drug in plasma samples with limits of detection (LOD) and quantification (LOQ) of 0.12 ng/mL and 0.35 ng/mL, respectively. The MIP selectivity was evaluated by analyzing of the dextromethorphan in presence of several substances with similar molecular structures and properties. Results from the HPLC analyses showed that the recoveries of dextromethorphan using MIP cartridges from human plasma samples in the range of 1-50 ng/mL were higher than 87%. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Specific ionic effect for simple and rapid colorimetric sensing assays of amino acids using gold nanoparticles modified with task-specific ionic liquid

    International Nuclear Information System (INIS)

    Wu, Datong; Cai, Pengfei; Tao, Zhihao; Pan, Yuanjiang

    2016-01-01

    In this study, a novel task-specific ionic liquid functionalized gold nanoparticle (TSIL-GNP) was successfully prepared and applied in the recognition of amino acids. Particularly, the surface of GNP was modified with the ionic liquid containing carbamido and ester group via thiol, which was characterized by Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The stability of this material in aqueous solution improves apparently and can remain unchanged for more than three months. The effect of pH was also discussed in this study. Attractive ionic interaction would effectively weaken intensity of the covalent coupling between the metal ion and the functional groups of amino acids. Thus, TSIL-GNP was successfully applied to recognizing serine, aspartic acid, lysine, arginine, and histidine in the presence of Cu"2"+ through distinctive color changes. Suspension would be generated once a spot of cysteine was added into the GNPs solution. Results indicated that it had a good linear relationship between extinction coefficients and concentration of amino acids in a wide range of 10"−"3–10"−"6 M. Moreover, the proposed strategy was successfully used to analyze the histidine in urinary samples. In brief, TSIL-GNP is a suitable substrate for discrimination of five amino acids in a rapid and simple way without sophisticated instruments. - Highlights: • A novel task-specific ionic liquid functionalized gold nanoparticle was successfully prepared. • This material was successfully applied to recognizing five amino acids with Cu(II) through distinctive color changes. • The proposed strategy was successfully used to analyze the histidine in real samples.

  16. Specific ionic effect for simple and rapid colorimetric sensing assays of amino acids using gold nanoparticles modified with task-specific ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Datong; Cai, Pengfei; Tao, Zhihao; Pan, Yuanjiang, E-mail: panyuanjiang@zju.edu.cn

    2016-01-01

    In this study, a novel task-specific ionic liquid functionalized gold nanoparticle (TSIL-GNP) was successfully prepared and applied in the recognition of amino acids. Particularly, the surface of GNP was modified with the ionic liquid containing carbamido and ester group via thiol, which was characterized by Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The stability of this material in aqueous solution improves apparently and can remain unchanged for more than three months. The effect of pH was also discussed in this study. Attractive ionic interaction would effectively weaken intensity of the covalent coupling between the metal ion and the functional groups of amino acids. Thus, TSIL-GNP was successfully applied to recognizing serine, aspartic acid, lysine, arginine, and histidine in the presence of Cu{sup 2+} through distinctive color changes. Suspension would be generated once a spot of cysteine was added into the GNPs solution. Results indicated that it had a good linear relationship between extinction coefficients and concentration of amino acids in a wide range of 10{sup −3}–10{sup −6} M. Moreover, the proposed strategy was successfully used to analyze the histidine in urinary samples. In brief, TSIL-GNP is a suitable substrate for discrimination of five amino acids in a rapid and simple way without sophisticated instruments. - Highlights: • A novel task-specific ionic liquid functionalized gold nanoparticle was successfully prepared. • This material was successfully applied to recognizing five amino acids with Cu(II) through distinctive color changes. • The proposed strategy was successfully used to analyze the histidine in real samples.

  17. Creating high-resolution time series land-cover classifications in rapidly changing forested areas with BULC-U in Google Earth Engine

    Science.gov (United States)

    Cardille, J. A.; Lee, J.

    2017-12-01

    With the opening of the Landsat archive, there is a dramatically increased potential for creating high-quality time series of land use/land-cover (LULC) classifications derived from remote sensing. Although LULC time series are appealing, their creation is typically challenging in two fundamental ways. First, there is a need to create maximally correct LULC maps for consideration at each time step; and second, there is a need to have the elements of the time series be consistent with each other, without pixels that flip improbably between covers due only to unavoidable, stray classification errors. We have developed the Bayesian Updating of Land Cover - Unsupervised (BULC-U) algorithm to address these challenges simultaneously, and introduce and apply it here for two related but distinct purposes. First, with minimal human intervention, we produced an internally consistent, high-accuracy LULC time series in rapidly changing Mato Grosso, Brazil for a time interval (1986-2000) in which cropland area more than doubled. The spatial and temporal resolution of the 59 LULC snapshots allows users to witness the establishment of towns and farms at the expense of forest. The new time series could be used by policy-makers and analysts to unravel important considerations for conservation and management, including the timing and location of past development, the rate and nature of changes in forest connectivity, the connection with road infrastructure, and more. The second application of BULC-U is to sharpen the well-known GlobCover 2009 classification from 300m to 30m, while improving accuracy measures for every class. The greatly improved resolution and accuracy permits a better representation of the true LULC proportions, the use of this map in models, and quantification of the potential impacts of changes. Given that there may easily be thousands and potentially millions of images available to harvest for an LULC time series, it is imperative to build useful algorithms

  18. Highly informative multiclass profiling of lipids by ultra-high performance liquid chromatography - Low resolution (quadrupole) mass spectrometry by using electrospray ionization and atmospheric pressure chemical ionization interfaces.

    Science.gov (United States)

    Beccaria, Marco; Inferrera, Veronica; Rigano, Francesca; Gorynski, Krzysztof; Purcaro, Giorgia; Pawliszyn, Janusz; Dugo, Paola; Mondello, Luigi

    2017-08-04

    A simple, fast, and versatile method, using an ultra-high performance liquid chromatography system coupled with a low resolution (single quadrupole) mass spectrometer was optimized to perform multiclass lipid profiling of human plasma. Particular attention was made to develop a method suitable for both electrospray ionization and atmospheric pressure chemical ionization interfaces (sequentially in positive- and negative-ion mode), without any modification of the chromatographic conditions (mobile phase, flow-rate, gradient, etc.). Emphasis was given to the extrapolation of the structural information based on the fragmentation pattern obtained using atmospheric pressure chemical ionization interface, under each different ionization condition, highlighting the complementary information obtained using the electrospray ionization interface, of support for related molecule ions identification. Furthermore, mass spectra of phosphatidylserine and phosphatidylinositol obtained using the atmospheric pressure chemical ionization interface are reported and discussed for the first time. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. HighResNPS.com – an Internet Database for Liquid Chromatography - High Resolution Mass Spectrometry Screening for New Psychoactive Substances

    DEFF Research Database (Denmark)

    Dalsgaard, Petur Weihe; Mollerup, Christian Brinch; Mardal, Marie

    /Discussions: . The overlapping entries of the database verify that similar fragment ions can be observed from identical compounds across different LC-HRMS systems. The inclusion of fragment ions from other labs can reduce false positive identifications, when no reference standard is available in-house. HighResNPS can serve......Background/Introduction: The number of new psychoactive substances (NPS) is constantly increasing which makes it challenging to keep the screening libraries updated with the relevant analytical targets. Liquid chromatography coupled High Resolution Mass Spectrometry (LC-HRMS) screening methods...... with most screening platforms after minor formatting. Results: Currently, 11 users from 9 laboratories in 7 counties have contributed with 318 entries to the database with experimental data containing at least one fragment ion. 66% of the uploaded data were based on reference standards. Synthetic...

  20. Identification of Organic Iodine Compounds and Their Transformation Products in Edible Iodized Salt Using Liquid Chromatography-High Resolution Mass Spectrometry.

    Science.gov (United States)

    Yun, Lifen; Peng, Yue'e; Chang, Qing; Zhu, Qingxin; Guo, Wei; Wang, Yanxin

    2017-07-05

    The consumption of edible iodized salt is a key strategy to control and eliminate iodine deficiency disorders worldwide. We herein report the identification of the organic iodine compounds present in different edible iodized salt products using liquid chromatography combined with high resolution mass spectrometry. A total of 38 organic iodine compounds and their transformation products (TPs) were identified in seaweed iodine salt from China. Our experiments confirmed that the TPs were generated by the replacement of I atoms from organic iodine compounds with Cl atoms. Furthermore, the organic iodine compound contents in 4 seaweed iodine salt samples obtained from different manufacturers were measured, with significant differences in content being observed. We expect that the identification of organic iodine compounds in salt will be important for estimating the validity and safety of edible iodized salt products.

  1. Analytical method by high resolution-liquid chromatography for assay of 2 g Clonazepam tablets disolution without lactose

    International Nuclear Information System (INIS)

    Garcia Penna, Caridad M; Diego Leon, Rafael; Castinneira Diaz, Mirta; Hernandez Cervera, Mirna; Martinez Espinosa, Vivian

    2007-01-01

    A valid method was developed to assess 2 mg Clonazepam tablets disolution without lactose by high-performance liquid chromatography by UV detection to 254 nm. Establishment of Clonazepam in dissolution medium was confirmed, and parameters of specificity, linearity, and accuracy were assessed, as well as influence of filtration and stability or active principle. Linearity curve was drawed in rank of 1, 2-2,6 μg/mL, with a correlation coefficient similar to 0,99418; statistical test wasn't statistically significant for interceptor and slope. In study, it was possible to demonstrate that stability or active principle in dissolution was maintained in more than double of duration of dissolution assay. (Author)

  2. An optimized method for neurotransmitters and their metabolites analysis in mouse hypothalamus by high performance liquid chromatography-Q Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry.

    Science.gov (United States)

    Yang, Zong-Lin; Li, Hui; Wang, Bing; Liu, Shu-Ying

    2016-02-15

    Neurotransmitters (NTs) and their metabolites are known to play an essential role in maintaining various physiological functions in nervous system. However, there are many difficulties in the detection of NTs together with their metabolites in biological samples. A new method for NTs and their metabolites detection by high performance liquid chromatography coupled with Q Exactive hybrid quadruple-orbitrap high-resolution accurate mass spectrometry (HPLC-HRMS) was established in this paper. This method was a great development of the applying of Q Exactive MS in the quantitative analysis. This method enabled a rapid quantification of ten compounds within 18min. Good linearity was obtained with a correlation coefficient above 0.99. The concentration range of the limit of detection (LOD) and the limit of quantitation (LOQ) level were 0.0008-0.05nmol/mL and 0.002-25.0nmol/mL respectively. Precisions (relative standard deviation, RSD) of this method were at 0.36-12.70%. Recovery ranges were between 81.83% and 118.04%. Concentrations of these compounds in mouse hypothalamus were detected by Q Exactive LC-MS technology with this method. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Rapid simultaneous determination of organophosphorus pesticides in human serum and urine by liquid chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Zlatković Milica

    2010-01-01

    Full Text Available Background/Aim. Analysis of organophosphosphorus compounds and their metabolites in a biological material includes the use of numerous methods, covering both preparation of samples for analysis and their identification that is considered to be very complex. Low concentrations monitoring requires implementation of highly sensitive analytical techniques. The aim of this study was to develop and validate an original and sensitive method for the detection and quantitation of organophosphorus pesticides (dimethoate, diazinon, malathion and malaoxon in human biological matrices (serum, urine. Methods. This method was based on a solid-phase extraction procedure, a chromatographic separation using an ACQUITY UPLC ® HSST3 column and mass spectrometric detection in the positve ion mode. Mobile phase: was consited of Solvent A (5 mM ammonium formate pH 3.0 and Solvent B (0.1% acetic formate in methanol, in a linear gradient (constant flow-rate 0.3 mL/min. Results. The standard curve was linear in the range of 0.05-5.00 mg/L for malathion and malaoxon, 0.10-5.00 mg/L for dimethoate and 0.05-2.50 mg/L for diazinon. The correlation coefficient was r ≥ 0.99. Extraction recoveries were satisfactory and ranged between 90-99%. The limits of detection (LOD was between 0.007- 0.07 mg/L and the limits of quantitation (LOQ ranged between 0.022-0.085 mg/L. Intra- and interassay precision and accuracy were satisfactory for all of the pesticides analyzed. Conclusion. The method of liquid chromatography - mass spectrometry is simple, accurate, and useful for the determination of organophosphorus pesticides in both clinical and forensic toxicology.

  4. Rapid liquid–liquid extraction of thallium(III from succinate media with 2-octylaminopyridine in chloroform as the extractant

    Directory of Open Access Journals (Sweden)

    SANDIP V. MAHAMUNI

    2008-04-01

    Full Text Available A simple solvent extraction study of thallium(III was conducted. Selective and quantitative extraction of thallium(III by 2-octylaminopyridine (2-OAP in chloroform occurred from aqueous sodium succinate medium (0.0075 M at pH 3.0. Thallium(III was back extracted with acetate buffer (pH 4.63. The effect of the concentration of succinate and 2-OAP, the role of various diluents, stripping agents, loading capacity of 2-OAP, equilibrium time and aqueous:organic volume ratio on the extraction of thallium(III was studied. The stoichiometry of the extracted species was determined based on the slope analysis method and found to be 1: 2: 1 (metal:acid:extractant. The temperature dependence of the extraction equilibrium constant was also examined to estimate the apparent thermodynamic functions ∆H, ∆G and ∆S for the extraction reaction. The method is free from interference of a large number of cations and anions. The method was used for the selective extraction of thallium(III from its binary mixture with Zn(II, Cd(II, Hg(II, Bi(III, Pb(II, Se(IV, Te(IV, Sb(III, Ga(III, In(III, Al(III, Tl(I and Fe(III. The proposed method was applied to the synthetic mixtures and alloys. It is simple, selective, rapid and eco-friendly.

  5. Rapid Development and Validation of Improved Reversed-Phase High-performance Liquid Chromatography Method for the Quantification of Mangiferin, a Polyphenol Xanthone Glycoside in Mangifera indica.

    Science.gov (United States)

    Naveen, P; Lingaraju, H B; Prasad, K Shyam

    2017-01-01

    Mangiferin, a polyphenolic xanthone glycoside from Mangifera indica , is used as traditional medicine for the treatment of numerous diseases. The present study was aimed to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC) method for the quantification of mangiferin from the bark extract of M. indica . RP-HPLC analysis was performed by isocratic elution with a low-pressure gradient using 0.1% formic acid: acetonitrile (87:13) as a mobile phase with a flow rate of 1.5 ml/min. The separation was done at 26°C using a Kinetex XB-C18 column as stationary phase and the detection wavelength at 256 nm. The proposed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification, and robustness by the International Conference on Harmonisation guidelines. In linearity, the excellent correlation coefficient more than 0.999 indicated good fitting of the curve and also good linearity. The intra- and inter-day precision showed high reliability and reproducibility of the method. The recovery values at three different levels (50%, 100%, and 150%) of spiked samples were found to be 100.47, 100.89, and 100.99, respectively, and low standard deviation value high accuracy of the method. In robustness, the results remain unaffected by small variation in the analytical parameters, which shows the robustness of the method. Liquid chromatography-mass spectrometry analysis confirmed the presence of mangiferin with M/Z value of 421. The assay developed by HPLC method is a simple, rapid, and reliable for the determination of mangiferin from M. indica . The present study was intended to develop and validate an RP-HPLC method for the quantification of mangiferin from the bark extract of M. indica . The developed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification and robustness by International Conference on Harmonization guidelines. This study proved that the developed

  6. A rapid approach for characterization of thiol-conjugated antibody-drug conjugates and calculation of drug-antibody ratio by liquid chromatography mass spectrometry.

    Science.gov (United States)

    Firth, David; Bell, Leonard; Squires, Martin; Estdale, Sian; McKee, Colin

    2015-09-15

    We present the demonstration of a rapid "middle-up" liquid chromatography mass spectrometry (LC-MS)-based workflow for use in the characterization of thiol-conjugated maleimidocaproyl-monomethyl auristatin F (mcMMAF) and valine-citrulline-monomethyl auristatin E (vcMMAE) antibody-drug conjugates. Deconvoluted spectra were generated following a combination of deglycosylation, IdeS (immunoglobulin-degrading enzyme from Streptococcus pyogenes) digestion, and reduction steps that provide a visual representation of the product for rapid lot-to-lot comparison-a means to quickly assess the integrity of the antibody structure and the applied conjugation chemistry by mass. The relative abundance of the detected ions also offer information regarding differences in drug conjugation levels between samples, and the average drug-antibody ratio can be calculated. The approach requires little material (<100 μg) and, thus, is amenable to small-scale process development testing or as an early component of a complete characterization project facilitating informed decision making regarding which aspects of a molecule might need to be examined in more detail by orthogonal methodologies. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Rapid and interference-free analysis of nine B-group vitamins in energy drinks using trilinear component modeling of liquid chromatography-mass spectrometry data.

    Science.gov (United States)

    Hu, Yong; Wu, Hai-Long; Yin, Xiao-Li; Gu, Hui-Wen; Xiao, Rong; Xie, Li-Xia; Liu, Zhi; Fang, Huan; Wang, Li; Yu, Ru-Qin

    2018-04-01

    The aim of the present work was to develop a rapid and interference-free method based on liquid chromatography-mass spectrometry (LC-MS) for the simultaneous determination of nine B-group vitamins in various energy drinks. A smart and green strategy that modeled the three-way data array of LC-MS with second-order calibration methods based on alternating trilinear decomposition (ATLD) and alternating penalty trilinear decomposition (APTLD) algorithms was developed. By virtue of "mathematical separation" and "second-order advantage", the proposed strategy successfully solved the co-eluted peaks and unknown interferents in LC-MS analysis with the elution time less than 4.5min and simple sample preparation. Satisfactory quantitative results were obtained by the ATLD-LC-MS and APTLD-LC-MS methods for the spiked recovery assays, with the average spiked recoveries ranging from 87.2-113.9% to 92.0-111.7%, respectively. These results acquired from the proposed methods were confirmed by the LC-MS/MS method, which shows a quite good consistency with each other. All these results demonstrated that the developed chemometrics-assisted LC-MS strategy had advantages of being rapid, green, accurate and low-cost, and it could be an attractive alternative for the determination of multiple vitamins in complex food matrices, which required no laborious sample preparation, tedious condition optimization or more sophisticated instrumentations. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Ultra-fast liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry for the rapid phenolic profiling of red maple (Acer rubrum) leaves.

    Science.gov (United States)

    Li, Chunting; Seeram, Navindra P

    2018-03-07

    The red maple (Acer rubrum) species is economically important to North America because of its sap, which is used to produce maple syrup. In addition, various other red maple plant parts, including leaves, were used as a traditional medicine by the Native Americans. Currently, red maple leaves are being used for nutraceutical and cosmetic applications but there are no published analytical methods for comprehensive phytochemical characterization of this material. Herein, a rapid and sensitive method using liquid chromatography with electrospray ionization time-of-flight tandem mass spectrometry was developed to characterize the phenolics in a methanol extract of red maple leaves and a proprietary phenolic-enriched red maple leaves extract (Maplifa™). Time-of-flight mass spectrometry and tandem mass spectrometry experiments led to the identification of 106 phenolic compounds in red maples leaves with the vast majority of these compounds also detected in Maplifa™. The compounds included 68 gallotannins, 25 flavonoids, gallic acid, quinic acid, catechin, epicatechin, and nine other gallic acid derivatives among which 11 are potentially new and 75 are being reported from red maple for the first time. The developed method to characterize red maple leaves phenolics is rapid and highly sensitive and could aid in future standardization and quality control of this botanical ingredient. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Online extraction-high performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry for rapid flavonoid profiling of Fructus aurantii immaturus.

    Science.gov (United States)

    Tong, Runna; Peng, Mijun; Tong, Chaoying; Guo, Keke; Shi, Shuyun

    2018-03-01

    Chemical profiling of natural products by high performance liquid chromatography (HPLC) was critical for understanding of their clinical bioactivities, and sample pretreatment steps have been considered as a bottleneck for analysis. Currently, concerted efforts have been made to develop sample pretreatment methods with high efficiency, low solvent and time consumptions. Here, a simple and efficient online extraction (OLE) strategy coupled with HPLC-diode array detector-quadrupole time-of-flight tandem mass spectrometry (HPLC-DAD-QTOF-MS/MS) was developed for rapid chemical profiling. For OLE strategy, guard column inserted with ground sample (2 mg) instead of sample loop was connected with manual injection valve, in which components were directly extracted and transferred to HPLC-DAD-QTOF-MS/MS system only by mobile phase without any extra time, solvent, instrument and operation. By comparison with offline heat-reflux extraction for Fructus aurantii immaturus (Zhishi), OLE strategy presented higher extraction efficiency perhaps because of the high pressure and gradient elution mode. A total of eighteen flavonoids were detected according to their retention times, UV spectra, exact mass, and fragmentation ions in MS/MS spectra, and compound 9, natsudaidain-3-O-glucoside, was discovered in Zhishi for the first time. It is concluded that the developed OLE-HPLC-DAD-QTOF-MS/MS system offers new perspectives for rapid chemical profiling of natural products. Copyright © 2018. Published by Elsevier B.V.

  10. Homogeneous liquid-liquid extraction (HoLLE) via flotation combined with gas chromatography-flame ionization detection as a very simple, rapid and sensitive method for the determination of fenitrothion in water samples.

    Science.gov (United States)

    Mashayekhi, Hossein Ali

    2013-01-01

    Homogeneous liquid-liquid extraction via flotation assistance (HoLLE-FA) and gas chromatography-flame ionization detection (GC-FID) was presented for the extraction and determination of fenitrothion in water samples. In this work, a rapid, simple and efficient HoLLE-FA method was developed based on applying low-density organic solvents without employing centrifugation. A special extraction cell was designed to facilitate the collection of low-density solvent extraction in the determination of fenitrothion in water samples. The water sample solution was added into an extraction cell that contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. Under the optimum conditions, the method performance was studied in terms of the linear dynamic range (LDR from 1.0 up to 100 μg L⁻¹), linearity (r² > 0.998), and precision (repeatability extraction and determination of fenitrothion in three different water samples.

  11. Establishment of a simple and rapid identification method for Listeria spp. by using high-resolution melting analysis, and its application in food industry.

    Science.gov (United States)

    Ohshima, Chihiro; Takahashi, Hajime; Phraephaisarn, Chirapiphat; Vesaratchavest, Mongkol; Keeratipibul, Suwimon; Kuda, Takashi; Kimura, Bon

    2014-01-01

    Listeria monocytogenes is the causative bacteria of listeriosis, which has a higher mortality rate than that of other causes of food poisoning. Listeria spp., of which L. monocytogenes is a member, have been isolated from food and manufacturing environments. Several methods have been published for identifying Listeria spp.; however, many of the methods cannot identify newly categorized Listeria spp. Additionally, they are often not suitable for the food industry, owing to their complexity, cost, or time consumption. Recently, high-resolution melting analysis (HRMA), which exploits DNA-sequence differences, has received attention as a simple and quick genomic typing method. In the present study, a new method for the simple, rapid, and low-cost identification of Listeria spp. has been presented using the genes rarA and ldh as targets for HRMA. DNA sequences of 9 Listeria species were first compared, and polymorphisms were identified for each species for primer design. Species specificity of each HRM curve pattern was estimated using type strains of all the species. Among the 9 species, 7 were identified by HRMA using rarA gene, including 3 new species. The remaining 2 species were identified by HRMA of ldh gene. The newly developed HRMA method was then used to assess Listeria isolates from the food industry, and the method efficiency was compared to that of identification by 16S rDNA sequence analysis. The 2 methods were in coherence for 92.6% of the samples, demonstrating the high accuracy of HRMA. The time required for identifying Listeria spp. was substantially low, and the process was considerably simplified, providing a useful and precise method for processing multiple samples per day. Our newly developed method for identifying Listeria spp. is highly valuable; its use is not limited to the food industry, and it can be used for the isolates from the natural environment.

  12. High resolution melting (HRM) analysis as a new tool for rapid identification of Salmonella enterica serovar Gallinarum biovars Pullorum and Gallinarum.

    Science.gov (United States)

    Ren, Xingxing; Fu, Ying; Xu, Chenggang; Feng, Zhou; Li, Miao; Zhang, Lina; Zhang, Jianmin; Liao, Ming

    2017-05-01

    Salmonella enterica serovar Gallinarum biovars Pullorum and Gallinarum represent the most common causative agents of chicken salmonellosis, which result in high mortality and morbidity throughout the world. It is difficult and laborious to discriminate these diseases based on biochemical or phenotypic methods. Herein, we report the development of a single nucleotide polymorphism (SNP) PCR-high resolution melt (PCR-HRM) assay for the detection and discrimination of both S. Pullorum and S. Gallinarun. The gene rfbS, which encodes a factor involved in the biosynthesis of ADP paratose in serogroup D of Salmonella, has been identified as a robust genetic marker for the identification of S. Pullorum and S. Gallinarun based on polymorphisms at positions 237 and 598. Therefore, PCR-HRM analyses were used to characterize this gene. A total of 15 reference and 33 clinical isolates of Salmonella and related Gram-negative bacteria were detected using 2 sets of primers. Our PCR-HRM assay could distinguish S. Pullorum from S. Gallinarun and other strains using the primer pair SP-237F/237R. Similarly, S. Gallinarun could be distinguished from S. Pullorum and other strains using primer set SG-598F/598R. These 2 assays showed high specificity (100%) for both S. Pullorum and S. Gallinarun; the sensitivity of these 2 assays was at least 100-fold greater than that of the allele-specific PCR assay. This present study demonstrated that HRM analysis represents a potent, simple, and economic tool for the rapid, specific, and sensitive detection of S. Pullorum and S. Gallinarun. Our approach also may aid efforts for purification of Avian Salmonella disease. © 2016 Poultry Science Association Inc.

  13. Rapid and simple extraction of lipids from blood plasma and urine for liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Bang, Dae Young; Byeon, Seul Kee; Moon, Myeong Hee

    2014-02-28

    A simple and fast lipid extraction method from human blood plasma and urine is introduced in this study. The effective lipid extraction from biological systems with a minimization of the matrix effect is important for the successful qualitative and quantitative analysis of lipids in liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The method described here is based on the modification of the quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction method, which was originally developed for pesticide residue analysis in food, for the purpose of isolating lipids from biological fluids. Applicability of QuEChERS method for lipids was evaluated by varying organic solvents for the extraction/partitioning of lipids in MgSO4/CH3COONa for the removal of water and by varying sorbents (primary secondary amines, graphitized carbon black, silica, strong anion exchange resins and C18 particles) for the dispersive solid-phase extraction (dSPE) step. This study shows that 2:1 (v/v) CHCl3/CH3OH is effective in the extraction/partitioning step and that 50mg of C18 particles (for 0.1mL plasma and 1mL of urine) are more suitable for sample cleanup for the dSPE step of the QuEChERS method. Matrix effects were calculated by comparing the recovery values of lipid standards spiked to both plasma and urine samples after extraction with those of the same standards in a neat solution using nanoflow LC-ESI-MS/MS, resulting in improved MS signals due to the decrease of the ion suppression compared to the conventional Folch method. The modified QuEChERS method was applied to lipid extracts from both human urine and plasma samples, demonstrating that it can be powerfully utilized for high-speed (<15min) preparation of lipids compared to the Folch method, with equivalent or slightly improved results in lipid identification using nLC-ESI-MS/MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Rapid, sensitive and reproducible method for point-of-collection screening of liquid milk for adulterants using a portable Raman spectrometer with novel optimized sample well

    Science.gov (United States)

    Nieuwoudt, Michel K.; Holroyd, Steve E.; McGoverin, Cushla M.; Simpson, M. Cather; Williams, David E.

    2017-02-01

    Point-of-care diagnostics are of interest in the medical, security and food industry, the latter particularly for screening food adulterated for economic gain. Milk adulteration continues to be a major problem worldwide and different methods to detect fraudulent additives have been investigated for over a century. Laboratory based methods are limited in their application to point-of-collection diagnosis and also require expensive instrumentation, chemicals and skilled technicians. This has encouraged exploration of spectroscopic methods as more rapid and inexpensive alternatives. Raman spectroscopy has excellent potential for screening of milk because of the rich complexity inherent in its signals. The rapid advances in photonic technologies and fabrication methods are enabling increasingly sensitive portable mini-Raman systems to be placed on the market that are both affordable and feasible for both point-of-care and point-of-collection applications. We have developed a powerful spectroscopic method for rapidly screening liquid milk for sucrose and four nitrogen-rich adulterants (dicyandiamide (DCD), ammonium sulphate, melamine, urea), using a combined system: a small, portable Raman spectrometer with focusing fibre optic probe and optimized reflective focusing wells, simply fabricated in aluminium. The reliable sample presentation of this system enabled high reproducibility of 8% RSD (residual standard deviation) within four minutes. Limit of detection intervals for PLS calibrations ranged between 140 - 520 ppm for the four N-rich compounds and between 0.7 - 3.6 % for sucrose. The portability of the system and reliability and reproducibility of this technique opens opportunities for general, reagentless adulteration screening of biological fluids as well as milk, at point-of-collection.

  15. Multiplex Biosensing Based on Highly Sensitive Magnetic Nanolabel Quantification: Rapid Detection of Botulinum Neurotoxins A, B, and E in Liquids.

    Science.gov (United States)

    Orlov, Alexey V; Znoyko, Sergey L; Cherkasov, Vladimir R; Nikitin, Maxim P; Nikitin, Petr I

    2016-11-01

    We present a multiplex quantitative lateral flow (LF) assay for simultaneous on-site detection of botulinum neurotoxin (BoNT) types A, B, and E in complex matrixes, which is innovative by virtually no sacrifice in performance while transition from the single-plex assays and by characteristics on the level of laboratory quantitative methods. The novel approach to easy multiplexing is realized via joining an on-demand set of single-plex LF strips, which employ magnetic nanolabels, into a miniature cylinder cartridge that mimics LF strip during all assay stages. The cartridge is read out by an original portable multichannel reader based on the magnetic particle quantification technique. The developed reader offers the unmatched 60 zmol detection limit and 7-order linear dynamic range for volumetric registration of magnetic labels inside a cartridge of several millimeters in diameter regardless of its optical transparency. Each of the test strips, developed here as building blocks for the multiplex assay, can be used "as is" for autonomous quantitative single-plex detection with the same measuring setup, exhibiting the limits of detection (LOD) of 0.22, 0.11, and 0.32 ng/mL for BoNT-A, -B, and -E, respectively. The proposed multiplex assay has demonstrated the remarkably similar LOD values of 0.20, 0.12, 0.35 ng/mL under the same conditions. The multiplex assay performance was successfully validated by BoNT detection in milk and apple and orange juices. The developed methods can be extended to other proteins and used for rapid multianalyte tests for point-of-care in vitro diagnostics, food analysis, biosafety and environmental monitoring, forensics, and security, etc.

  16. Setting up of a liquid chromatography-high resolution tandem mass spectrometry method for the detection of caseins in food. A comparison with ELISA method

    Directory of Open Access Journals (Sweden)

    Daniela Gastaldi

    2013-06-01

    Full Text Available Determination of caseins in food matrices is usually performed by using the competitiveenzyme- linked immunosorbent assay (ELISA technique. However such a technique suffers from a number of limitations. Among these, the applicability to a narrow concentration range, a non linear (logarithmic response, a non-negligible cross-reactivity and a high cost per kit. At the time of the completion of this study, in case of ELISA positive feedback, there was poor availability in the literature of finding reliable instrumental methods able to determine both qualitatively and quantitatively this class of substances. In the present study, a liquid chromatography-high resolution tandem mass spectrometry (HPLC-HRMS/MS instrumental method was developed with a high resolution mass spectrometer (Orbitrap. Real samples of sausages in which caseins were detected by ELISA technique were analysed. A casein-free sample of ham was used as a blank. The analytical characteristics of the instrumental method were compared with those of a commercial ELISA test, declared specific for α- and β-casein.

  17. Molecular-level characterization of crude oil compounds combining reversed-phase high-performance liquid chromatography with off-line high-resolution mass spectrometry

    Science.gov (United States)

    Sim, Arum; Cho, Yunju; Kim, Daae; Witt, Matthias; Birdwell, Justin E.; Kim, Byung Ju; Kim, Sunghwan

    2014-01-01

    A reversed-phase separation technique was developed in a previous study (Loegel et al., 2012) and successfully applied to the de-asphalted fraction of crude oil. However, to the best of our knowledge, the molecular-level characterization of oil fractions obtained by reversed-phase high-performance liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (MS) has not yet been reported. A detailed characterization of the oil fractions prepared by reversed-phase HPLC was performed in this study. HPLC fractionation was carried out on conventional crude oil and an oil shale pyrolysate. The analyses of the fractions showed that the carbon number of alkyl chains and the double bond equivalent (DBE) value were the major factors determining elution order. The compounds with larger DBE (presumably more condensed aromatic structures) and smaller carbon number (presumably compounds with short side chains) were eluted earlier but those compounds with lower DBE values (presumably less aromatic structures) and higher carbon number (presumably compounds with longer alkyl chains) eluted later in the chromatograms. This separation behavior is in good agreement with that expected from the principles of reversed-phase separation. The data presented in this study show that reversed-phase chromatography is effective in separating crude oil compounds and can be combined with ultrahigh-resolution MS data to better understand natural oils and oil shale pyrolysates.

  18. Tentative identification of polar and mid-polar compounds in extracts from wine lees by liquid chromatography-tandem mass spectrometry in high-resolution mode.

    Science.gov (United States)

    Delgado de la Torre, M P; Priego-Capote, F; Luque de Castro, M D

    2015-06-01

    Sustainable agriculture has a pending goal in the revalorization of agrofood residues. Wine lees are an abundant residue in the oenological industry. This residue, so far, has been used to obtain tartaric acid or pigments but not for being qualitatively characterized as a source of polar and mid-polar compounds such as flavonoids, phenols and essential amino acids. Lees extracts from 11 Spanish wineries have been analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in high resolution mode. The high-resolution power of LC-MS/MS has led to the tentative identification of the most representative compounds present in wine lees, comprising primary amino acids, anthocyans, flavanols, flavonols, flavones and non-flavonoid phenolic compounds, among others. Attending to the profile and content of polar and mid-polar compounds in wine lees, this study underlines the potential of wine lees as an exploitable source to isolate interesting compounds. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Development of a new screening method for the detection of antibiotic residues in muscle tissues using liquid chromatography and high resolution mass spectrometry with a LC-LTQ-Orbitrap instrument.

    OpenAIRE

    2011-01-01

    Abstract In the present work, a liquid chromatography- high resolution mass spectrometry method was developed for the screening in meat of a wide range of antibiotics used in veterinary medicine. Full scan mode under high resolution mass spectral conditions using LTQ-Orbitrap mass spectrometer with resolving power 60.000 FWHM was applied for analysis of the samples. Samples were prepared using two extractions protocols prior to LC-MS analysis. The scope of the method focuses on the...

  20. Flux Analysis of Free Amino Sugars and Amino Acids in Soils by Isotope Tracing with a Novel Liquid Chromatography/High Resolution Mass Spectrometry Platform.

    Science.gov (United States)

    Hu, Yuntao; Zheng, Qing; Wanek, Wolfgang

    2017-09-05

    Soil fluxomics analysis can provide pivotal information for understanding soil biochemical pathways and their regulation, but direct measurement methods are rare. Here, we describe an approach to measure soil extracellular metabolite (amino sugar and amino acid) concentrations and fluxes based on a 15 N isotope pool dilution technique via liquid chromatography and high-resolution mass spectrometry. We produced commercially unavailable 15 N and 13 C labeled amino sugars and amino acids by hydrolyzing peptidoglycan isolated from isotopically labeled bacterial biomass and used them as tracers ( 15 N) and internal standards ( 13 C). High-resolution (Orbitrap Exactive) MS with a resolution of 50 000 allowed us to separate different stable isotope labeled analogues across a large range of metabolites. The utilization of 13 C internal standards greatly improved the accuracy and reliability of absolute quantification. We successfully applied this method to two types of soils and quantified the extracellular gross fluxes of 2 amino sugars, 18 amino acids, and 4 amino acid enantiomers. Compared to the influx and efflux rates of most amino acids, similar ones were found for glucosamine, indicating that this amino sugar is released through peptidoglycan and chitin decomposition and serves as an important nitrogen source for soil microorganisms. d-Alanine and d-glutamic acid derived from peptidoglycan decomposition exhibited similar turnover rates as their l-enantiomers. This novel approach offers new strategies to advance our understanding of the production and transformation pathways of soil organic N metabolites, including the unknown contributions of peptidoglycan and chitin decomposition to soil organic N cycling.

  1. Flux Analysis of Free Amino Sugars and Amino Acids in Soils by Isotope Tracing with a Novel Liquid Chromatography/High Resolution Mass Spectrometry Platform

    Science.gov (United States)

    2017-01-01

    Soil fluxomics analysis can provide pivotal information for understanding soil biochemical pathways and their regulation, but direct measurement methods are rare. Here, we describe an approach to measure soil extracellular metabolite (amino sugar and amino acid) concentrations and fluxes based on a 15N isotope pool dilution technique via liquid chromatography and high-resolution mass spectrometry. We produced commercially unavailable 15N and 13C labeled amino sugars and amino acids by hydrolyzing peptidoglycan isolated from isotopically labeled bacterial biomass and used them as tracers (15N) and internal standards (13C). High-resolution (Orbitrap Exactive) MS with a resolution of 50 000 allowed us to separate different stable isotope labeled analogues across a large range of metabolites. The utilization of 13C internal standards greatly improved the accuracy and reliability of absolute quantification. We successfully applied this method to two types of soils and quantified the extracellular gross fluxes of 2 amino sugars, 18 amino acids, and 4 amino acid enantiomers. Compared to the influx and efflux rates of most amino acids, similar ones were found for glucosamine, indicating that this amino sugar is released through peptidoglycan and chitin decomposition and serves as an important nitrogen source for soil microorganisms. d-Alanine and d-glutamic acid derived from peptidoglycan decomposition exhibited similar turnover rates as their l-enantiomers. This novel approach offers new strategies to advance our understanding of the production and transformation pathways of soil organic N metabolites, including the unknown contributions of peptidoglycan and chitin decomposition to soil organic N cycling. PMID:28776982

  2. Metabolism of clofibric acid in zebrafish embryos (Danio rerio) as determined by liquid chromatography-high resolution-mass spectrometry.

    Science.gov (United States)

    Brox, Stephan; Seiwert, Bettina; Haase, Nora; Küster, Eberhard; Reemtsma, Thorsten

    2016-01-01

    The zebrafish embryo (ZFE) is increasingly used in ecotoxicology research but detailed knowledge of its metabolic potential is still limited. This study focuses on the xenobiotic metabolism of ZFE at different life-stages using the pharmaceutical compound clofibric acid as study compound. Liquid chromatography with quadrupole-time-of-flight mass spectrometry (LC-QToF-MS) is used to detect and to identify the transformation products (TPs). In screening experiments, a total of 18 TPs was detected and structure proposals were elaborated for 17 TPs, formed by phase I and phase II metabolism. Biotransformation of clofibric acid by the ZFE involves conjugation with sulfate or glucuronic acid, and, reported here for the first time, with carnitine, taurine, and aminomethanesulfonic acid. Further yet unknown cyclization products were identified using non-target screening that may represent a new detoxification pathway. Sulfate containing TPs occurred already after 3h of exposure (7hpf), and from 48h of exposure (52hpf) onwards, all TPs were detected. The detection of these TPs indicates the activity of phase I and phase II enzymes already at early life-stages. Additionally, the excretion of one TP into the exposure medium was observed. The results of this study outline the high metabolic potential of the ZFE with respect to the transformation of xenobiotics. Similarities but also differences to other test systems were observed. Biotransformation of test chemicals in toxicity testing with ZFE may therefore need further consideration. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Ganglioside Composition in Beef, Chicken, Pork, and Fish Determined Using Liquid Chromatography-High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Fong, Bertram Y; Ma, Lin; Khor, Geok Lin; van der Does, Yvonne; Rowan, Angela; McJarrow, Paul; MacGibbon, Alastair K H

    2016-08-17

    Gangliosides (GA) are found in animal tissues and fluids, such as blood and milk. These sialo-glycosphingolipids have bioactivities in neural development, the gastrointestinal tract, and the immune system. In this study, a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method was validated to characterize and quantitate the GA in beef, chicken, pork, and fish species (turbot, snapper, king salmon, and island mackerel). For the first time, we report the concentration of GM3, the dominant GA in these foods, as ranging from 0.35 to 1.1 mg/100 g and 0.70 to 5.86 mg/100 g of meat and fish, respectively. The minor GAs measured were GD3, GD1a, GD1b, and GT1b. Molecular species distribution revealed that the GA contained long- to very-long-chain acyl fatty acids attached to the ceramide moiety. Fish GA contained only N-acetylneuraminic acid (NeuAc) sialic acid, while beef, chicken, and pork contained GD1a/b species that incorporated both NeuAc and N-glycolylneuraminic acid (NeuGc) and hydroxylated fatty acids.

  4. Ultra-high-performance liquid chromatography-Time-of-flight high resolution mass spectrometry to quantify acidic drugs in wastewater.

    Science.gov (United States)

    Becerra-Herrera, Mercedes; Honda, Luis; Richter, Pablo

    2015-12-04

    A novel analytical approach involving an improved rotating-disk sorptive extraction (RDSE) procedure and ultra-high-performance liquid chromatography (UHPLC) coupled to an ultraspray electrospray ionization source (UESI) and time-of-flight mass spectrometry (TOF/MS), in trap mode, was developed to identify and quantify four non-steroidal anti-inflammatory drugs (NSAIDs) (naproxen, ibuprofen, ketoprofen and diclofenac) and two anti-cholesterol drugs (ACDs) (clofibric acid and gemfibrozil) that are widely used and typically found in water samples. The method reduced the amount of both sample and reagents used and also the time required for the whole analysis, resulting in a reliable and green analytical strategy. The analytical eco-scale was calculated, showing that this methodology is an excellent green analysis, increasing its ecological worth. The detection limits (LOD) and precision (%RSD) were lower than 90ng/L and 10%, respectively. Matrix effects and recoveries were studied using samples from the influent of a wastewater treatment plant (WWTP). All the compounds exhibited suppression of their signals due to matrix effects, and the recoveries were approximately 100%. The applicability and reliability of this methodology were confirmed through the analysis of influent and effluent samples from a WWTP in Santiago, Chile, obtaining concentrations ranging from 1.1 to 20.5μg/L and from 0.5 to 8.6μg/L, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Investigating the presence of omeprazole in waters by liquid chromatography coupled to low and high resolution mass spectrometry: degradation experiments.

    Science.gov (United States)

    Boix, C; Ibáñez, M; Sancho, J V; Niessen, W M A; Hernández, F

    2013-10-01

    Omeprazole is one of the most consumed pharmaceuticals around the world. However, this compound is scarcely detected in urban wastewater and surface water. The absence of this pharmaceutical in the aquatic ecosystem might be due to its degradation in wastewater treatment plants, as well as in receiving water. In this work, different laboratory-controlled degradation experiments have been carried out on surface water in order to elucidate generated omeprazole transformation products (TPs). Surface water spiked with omeprazole was subjected to hydrolysis, photo-degradation under both sunlight and ultraviolet radiation and chlorination. Analyses by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF MS) permitted identification of up to 17 omeprazole TPs. In a subsequent step, the TPs identified were sought in surface water and urban wastewater by LC-QTOF MS and by LC coupled to tandem mass spectrometry with triple quadrupole. The parent omeprazole was not detected in any of the samples, but four TPs were found in several water samples. The most frequently detected compound was OTP 5 (omeprazole sulfide), which might be a reasonable candidate to be included in monitoring programs rather than the parent omeprazole. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Metabolic profile modifications in milk after enrofloxacin administration studied by liquid chromatography coupled with high resolution mass spectrometry.

    Science.gov (United States)

    Junza, A; Saurina, J; Barrón, D; Minguillón, C

    2016-08-19

    High resolution accurate mass spectrometry (HRMS) operating in full scan MS mode was used in the search and identification of metabolites in raw milk from cows medicated with enrofloxacin. Data consisting of m/z features were taken throughout the entire chromatogram of milk samples from medicated animals and were compared with blank samples. Twenty six different compounds were identified. Some of them were attributed to structures related to enrofloxacin while others were dipeptides or tripeptides. Additionally, enrofloxacin was administered in a controlled treatment for three days. Milk was collected daily from the first day of treatment and until four days after in the search for the identified compounds. The obtained data were chemometrically treated by Principal Component Analysis. Samples were classified by this method into three different groups corresponding to days 1-2, day 3 and days 4-7 considering the different concentration profile evolution of metabolites during the days studied. Tentative metabolic pathways were designed to rationalize the presence of the newly identified compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Detection of anabolic and androgenic steroids and/or their esters in horse hair using ultra-high performance liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Kwok, Karen Y; Choi, Timmy L S; Kwok, Wai Him; Wong, Jenny K Y; Wan, Terence S M

    2017-04-14

    Anabolic and androgenic steroids (AASs) are a class of prohibited substances banned in horseracing at all times. The common approach for controlling the misuse of AASs in equine sports is by detecting the presence of AASs and/or their metabolites in urine and blood samples using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). This approach, however, often falls short as the duration of effect for many AASs are longer than their detection time in both urine and blood. As a result, there is a high risk that such AASs could escape detection in their official race-day samples although they may have been used during the long period of training. Hair analysis, on the other hand, can afford significantly longer detection windows. In addition, the identification of synthetic ester derivatives of AASs in hair, particularly for the endogenous ones, can provide unequivocal proof of their exogenous origin. This paper describes the development of a sensitive method (at sub to low parts-per-billion or ppb levels) for detecting 48 AASs and/or their esters in horse hair using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Decontaminated horse hair was pulverised and subjected to in-situ liquid-liquid extraction in a mixture of hexane - ethyl acetate (7:3, v/v) and phosphate buffer (0.1M, pH 9.5), followed by additional clean-up using mixed-mode solid-phase extraction. The final extract was analysed using UHPLC-HRMS in the positive electrospray ionisation (ESI) mode with both full scan and parallel reaction monitoring (PRM). This method was validated for qualitative identification purposes. Validation data, including method specificity, method sensitivity, extraction recovery, method precision and matrix effect are presented. Method applicability was demonstrated by the successful detection and confirmation of testosterone propionate in a referee hair sample. To our knowledge, this was

  8. Rapid determination of six carcinogenic primary aromatic amines in mainstream cigarette smoke by two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Bie, Zhenying; Lu, Wei; Zhu, You; Chen, Yusong; Ren, Hubo; Ji, Lishun

    2017-01-27

    A fully automated, rapid, and reliable method for simultaneous determination of six carcinogenic primary aromatic amines (AAs), including o-toluidine (o-TOL), 2, 6-dimethylaniline (2, 6-DMA), o-anisidine (o-ASD), 1-naphthylamine (1-ANP), 2-naphthylamine (2-ANP), and 4-aminobiphenyl (4-ABP), in mainstream cigarette smoke was established. The proposed method was based on two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry (SPE/LC-MS/MS). The particulate phase of the mainstream cigarette smoke was collected on a Cambridge filter pad and pretreated via ultrasonic extraction with 2% formic acid (FA), while the gas phase was trapped by 2% FA without pretreatment for determination. The two-dimensional online SPE comprised of two cartridges with different absorption characteristics was applied for sample pretreatment. Analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) under multiple reaction monitoring mode. Each sample required about 0.5h for solid phase extraction and analysis. The limit of detections (LODs) for six AAs ranged from 0.04 to 0.58ng/cig and recoveries were within 84.5%-122.9%. The relative standard deviations of intra- and inter-day tests for 3R4F reference cigarette were less than 6% and 7%, respectively, while no more than 7% and 8% separately for a type of Virginia cigarette. The proposed method enabled minimum sample pretreatment, full automation, and high throughput with high selectivity, sensitivity, and accuracy. As a part of the validation procedure, fifteen brands of cigarettes were tested by the designed method. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography–mass spectrometry

    International Nuclear Information System (INIS)

    Jiao, Jiao; Ma, Dan-Hui; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Fu, Yu-Jie; Ma, Wei

    2013-01-01

    Graphical abstract: -- Highlights: •A new ILAMD-HS-SDME method is developed for the microextraction of essential oil. •ILs used as destruction agent of plant cell walls and microwave absorption medium. •Parameters affecting the extraction efficiency are optimized by Box–Behnken design. •Procedure benefits: similar constituents, shorter duration and smaller sample amount. •ILAMD-HS-SDME followed by GC–MS is a promising technique in analytical fields. -- Abstract: A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography–mass spectrometry (GC–MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C 2 mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78 °C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences

  10. Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography–mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Jiao [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); Ma, Dan-Hui [College of Life Sciences, Northeast Forestry University, Harbin 150040 (China); Gai, Qing-Yan; Wang, Wei; Luo, Meng [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Fu, Yu-Jie, E-mail: yujie_fu2002@yahoo.com [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Ma, Wei, E-mail: mawei@hljucm.net [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); School of Pharmaceutical, Heilongjiang University of Chinese Medicine, Harbin 150040 (China)

    2013-12-04

    Graphical abstract: -- Highlights: •A new ILAMD-HS-SDME method is developed for the microextraction of essential oil. •ILs used as destruction agent of plant cell walls and microwave absorption medium. •Parameters affecting the extraction efficiency are optimized by Box–Behnken design. •Procedure benefits: similar constituents, shorter duration and smaller sample amount. •ILAMD-HS-SDME followed by GC–MS is a promising technique in analytical fields. -- Abstract: A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography–mass spectrometry (GC–MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C{sub 2}mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78 °C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences.

  11. Bioconversion of red ginseng saponins in the gastro-intestinal tract in vitro model studied by high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry

    NARCIS (Netherlands)

    Kong, H.; Wang, M.; Venema, K.; Maathuis, A.; Heijden, R. van der; Greef, J. van der; Xu, G.; Hankemeier, T.

    2009-01-01

    A high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FTICR-MS) method was developed to investigate the metabolism of ginsenosides in in vitro models of the gastro-intestinal tract. The metabolites were identified by

  12. Rapid analysis of aminoglycoside antibiotics in bovine tissues using disposable pipette extraction and ultrahigh performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lehotay, Steven J; Mastovska, Katerina; Lightfield, Alan R; Nuñez, Alberto; Dutko, Terry; Ng, Chilton; Bluhm, Louis

    2013-10-25

    A high-throughput qualitative screening and identification method for 9 aminoglycosides of regulatory interest has been developed, validated, and implemented for bovine kidney, liver, and muscle tissues. The method involves extraction at previously validated conditions, cleanup using disposable pipette extraction, and analysis by a 3 min ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. The drug analytes include neomycin, streptomycin, dihydrosptreptomycin, and spectinomycin, which have residue tolerances in bovine in the US, and kanamicin, gentamicin, apramycin, amikacin, and hygromycin, which do not have US tolerances established in bovine tissues. Tobramycin was used as an internal standard. An additional drug, paromomycin also was validated in the method, but it was dropped during implementation due to conversion of neomycin into paromomycin. Proposed fragmentation patterns for the monitored ions of each analyte were elucidated with the aid of high resolution MS using a quadrupole-time-of-flight instrument. Recoveries from spiking experiments at regulatory levels of concern showed that all analytes averaged 70-120% recoveries in all tissues, except hygromycin averaged 61% recovery. Lowest calibrated levels were as low as 0.005 μg/g in matrix extracts, which approximately corresponded to the limit of detection for screening purposes. Drug identifications at levels advantages compared to the previous microbial inhibition screening assay, especially for distinguishing individual drugs from a mixture and improving identification of gentamicin in tissue samples. Published by Elsevier B.V.

  13. Rapid microwave hydrothermal synthesis of ZnGa2O4 with high photocatalytic activity toward aromatic compounds in air and dyes in liquid water

    International Nuclear Information System (INIS)

    Sun Meng; Li Danzhen; Zhang Wenjuan; Chen Zhixin; Huang Hanjie; Li Wenjuan; He Yunhui; Fu Xianzhi

    2012-01-01

    ZnGa 2 O 4 was synthesized from Ga(NO 3 ) 3 and ZnCl 2 via a rapid and facile microwave-assisted hydrothermal method. The photocatalytic properties of the as-prepared ZnGa 2 O 4 were evaluated by the degradation of pollutants in air and aqueous solution under ultraviolet (UV) light illumination. The results demonstrated that ZnGa 2 O 4 had exhibited efficient photocatalytic activities higher than that of commercial P25 (Degussa Co.) in the degradation of benzene, toluene, and ethylbenzene, respectively. In the liquid phase degradation of dyes (methyl orange, Rhodamine B, and methylene blue), ZnGa 2 O 4 has also exhibited remarkable activities higher than that of P25. After 32 min of UV light irradiation, the decomposition ratio of methyl orange (10 ppm, 150 mL) over ZnGa 2 O 4 (0.06 g) was up to 99%. The TOC tests revealed that the mineralization ratio of MO (10 ppm, 150 mL) was 88.1% after 90 min of reaction. A possible mechanism of the photocatalysis over ZnGa 2 O 4 was also proposed. - Graphical abstract: In the degradation of RhB under UV light irradiation, ZnGa 2 O 4 had exhibited efficient photo-activity, and after only 24 min of irradiation the decomposition ratio was up to 99.8%. Highlights: ► A rapid and facile M–H method to synthesize ZnGa 2 O 4 photocatalyst. ► The photocatalyst exhibits high activity toward benzene and dyes. ► The catalyst possesses more surface hydroxyl sites than TiO 2 (P25). ► Deep oxidation of different aromatic compounds and dyes over catalyst.

  14. Decomposition of pilocarpine eye drops assessed by a highly efficient high pressure liquid chromatographic method

    NARCIS (Netherlands)

    Kuks, P. F.; Weekers, L. E.; Goldhoorn, P. B.

    1990-01-01

    A rapid high-resolution high pressure liquid chromatographic method was developed for assaying pilocarpine. Pilocarpine in ophthalmic solutions decomposes fairly rapidly to give isopilocarpine, pilocarpic acid and isopilocarpic acid. The quality of an ophthalmic solution can be assessed by assaying

  15. SIMULTANEOUS ANALYSIS OF AZIDOTHYMIDINE AND ITS MONOPHOSPHATE, DIPHOSPHATE AND TRIPHOSPHATE DERIVATIVES IN BIOLOGICAL-FLUIDS, TISSUE AND CULTURED-CELLS BY A RAPID HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD

    NARCIS (Netherlands)

    MOLEMA, G; JANSEN, RW; Visser, Jan; MEIJER, DKF

    1992-01-01

    A rapid high-performance liquid chromatographic (HPLC) method for the simultaneous analysis of the antiviral drug azidothymidine (AZT), AZT monophosphate, AZT diphosphate and AZT triphosphate, with ultraviolet detection in the nanomolar range, is described. Determination of these compounds in vitro

  16. Analysis of lipophilic marine biotoxins by liquid chromatography coupled with high-resolution mass spectrometry in seawater from the Catalan Coast.

    Science.gov (United States)

    Bosch-Orea, Cristina; Sanchís, Josep; Farré, Marinella; Barceló, Damià

    2017-09-01

    Marine biotoxins regularly occur along the coast, with several consequences for the environment as well as the food industry. Monitoring of these compounds in seawater is required to assure the safety of marine resources for human consumption, providing a means for forecasting shellfish contamination events. In this study, an analytical method was developed for the detection of ten lipophilic marine biotoxins in seawater: azaspiracids 1, 2, 3, 4 and 5, classified as azaspiracid shellfish poisoning toxins, and pectenotoxin 2, okadaic acid and the related dinophysistoxin 1, yessotoxin and homoyessotoxin, classified as diarrheic shellfish poisoning toxins. The method is based on the application of solid-liquid ultrasound-assisted extraction and solid-phase extraction, followed by high-performance liquid chromatography coupled with high-resolution mass spectrometry. The limits of detection of this method are in the range of nanograms per litre and picograms per litre for most of the compounds, and recoveries range from 20.5% to 97.2%. To validate the effectiveness of this method, 36 samples of surface water from open coastal areas and marinas located along the Catalan coast on the Mediterranean Sea were collected and analysed. Eighty-eight per cent of these samples exhibited okadaic acid in particulate and aqueous phases in concentrations ranging from 0.11 to 560 μg/g and from 2.1 to 1780 ng/L respectively. Samples from open coastal areas exhibited higher concentrations of okadaic acid in particulate material, whereas in samples collected in sportive ports, the particulate material exhibited lower levels than the aqueous phase. Graphical Abstract Biotoxins investigated in seawater of the Catalan coast.

  17. Study of the influence of the fast neutron spectrum on the production of defects in solids and liquids; Etude de l'influence du spectre des neutrons rapides sur la creation de defauts dans les solides et les liquides

    Energy Technology Data Exchange (ETDEWEB)

    Mas, P; Droulers, Y [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    In the first part of this work a calculation has been made of the number of defects formed in graphite by a given neutron flux having various spectral distributions. The defect formation function is that of KINCHIN and PEASE; its formulation is briefly given. An efficiency function is then defined for a fast neutron spectrum. This defects produced in a light water reactor and those produced in a graphite reactor. Finally an application of this method is given for comparing the defect forming tendency in graphite in the case of the reactor Melusine and of the reactor G-2 and G-3. In the second part are calculated the integrals for the energy release brought about by fast neutrons in carbon oxygen and hydrogen. In a region of 25 cm around the core of a swimming-pool type reactor these energy release integrals are approximately proportional to the neutron flux above 1 MeV. The determination of the energy released as a result of the passage of neutrons in organic liquids can therefore be reduced to the measurement of the flux above 1 MeV for the real spectral distribution. A calorimetric verification has been carried out in the case of water. (authors) [French] Dans la premiere partie de cette etude, on a calcule le nombre de defauts crees dans le graphite par un flux de neutrons donne, pris sous differents spectres. On a ainsi fait les calculs pour 4 spectres de pile. piscine et 2 spectres de pile au graphite. La fonction creation de defauts est celle de KINCHIN et PEASE. On rappelle brievement sa formulation. Puis on definit une fonction efficacite d'un spectre de neutrons rapides. Cette fonction permet alors d'etablir la relation entre defauts crees dans une pile a eau legere et defauts crees dans une pile au graphite. Enfin, une application de cette methode est donnee pour comparer l'aptitude a creer les defauts dans le graphite par la pile MELUSINE et les piles G-2 ou G-3. Dans la deuxieme partie, on a calcule les integrales de degagement d'energie provoque par

  18. Determination of anthelmintic drug residues in milk using ultra high performance liquid chromatography-tandem mass spectrometry with rapid polarity switching.

    Science.gov (United States)

    Whelan, Michelle; Kinsella, Brian; Furey, Ambrose; Moloney, Mary; Cantwell, Helen; Lehotay, Steven J; Danaher, Martin

    2010-07-02

    A new UHPLC-MS/MS (ultra high performance liquid chromatography coupled to tandem mass spectrometry) method was developed and validated to detect 38 anthelmintic drug residues, consisting of benzimidazoles, avermectins and flukicides. A modified QuEChERS-type extraction method was developed with an added concentration step to detect most of the analytes at keeper to ensure analytes remain in solution. Using rapid polarity switching in electrospray ionisation, a single injection was capable of detecting both positively and negatively charged ions in a 13 min run time. The method was validated at two levels: the unapproved use level and at the maximum residue level (MRL) according to Commission Decision (CD) 2002/657/EC criteria. The decision limit (CCalpha) of the method was in the range of 0.14-1.9 and 11-123 microg kg(-1) for drugs validated at unapproved and MRL levels, respectively. The performance of the method was successfully verified for benzimidazoles and levamisole by participating in a proficiency study.

  19. Rapid, Sensitive and Validated Ultra-Performance Liquid Chromatography/Mass Spectrometric Method for the Determination of Fenofibric Acid and its Application to Human Pharmacokinetic Study

    Directory of Open Access Journals (Sweden)

    Sunil K. Dubey

    2010-01-01

    Full Text Available The first, rapid and sensitive ultra performance liquid chromatography mass spectrometric method for the determination of fenofibric acid, the active metabolite of fenofibrate, a lipid regulating agent, in human EDTA plasma has been developed and validated using fenofibric d6 acid as internal standard and Waters LC-MS/MS. Negative ions of fenofibric acid and fenofibric d6 acid were detected in multiple reaction-monitoring (MRM mode. The method was validated over a concentration range of 0.176 μg/mL to 19.837 μg/mL (r ≥ 0.99. It took only 1.5 minute to analyse a sample. Intra- and inter-run precision of fenofibric acid assay at four concentrations ranged from 0.5% to 4.3% with accuracy varied from 93.1 to 108.1% indicating good precision and accuracy. Analytical recoveries of fenofibric acid and internal standard in plasma were less than 90%. This method was successfully applied for evaluation of pharmacokinetics of fenofibric acid after a single oral dose of 145 mg fenofibrate to 10 Indian healthy volunteers

  20. Rapid and precise measurement of serum branched-chain and aromatic amino acids by isotope dilution liquid chromatography tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Ruiyue Yang

    Full Text Available BACKGROUND: Serum branched-chain and aromatic amino acids (BCAAs and AAAs have emerged as predictors for the future development of diabetes and may aid in diabetes risk assessment. However, the current methods for the analysis of such amino acids in biological samples are time consuming. METHODS: An isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS method for serum BCAAs and AAAs was developed. The serum was mixed with isotope-labeled BCAA and AAA internal standards and the amino acids were extracted with acetonitrile, followed by analysis using LC/MS/MS. The LC separation was performed on a reversed-phase C18 column, and the MS/MS detection was performed via the positive electronic spray ionization in multiple reaction monitoring mode. RESULTS: Specific analysis of the amino acids was achieved within 2 min. Intra-run and total CVs for the amino acids were less than 2% and 4%, respectively, and the analytical recoveries ranged from 99.6 to 103.6%. CONCLUSION: A rapid and precise method for the measurement of serum BCAAs and AAAs was developed and may serve as a quick tool for screening serum BCAAs and AAAs in studies assessing diabetes risk.

  1. Homogeneous (Cu, Ni)6Sn5 intermetallic compound joints rapidly formed in asymmetrical Ni/Sn/Cu system using ultrasound-induced transient liquid phase soldering process.

    Science.gov (United States)

    Li, Z L; Dong, H J; Song, X G; Zhao, H Y; Tian, H; Liu, J H; Feng, J C; Yan, J C

    2018-04-01

    Homogeneous (Cu, Ni) 6 Sn 5 intermetallic compound (IMC) joints were rapidly formed in asymmetrical Ni/Sn/Cu system by an ultrasound-induced transient liquid phase (TLP) soldering process. In the traditional TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system consisted of major (Cu, Ni) 6 Sn 5 and minor Cu 3 Sn IMCs, and the grain morphology of (Cu, Ni) 6 Sn 5 IMCs subsequently exhibited fine rounded, needlelike and coarse rounded shapes from the Ni side to the Cu side, which was highly in accordance with the Ni concentration gradient across the joints. However, in the ultrasound-induced TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system only consisted of the (Cu, Ni) 6 Sn 5 IMCs which exhibited an uniform grain morphology of rounded shape with a remarkably narrowed Ni concentration gradient. The ultrasound-induced homogeneous intermetallic joints exhibited higher shear strength (61.6 MPa) than the traditional heterogeneous intermetallic joints (49.8 MPa). Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Rapid determination of methadone and its major metabolite in biological fluids by gas-liquid chromatography with thermionic detection for maintenance treatment of opiate addicts.

    Science.gov (United States)

    Chikhi-Chorfi, N; Pham-Huy, C; Galons, H; Manuel, N; Lowenstein, W; Warnet, J M; Claude, J R

    1998-11-06

    A rapid gas-liquid chromatographic assay is developed for the quantification of methadone (Mtd) and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), in biological fluids of opiate addicts. After alkaline extraction from samples with lidocaine hydrochloride as internal standard, Mtd and EDDP are separated on SP-2250 column at 220 degrees C and detected with a thermionic detector. The chromatographic time is about 6 min. The relative standard deviations (R.S.D.) of Mtd and EDDP standards are between 1.5 and 5.5%. Most drugs of abuse (morphine, codeine, narcotine, cocaine, benzoylecgonine, cocaethylene, dextropropoxyphene etc) are shown not to interfere with this technique. The method has been applied to study the levels of Mtd and EDDP metabolite in serum, saliva and urine of patients under maintenance treatment for opiate dependence. EDDP levels were found higher than those of Mtd in urine samples from four treated patients, but lower in serum and undetectable in saliva. However, Mtd concentrations were higher in saliva than in serum.

  3. Optimization of pressurized liquid extraction (PLE) for rapid determination of mineral oil saturated (MOSH) and aromatic hydrocarbons (MOAH) in cardboard and paper intended for food contact.

    Science.gov (United States)

    Moret, Sabrina; Sander, Maren; Purcaro, Giorgia; Scolaro, Marianna; Barp, Laura; Conte, Lanfranco S

    2013-10-15

    Packaging can represent a primary source of food contamination with mineral oil saturated hydrocarbons (MOSH) and aromatic hydrocarbons (MOAH), especially when recycled cardboard or mineral oil based printing inks are used. A pressurized liquid extraction (PLE) method, followed by on-line LC-GC analysis, has been optimized for rapid mineral oil determination in cardboard and paper samples. The proposed method involves extraction with hexane (2 cycles) at 60°C for 5 min, and allows for the processing of up to 6 samples in parallel with minimal sample manipulation and solvent consumption. It gave good repeatability (coefficient of variation lower than 5%) and practically quantitative extraction yield (less than 2% of the total contamination found in a third separate cycle). The method was applied to different cardboards and paper materials intended for food contact. Results obtained were similar to those obtained by applying classical solvent extraction with hexane/ethanol 1:1 (v/v) as described by Lorenzini et al. [20]. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Rapid and sensitive determination of phenylurea herbicides in water in the presence of their anilines by extraction with a Carbopack cartridge followed by liquid chromatography.

    Science.gov (United States)

    Di Corcia, A; Marchetti, M

    1991-03-22

    A rapid and sensitive method for determining phenylurea herbicides in environmental aqueous samples in the presence of their anilines is described. The water sample is preconcentrated by passage at a flow-rate of ca. 150 ml/min through a 250-mg graphitized carbon black (Carbopack B) cartridge. After washing with 0.6 ml of methanol, the Carbopack B trap is connected with a cartridge containing a strong cation exchanger. Organics trapped by the Carbopack cartridge are eluted by passage of 6 ml of methylene chloride-methanol (95:5, v/v). Anilines and other basic compounds are quantitatively subtracted from the solvent system while flowing through the cation-exchange cartridge. After evaporation and redissolution, the sample is subjected to reversed-phase gradient elution high-performance liquid chromatography with UV detection at 250 nm. Recoveries of phenylureas added to water at levels between 30 and 3000 ng/l were higher than 92%. The limit of detection was about 1 ng/l, for a 2-1 sample. With respect to an octadecyl (C18)-bonded silica cartridge, the Carbopack B cartridge had a far better extraction efficiency for polar phenylureas.

  5. [Rapid screening and confirmation of 205 pesticide residues in rice by QuEChERS and liquid chromatography-mass spectrometry].

    Science.gov (United States)

    Chen, Xi; Cheng, Lei; Qu, Shichao; Huang, Daliang; Liu, Jiacheng; Cui, Han; Jia, Yanbo; Ji, Mingshan

    2015-10-01

    A method for rapid screening and confirmation of 205 pesticide residues in rice was developed by combining QuEChERS and high performance liquid chromatography-triple quadrupole-linear ion trap mass spectrometry (LC-Q-TRAP/MS). The rice samples were extracted with acetonitrile, and then cleaned up with primary secondary amine (PSA), anhydrous magnesium sulfate (MgSO4) and C18 adsorbent. Finally, the samples were detected by LC-Q-TRAP/MS in multiple reaction monitoring with information-dependent acquisition of enhanced product ion (MRM-IDA-EPI) mode followed with database searching. A total of 205 pesticide residues were confirmed by retention times, ion pairs and the database searching using EPI library, and quantified by external standard method. All the pesticides showed good linearities with linear correlation coefficients all above 0.995. The limits of quantification (LOQs) for the 205 pesticides were 0.5-10.0 μg/kg. The average recoveries of the 205 pesticides ranged from 62.4% to 127.1% with the relative standard deviations (RSDs) of 1.0% - 20.0% at spiked levels of 10 μg/kg and 50 μg/kg, and only 20 min were needed for the analysis of an actual rice sample. In brief, the method is fast, accurate and highly sensitive, and is suitable for the screening and confirmation of pesticide residues in rice.

  6. Simple and rapid method on High Performance Liquid Chromatography for simultaneous determination of benzylpenicillin potassium, streptomycin sulphate and related substances in Ascomicin – a veterinary use ointment

    Directory of Open Access Journals (Sweden)

    Neagu Maria

    2015-06-01

    Full Text Available A new simple, rapid, accurate and precise High – Performance Liquid Chromatography (HPLC method for determination of benzylpenicillin potassium and streptomycin sulphate in Ascomicin ointment was developed and validated. The method can be used for the detection and quantification of known and unknown impurities and degradation products in this pharmaceutical product during routine analysis and also for stability studies in view of its capability to separate degradation products. The method was validated for accuracy, precision, specificity, robustness and quantification limits according to ICH Guidelines. The estimation of benzylpenicillin potassium and streptomycin sulphate was done by Waters HPLC 2695. The chromatographic conditions comprised a reverse-phased C18 column (5 µm particle size, 250 mm×4.6 mm i.d. with a mobile phase consisting of a mixture of solution in water containing 0.025 M of sodium phosphate dibasic and 0.02 of sodium hexansulfonate adjusted to pH 6.0 with 22.5 g/lsolution of phosphoric acid and acetonitrile in gradient elution. The flow rate was 0.8 ml/min. Standard curves were linear over the concentration range of 5.00 µg/ml to 5.00 mg/ml for streptomycin sulphate and 3.26 µg/ml to 3.26 mg/ml for benzylpenicillin potassium. Statistical analyses proved the method was precise, reproducible, selective, specific and accurate for analysis of benzylpenicillin potassium, streptomycin sulphate and related substances.

  7. A simple and rapid ultra-high-performance liquid chromatography-tandem mass spectrometry method to determine plasma biotin in hemodialysis patients.

    Science.gov (United States)

    Yagi, Shigeaki; Nishizawa, Manabu; Ando, Itiro; Oguma, Shiro; Sato, Emiko; Imai, Yutaka; Fujiwara, Masako

    2016-08-01

    A simple, rapid, and selective method for determination of plasma biotin was developed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). After single-step protein precipitation with methanol, biotin and stable isotope-labeled biotin as an internal standard (IS) were chromatographed on a pentafluorophenyl stationary-phase column (2.1 × 100 mm, 2.7 μm) under isocratic conditions using 10 mm ammonium formate-acetonitrile (93:7, v/v) at a flow rate of 0.6 mL/min. The total chromatographic runtime was 5 min for each injection. Detection was performed in a positive electrospray ionization mode by monitoring selected ion transitions at m/z 245.1/227.0 and 249.1/231.0 for biotin and the IS, respectively. The calibration curve was linear in the range of 0.05-2 ng/mL using 300 μL of plasma. The intra- and inter-day precisions were all biotin concentrations in hemodialysis patients. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Rapid and selective screening of melamine in bovine milk using molecularly imprinted matrix solid-phase dispersion coupled with liquid chromatography-ultraviolet detection.

    Science.gov (United States)

    Yan, Hongyuan; Cheng, Xiaoling; Sun, Ning; Cai, Tianyu; Wu, Ruijun; Han, Kun

    2012-11-01

    A simple, convenient and high selective molecularly imprinted matrix solid-phase dispersion (MI-MSPD) using water-compatible cyromazine-imprinted polymer as adsorbent was proposed for the rapid screening of melamine from bovine milk coupled with liquid chromatography-ultraviolet detection. The molecularly imprinted polymers (MIPs) synthesized by cyromazine as dummy template and reformative methanol-water system as reaction medium showed higher affinity and selectivity to melamine, and so they were applied as the specific dispersant of MSPD to extraction of melamine and simultaneously eliminate the effect of template leakage on quantitative analysis. Under the optimized conditions, good linearity was obtained in a range of 0.24-60.0μgg(-1) with the correlation coefficient of 0.9994. The recoveries of melamine at three spiked levels were ranged from 86.0 to 96.2% with the relative standard deviation (RSD)≤4.0%. This proposed MI-MSPD method combined the advantages of MSPD and MIPs, and could be used as an alternative tool for analyzing the residues of melamine in complex milk samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. A simple, sensitive and rapid isocratic reversed-phase high-performance liquid chromatography method for determination and stability study of curcumin in pharmaceutical samples

    Science.gov (United States)

    Amanolahi, Farjad; Mohammadi, Ali; Kazemi Oskuee, Reza; Nassirli, Hooriyeh; Malaekeh-Nikouei, Bizhan

    2017-01-01

    Objective: This study was designed to develop and validate a new reversed-phase high-performance liquid chromatography (RP-HPLC) method based on Q2 (R1) International Conference on Harmonization (ICH) guideline for determination of curcumin in pharmaceutical samples. Materials and Methods: The HPLC instrument method was optimized with isocratic elution with acetonitrile: ammonium acetate (45:55, v/v, pH 3.5), C18 column (150 mm×4.6 mm×5 µm particle size) and a flow rate of 1 ml/min in ambient condition and total retention time of 17 min. The volume of injection was set at 20 µl and detection was recorded at 425 nm. The robustness of the method was examined by changing the mobile phase composition, mobile phase pH, and flow rate. Results: The method was validated with respect to precision, accuracy and linearity in a concentration range of 2-100 µg/ml. The limit of detection (LOD) and limit of quantification (LOQ) were 0.25 and 0.5 µg/ml, respectively. The percentage of recovery was 98.9 to 100.5 with relative standard deviation (RSD) < 0.638%. Conclusion: The method was found to be simple, sensitive and rapid for determination of curcumin in pharmaceutical samples and had enough sensitivity to detect degradation product of curcumin produced under photolysis and hydrolysis stress condition. PMID:29062806

  10. Determination of moxifloxacin in human plasma, plasma ultrafiltrate, and cerebrospinal fluid by a rapid and simple liquid chromatography- tandem mass spectrometry method.

    Science.gov (United States)

    Pranger, Arianna D; Alffenaar, Jan-Willem C; Wessels, A Mireille A; Greijdanus, Ben; Uges, Donald R A

    2010-04-01

    Moxifloxacin (MFX) is a useful agent in the treatment of multi-drug-resistant tuberculosis (MDR-TB). At Tuberculosis Centre Beatrixoord, a referral center for tuberculosis in the Netherlands, approximately 36% of the patients have received MFX as treatment. Based on the variability of MFX AUC, the variability of in vitro susceptibility to MFX of M. tuberculosis, and the variability of penetration into sanctuary sites, measuring the concentration of MFX in plasma and cerebrospinal fluid (CSF) could be recommended. Therefore, a rapid and validated liquid chromatography-tandem mass spectrometry (LC-MS-MS) analyzing method with a simple pretreatment procedure was developed for therapeutic drug monitoring of MFX in human plasma and CSF. Because of the potential influence of protein binding on efficacy, we decided to determine both bound and unbound (ultrafiltrate) fraction of MFX. The calibration curves were linear in the therapeutic range of 0.05 to 5.0 mg/L plasma and CSF with CV in the range of -5.4% to 9.3%. MFX ultrafiltrate samples could be determined with the same method setup for analysis of MFX in CSF. The LC-MS-MS method developed in this study is suitable for monitoring MFX in human plasma, plasma ultrafiltrate, and CSF.

  11. Feature extraction from high resolution satellite imagery as an input to the development and rapid update of a METRANS geographic information system (GIS).

    Science.gov (United States)

    2011-06-01

    This report describes an accuracy assessment of extracted features derived from three : subsets of Quickbird pan-sharpened high resolution satellite image for the area of the : Port of Los Angeles, CA. Visual Learning Systems Feature Analyst and D...

  12. A Method for Simultaneous Determination of 20 Fusarium Toxins in Cereals by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry with a Pentafluorophenyl Column

    Science.gov (United States)

    Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Harayama, Koichi; Toriba, Akira; Hayakawa, Kazuichi

    2015-01-01

    A high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS) method was developed for simultaneous determination of 20 Fusarium toxins (nivalenol, fusarenon-X, deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, HT-2 toxin, T-2 toxin, neosolaniol, diacetoxyscirpenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisin A1, fumonisin A2, fumonisin A3, zearalenone, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol) in cereals. The separation of 20 Fusarium toxins with good peak shapes was achieved using a pentafluorophenyl column, and Orbitrap MS was able to detect accurately from cereal matrix components within ±0.77 ppm. The samples were prepared using a QuEChERS kit for extraction and a multifunctional cartridge for purification. The linearity, repeatability, and recovery of the method were >0.9964, 0.8%–14.7%, and 71%–106%, respectively. Using this method, an analysis of 34 commercially available cereals detected the presence of deoxynivalenol, 15-acetyl deoxynivalenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisn A1, fumonisin A2, fumonisin A3, and zearalenone in corn samples with high concentration and frequency. Trichothecenes was detected from wheat samples with high frequency; in particular, the concentration of deoxynivalenol was high. Conversely, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol were not detected in any of the samples. PMID:26008230

  13. Determination of Triazine Herbicides in Drinking Water by Dispersive Micro Solid Phase Extraction with Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometric Detection.

    Science.gov (United States)

    Chen, Dawei; Zhang, Yiping; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

    2015-11-11

    A novel dispersive micro solid phase extraction (DMSPE) method based on a polymer cation exchange material (PCX) was applied to the simultaneous determination of the 30 triazine herbicides in drinking water with ultrahigh-performance liquid chromatography-high-resolution mass spectrometric detection. Drinking water samples were acidified with formic acid, and then triazines were adsorbed by the PCX sorbent. Subsequently, the analytes were eluted with ammonium hydroxide/acetonitrile. The chromatographic separation was performed on an HSS T3 column using water (4 mM ammonium formate and 0.1% formic acid) and acetonitrile (0.1% formic acid) as the mobile phase. The method achieved LODs of 0.2-30.0 ng/L for the 30 triazines, with recoveries in the range of 70.5-112.1%, and the precision of the method was better than 12.7%. These results indicated that the proposed method had the advantages of convenience and high efficiency when applied to the analysis of the 30 triazines in drinking water.

  14. Development of a quantitation method to assay both lyoniresinol enantiomers in wines, spirits, and oak wood by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Cretin, Blandine N; Dubourdieu, Denis; Marchal, Axel

    2016-05-01

    Wine taste balance evolves during oak aging by the release of volatile and non-volatile compounds from wood. Among them, an enantiomer of lyoniresinol, (+)-lyoniresinol, has been shown to exhibit bitterness. To evaluate the impact of (+)-lyoniresinol on wine taste, a two-step quantitation method was developed and validated. First, (±)-lyoniresinol was assayed in wines, spirits, and oak wood macerates by C-18 liquid chromatography-high resolution mass spectrometry (LC-HRMS). Then, the lyoniresinol enantiomeric ratio was determined by chiral LC-HRMS in order to calculate the (+)-lyoniresinol content. In red and white wines, the average concentrations of (+)-lyoniresinol were 1.9 and 0.8 mg/L, respectively. The enantiomer proportions were not affected by bottle aging, and lyoniresinol appeared to remain stable over time. The sensory study of (+)-lyoniresinol established its perception threshold at 0.46 mg/L in wine. All the commercial wines quantitated were above this perception threshold, demonstrating its impact on wine taste by an increase in bitterness. In spirits, (+)-lyoniresinol ranged from 2.0 to 10.0 mg/L and was found to be released continuously during oak aging. Finally, neither botanical origin nor toasting was found to significantly affect the (+)-lyoniresinol content of oak wood. Graphical abstract From oak wood to wine: evaluation of the influence of (+)-lyoniresinol on the bitterness of wines and spirits.

  15. Dilute-and-shoot coupled to nanoflow liquid chromatography high resolution mass spectrometry for the determination of drugs of abuse and sport drugs in human urine.

    Science.gov (United States)

    Alcántara-Durán, Jaime; Moreno-González, David; Beneito-Cambra, Miriam; García-Reyes, Juan F

    2018-05-15

    In this work, a sensitive nanoflow liquid chromatography high-resolution mass spectrometry screening method has been developed for the determination of multiclass drugs of abuse and sport drugs in human urine. 81 drugs belonging to different multiclass pharmaceuticals were targeted. The method is based on the use of a nanoLC column (75 µm × 150 mm, 3 µm particle size and 100 Å pore) with the nanospray emitter tip integrated so that dead volumes are significantly minimized. Data acquisition method included both full-scan and all ion fragmentation experiments using an Orbitrap analyser (Q-Exactive) operated in the positive ionization mode. To increase laboratory throughput, a dilute-and-shoot methodology has been tested and proposed, based solely on direct urine dilution without further sample workup. Matrix effects were evaluated, showing a negligible effect for all studied compounds when a dilution 1:50 was implemented. Despite this high-dilution factor, limits of quantification were still satisfactory, with values below 5 µg L -1 in most cases, being lower than their minimum required performance limits correspond established by the World Anti-Doping Agency. Therefore, the use of the dilute-and-shoot method with the enhanced sensitivity provided by nanoflow LC setup could be useful tool for the determination of studied compounds in drug testing, thus increasing laboratory performance, because a minimum sample treatment steps are required. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Detection of Type A Trichothecene Di-Glucosides Produced in Corn by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hitoshi Nagashima

    2013-03-01

    Full Text Available The existence of di-glucosylated derivative of T-2 toxin in plant (corn powder was confirmed for the first time in addition to that of HT-2 toxin. These masked mycotoxins (mycotoxin glucosides were identified as T-2 toxin-di-glucoside (T2GlcGlc and HT-2 toxin-di-glucoside (HT2GlcGlc based on accurate mass measurements of characteristic ions and fragmentation patterns using high-resolution liquid chromatography-Orbitrap mass spectrometric (LC-Orbitrap MS analysis. Although the absolute structure of T2GlcGlc was not clarified, two glucose molecules were suggested to be conjugated at 3-OH position in tandem when considering the structure of T-2 toxin. On the other hand, the specification of the structure seems to be more complicated in the case of HT2GlcGlc, since HT-2 toxin has two possible positions (at 3-OH and 4-OH to be glusocylated. In addition, 15-monoacetoxyscirpenol-glucoside (MASGlc was also detected in the identical sample.

  17. Liquid chromatography with high resolution mass spectrometry for identification of organic contaminants in fish fillet: screening and quantification assessment using two scan modes for data acquisition.

    Science.gov (United States)

    Munaretto, Juliana S; May, Marília M; Saibt, Nathália; Zanella, Renato

    2016-07-22

    This study proposed a strategy to identify and quantify 182 organic contaminants from different chemical classes, as for instance pesticides, veterinary drug and personal care products, in fish fillet using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QToF/MS). For this purpose, two different scan methods (full scan and all ions MS/MS) were evaluated to assess the best option for screening analysis in spiked fish fillet samples. In general, full scan acquisition was found to be more reliable (84%) in the automatic identification and quantification when compared to all ions MS/MS with 72% of the compounds detected. Additionally, a qualitative automatic search showed a mass accuracy error below 5ppm for 77% of the compounds in full scan mode compared to only 52% in all ions MS/MS scan. However, all ions MS/MS provides fragmentation information of the target compounds. Undoubtedly, structural information of a wide number of compounds can be obtained using high resolution mass spectrometry (HRMS), but it is necessary thoroughly assess it, in order to choose the best scan mode. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Development and validation of a QuEChERS method coupled to liquid chromatography and high resolution mass spectrometry to determine pyrrolizidine and tropane alkaloids in honey.

    Science.gov (United States)

    Martinello, Marianna; Borin, Alice; Stella, Roberto; Bovo, Davide; Biancotto, Giancarlo; Gallina, Albino; Mutinelli, Franco

    2017-11-01

    Awareness about pyrrolizidine alkaloids (PAs) and tropane alkaloids (TAs) in food was recently raised by the European Food Safety Authority stressing the lack of data and gaps of knowledge required to improve the risk assessment strategy. The present study aimed at the elaboration and validation of a method to determine PAs and TAs in honey. QuEChERS sample treatment and liquid chromatography coupled to hybrid high resolution mass spectrometry, were used. The method resulted in good linearity (R 2 >0.99) and low limits of detection and quantification, ranging from 0.04 to 0.2µgkg -1 and from 0.1 to 0.7µgkg -1 respectively. Recoveries ranged from 92.3 to 114.8% with repeatability lying between 0.9 and 15.1% and reproducibility between 1.1 and 15.6%. These performances demonstrate the selectivity and sensitivity of the method for simultaneous trace detection and quantification of PAs and TAs in honey, verified through the analysis of forty commercial samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Triple aldose reductase/α-glucosidase/radical scavenging high-resolution profiling combined with high-performance liquid chromatography – high-resolution mass spectrometry – solid-phase extraction – nuclear magnetic resonance spectroscopy for identification of antidiabetic constituents in crude, extract of Radix Scutellariae

    DEFF Research Database (Denmark)

    Tahtah, Yousof; Kongstad, Kenneth Thermann; Wubshet, Sileshi Gizachew

    2015-01-01

    high-performance liquid chromatography – high-resolution mass spectrometry – solid-phase extraction – nuclear magnetic resonance spectroscopy. The only α-glucosidase inhibitor was baicalein, whereas main aldose reductase inhibitors in the crude extract were baicalein and skullcapflavone II, and main....../α-glucosidase/radical scavenging high-resolution inhibition profile - allowing proof of concept with Radix Scutellariae crude extract as a polypharmacological herbal drug. The triple bioactivity high-resolution profiles were used to pinpoint bioactive compounds, and subsequent structure elucidation was performed with hyphenated...

  20. Application of a rapid and sensitive liquid chromatography-tandem mass spectrometry method for determination of bumetanide in human plasma for a bioequivalence study.

    Science.gov (United States)

    Patel, Dinesh S; Sharma, Naveen; Patel, Mukesh C; Patel, Bhavin N; Shrivastav, Pranav S; Sanyal, Mallika

    2012-07-01

    A rapid, selective and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay has been proposed for the determination of bumetanide in human plasma using tamsulosin as internal standard (IS). The analyte and IS were extracted from 200 μL of human plasma via solid phase extraction and the chromatographic separation was achieved on Peerless Basic C18 (100 mm × 4.6 mm, 3 μm) column under isocratic conditions. Detection of bumetanide and IS was done by tandem mass spectrometry, operating in positive ionization and multiple reaction monitoring (MRM) acquisition mode. The protonated precursor to product ion transitions monitored for bumetanide and IS were m/z 365.2→240.2 and 409.2→228.2 respectively. The method was fully validated as per the US FDA guidelines. The limit of detection and lower limit of quantitation of the method were 0.03 and 0.30 ng/mL respectively with a linear dynamic range of 0.30-200.0 ng/mL for bumetanide. The intra-batch and inter-batch precision (% CV) was ≤6.9% while the mean extraction recovery was >90% across quality control levels. The method is selective in presence of four diuretic drugs and some commonly used medications by healthy volunteers. It was successfully applied to a bioequivalence study of 2mg bumetanide tablet formulation in 10 healthy Indian male subjects under fasting condition. The reproducibility in the measurement of study data was demonstrated by reanalysis of 42 incurred samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Rapid screening for cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L. using liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Xing, Jie; Yang, Zijuan; Lv, Beibei; Xiang, Lan

    2008-05-01

    A simple and rapid qualitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for screening cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L. at sub-ppm levels. An electrospray ionization orbitrap mass spectrometer, which provides accurate full scan MS and MS/MS data, was used in this study. After simple extraction with ethanol and purification by AB-8 resin, the extracts were subjected to LC/MS/MS analysis. A high mass tolerance (10 ppm) was used in the initial screening to filter the full scan MS data. The cyclo-dopa and diketopiperazine alkaloid standards gave limits of detection (LODs) at or below 5 ng/mL. The results also indicated that the method had an acceptable precision for day-to-day use in the identification of compounds. The alkaloids could be identified based on their MS/MS data, elemental compositions, and retention behavior. This system was used to assay trace amounts of cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L., leading to the identification of 5/2 confirmed/unconfirmed cyclo-dopa and 7/6 confirmed/unconfirmed diketopiperazine alkaloids, respectively. The screening method considerably reduces the time and cost involved in the identification of cyclo-dopa and diketopiperazine alkaloids in Portulaca oleracea L., as well as being a simple and convenient approach to the identification of other structural families of natural products. Copyright (c) 2008 John Wiley & Sons, Ltd.

  2. Development and validation of a rapid multi-biomarker liquid chromatography/tandem mass spectrometry method to assess human exposure to mycotoxins.

    Science.gov (United States)

    Warth, Benedikt; Sulyok, Michael; Fruhmann, Philipp; Mikula, Hannes; Berthiller, Franz; Schuhmacher, Rainer; Hametner, Christian; Abia, Wilfred Angie; Adam, Gerhard; Fröhlich, Johannes; Krska, Rudolf

    2012-07-15

    Mycotoxins regularly occur in food worldwide and pose serious health risks to consumers. Since individuals can be exposed to a variety of these toxic secondary metabolites of fungi at the same time, there is a demand for proper analytical methods to assess human exposure by suitable biomarkers. This study reports on the development of a liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method for the quantitative measurement of 15 mycotoxins and key metabolites in human urine using polarity switching. Deoxynivalenol (DON), DON-3-O-glucuronide, DON-15-O-glucuronide (D15GlcA), de-epoxy DON, nivalenol (NIV), T-2 toxin, HT-2 toxin, zearalenone, zearalenone-14-O-glucuronide, α- and β-zearalenol, fumonisins B(1) and B(2) (FB(1), FB(2)), ochratoxin A (OTA) and aflatoxin M(1) (AFM(1)) were determined without the need for any cleanup using a rapid and simple dilute and shoot approach. Validation was performed in the range of 0.005-40 µg L(-1) depending on the analyte and expected urinary concentration levels. Apparent recoveries between 78 and 119% and interday precisions of 2-17% relative standard deviation (RSD) were achieved. The applicability of the method was demonstrated by the analysis of urine samples obtained from Cameroon. In naturally contaminated urine samples up to six biomarkers of exposure (AFM(1), DON, D15GlcA, NIV, FB(1), and OTA) were detected simultaneously. We conclude that the developed LC/MS/MS method is well suited to quantify multiple mycotoxin biomarkers in human urine down to the sub-ppb range within 18 min and without any prior cleanup. The co-occurrence of several mycotoxins in the investigated samples clearly emphasizes the great potential and importance of this method to assess exposure of humans and animals to naturally occurring mycotoxins. Copyright © 2012 John Wiley & Sons, Ltd.

  3. Rapid Quantification and Quantitation of Alkaloids in Xinjiang Fritillaria by Ultra Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Aziz Mohammat

    2017-05-01

    Full Text Available The Fritillaria genus, including different kinds of medicinal and edible plants belonging to the Liliaceae family which have the function of treating and relieving a cough and eliminating phlegm, is widely planted in Xinjiang (China. There are few comprehensive studies reporting on the characterization of the chemical constituents of Fritillaria from Xinjiang, and to date, no work describing the quantitative differences between the components in Fritillaria from Xinjiang and related species. The purpose of this study was to develop qualitative and quantitative analytical methods by Ultra Performance Liquid Chromatography-Quadrupole Time-of-flight Mass Spectrometry (UPLC-QTOF-MS for the rapid quantification and quantitation of alkaloids in wild and cultivated Xinjiang Fritillaria, which could be used in the quality control of medicine based on this natural herb. Using the UPLC-QTOF-MS method, the chemical constituents of Xinjiang Fritillaria were identified by fragmentation information and retention behavior, and were compared to reference standards. Furthermore, a quantitative comparision of four major alkaloids in wild and cultivated Xinjiang Fritillaria was conducted by determining the content of Sipeimine-3β-d-glucoside, Sipeimine, Peimisine, and Yibeinoside A, respectively. A total of 89 characteristic peaks, including more than 40 alkaloids, were identified in the chromatographic results of Fritillaria. Four main alkaloids were quantified by using a validated method based on UPLC-QTOF-MS. The relative contents of Sipeimine-3β-d-glucoside, Sipeimine, Peimisine, and Yibeinoside A varied from 0.0013%~0.1357%, 0.0066%~0.1218%, 0.0033%~0.0437%, and 0.0019%~0.1398%, respectively. A rough separation of wild and cultivated Fritillaria could be achieved by the cluster analysis method.

  4. A rapid method based on hot water extraction and liquid chromatography-tandem mass spectrometry for analyzing tetracycline antibiotic residues in cheese.

    Science.gov (United States)

    Bogialli, Sara; Coradazzi, Cristina; Di Corcia, Antonio; Lagana, Aldo; Sergi, Manuel

    2007-01-01

    A rapid, specific, and sensitive procedure for determining residues of 4 widely used tetracycline antibiotics and 3 of their 4-epimers in cheese is presented. The method is based on the matrix solid-phase dispersion (MSPD) technique followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). After dispersing samples of mozzarella, asiago, parmigiano, gruyere, emmenthal, and camembert on sand, target compounds were eluted from the MSPD column by passing through it 6 mL water heated at 70 degrees C. After acidification and filtration, 200 microL of the aqueous extract was directly injected into the LC column. For analyte identification and quantification, MS data acquisition was performed in the multireaction monitoring mode, selecting 2 precursor ion-to-product ion transitions for each target compound. Hot water appeared to be an efficient extractant, because absolute recoveries were no lower than 78%. Using demeclocycline as a surrogate analyte, recoveries of analyte added to the 6 types of cheeses at the 30 ng/g level were 96-117%, with relative standard deviation (RSD) not higher than 9%. Statistical analysis of the mean recovery data showed that the extraction efficiency was not dependent on the type of cheese analyzed. This result indicates that this method could be applied to other cheese types not considered here. At the lowest concentration considered, i.e., 10 ng/g, the accuracy of the method ranged between 90 and 107%, with RSDs not larger than 12%. Based on a signal-to-noise ratio of 10, limits of quantitation were estimated to be 1-2 ng/g.

  5. Modelling multi-phase liquid-sediment scour and resuspension induced by rapid flows using Smoothed Particle Hydrodynamics (SPH) accelerated with a Graphics Processing Unit (GPU)

    Science.gov (United States)

    Fourtakas, G.; Rogers, B. D.

    2016-06-01

    A two-phase numerical model using Smoothed Particle Hydrodynamics (SPH) is applied to two-phase liquid-sediments flows. The absence of a mesh in SPH is ideal for interfacial and highly non-linear flows with changing fragmentation of the interface, mixing and resuspension. The rheology of sediment induced under rapid flows undergoes several states which are only partially described by previous research in SPH. This paper attempts to bridge the gap between the geotechnics, non-Newtonian and Newtonian flows by proposing a model that combines the yielding, shear and suspension layer which are needed to predict accurately the global erosion phenomena, from a hydrodynamics prospective. The numerical SPH scheme is based on the explicit treatment of both phases using Newtonian and the non-Newtonian Bingham-type Herschel-Bulkley-Papanastasiou constitutive model. This is supplemented by the Drucker-Prager yield criterion to predict the onset of yielding of the sediment surface and a concentration suspension model. The multi-phase model has been compared with experimental and 2-D reference numerical models for scour following a dry-bed dam break yielding satisfactory results and improvements over well-known SPH multi-phase models. With 3-D simulations requiring a large number of particles, the code is accelerated with a graphics processing unit (GPU) in the open-source DualSPHysics code. The implementation and optimisation of the code achieved a speed up of x58 over an optimised single thread serial code. A 3-D dam break over a non-cohesive erodible bed simulation with over 4 million particles yields close agreement with experimental scour and water surface profiles.

  6. Mildronate (Meldonium) in professional sports - monitoring doping control urine samples using hydrophilic interaction liquid chromatography - high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Dib, Josef; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2015-01-01

    To date, substances such as Mildronate (Meldonium) are not on the radar of anti-doping laboratories as the compound is not explicitly classified as prohibited. However, the anti-ischemic drug Mildronate demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system (CNS) functions. In the present study, the existing evidence of Mildronate's usage in sport, which is arguably not (exclusively) based on medicinal reasons, is corroborated by unequivocal analytical data allowing the estimation of the prevalence and extent of misuse in professional sports. Such data are vital to support decision-making processes, particularly regarding the ban on drugs in sport. Due to the growing body of evidence (black market products and athlete statements) concerning its misuse in sport, adequate test methods for the reliable identification of Mildronate are required, especially since the substance has been added to the 2015 World Anti-Doping Agency (WADA) monitoring program. In the present study, two approaches were established using an in-house synthesized labelled internal standard (Mildronate-D3 ). One aimed at the implementation of the analyte into routine doping control screening methods to enable its monitoring at the lowest possible additional workload for the laboratory, and another that is appropriate for the peculiar specifics of the analyte, allowing the unequivocal confirmation of findings using hydrophilic interaction liquid chromatography-high resolution/high accuracy mass spectrometry (HILIC-HRMS). Here, according to applicable regulations in sports drug testing, a full qualitative validation was conducted. The assay demonstrated good specificity, robustness (rRT=0.3%), precision (intra-day: 7.0-8.4%; inter-day: 9.9-12.9%), excellent linearity (R>0.99) and an adequate lower limit of detection (<10 ng/mL). Copyright © 2015 John Wiley & Sons, Ltd.

  7. Mildronate (Meldonium) in professional sports – monitoring doping control urine samples using hydrophilic interaction liquid chromatography – high resolution/high accuracy mass spectrometry

    Science.gov (United States)

    Görgens, Christian; Dib, Josef; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2015-01-01

    To date, substances such as Mildronate (Meldonium) are not on the radar of anti‐doping laboratories as the compound is not explicitly classified as prohibited. However, the anti‐ischemic drug Mildronate demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system (CNS) functions. In the present study, the existing evidence of Mildronate's usage in sport, which is arguably not (exclusively) based on medicinal reasons, is corroborated by unequivocal analytical data allowing the estimation of the prevalence and extent of misuse in professional sports. Such data are vital to support decision‐making processes, particularly regarding the ban on drugs in sport. Due to the growing body of evidence (black market products and athlete statements) concerning its misuse in sport, adequate test methods for the reliable identification of Mildronate are required, especially since the substance has been added to the 2015 World Anti‐Doping Agency (WADA) monitoring program. In the present study, two approaches were established using an in‐house synthesized labelled internal standard (Mildronate‐D3). One aimed at the implementation of the analyte into routine doping control screening methods to enable its monitoring at the lowest possible additional workload for the laboratory, and another that is appropriate for the peculiar specifics of the analyte, allowing the unequivocal confirmation of findings using hydrophilic interaction liquid chromatography‐high resolution/high accuracy mass spectrometry (HILIC‐HRMS). Here, according to applicable regulations in sports drug testing, a full qualitative validation was conducted. The assay demonstrated good specificity, robustness (rRT=0.3%), precision (intra‐day: 7.0–8.4%; inter‐day: 9.9–12.9%), excellent linearity (R>0.99) and an adequate lower limit of detection (<10 ng/mL). © 2015 The Authors

  8. Simplifying and expanding analytical capabilities for various classes of doping agents by means of direct urine injection high performance liquid chromatography high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Thomas, Andreas; Wachsmuth, Philipp; Orlovius, Anne-Katrin; Sigmund, Gerd; Thevis, Mario; Schänzer, Wilhelm

    2016-11-30

    So far, in sports drug testing compounds of different classes are processed and measured using different screening procedures. The constantly increasing number of samples in doping analysis, as well as the large number of substances with doping related, pharmacological effects require the development of even more powerful assays than those already employed in sports drug testing, indispensably with reduced sample preparation procedures. The analysis of native urine samples after direct injection provides a promising analytical approach, which thereby possesses a broad applicability to many different compounds and their metabolites, without a time-consuming sample preparation. In this study, a novel multi-target approach based on liquid chromatography and high resolution/high accuracy mass spectrometry is presented to screen for more than 200 analytes of various classes of doping agents far below the required detection limits in sports drug testing. Here, classic groups of drugs as diuretics, stimulants, β 2 -agonists, narcotics and anabolic androgenic steroids as well as various newer target compounds like hypoxia-inducible factor (HIF) stabilizers, selective androgen receptor modulators (SARMs), selective estrogen receptor modulators (SERMs), plasma volume expanders and other doping related compounds, listed in the 2016 WADA prohibited list were implemented. As a main achievement, growth hormone releasing peptides could be implemented, which chemically belong to the group of small peptides (0.99), limit of detection (0.1-25ng/mL; 3'OH-stanozolol glucuronide: 50pg/mL; dextran/HES: 10μg/mL) and matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Target analysis of primary aromatic amines combined with a comprehensive screening of migrating substances in kitchen utensils by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Sanchis, Yovana; Coscollà, Clara; Roca, Marta; Yusà, Vicent

    2015-06-01

    An analytical strategy including both the quantitative target analysis of 8 regulated primary aromatic amines (PAAs), as well as a comprehensive post-run target screening of 77 migrating substances, was developed for nylon utensils, using liquid chromatography-orbitrap-high resolution mass spectrometry (LC-HRMS) operating in full scan mode. The accurate mass data were acquired with a resolving power of 50,000 FWHM (scan speed, 2 Hz), and by alternating two acquisition events, ESI+ with and without fragmentation. The target method was validated after statistical optimization of the main ionization and fragmentation parameters. The quantitative method presented appropriate performance to be used in official monitoring with recoveries ranging from 78% to 112%, precision in terms of Relative Standard Deviation (RSD) was less than 15%, and the limits of quantification were between 2 and 2.5 µg kg(-1). For post-target screening, a customized theoretical database was built for food contact material migrants, including bisphenols, phthalates, and other amines. For identification purposes, accurate exact mass (<5 ppm) and some diagnostic ions including fragments were used. The strategy was applied to 10 real samples collected from different retailers in the Valencian Region (Spain) during 2014. Six out of eight target PAAs were detected in at least one sample in the target analysis. The most frequently detected compounds were 4,4'-methylenedianiline and aniline, with concentrations ranging from 2.4 to 19,715 µg kg(-1) and 2.5 to 283 µg kg(-1), respectively. Two phthalates were identified and confirmed in the post-run target screening analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Identification and quantification of the main isoflavones and other phytochemicals in soy based nutraceutical products by liquid chromatography-orbitrap high resolution mass spectrometry.

    Science.gov (United States)

    López-Gutiérrez, Noelia; Romero-González, Roberto; Garrido Frenich, Antonia; Martínez Vidal, José Luis

    2014-06-27

    The specific phytochemicals composition of soy nutritional supplements is usually not labelled. Hence, 12 dietary supplements were analyzed in order to detect and identify the main phytochemicals present in these samples, using a database containing 60 compounds. Ultra-high performance liquid chromatography coupled to single-stage Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-MS) has been used. Two consecutive extractions, using as extraction solvent a mixture of methanol:water (80:20, v/v), were employed, followed by two dilutions (10 or 100 times depending on the concentration of the components in the sample) with a mixture of an aqueous solution of ammonium acetate 30mM:methanol (50:50, v/v). The method was validated, obtaining adequate recovery and precision values. Limits of detection (LODs) and quantification (LOQs) were calculated, ranging from 2 to 150μgL(-1). Isoflavones were the predominant components present in the analyzed supplements with values higher than 93% of the total amount of phytochemicals in all cases. The aglycones (genistein, daidzein, glycitein and biochanin A) as well as their three conjugated forms, β-glucosides (genistin, daizin and glycitin) were detected and quantified, being daidzein the isoflavone detected at higher concentration in 8 out of 12 samples reported, with values ranging from 684 to 35,970mgkg(-1), whereas biochanin A was detected at very low concentrations, ranging from 18 to 50mgkg(-1). Moreover, other phytochemicals as flavones, flavonols, flavanones and phenolic acids were also detected and quantified. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Simultaneous quantification of amino acids and Amadori products in foods through ion-pairing liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Troise, Antonio Dario; Fiore, Alberto; Roviello, Giovanni; Monti, Simona Maria; Fogliano, Vincenzo

    2015-01-01

    The formation of the Amadori products (APs) is the first key step of Maillard reaction. Only few papers have dealt with simultaneous quantitation of amino acids and corresponding APs (1-amino-1-deoxy-2-ketose). Chromatographic separation of APs is affected by several drawbacks mainly related to their poor retention in conventional reversed phase separation. In this paper, a method for the simultaneous quantification of amino acids and their respective APs was developed combining high-resolution mass spectrometry with ion-pairing liquid chromatography. The limit of detection was 0.1 ng/mL for tryptophan, valine and arginine, while the limit of quantification ranged from 2 to 5 ng/mL according to the specific sensitivity of each analyte. The relative standard deviation % was lower than 10 % and the coefficient of correlation was higher than 0.99 for each calibration curve. The method was applied to milk, milk-based products, raw and processed tomato. Among the analyzed products, the most abundant amino acid was glutamic acid (16,646.89 ± 1,385.40 µg/g) and the most abundant AP was fructosyl-arginine in tomato puree (774.82 ± 10.01 µg/g). The easiness of sample preparation coupled to the analytical performances of the proposed method introduced the possibility to use the pattern of free amino acids and corresponding APs in the evaluation of the quality of raw food as well as the extent of thermal treatments in different food products.

  12. Combining a Deconvolution and a Universal Library Search Algorithm for the Nontarget Analysis of Data-Independent Acquisition Mode Liquid Chromatography-High-Resolution Mass Spectrometry Results.

    Science.gov (United States)

    Samanipour, Saer; Reid, Malcolm J; Bæk, Kine; Thomas, Kevin V

    2018-04-17

    Nontarget analysis is considered one of the most comprehensive tools for the identification of unknown compounds in a complex sample analyzed via liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Due to the complexity of the data generated via LC-HRMS, the data-dependent acquisition mode, which produces the MS 2 spectra of a limited number of the precursor ions, has been one of the most common approaches used during nontarget screening. However, data-independent acquisition mode produces highly complex spectra that require proper deconvolution and library search algorithms. We have developed a deconvolution algorithm and a universal library search algorithm (ULSA) for the analysis of complex spectra generated via data-independent acquisition. These algorithms were validated and tested using both semisynthetic and real environmental data. A total of 6000 randomly selected spectra from MassBank were introduced across the total ion chromatograms of 15 sludge extracts at three levels of background complexity for the validation of the algorithms via semisynthetic data. The deconvolution algorithm successfully extracted more than 60% of the added ions in the analytical signal for 95% of processed spectra (i.e., 3 complexity levels multiplied by 6000 spectra). The ULSA ranked the correct spectra among the top three for more than 95% of cases. We further tested the algorithms with 5 wastewater effluent extracts for 59 artificial unknown analytes (i.e., their presence or absence was confirmed via target analysis). These algorithms did not produce any cases of false identifications while correctly identifying ∼70% of the total inquiries. The implications, capabilities, and the limitations of both algorithms are further discussed.

  13. Determination of steroid hormones and their metabolite in several types of meat samples by ultra high performance liquid chromatography-Orbitrap high resolution mass spectrometry.

    Science.gov (United States)

    López-García, Marina; Romero-González, Roberto; Garrido Frenich, Antonia

    2018-03-09

    A new analytical method based on ultra-high performance liquid chromatography (UHPLC) coupled to Orbitrap high resolution mass spectrometry (Orbitrap-HRMS) has been developed for the determination of steroid hormones (hydrocortisone, cortisone, progesterone, prednisone, prednisolone, testosterone, melengesterol acetate, hydrocortisone-21-acetate, cortisone-21-acetate, testosterone propionate, 17α-methyltestosterone, 6α-methylprednisolone and medroxyprogesterone) and their metabolite (17α-hydroxyprogesterone) in three meat samples (chicken, pork and beef). Two different extraction approaches were tested (QuEChERS "quick, easy, cheap, effective, rugged and safe" and "dilute and shoot"), observing that the QuEChERS method provided the best results in terms of recovery. A clean-up step was applied comparing several sorbents, obtaining the best results when florisil and aluminum oxide were used. The optimized method was validated, obtaining suitable results for all validation parameters in the three meat matrices evaluated. Recovery values ranged from 70% to 103% (except for prednisone in beef samples), meanwhile repeatability and reproducibility were obtained at values lower than 18% and 21%, respectively. The limit of quantification (LOQ) was established for most of the compounds at 1.0 μg/kg, except for testosterone in chicken and hydrocortisone-21-acetate and cortisone-21-acetate in pork at 2.0 μg/kg. Decision limit (CCα) and detection capability (CCβ) values ranged from 1.0-2.7 μg/kg and 1.9-5.5 μg/kg, respectively, in the three matrices. Finally, thirty one meat samples were analyzed and two hormones, progesterone and hydrocortisone, were detected in a beef and pork sample at 1.7 and 2.8 μg/kg respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Identification and quantification of fumonisin A1, A2, and A3 in corn by high-resolution liquid chromatography-orbitrap mass spectrometry.

    Science.gov (United States)

    Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Harayama, Koichi; Toriba, Akira; Hayakawa, Kazuichi

    2015-02-16

    Three compounds, hypothesized as fumonisin A1 (FA1), fumonisin A2 (FA2), and fumonisin A3 (FA3), were detected in a corn sample contaminated with mycotoxins by high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS). One of them has been identified as FA1 synthesized by the acetylation of fumonisin B1 (FB1), and established a method for its quantification. Herein, we identified the two remaining compounds as FA2 and FA3, which were acetylated fumonisin B2 (FB2) and fumonisin B3 (FB3), respectively. Moreover, we examined a method for the simultaneous analysis of FA1, FA2, FA3, FB1, FB2, and FB3. The corn samples were prepared by extraction using a QuEChERS kit and purification using a multifunctional cartridge. The linearity, recovery, repeatability, limit of detection, and limit of quantification of the method were >0.99, 82.9%-104.6%, 3.7%-9.5%, 0.02-0.60 μg/kg, and 0.05-1.98 μg/kg, respectively. The simultaneous analysis of the six fumonisins revealed that FA1, FA2, and FA3 were present in all corn samples contaminated with FB1, FB2, and FB3. The results suggested that corn marketed for consumption can be considered as being contaminated with both the fumonisin B-series and with fumonisin A-series. This report presents the first identification and quantification of FA1, FA2, and FA3 in corn samples.

  15. [Determination of 11 mycotoxins in baked foods and raw materials by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry].

    Science.gov (United States)

    Li, Rong; He, Chunmei; Yang, Luqi; Wang, Yong; Zhang, Pengjie; Gao, Yongqing

    2017-08-08

    A method for the determination of 11 mycotoxins in baked foods and raw materials by ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry (UPLC-HRMS) is reported in this paper. The samples were extracted with 20 mL 90% (v/v) acetonitrile aqueous solution containing 1% (v/v) formic acid, and the extracts were salted out by 2.0 g MgSO 4 and 0.5 g NaCl, cleaned up by 300 mg C18. The analytes were carried out on a CORTECS C18 column (100 mm×2.1 mm, 1.6 μ m) by gradient elution with 2 mmol/L ammonium acetate with 0.1% (v/v) formic acid aqueous solution and 2 mmol/L ammonium acetate methanol with 0.1% (v/v) formic acid. The results showed that the 11 mycotoxins had good linear relationships in their respective mass concentration ranges. The correlation coefficients were not less than 0.9960 and the limits of quantitation (LOQs) were from 0.15 to 20.00 μ g/kg. The recoveries of the 11 mycotoxins in bread ranged from 64.38% to 122.61% with the relative standard deviations (RSDs) from 1.52% to 12.99% at three spiked levels ( n =6). The method is demonstrated to be simple, fast, highly sensitive, reliable and it is effective to detect common mycotoxins in baked foods and raw materials.

  16. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) determination of stimulants, anorectic drugs and phosphodiesterase 5 inhibitors (PDE5I) in food supplements.

    Science.gov (United States)

    Strano-Rossi, Sabina; Odoardi, Sara; Castrignanò, Erika; Serpelloni, Giovanni; Chiarotti, Marcello

    2015-03-15

    The paper describes a liquid chromatography/high resolution mass spectrometry LC/HRMS method for the simultaneous identification and quantification of stimulants (ephedrines, caffeine, anorectic drugs such as phentermine, phendimetrazine, phenmetrazine, fenfluramine, benfluorex, mephentermine, fencanfamine, sibutramine) and PDE5I (sildenafil, vardenafil and tadalafil) in food supplements using a benchtop Orbitrap mass spectrometer. The mass detector, with a nominal resolving power of 100,000 (FWHM at m/z 200), operated in full scan mode in ESI positive ionization mode. Analytes were identified by retention times, accurate masses and correspondence of experimental and calculated isotopic patterns. The limits of detection (LOD) obtained varied from 1 to 25 ng g(-1) and limits of quantification (LOQ) were 50 ng g(-1) for all compounds. The method was linear for all the analytes in the ranges from 50 to 2000 ng g(-1), giving correlation coefficients>0.99. Accuracy (intended as %E) and repeatability (% CV) were always lower than 15%. The method was applied to the analysis of 36 dietary supplements, revealing the presence of ephedrine and/or pseudoephedrine in four of them, caffeine in eight of them and sildenafil in four of them. In one case, ephedrine was not reported on the label of the dietary supplement, as well as for caffeine in other two cases. A further confirmation of the analytes identity in positive samples was obtained through in-source fragmentation and comparison of the obtained fragments and their relative abundances with those from certified standards. As the acquisition mode is full scan, it would be also possible to re-process a previously acquired datafile for the investigation of untargeted analytes. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Identification and accurate quantification of structurally related peptide impurities in synthetic human C-peptide by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Li, Ming; Josephs, Ralf D; Daireaux, Adeline; Choteau, Tiphaine; Westwood, Steven; Wielgosz, Robert I; Li, Hongmei

    2018-06-04

    Peptides are an increasingly important group of biomarkers and pharmaceuticals. The accurate purity characterization of peptide calibrators is critical for the development of reference measurement systems for laboratory medicine and quality control of pharmaceuticals. The peptides used for these purposes are increasingly produced through peptide synthesis. Various approaches (for example mass balance, amino acid analysis, qNMR, and nitrogen determination) can be applied to accurately value assign the purity of peptide calibrators. However, all purity assessment approaches require a correction for structurally related peptide impurities in order to avoid biases. Liquid chromatography coupled to high resolution mass spectrometry (LC-hrMS) has become the key technique for the identification and accurate quantification of structurally related peptide impurities in intact peptide calibrator materials. In this study, LC-hrMS-based methods were developed and validated in-house for the identification and quantification of structurally related peptide impurities in a synthetic human C-peptide (hCP) material, which served as a study material for an international comparison looking at the competencies of laboratories to perform peptide purity mass fraction assignments. More than 65 impurities were identified, confirmed, and accurately quantified by using LC-hrMS. The total mass fraction of all structurally related peptide impurities in the hCP study material was estimated to be 83.3 mg/g with an associated expanded uncertainty of 3.0 mg/g (k = 2). The calibration hierarchy concept used for the quantification of individual impurities is described in detail. Graphical abstract ᅟ.

  18. CHARACTERIZATION OF ENALAPRIL AND RANITIDINE CHLORINATION BY-PRODUCTS BY LIQUID CHROMATOGRAPHY/HIGH-RESOLUTION MASS SPECTROMETRY AND THEIR TOXICITY EVALUATION

    Directory of Open Access Journals (Sweden)

    Frederico Jehár Oliveira Quintão

    Full Text Available Due to its low cost, its capability for disinfection and oxidation, chlorination using gaseous chlorine or hypochlorite salts, has also been commonly applied in water treatment plants for oxidation and disinfection purposes. Little is known about the identity and toxicity of by-products resulting from the chlorination of pharmaceutical micropollutants, such as enalapril (ENA and ranitidine (RAN. ENA and RAN chlorination by-products were characterized in this study by high-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC/HRMS and their toxicity were assessed by MTT assay. Chlorination experiments with ENA and RAN solutions (10 mg L-1 indicate degradation efficiencies of 100% for both compounds after only 5 min of exposure to chlorine at concentration of 9.53 mg Cl2 L-1. On the other hand mineralization rates were lower than 3%, thereby indicating there was accumulation of degradation by-products in all experiments. Mass spectrometric analysis revealed, at all times of reaction after the addition of hypochlorite, the presence of 1-(2-((4-(chlorophenyl-1-ethoxy-1-oxobutan-2-ylaminopropanoylpyrrolidine-2-carboxylic acid (enalapril by-product and N-chloro-N-(2-(((chloro-5-((dimethylaminomethylfuran-2-ylmethylsulfinylethyl-N-methyl-2-nitroethene 1,1-diamine (ranitidine by-product. Despite the formation of oxidized chlorinated by-products in all chlorination assays, the treated solutions were nontoxic to HepG2 cells by the MTT assay. It has been observed that chlorination (10 mg L-1, 5 min of ENA and RAN solutions exhibited high degradation efficiencies of the target compounds and low mineralization rates. Based on the mass spectrometry data, the routes for ENA and RAN successive oxidation by chlorine has been proposed.

  19. Analysis of Non-Volatile Chemical Constituents of Menthae Haplocalycis Herba by Ultra-High Performance Liquid Chromatography-High Resolution Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Lu-Lu Xu

    2017-10-01

    Full Text Available Menthae Haplocalycis herba, one kind of Chinese edible herbs, has been widely utilized for the clinical use in China for thousands of years. Over the last decades, studies on chemical constituents of Menthae Haplocalycis herba have been widely performed. However, less attention has been paid to non-volatile components which are also responsible for its medical efficacy than the volatile constituents. Therefore, a rapid and sensitive method was developed for the comprehensive identification of the non-volatile constituents in Menthae Haplocalycis herba using ultra-high performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap. Separation was performed with Acquity UPLC® BEH C18 column (2.1 mm × 100 mm, 1.7 μm with 0.2% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. Based on the accurate mass measurement (<5 ppm, MS/MS fragmentation patterns and different chromatographic behaviors, a total of 64 compounds were unambiguously or tentatively characterized, including 30 flavonoids, 20 phenolic acids, 12 terpenoids and two phenylpropanoids. Finally, target isolation of three compounds named Acacetin, Rosmarinic acid and Clemastanin A (first isolated from Menthae Haplocalycis herba were performed based on the obtained results, which further confirmed the deduction of fragmentation patterns and identified the compounds profile in Menthae Haplocalycis herba. Our research firstly systematically elucidated the non-volatile components of Menthae Haplocalycis herba, which laid the foundation for further pharmacological and metabolic studies. Meanwhile, our established method was useful and efficient to screen and identify targeted constituents from traditional Chinese medicine extracts.

  20. High-resolution melt PCR analysis for rapid identification of Chlamydia abortus live vaccine strain 1B among C. abortus strains and field isolates.

    Science.gov (United States)

    Vorimore, Fabien; Cavanna, Noémie; Vicari, Nadia; Magnino, Simone; Willems, Hermann; Rodolakis, Annie; Siarkou, Victoria I; Laroucau, Karine

    2012-09-01

    We describe a novel high-resolution melt assay that clearly differentiates Chlamydia abortus live vaccine strain 1B from field C. abortus strains and field wild-type isolates based on previously described single nucleotide polymorphisms. This modern genotyping technique is inexpensive, easy to use, and less time-consuming than PCR-RFLP. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Rapid determination of retinoic acid and its main isomers in plasma by second-order high-performance liquid chromatography data modeling.

    Science.gov (United States)

    Teglia, Carla M; Cámara, María S; Goicoechea, Héctor C

    2014-12-01

    This paper reports the development of a method based on high-performance liquid chromatography (HPLC) coupled to second-order data modeling with multivariate curve resolution-alternating least-squares (MCR-ALS) for quantification of retinoic acid and its main isomers in plasma in only 5.5 min. The compounds retinoic acid (RA), 13-cis-retinoic acid, 9-cis-retinoic acid, and 9,13-di-cis-retinoic acid were partially separated by use of a Poroshell 120 EC-C18 (3.0 mm × 30 mm, 2.7 μm particle size) column. Overlapping not only among the target analytes but also with the plasma interferents was resolved by exploiting the second-order advantage of the multi-way calibration. A validation study led to the following results: trueness with recoveries of 98.5-105.9 % for RA, 95.7-110.1 % for 13-cis-RA, 97.1-110.8 % for 9-cis-RA, and 99.5-110.9 % for 9,13-di-cis-RA; repeatability with RSD of 3.5-3.1 % for RA, 3.5-1.5 % for 13-cis-RA, 4.6-2.7 % for 9-cis-RA, and 5.2-2.7 % for 9,13-di-cis-RA (low and high levels); and intermediate precision (inter-day precision) with RSD of 3.8-3.0 % for RA, 2.9-2.4 % for 13-cis-RA, 3.6-3.2 % for 9,13-di-cis-RA, and 3.2-2.9 % for 9-cis-RA (low and high levels). In addition, a robustness study revealed the method was suitable for monitoring patients with dermatological diseases treated with pharmaceutical products containing RA and 13-cis-RA.

  2. Development and validation of a rapid ultra-high performance liquid chromatography diode array detector method for Vitex agnus-castus.

    Science.gov (United States)

    Högner, C; Sturm, S; Seger, C; Stuppner, H

    2013-05-15

    A rapid ultra-high performance liquid chromatography diode array detector (UHPLC-DAD) method was developed and validated for the simultaneous determination of all classes of non-volatile phytochemicals (iridoids, flavonoids and diterpenes) in Vitex agnus-castus (Lamiaceae) fruits, a traditional medicinal plant used against premenstrual symptoms (PMS) and other disorders. Seven marker compounds, 3,4-dihydroxybenzoic acid, p-hydroxybenzoic acid, agnuside, 5-hydroxykaempferol-3,6,7,4'-tetramethylether, 1,2-dibenzoic acid glucose, methoxy-vitexilactone, and vitetrifolin D were isolated from the methanol extract of V. agnus-castus to be used as reference substances. Chromatographic separation was performed on a Zorbax Eclipse XDB-C18 (50mm×2.1mm) UHPLC column with 1.8μm particle size, within 20min. A solvent gradient from 0.5% acetic acid to acetonitrile at a flow rate of 0.6mL/min was used as mobile phase. Analyte detection and quantification was realized at 210nm and 260nm. The UHPLC-DAD assay was validated for the quantitative analysis of agnuside, isovitexin, casticin, 5-hydroxykaempferol-3,6,7,4'-tetramethylether and vitetrifolin D. It was found to be specific, accurate, precise, and reproducible for the quantification of these compound within a concentration range of 0.7-500.0μg/mL for casticin and 5-hydroxykaempferol-3,6,7,4'-tetramethylether, 1.4-1000.0μg/mL for isovitexin and agnuside, and 12.4-1000.0μg/mL for vitetrifolin D. Intra- and inter-day variations showed relative standard deviations (RSD) of less than 3.9% and 6.4%, respectively. Tentatively assignment of 62 chromatographic features found in the UHPLC-DAD assay was carried out by coupling the UHPLC instrument to a quadrupole time-of-flight mass spectrometer via an electrospray ionization interface (ESI-QTOF-MS) operated in positive and negative ion mode. By using the established quantitative UHPLC-DAD assay to asses agnuside, isovitexin, casticin, 5-hydroxykaempferol-3,6,7,4'-tetramethylether and

  3. Signal processing for liquid ionization calorimeters

    International Nuclear Information System (INIS)

    Cleland, W.E.; Stern, E.G.

    1992-01-01

    We present the results of a study of the effects of thermal and pileup noise in liquid ionization calorimeters operating in a high luminosity calorimeters operating in a high luminosity environment. The method of optimal filtering of multiply-sampled signals which may be used to improve the timing and amplitude resolution of calorimeter signals is described, and its implications for signal shaping functions are examined. The dependence of the time and amplitude resolution on the relative strength of the pileup and thermal noise, which varies with such parameters as luminosity, rapidity and calorimeter cell size, is examined

  4. Rapid analysis of heterogeneously methylated DNA using digital methylation-sensitive high resolution melting: application to the CDKN2B (p15) gene

    DEFF Research Database (Denmark)

    Candiloro, Ida Lm; Mikeska, Thomas; Hokland, Peter

    2008-01-01

    ABSTRACT: BACKGROUND: Methylation-sensitive high resolution melting (MS-HRM) methodology is able to recognise heterogeneously methylated sequences by their characteristic melting profiles. To further analyse heterogeneously methylated sequences, we adopted a digital approach to MS-HRM (dMS-HRM) t......ABSTRACT: BACKGROUND: Methylation-sensitive high resolution melting (MS-HRM) methodology is able to recognise heterogeneously methylated sequences by their characteristic melting profiles. To further analyse heterogeneously methylated sequences, we adopted a digital approach to MS-HRM (d......MS-HRM) that involves the amplification of single templates after limiting dilution to quantify and to determine the degree of methylation. We used this approach to study methylation of the CDKN2B (p15) cell cycle progression inhibitor gene which is inactivated by DNA methylation in haematological malignancies...... the methylated alleles and assess the degree of methylation. Direct sequencing of selected dMS-HRM products was used to determine the exact DNA methylation pattern and confirmed the degree of methylation estimated by dMS-HRM. CONCLUSION: dMS-HRM is a powerful technique for the analysis of methylation in CDKN2B...

  5. Nontargeted SWATH acquisition for identifying 47 synthetic cannabinoid metabolites in human urine by liquid chromatography-high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Scheidweiler, Karl B; Jarvis, Michael J Y; Huestis, Marilyn A

    2015-01-01

    Clandestine laboratories constantly produce new synthetic cannabinoids to circumvent legislative scheduling efforts, challenging and complicating toxicological analysis. Sundstrom et al. (Anal Bioanal Chem 405(26):8463-8474, [9]) and Kronstrand et al. (Anal Bioanal Chem 406(15):3599-3609, [10]) published nontargeted liquid chromatography, high-resolution, quadrupole/time-of-flight mass spectrometric (LC-QTOF) assays with validated detection of 18 and 38 urinary synthetic cannabinoid metabolites, respectively. We developed and validated a LC-QTOF urine method for simultaneously identifying the most current 47 synthetic cannabinoid metabolites from 21 synthetic cannabinoid families (5-fluoro AB-PINACA, 5-fluoro-AKB48, 5-fluoro PB-22, AB-PINACA, ADB-PINACA, AKB48, AM2201, JWH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-200, JWH-210, JWH-250, JWH-398, MAM2201, PB-22, RCS-4, UR-144, and XLR11). β-Glucuronidase-hydrolyzed urine was extracted with 1-mL Biotage SLE+ columns. Specimens were reconstituted in 150-μL mobile phase consisting of 80% A (0.1% formic acid in water) and 20% B (0.1% formic acid in acetonitrile). Fifty microliters was injected, and SWATH™ MS data were acquired in positive electrospray mode. The LC-QTOF instrument consisted of a Shimadzu UFLCxr system and an ABSciex 5600+ TripleTOF® mass spectrometer. Gradient chromatographic separation was achieved with a Restek Ultra Biphenyl column with a 0.5-mL/min flow rate and an overall run time of 15 min. Identification criteria included molecular ion mass error, isotopic profiles, retention time, and library fit criteria. Limits of detection were 0.25-5 μg/L (N = 10 unique fortified urine samples), except for two PB-22 metabolites with limits of 10 and 20 μg/L. Extraction efficiencies and matrix effects (N = 10) were 55-104 and -65-107%, respectively. We present a highly useful novel LC-QTOF method for simultaneously confirming 47 synthetic cannabinoid metabolites in human urine.

  6. Rapid simultaneous high-resolution mapping of myelin water fraction and relaxation times in human brain using BMC-mcDESPOT.

    Science.gov (United States)

    Bouhrara, Mustapha; Spencer, Richard G

    2017-02-15

    A number of central nervous system (CNS) diseases exhibit changes in myelin content and magnetic resonance longitudinal, T 1 , and transverse, T 2 , relaxation times, which therefore represent important biomarkers of CNS pathology. Among the methods applied for measurement of myelin water fraction (MWF) and relaxation times, the multicomponent driven equilibrium single pulse observation of T 1 and T 2 (mcDESPOT) approach is of particular interest. mcDESPOT permits whole brain mapping of multicomponent T 1 and T 2 , with data acquisition accomplished within a clinically realistic acquisition time. Unfortunately, previous studies have indicated the limited performance of mcDESPOT in the setting of the modest signal-to-noise range of high-resolution mapping, required for the depiction of small structures and to reduce partial volume effects. Recently, we showed that a new Bayesian Monte Carlo (BMC) analysis substantially improved determination of MWF from mcDESPOT imaging data. However, our previous study was limited in that it did not discuss determination of relaxation times. Here, we extend the BMC analysis to the simultaneous determination of whole-brain MWF and relaxation times using the two-component mcDESPOT signal model. Simulation analyses and in-vivo human brain studies indicate the overall greater performance of this approach compared to the stochastic region contraction (SRC) algorithm, conventionally used to derive parameter estimates from mcDESPOT data. SRC estimates of the transverse relaxation time of the long T 2 fraction, T 2,l , and the longitudinal relaxation time of the short T 1 fraction, T 1,s , clustered towards the lower and upper parameter search space limits, respectively, indicating failure of the fitting procedure. We demonstrate that this effect is absent in the BMC analysis. Our results also showed improved parameter estimation for BMC as compared to SRC for high-resolution mapping. Overall we find that the combination of BMC analysis

  7. Development and validation of a rapid high performance liquid chromatography - photodiode array detection method for estimation of a bioactive compound wedelolactone in extracts of Eclipta alba

    Directory of Open Access Journals (Sweden)

    Satyanshu Kumar

    2013-03-01

    Full Text Available Following optimization of extraction, separation and analytical conditions, a rapid, sensitive and simple reverse-phase high performance liquid chromatography-photo diode array (HPLC-PDA method has been developed for the identification and quantification of wedelolactone in different extracts of Eclipta alba. The separation of wedelolactone was achieved on a C18 column using the solvent system consisting of a mixture of methanol: water: acetic acid (95: 5: 0.04 as a mobile phase in isocratic elution mode followed by photo diode array detection at 352 nm. The developed method was validated as per the guidelines of the International Conference on Harmonization (ICH. Calibration curve presented good linear regression (r²>0.998 within the test range and the maximum relative standard deviation (RSD, % values for intra-day assay were found to be 0.15, 1.30 and 1.1 for low (5 µg/mL, medium (20 µg/mL and high (80 µg/mL concentrations of wedelolactone. For inter-day assay the maximum RSD (% values were found to be 2.83, 1.51 and 2.06 for low, medium and high concentrations, respectively. Limit of detection (LOD and limit of quantification (LOQ were calculated to be 2 and 5 µg/mL respectively. Analytical recovery of wedelolactone was greater than 95%. Wedelolactone in different extracts of Eclipta alba was identified and quantified using the developed HPLC method. The validated HPLC method allowed precise quantitative analysis of wedelolactone in Eclipta. alba extracts.Desenvolveu-se método rápido, sensível e simples de Cromatografia Líquida de Alta Eficiência em fase reversa, utilizando-se arranjo de fotodiodo (HPLC-PDA, visando à separação, extração e às condições analíticas para a identificação e quantificação de wedelolactona em diferentes extratos de Eclipta alba. A separação de wedelolactona foi efetuada por meio de uma coluna C18, utilizando mistura de metanol:água:ácido acético (95:5:0.04 como fase móvel, em sistema de

  8. A refined, rapid and reproducible high resolution melt (HRM-based method suitable for quantification of global LINE-1 repetitive element methylation

    Directory of Open Access Journals (Sweden)

    Tse M Yat

    2011-12-01

    Full Text Available Abstract Background The methylation of DNA is recognized as a key mechanism in the regulation of genomic stability and evidence for its role in the development of cancer is accumulating. LINE-1 methylation status represents a surrogate measure of genome-wide methylation. Findings Using high resolution melt (HRM curve analysis technology, we have established an in-tube assay that is linear (r > 0.9986 with a high amplification efficiency (90-105%, capable of discriminating between partcipant samples with small differences in methylation, and suitable for quantifying a wide range of LINE-1 methylation levels (0-100%--including the biologically relevant range of 50-90% expected in human DNA. We have optimized this procedure to perform using 2 μg of starting DNA and 2 ng of bisulfite-converted DNA for each PCR reaction. Intra- and inter-assay coefficients of variation were 1.44% and 0.49%, respectively, supporting the high reproducibility and precision of this approach. Conclusions In summary, this is a completely linear, quantitative HRM PCR method developed for the measurement of LINE-1 methylation. This cost-efficient, refined and reproducible assay can be performed using minimal amounts of starting DNA. These features make our assay suitable for high throughput analysis of multiple samples from large population-based studies.

  9. Rapid Linguistic Ambiguity Resolution in Young Children with Autism Spectrum Disorder: Eye Tracking Evidence for the Limits of Weak Central Coherence.

    Science.gov (United States)

    Hahn, Noemi; Snedeker, Jesse; Rabagliati, Hugh

    2015-12-01

    Individuals with autism spectrum disorders (ASD) have often been reported to have difficulty integrating information into its broader context, which has motivated the Weak Central Coherence theory of ASD. In the linguistic domain, evidence for this difficulty comes from reports of impaired use of linguistic context to resolve ambiguous words. However, recent work has suggested that impaired use of linguistic context may not be characteristic of ASD, and is instead better explained by co-occurring language impairments. Here, we provide a strong test of these claims, using the visual world eye tracking paradigm to examine the online mechanisms by which children with autism resolve linguistic ambiguity. To address concerns about both language impairments and compensatory strategies, we used a sample whose verbal skills were strong and whose average age (7; 6) was lower than previous work on lexical ambiguity resolution in ASD. Participants (40 with autism and 40 controls) heard sentences with ambiguous words in contexts that either strongly supported one reading or were consistent with both (John fed/saw the bat). We measured activation of the unintended meaning through implicit semantic priming of an associate (looks to a depicted baseball glove). Contrary to the predictions of weak central coherence, children with ASD, like controls, quickly used context to resolve ambiguity, selecting appropriate meanings within a second. We discuss how these results constrain the generality of weak central coherence. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  10. Rapid Identification of Echinococcus granulosus and E. canadensis Using High-Resolution Melting (HRM) Analysis by Focusing on a Single Nucleotide Polymorphism.

    Science.gov (United States)

    Safa, Ahmad Hosseini; Harandi, Majid Fasihi; Tajaddini, Mohammadhasan; Rostami-Nejad, Mohammad; Mohtashami-Pour, Mehdi; Pestehchian, Nader

    2016-07-22

    High-resolution melting (HRM) is a reliable and sensitive scanning method to detect variation in DNA sequences. We used this method to better understand the epidemiology and transmission of Echinococcus granulosus. We tested the use of HRM to discriminate the genotypes of E. granulosus and E. canadensis. One hundred forty-one hydatid cysts were collected from slaughtered animals in different parts of Isfahan-Iran in 2013. After DNA extraction, the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was amplified using PCR coupled with the HRM curve. The result of HRM analysis using partial the sequences of cox1 gene revealed that 93, 35, and 2 isolates were identified as G1, G3, and G6 genotypes, respectively. A single nucleotide polymorphism (SNP) was found in locus 9867 of the cox1 gene. This is a critical locus for the differentiation between the G6 and G7 genotypes. In the phylogenic tree, the sample with a SNP was located between the G6 and G7 genotypes, which suggest that this isolate has a G6/G7 genotype. The HRM analysis developed in the present study provides a powerful technique for molecular and epidemiological studies on echinococcosis in humans and animals.

  11. Ultra-high resolution pollen record from the northern Andes reveals rapid shifts in montane climates within the last two glacial cycles

    Directory of Open Access Journals (Sweden)

    M. H. M. Groot

    2011-03-01

    Full Text Available Here we developed a composite pollen-based record of altitudinal vegetation changes from Lake Fúquene (5° N in Colombia at 2540 m elevation. We quantitatively calibrated Arboreal Pollen percentages (AP% into mean annual temperature (MAT changes with an unprecedented ~60-year resolution over the past 284 000 years. An age model for the AP% record was constructed using frequency analysis in the depth domain and tuning of the distinct obliquity-related variations to the latest marine oxygen isotope stacked record. The reconstructed MAT record largely concurs with the ~100 and 41-kyr (obliquity paced glacial cycles and is superimposed by extreme changes of up to 7 to 10° Celsius within a few hundred years at the major glacial terminations and during marine isotope stage 3, suggesting an unprecedented North Atlantic – equatorial link. Using intermediate complexity transient climate modelling experiments, we demonstrate that ice volume and greenhouse gasses are the major forcing agents causing the orbital-related MAT changes, while direct precession-induced insolation changes had no significant impact on the high mountain vegetation during the last two glacial cycles.

  12. Development and assessment of multiplex high resolution melting assay as a tool for rapid single-tube identification of five Brucella species.

    Science.gov (United States)

    Gopaul, Krishna K; Sells, Jessica; Lee, Robin; Beckstrom-Sternberg, Stephen M; Foster, Jeffrey T; Whatmore, Adrian M

    2014-12-11

    The zoonosis brucellosis causes economically significant reproductive problems in livestock and potentially debilitating disease of humans. Although the causative agent, organisms from the genus Brucella, can be differentiated into a number of species based on phenotypic characteristics, there are also significant differences in genotype that are concordant with individual species. This paper describes the development of a five target multiplex assay to identify five terrestrial Brucella species using real-time polymerase chain reaction (PCR) and subsequent high resolution melt curve analysis. This technology offers a robust and cost effective alternative to previously described hydrolysis-probe Single Nucleotide Polymorphism (SNP)-based species defining assays. Through the use of Brucella whole genome sequencing five species defining SNPs were identified. Individual HRM assays were developed to these target these changes and, following optimisation of primer concentrations, it was possible to multiplex all five assays in a single tube. In a validation exercise using a panel of 135 Brucella strains of terrestrial and marine origin, it was possible to distinguish the five target species from the other species within this panel. The HRM multiplex offers a number of diagnostic advantages over previously described SNP-based typing approaches. Further, and uniquely for HRM, the successful multiplexing of five assays in a single tube allowing differentiation of five Brucella species in the diagnostic laboratory in a cost-effective and timely manner is described. However there are possible limitations to using this platform on DNA extractions direct from clinical material.

  13. Rapid determination of 99Tc in environmental samples by high resolution ICP-MS coupled with on-line flow injection system

    International Nuclear Information System (INIS)

    Kim, C.K.; Kim, C.S.; Rho, B.H.; Lee, J.I.

    2002-01-01

    High resolution inductively coupled plasma mass spectrometry coupled with an on-line flow injection system (FI-HR-ICP-MS) was applied to determine the ultra-trace level 99 Tc in soil. The flow injection system (PrepLab TM ) was composed of two TEVA-Spec R resins, reduced remarkably the sample amounts and the analysis time, compared to the conventional analytical methods. In the flow injection system, Mo and Ru were sufficiently eliminated by using the flow injection system, with the decontamination factors of 1.6 x 10 4 and 9.9 x 10 5 , respectively. With the present method, it was possible to determine ultra-low level of 99 Tc in 3∼6 soil at 3-5 hours of analysis time per sample. The relative standard deviation for each sample was less than 4%. The detection limits for 99 Tc was 85 fg x ml -1 (0.05 mBq x ml -1 ), which was calculated from the three times standard deviation of the count rate of the blank. (author)

  14. Versatile lipid profiling by liquid chromatography–high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gallart-Ayala, H., E-mail: laberca@oniris-nantes.fr [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France); Courant, F.; Severe, S.; Antignac, J.-P. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France); Morio, F.; Abadie, J. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), Cancers Animaux, Modèles pour la Recherche en Oncologie Comparée (AMaROC), Site de la Chantrerie–CS50707, 44307 Nantes cedex 3 (France); Le Bizec, B. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France)

    2013-09-24

    Graphical abstract: -- Highlights: •Lipidomics, high resolution mass spectrometry, polarity switching, serum, canine mammary cancer. -- Abstract: Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC–HRMS or LC–MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC–HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and “all ion fragmentation” (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale.

  15. Versatile lipid profiling by liquid chromatography–high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer

    International Nuclear Information System (INIS)

    Gallart-Ayala, H.; Courant, F.; Severe, S.; Antignac, J.-P.; Morio, F.; Abadie, J.; Le Bizec, B.

    2013-01-01

    Graphical abstract: -- Highlights: •Lipidomics, high resolution mass spectrometry, polarity switching, serum, canine mammary cancer. -- Abstract: Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC–HRMS or LC–MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC–HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and “all ion fragmentation” (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale

  16. Diffusible iodine-based contrast-enhanced computed tomography (diceCT): an emerging tool for rapid, high-resolution, 3-D imaging of metazoan soft tissues.

    Science.gov (United States)

    Gignac, Paul M; Kley, Nathan J; Clarke, Julia A; Colbert, Matthew W; Morhardt, Ashley C; Cerio, Donald; Cost, Ian N; Cox, Philip G; Daza, Juan D; Early, Catherine M; Echols, M Scott; Henkelman, R Mark; Herdina, A Nele; Holliday, Casey M; Li, Zhiheng; Mahlow, Kristin; Merchant, Samer; Müller, Johannes; Orsbon, Courtney P; Paluh, Daniel J; Thies, Monte L; Tsai, Henry P; Witmer, Lawrence M

    2016-06-01

    Morphologists have historically had to rely on destructive procedures to visualize the three-dimensional (3-D) anatomy of animals. More recently, however, non-destructive techniques have come to the forefront. These include X-ray computed tomography (CT), which has been used most commonly to examine the mineralized, hard-tissue anatomy of living and fossil metazoans. One relatively new and potentially transformative aspect of current CT-based research is the use of chemical agents to render visible, and differentiate between, soft-tissue structures in X-ray images. Specifically, iodine has emerged as one of the most widely used of these contrast agents among animal morphologists due to its ease of handling, cost effectiveness, and differential affinities for major types of soft tissues. The rapid adoption of iodine-based contrast agents has resulted in a proliferation of distinct specimen preparations and scanning parameter choices, as well as an increasing variety of imaging hardware and software preferences. Here we provide a critical review of the recent contributions to iodine-based, contrast-enhanced CT research to enable researchers just beginning to employ contrast enhancement to make sense of this complex new landscape of methodologies. We provide a detailed summary of recent case studies, assess factors that govern success at each step of the specimen storage, preparation, and imaging processes, and make recommendations for standardizing both techniques and reporting practices. Finally, we discuss potential cutting-edge applications of diffusible iodine-based contrast-enhanced computed tomography (diceCT) and the issues that must still be overcome to facilitate the broader adoption of diceCT going forward. © 2016 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

  17. Supported liquid membrane extraction coupled in-line to commercial capillary electrophoresis for rapid determination of formate in undiluted blood samples

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2013-01-01

    Roč. 1299, JUL (2013), s. 33-39 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * supported liquid membranes * methanol intoxication Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.258, year: 2013

  18. Rapid determination of alkaloids in Macleaya cordata using ionic liquid extraction followed by multiple reaction monitoring UPLC-MS/MS analysis.

    Science.gov (United States)

    Li, Linqiu; Huang, Mingyuan; Shao, Junli; Lin, Bokun; Shen, Qing

    2017-02-20

    The ultrasonic-assisted extraction (UAE) and ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) have been successfully applied in extracting of six alkaloids from M. cordata. 1-hexyl-3-methylimidazolium tetrafluoroborate ([C 6 MIM][BF 4 ]) aqueous solution was used as extraction solvent. The target analytes in raw material were deposited into a single drop of 1-hexyl-3-methylimidazolium hexafluorophosphate ([C 6 MIM][PF 6 ]), which was in situ formed by mixing [C 6 MIM][BF 4 ] and potassium hexafluorophosphate ([K][PF 6 ]. Afterwards, the extract was analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in multiple-reaction monitoring (MRM) mode. The proposed method was fully validated in terms of linearity (0.9983-0.9992), LOD (0.080ngmL -1 ), LOQ (0.25ngmL -1 ), intra-day precision (MS/MS is powerful and practical for analyzing alkaloids in M. cordata., and it also has great potential for comprehensive quality control of other herbal medicines. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Rapid and sensitive determination of phytosterols in functional foods and medicinal herbs by using UHPLC-MS/MS with microwave-assisted derivatization combined with dual ultrasound-assisted dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Sun, Jing; Zhao, Xian-En; Dang, Jun; Sun, Xiaoyan; Zheng, Longfang; You, Jinmao; Wang, Xiao

    2017-02-01

    In this work, a hyphenated technique of dual ultrasound-assisted dispersive liquid-liquid microextraction combined with microwave-assisted derivatization followed by ultra high performance liquid chromatography tandem mass spectrometry has been developed for the determination of phytosterols in functional foods and medicinal herbs. Multiple reaction monitoring mode was used for the tandem mass spectrometry detection. A mass spectrometry sensitive reagent, 4'-carboxy-substituted rosamine, has been used as the derivatization reagent for five phytosterols, and internal standard diosgenin was used for the first time. Parameters for the dual microextraction, microwave-assisted derivatization, and ultra high performance liquid chromatography tandem mass spectrometry were all optimized in detail. Satisfactory linearity, recovery, repeatability, accuracy and precision, absence of matrix effect, extremely low limits of detection (0.005-0.015 ng/mL) and limits of quantification (0.030-0.10 ng/mL) were achieved. The proposed method was compared with previously reported methods. It showed better sensitivity, selectivity, and accuracy. The matrix effect was also significantly reduced. The proposed method was successfully applied to the determination of five phytosterols in vegetable oil (sunflower oil, olive oil, corn oil, peanut oil), milk and orange juice (soymilk, peanut milk, orange juice), and medicinal herbs (Ginseng, Ganoderma lucidum, Cordyceps, Polygonum multiflorum) for the quality control of functional foods and medicinal herbs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Intra-and-Inter Species Biomass Prediction in a Plantation Forest: Testing the Utility of High Spatial Resolution Spaceborne Multispectral RapidEye Sensor and Advanced Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Timothy Dube

    2014-08-01

    Full Text Available The quantification of aboveground biomass using remote sensing is critical for better understanding the role of forests in carbon sequestration and for informed sustainable management. Although remote sensing techniques have been proven useful in assessing forest biomass in general, more is required to investigate their capabilities in predicting intra-and-inter species biomass which are mainly characterised by non-linear relationships. In this study, we tested two machine learning algorithms, Stochastic Gradient Boosting (SGB and Random Forest (RF regression trees to predict intra-and-inter species biomass using high resolution RapidEye reflectance bands as well as the derived vegetation indices in a commercial plantation. The results showed that the SGB algorithm yielded the best performance for intra-and-inter species biomass prediction; using all the predictor variables as well as based on the most important selected variables. For example using the most important variables the algorithm produced an R2 of 0.80 and RMSE of 16.93 t·ha−1 for E. grandis; R2 of 0.79, RMSE of 17.27 t·ha−1 for P. taeda and R2 of 0.61, RMSE of 43.39 t·ha−1 for the combined species data sets. Comparatively, RF yielded plausible results only for E. dunii (R2 of 0.79; RMSE of 7.18 t·ha−1. We demonstrated that although the two statistical methods were able to predict biomass accurately, RF produced weaker results as compared to SGB when applied to combined species dataset. The result underscores the relevance of stochastic models in predicting biomass drawn from different species and genera using the new generation high resolution RapidEye sensor with strategically positioned bands.

  1. STUDY OF RAPID FORMATION OF A δ SUNSPOT ASSOCIATED WITH THE 2012 JULY 2 C7.4 FLARE USING HIGH-RESOLUTION OBSERVATIONS OF THE NEW SOLAR TELESCOPE

    International Nuclear Information System (INIS)

    Wang Haimin; Liu Chang; Wang Shuo; Deng Na; Xu Yan; Jing Ju; Cao Wenda

    2013-01-01

    Rapid, irreversible changes of magnetic topology and sunspot structure associated with flares have been systematically observed in recent years. The most striking features include the increase of the horizontal field at the polarity inversion line (PIL) and the co-spatial penumbral darkening. A likely explanation of the above phenomenon is the back reaction to the coronal restructuring after eruptions: a coronal mass ejection carries the upward momentum while the downward momentum compresses the field lines near the PIL. Previous studies could only use low-resolution (above 1'') magnetograms and white-light images. Therefore, the changes are mostly observed for X-class flares. Taking advantage of the 0.''1 spatial resolution and 15 s temporal cadence of the New Solar Telescope at the Big Bear Solar Observatory, we report in detail the rapid formation of sunspot penumbra at the PIL associated with the C7.4 flare on 2012 July 2. It is unambiguously shown that the solar granulation pattern evolves to an alternating dark and bright fibril structure, the typical pattern of penumbra. Interestingly, the appearance of such a penumbra creates a new δ sunspot. The penumbral formation is also accompanied by the enhancement of the horizontal field observed using vector magnetograms from the Helioseismic and Magnetic Imager. We explain our observations as being due to the eruption of a flux rope following magnetic cancellation at the PIL. Subsequently, the re-closed arcade fields are pushed down toward the surface to form the new penumbra. NLFFF extrapolation clearly shows both the flux rope close to the surface and the overlying fields

  2. Rapid activity-directed screening of estrogens by parallel coupling of liquid chromatography with a functional gene reporter assay and mass spectrometry

    NARCIS (Netherlands)

    Jonker, W.; Lamoree, M.H.; Houtman, C.J.; Hamers, T.; Somsen, G.W.; Kool, J.

    2015-01-01

    In this study we developed a new LC nanofractionation platform that combines a human cell (BG1.Luc) gene reporter assay with a high resolution mass spectrometer for the detection and identification of estrogenic and anti-estrogenic compounds in environmental waters. The selection of this assay was

  3. Rapid and Precise Measurement of Serum Branched-Chain and Aromatic Amino Acids by Isotope Dilution Liquid Chromatography Tandem Mass Spectrometry

    OpenAIRE

    Yang, Ruiyue; Dong, Jun; Guo, Hanbang; Li, Hongxia; Wang, Shu; Zhao, Haijian; Zhou, Weiyan; Yu, Songlin; Wang, Mo; Chen, Wenxiang

    2013-01-01

    BACKGROUND: Serum branched-chain and aromatic amino acids (BCAAs and AAAs) have emerged as predictors for the future development of diabetes and may aid in diabetes risk assessment. However, the current methods for the analysis of such amino acids in biological samples are time consuming. METHODS: An isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) method for serum BCAAs and AAAs was developed. The serum was mixed with isotope-labeled BCAA and AAA internal standar...

  4. A simple, rapid and validated high-performance liquid chromatography method suitable for clinical measurements of human mercaptalbumin and non-mercaptalbumin.

    Science.gov (United States)

    Yasukawa, Keiko; Shimosawa, Tatsuo; Okubo, Shigeo; Yatomi, Yutaka

    2018-01-01

    Background Human mercaptalbumin and human non-mercaptalbumin have been reported as markers for various pathological conditions, such as kidney and liver diseases. These markers play important roles in redox regulations throughout the body. Despite the recognition of these markers in various pathophysiologic conditions, the measurements of human mercaptalbumin and non-mercaptalbumin have not been popular because of the technical complexity and long measurement time of conventional methods. Methods Based on previous reports, we explored the optimal analytical conditions for a high-performance liquid chromatography method using an anion-exchange column packed with a hydrophilic polyvinyl alcohol gel. The method was then validated using performance tests as well as measurements of various patients' serum samples. Results We successfully established a reliable high-performance liquid chromatography method with an analytical time of only 12 min per test. The repeatability (within-day variability) and reproducibility (day-to-day variability) were 0.30% and 0.27% (CV), respectively. A very good correlation was obtained with the results of the conventional method. Conclusions A practical method for the clinical measurement of human mercaptalbumin and non-mercaptalbumin was established. This high-performance liquid chromatography method is expected to be a powerful tool enabling the expansion of clinical usefulness and ensuring the elucidation of the roles of albumin in redox reactions throughout the human body.

  5. Investigation of drugs of abuse and relevant metabolites in Dutch sewage water by liquid chromatography coupled to high resolution mass spectrometry

    NARCIS (Netherlands)

    Bijlsma, L.; Emke, E.; Hernández, F.; de Voogt, P.

    2012-01-01

    An extensive study on the presence of illicit drugs and pharmaceuticals with potential for abuse in sewage waters was made for the first time in the Netherlands. A total number of 24 target drugs were investigated in influent and effluent wastewater using liquid chromatography coupled to a high

  6. Resolution of D- and L-glucoses by chiral N-octyl-beta-D-glycoside-Cu(II) complex adsorbed at the gas/liquid interface of small bubbles

    NARCIS (Netherlands)

    Sakai, M.; Miyazawa, K.; Jitsumatsu, H.; Kamio, K.; Mitsuiki, S.; Toh, N.; Sugihara, G.; Norde, W.

    2010-01-01

    A new technique of the jet drop method (JDM) was applied to a chiral molecular discrimination of optically active D- or L-glucose (guest) by chiral N-octyl-beta-D-glycoside (O beta DG)-Cu(II) complex (host) at the gas/liquid interface of small bubbles. The discrimination of glucoses as the guests is

  7. The EPA iCSS Chemistry Dashboard to Support Compound Identification Using High Resolution Mass Spectrometry Data (ACS Fall meeting)

    Science.gov (United States)

    Abstract: There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chr...

  8. Environmental Chemistry Compound Identification Using High Resolution Mass Spectrometry Data Integrated to the EPA Chemistry Dashboard (EAS)

    Science.gov (United States)

    There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chromatograph...

  9. A rapid and simple determination of A77 1726 in human serum by high-performance liquid chromatography and its application for optimization of leflunomide therapy

    NARCIS (Netherlands)

    van Roon, EN; Yska, JP; Raemaekers, J; Jansen, TLTA; van Wanrooy, M; Brouwers, JRBJ

    2004-01-01

    Leflunomide is a disease-modifying antirheumatic drug, which is bioactivated by fort-nation of A77 1726. In this study a rapid and simple quantitative assay using a reversed phase HPLC-UV method is validated for detection of A77 1726 in human serum. The HPLC-UV method uses a mobile phase consisting

  10. Rapid isolation of biomarkers for compound specific radiocarbon dating using high-performance liquid chromatography and flow injection analysis-atmospheric pressure chemical ionisation mass spectrometry

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Smittenberg, R.H.; Hopmans, E.C.; Schouten, S.

    2002-01-01

    Repeated semi-preparative normal-phase HPLC was performed to isolate selected biomarkers from sediment extracts for radiocarbon analysis. Flow injection analysis mass spectrometry was used for rapid analysis of collected fractions to evaluate the separation procedure, taking only 1 min per fraction.

  11. An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes

    NARCIS (Netherlands)

    Zhang, Q.; Klift, van der E.J.C.; Janssen, H.G.; Beek, van T.A.

    2009-01-01

    An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high

  12. Comprehensive Two-Dimensional Hydrophilic Interaction Chromatography (HILIC) × Reversed-Phase Liquid Chromatography Coupled to High-Resolution Mass Spectrometry (RP-LC-UV-MS) Analysis of Anthocyanins and Derived Pigments in Red Wine.

    Science.gov (United States)

    Willemse, Chandré M; Stander, Maria A; Vestner, Jochen; Tredoux, Andreas G J; de Villiers, André

    2015-12-15

    Changes in anthocyanin chemistry represent some of the most important transformations involved in red wine aging. However, accurate analysis of the derived pigments, as required to study the evolution of anthocyanins and tannins during aging, is hampered by their extreme structural diversity, low levels, and the fact that many of these compounds have identical mass spectral characteristics. In this context, chromatographic separation is critical. In this contribution, the application of online hydrophilic interaction chromatography (HILIC) × reversed-phase liquid chromatography (RP-LC) separation coupled to high-resolution mass spectrometry (MS) is described for the detailed characterization of anthocyanins and their derived pigments in aged red wine. A systematic approach was followed for the optimization of HILIC × RP-LC separation parameters using a capillary liquid chromatography (LC) system in the first dimension and an ultrahigh-pressure LC system in the second dimension to ensure maximum sensitivity and performance. Ninety four (94) anthocyanin-derived pigments were tentatively identified in one- and six-year-old Pinotage wines using accurate mass and fragmentation information obtained using quadrupole-time-of-flight mass spectrometry (Q-TOF-MS). Online HILIC × RP-LC-MS was found to offer high-resolution separation, because of the combination of two different separation modes, while the structured elution order observed improved the certainty in compound identification. Therefore, this approach shows promise for the detailed elucidation of the chemical alteration of anthocyanins during wine aging.

  13. Versatile lipid profiling by liquid chromatography-high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer.

    Science.gov (United States)

    Gallart-Ayala, H; Courant, F; Severe, S; Antignac, J-P; Morio, F; Abadie, J; Le Bizec, B

    2013-09-24

    Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC-HRMS or LC-MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and "all ion fragmentation" (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium.

    Science.gov (United States)

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-05-01

    Electromembrane extraction was used for simultaneous sample cleanup and preconcentration of lithium from untreated human body fluids. The sample of a body fluid was diluted 100 times with 0.5 mM Tris solution and lithium was extracted by electromigration through a supported liquid membrane composed of 1-octanol into 100 mM acetic acid acceptor solution. Matrix compounds, such as proteins, red blood cells, and other high-molecular-weight compounds were efficiently retained on the supported liquid membrane. The liquid membrane was anchored in pores of a short segment of a polypropylene hollow fiber, which represented a low cost, single use, disposable extraction unit and was discarded after each use. Acceptor solutions were analyzed using capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4) D) and baseline separation of lithium was achieved in a background electrolyte solution consisting of 18 mM L-histidine and 40 mM acetic acid at pH 4.6. Repeatability of the electromembrane extraction-CE-C(4) D method was evaluated for the determination of lithium in standard solutions and real samples and was better than 0.6 and 8.2% for migration times and peak areas, respectively. The concentration limit of detection of 9 nM was achieved. The developed method was applied to the determination of lithium in urine, blood serum, blood plasma, and whole blood at both endogenous and therapeutic concentration levels. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. The Optical Resolution of Chiral Tetrahedrone-type Clusters Contai- ning SCoFeM (M=Mo or W) Using High Performance Liquid Chromatography Chiral Stationary Phase

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amylose tris (phenylcarbamate) chiral stationary phase (ATPC-CSP) was prepared and used for optical resolution of clusters 1 and 2. n-Hexane/2-propanol ( 99/1; v/v) were found to be the most suitable mobile phase on ATPC-CSP.

  16. A high-resolution detector based on liquid-core scintillating fibres with readout via an electron-bombarded charge-coupled device

    International Nuclear Information System (INIS)

    Cianfarani, C.; Duane, A.; Fabre, J.P.; Frenkel, A.; Golovkin, S.V.; Gorin, A.M.; Harrison, K.; Kozarenko, E.N.; Kushnirenko, A.E.; Ladygin, E.A.; Martellotti, G.; Medvedkov, A.M.; Nass, P.A.; Obudovski, V.P.; Penso, G.; Petukhov, Yu.P.; Siegmund, W.P.; Tyukov, V.E.; Vasilchenko, V.G.

    1994-01-01

    This paper is a presentation of results from tests in a 5 GeV/c hadron beam of detectors based on liquid-core scintillating fibres, each fibre consisting of a glass capillary filled with organic liquid scintillator. Fibre readout was performed via an Electron-Bombarded Charge-Coupled Device (EBCCD) image tube, a novel instrument that combines the functions of a high-gain, gated image intensifier and a Charge-Coupled Device. Using 1-methylnaphthalene doped with 3 g/l of R45 as liquid scintillator, the attenuation lengths obtained for light propagation over distances greater than 16 cm were 1.5 m in fibres of 20 μm core and 1.0 m in fibres of 16 μm core. For particles that crossed the fibres of 20 μm core at distances of ∼1.8 cm and ∼95 cm from the fibres' readout ends, the recorded hit densities were 5.3 mm -1 and 2.5 mm -1 respectively. Using 1-methylnaphthalene doped with 3.6 g/l of R39 as liquid scintillator and fibres of 75 μm core, the hit density obtained for particles that crossed the fibres at a distance of ∼1.8 cm from their readout ends was 8.5 mm -1 . With a specially designed bundle of tapered fibres, having core diameters that smoothly increase from 16 μm to 75 μm, a spatial precision of 6 μm was measured. (orig.)

  17. Rapid determination of the various native forms of vitamin B6 and B2 in cow's milk using ultra-high performance liquid chromatography.

    Science.gov (United States)

    Schmidt, A; Schreiner, M G; Mayer, H K

    2017-06-02

    As the formation of pyridoxal phosphate, the active cofactor of vitamin B 6 , is dependent on riboflavin 5-phosphate, we propose a fast and simple ultra-high performance liquid chromatography method for the simultaneous determination of the native B 6 vitamers pyridoxal, pyridoxine, pyridoxamine, their mono phosphorus esters and 4-pyridoxic acid as well as vitamin B 2 as riboflavin and its phosphorus ester riboflavin 5-phosphate in milk. Separation was achieved under 6.0min by reversed-phase and pH gradient elution. Sample preparation was optimized regarding various acids and pH levels. Changes in those parameters led to significant deviations of sample matrix breakdown efficiency. The optimized method was then validated regarding specificity, accuracy, precision, linearity, range, detection and quantification limits. As the method performed satisfactory, is was used to study commercial liquid cow's milk (n=31), regarding effects of the employed preservation technique (pasteurization, extended shelf-life, ultra-high temperature) on the composition and content of B 6 and B 2 vitamers. In cow's milk, vitamin B 6 mostly consists of pyridoxal and its phosphate ester, with pyridoxal phosphate being the bulk component. The catabolite of the vitamin B 6 metabolism, 4-pyridoxic acid was present in significant amounts in all studied samples, with up to 2.69μmolL -1 . Vitamin B 2 was present as riboflavin and its phosphate ester up to 12.86μmolL -1 . Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Simultaneous and rapid determination of deoxynivalenol and its acetylate derivatives in wheat flour and rice by ultra high performance liquid chromatography with photo diode array detection.

    Science.gov (United States)

    Xu, Jiao-Jiao; Zhou, Jian; Huang, Bai-Fen; Cai, Zeng-Xuan; Xu, Xiao-Min; Ren, Yi-Ping

    2016-06-01

    A simple and reliable method of ultra high performance liquid chromatography coupled with photo-diode array detection has been proposed for the simultaneous determination of deoxynivalenol and its acetylated derivatives in wheat flour and rice, especially focusing on the optimization of sample extraction, cleanup, and chromatographic separation conditions. Sample pretreatment consisted of a first step using a quick, easy, cheap, effective, rugged, and safe based extraction procedure and a subsequent cleanup step based on solid-phase extraction. The method was extensively validated in wheat flour and rice, obtaining satisfactory analytical performance with good linearity (R(2) ≥ 0.999), acceptable recoveries (80.0-104.4%), and repeatability (RSDs 1.3-10.7%). The limits of detection (21.7-57.4 μg/kg) and quantitation (72.3-191.4 μg/kg) for deoxynivalenols were lower than those usually permitted by various countries' legislation in these food matrices. The method was applied to 34 wheat and rice samples. The results were further compared with results of ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Rapid and accurate liquid chromatography and tandem mass spectrometry method for the simultaneous quantification of ten metabolic reactions catalyzed by hepatic cytochrome P450 enzymes.

    Science.gov (United States)

    Shi, Rong; Ma, Bingliang; Wu, Jiasheng; Wang, Tianming; Ma, Yueming

    2015-10-01

    The hepatic cytochrome P450 enzymes play a central role in the biotransformation of endogenous and exogenous substances. A sensitive high-throughput liquid chromatography with tandem mass spectrometry assay was developed and validated for the simultaneous quantification of the products of ten metabolic reactions catalyzed by hepatic cytochrome P450 enzymes. After the substrates were incubated separately, the samples were pooled and analyzed by liquid chromatography with tandem mass spectrometry using an electrospray ionization source in the positive and negative ion modes. The method exhibited linearity over a broad concentration range, insensitivity to matrix effects, and high accuracy, precision, and stability. The novel method was successfully applied to study the kinetics of phenacetin-O deethylation, coumarin-7 hydroxylation, bupropion hydroxylation, taxol-6 hydroxylation, omeprazole-5 hydroxylation, dextromethorphan-O demethylation, tolbutamide-4 hydroxylation, chlorzoxazone-6 hydroxylation, testosterone-6β hydroxylation, and midazolam-1 hydroxylation in rat liver microsomes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Rapid Evaporation of microbubbles

    Science.gov (United States)

    Gautam, Jitendra; Esmaeeli, Asghar

    2008-11-01

    When a liquid is heated to a temperature far above its boiling point, it evaporates abruptly. Boiling of liquid at high temperatures can be explosive and destructive, and poses a potential hazard for a host of industrial processes. Explosive boiling may occur if a cold and volatile liquid is brought into contact with a hot and non-volatile liquid, or if a liquid is superheated or depressurized rapidly. Such possibilities are realized, for example, in the depressurization of low boiling point liquefied natural gas (LNG) in the pipelines or storage tanks as a result of a leak. While boiling of highly heated liquids can be destructive at macroscale, the (nearly) instantaneous pace of the process and the release of large amount of kinetic energy make the phenomena extremely attractive at microscale where it is possible to utilize the released energy to derive micromechanical systems. For instance, there is currently a growing interest in micro-explosion of liquid for generation of micro bubbles for actuation purposes. The aim of the current study is to gain a fundamental understanding of the subject using direct numerical simulations. In particular, we seek to investigate the boundary between stable and unstable nucleus growth in terms of the degree of liquid superheat and to compare the dynamics of unstable and stable growth.

  1. Analysis of bovine milk caseins on organic monolithic columns: an integrated capillary liquid chromatography-high resolution mass spectrometry approach for the study of time-dependent casein degradation.

    Science.gov (United States)

    Pierri, Giuseppe; Kotoni, Dorina; Simone, Patrizia; Villani, Claudio; Pepe, Giacomo; Campiglia, Pietro; Dugo, Paola; Gasparrini, Francesco

    2013-10-25

    Casein proteins constitute approximately 80% of the proteins present in bovine milk and account for many of its nutritional and technological properties. The analysis of the casein fraction in commercially available pasteurized milk and the study of its time-dependent degradation is of considerable interest in the agro-food industry. Here we present new analytical methods for the study of caseins in fresh and expired bovine milk, based on the use of lab-made capillary organic monolithic columns. An integrated capillary high performance liquid chromatography and high-resolution mass spectrometry (Cap-LC-HRMS) approach was developed, exploiting the excellent resolution, permeability and biocompatibility of organic monoliths, which is easily adaptable to the analysis of intact proteins. The resolution obtained on the lab-made Protein-Cap-RP-Lauryl-γ-Monolithic column (270 mm × 0.250 mm length × internal diameter, L × I.D.) in the analysis of commercial standard caseins (αS-CN, β-CN and κ-CN) through Cap-HPLC-UV was compared to the one observe using two packed capillary C4 columns, the ACE C4 (3 μm, 150 mm × 0.300 mm, L × I.D.) and the Jupiter C4 column (5 μm, 150 mm × 0.300 mm, L × I.D.). Thanks to the higher resolution observed, the monolithic capillary column was chosen for the successive degradation studies of casein fractions extracted from bovine milk 1-4 weeks after expiry date. The comparison of the UV chromatographic profiles of skim, semi-skim and whole milk showed a major stability of whole milk towards time-dependent degradation of caseins, which was further sustained by high-resolution analysis on a 50-cm long monolithic column using a 120-min time gradient. Contemporarily, the exact monoisotopic and average molecular masses of intact αS-CN and β-CN protein standards were obtained through high resolution mass spectrometry and used for casein identification in Cap-LC-HRMS analysis. Finally, the proteolytic degradation of β-CN in skim milk

  2. Development of dispersive liquid-liquid microextraction technique using ternary solvents mixture followed by heating for the rapid and sensitive analysis of phthalate esters and di(2-ethylhexyl) adipate.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Khoshmaram, Leila

    2015-01-30

    In this study, for the first time, a dispersive liquid-liquid microextraction technique using a ternary solvent mixture is reported. In order to extract five phthalate esters and di(2-ethylhexyl) adipate with different polarities from aqueous samples, a simplex centroid experimental design method was used to select an optimal mixture of ternary solvents prior to gas chromatographyflame ionization detection. In this work, dimethyl formamide as a disperser solvent containing dichloromethane, chloroform, and carbon tetrachloride as a ternary extraction solvent mixture is injected into sample solution and a cloudy solution is formed. After centrifuging, 250μL of the obtained sedimented phase was transferred into another tube and 5μL DMF was added to it. Then, the tube was heated in a water bath at 75°C for 5min in order to evaporate the main portion of the extraction solvents. Finally, 2μL of the remained phase is injected into the separation system. Under the optimum extraction conditions, the method shows wide linear ranges and low limits of detection and quantification between 0.03-0.15 and 0.09-0.55μgL(-1), respectively. Enrichment factors and extraction recoveries are in the ranges of 980-4500 and 20-90%, respectively. The method is successfully applied in the determination of the target analytes in mineral water, soda, lemon juice, vinegar, dough, and yogurt packed in plastic packages. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Rapid actinide analysis method coupling liquid chromatography/ICP-MS and "9"0Sr gas proportional counter in post-accidental situation environmental samples

    International Nuclear Information System (INIS)

    Habibi, Azza

    2015-01-01

    The present study follows the Fukushima power plant accident and aimed to develop an analytical method to achieve, during an emergency situation, a rapid identification and quantification of alpha and beta emitters in environmental samples. The first step of this study allowed us to list the alpha and beta emitters which can be released in the environment in case of a nuclear accident. The second step aimed towards the development of a rapid analysis method to quantify 17 radionuclides of U, Th, Pu, Am, Np and Sr. The main objective was the automation of the radiochemical separation step and its coupling for the measurement. The separation is performed using columns containing extraction resins, namely TEVA, TRU and Sr. The measurement is performed using an ICP-MS (inductively coupled plasma mass spectrometry) and in some cases a gas proportional counter to quantify radiostrontium ("8"9Sr and "9"0Sr). Excellent figures of merit were obtained, off line, with water (tap, river and sea water) and solid matrices (soil and aerosol filters), after a micro-wave digestion or an alkaline fusion dissolution followed by a Ca_3(PO_4)_2 coprecipitation. The proposed analytical strategy showed yields between 70 % and 100 % and standard deviations between 5 % and 10 %. The newly developed separation method was then automated and coupled on-line to ICP-MS. The operating parameters were optimized using a design of experiments and the results were processed with Minitab. The optimized automated separation coupled on-line to the ICP-MS allows the rapid quantification, in 1.5 h per sample, of U, Th, Pu, Am, Np and Sr with detection limits gain as high as 20 times for artificial radionuclide. (author)

  4. Rapid identification and quantitation of compounds with forensic interest using fast liquid chromatography-ion trap mass spectrometry and library searching.

    Science.gov (United States)

    Pihlainen, Katja; Sippola, Erkki; Kostiainen, Risto

    2003-04-25

    A fast liquid chromatography-electrospray tandem mass spectrometric (LC-ESI-MS-MS) method by using a monolithic column, gradient elution and ion trap mass spectrometer was developed for 14 forensically interesting and chemically different compounds. All compounds were eluted within 2.5 min and the total analysis time was 5 min including stabilisation time required for the next injection. All the compounds, basics, neutrals and acids were efficiently ionised by positive ion ESI. A laboratory library including MS-MS spectra and retention times was developed and tested. Results with 476 standard samples and 50 authentic samples showed that the compounds studied can be unambiguously identified with the library. A quantitative method was developed for the compounds using external calibration. The evaluation process showed good linearity of the method and reasonable repeatability. Limits of detection ranged from 10.0 to 50.0 ng/ml.

  5. Rapid screening of anabolic steroids in horse urine with ultra-high-performance liquid chromatography/tandem mass spectrometry after chemical derivatisation.

    Science.gov (United States)

    Wong, Colton H F; Leung, David K K; Tang, Francis P W; Wong, Jenny K Y; Yu, Nola H; Wan, Terence S M

    2012-04-06

    Liquid chromatography/mass spectrometry (LC/MS) has been successfully applied to the detection of anabolic steroids in biological samples. However, the sensitive detection of saturated hydroxysteroids, such as androstanediols, by electrospray ionisation (ESI) is difficult because of their poor ability to ionise. In view of this, chemical derivatisation has been used to enhance the detection sensitivity of hydroxysteroids by LC/MS. This paper describes the development of a sensitive ultra-high-performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) method for the screening of anabolic steroids in horse urine by incorporating a chemical derivatisation step, using picolinic acid as the derivatisation reagent. The method involved solid-phase extraction (SPE) of both free and conjugated anabolic steroids in horse urine using a polymer-based SPE cartridge (Abs Elut Nexus). The conjugated steroids in the eluate were hydrolysed by methanolysis and the resulting extract was further cleaned up by liquid-liquid extraction. The resulting free steroids in the extract were derivatised with picolinic acid to form the corresponding picolinoyl esters and analysed by UHPLC/MS/MS in the positive ESI mode with selected-reaction-monitoring. Separation of the targeted steroids was performed on a C18 UHPLC column. The instrument turnaround time was 10.5 min inclusive of post-run equilibration. A total of thirty-three anabolic steroids (including 17β-estradiol, 5(10)-estrene-3β,17α-diol, 5α-estrane-3β,17α-diol, 17α-ethyl-5α-estran-3α,17β-diol, 17α-methyl-5α-androstan-3,17β-diols, androstanediols, nandrolone and testosterone) spiked in negative horse urine at the QC levels (ranging from 0.75 to 30 ng/mL) could be consistently detected. The intra-day and inter-day precisions (% RSD) for the peak area ratios were around 7-51% and around 1-72%, respectively. The intra-day and inter-day precisions (% RSD) for the relative retention times were both less than 1% for

  6. Rapid and slow pyrolysis of pistachio shell: effect of pyrolysis conditions on the product yields and characterization of the liquid product

    Energy Technology Data Exchange (ETDEWEB)

    Putun, Ayse E [Department of Chemical Engineering, Anadolu University, Eskisehir 26470, (Turkey); Ozbay, Nurgul [Bozuyuk Vocational School, Anadolu University, Bozuyuk/Bilecik, (Turkey); Varol, Esin Apaydin; Uzun, Basak B; Ates, Fuda [Department of Chemical Engineering, Anadolu University, Eskisehir 26470, (Turkey)

    2006-10-30

    This study reports the experimental results for the pyrolysis of pistachio shell under different conditions in a tubular reactor under a nitrogen flow. For the different conditions of pyrolysis temperature, nitrogen flow rate and heating rate, pyrolysis temperature of 773 K gave the highest bio-oil yield with a value of 27.7% when the heating rate and carrier gas flow rate were chosen as 300 K min{sup -1} and 100 cm{sup 3} min{sup -1}, respectively. Column chromatography was applied to this bio-oil and its subfractions were characterized by elemental analysis, FT-IR and 1H-NMR. Aliphatic subfraction was conducted to gas chromatography-mass spectroscopy for further characterization. The results for the characterization show that using pistachio shell as a renewable source to produce valuable liquid products is applicable via pyrolysis. (Author)

  7. A rapid high-performance liquid-chromatographic method for simultaneously determining the concentrations of TFM and Bayer 73 in water during lampricide treatments

    Science.gov (United States)

    Dawson, V.K.

    1982-01-01

    The high-performance liquid-chromatography (HPLC) procedure requires only minutes per sample, is specific, and is relatively sensitive (limit of detection 18 disposable cartridge. The cartridge adsorbs and retains both the lampricides and the internal standard. The quantitative elution of the three chemicals from the cartridge with a small volume of methanol effectively concentrates the sample and provides sample cleanup. The methanol extract is then analyzed directly by HPLC on an MCH 10 reverse phase column by using a methanol:0.01 mol/L acetate buffer (87:13, v:v) as the mobile phase at 2 mL/min and detected by ultraviolet spectrophotometry at 330 (or 254) nm. A microprocessor data system further facilitates the procedure by quantifying off-scale peaks and yielding results directly in units of concentration (mg/L).

  8. Rapid structural analysis of nanomaterials in aqueous solutions

    Science.gov (United States)

    Ryuzaki, Sou; Tsutsui, Makusu; He, Yuhui; Yokota, Kazumichi; Arima, Akihide; Morikawa, Takanori; Taniguchi, Masateru; Kawai, Tomoji

    2017-04-01

    Rapid structural analysis of nanoscale matter in a liquid environment represents innovative technologies that reveal the identities and functions of biologically important molecules. However, there is currently no method with high spatio-temporal resolution that can scan individual particles in solutions to gain structural information. Here we report the development of a nanopore platform realizing quantitative structural analysis for suspended nanomaterials in solutions with a high z-axis and xy-plane spatial resolution of 35.8 ± 1.1 and 12 nm, respectively. We used a low thickness-to-diameter aspect ratio pore architecture for achieving cross sectional areas of analyte (i.e. tomograms). Combining this with multiphysics simulation methods to translate ionic current data into tomograms, we demonstrated rapid structural analysis of single polystyrene (Pst) beads and single dumbbell-like Pst beads in aqueous solutions.

  9. Rapid isolation of biomarkers for compound specific radiocarbon dating using high-performance liquid chromatography and flow injection analysis-atmospheric pressure chemical ionisation mass spectrometry.

    Science.gov (United States)

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Sinninghe Damsté, Jaap S

    2002-11-29

    Repeated semi-preparative normal-phase HPLC was performed to isolate selected biomarkers from sediment extracts for radiocarbon analysis. Flow injection analysis-mass spectrometry was used for rapid analysis of collected fractions to evaluate the separation procedure, taking only 1 min per fraction. In this way 100-1000 microg of glycerol dialkyl glycerol tetraethers, sterol fractions and chlorophyll-derived phytol were isolated from typically 100 g of marine sediment, i.e., in sufficient quantities for radiocarbon analysis, without significant carbon isotopic fractionation or contamination.

  10. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  11. Development and validation of an ultra-performance liquid chromatography quadrupole time of flight mass spectrometry method for rapid quantification of free amino acids in human urine.

    Science.gov (United States)

    Joyce, Richard; Kuziene, Viktorija; Zou, Xin; Wang, Xueting; Pullen, Frank; Loo, Ruey Leng

    2016-01-01

    An ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-qTOF-MS) method using hydrophilic interaction liquid chromatography was developed and validated for simultaneous quantification of 18 free amino acids in urine with a total acquisition time including the column re-equilibration of less than 18 min per sample. This method involves simple sample preparation steps which consisted of 15 times dilution with acetonitrile to give a final composition of 25 % aqueous and 75 % acetonitrile without the need of any derivatization. The dynamic range for our calibration curve is approximately two orders of magnitude (120-fold from the lowest calibration curve point) with good linearity (r (2) ≥ 0.995 for all amino acids). Good separation of all amino acids as well as good intra- and inter-day accuracy (amino acids in the prepared urine samples was found to be stable for 72 h at 4 °C, after one freeze thaw cycle and for up to 4 weeks at -80 °C. We have applied this method to quantify the content of 18 free amino acids in 646 urine samples from a dietary intervention study. We were able to quantify all 18 free amino acids in these urine samples, if they were present at a level above the LOD. We found our method to be reproducible (accuracy and precision were typically <10 % for QCL, QCM and QCH) and the relatively high sample throughput nature of this method potentially makes it a suitable alternative for the analysis of urine samples in clinical setting.

  12. Enantioseparation with liquid membranes

    NARCIS (Netherlands)

    Gössi, Angelo; Riedl, Wolfgang; Schuur, Boelo

    Chiral resolution of racemic products is a challenging and important task in the pharmaceutical, agrochemical, flavor, polymer and fragrances industries. One of the options for these challenging separations is to use liquid membranes. Although liquid membranes have been known for almost four decades

  13. Rapid differentiation of rocky mountain spotted fever from chickenpox, measles, and enterovirus infections and bacterial meningitis by frequency-pulsed electron capture gas-liquid chromatographic analysis of sera.

    Science.gov (United States)

    Brooks, J B; McDade, J E; Alley, C C

    1981-01-01

    Normal sera and sera from patients with Rocky Mountain spotted fever, chickenpox, enterovirus infections, measles, and Neisseria meningitidis infections were extracted with organic solvents under acidic and basic conditions and then derivatized with trichloroethanol or heptafluorobutyric anhydride-ethanol to form electron-capturing derivatives of organic acids, alcohols, and amines. The derivatives were analyzed by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). There were unique differences in the FPEC-GLC profiles of sera obtained from patients with these respective diseases. With Rocky Mountain spotted fever patients, typical profiles were detected as early as 1 day after onset of disease and before antibody could be detected in the serum. Rapid diagnosis of Rocky Mountain spotted fever by FPEC-GLC could permit early and effective therapy, thus preventing many deaths from this disease. PMID:7276147

  14. Rapid identification of tomato Sw-5 resistance-breaking isolates of Tomato spotted wilt virus using high resolution melting and TaqMan SNP Genotyping assays as allelic discrimination techniques.

    Directory of Open Access Journals (Sweden)

    Valentina di Rienzo

    Full Text Available In tomato, resistance to Tomato spotted wilt virus (TSWV is conferred by the dominant gene, designated Sw-5. Virulent Sw-5 resistance breaking (SRB mutants of TSWV have been reported on Sw-5 tomato cultivars. Two different PCR-based allelic discrimination techniques, namely Custom TaqMan™ SNP Genotyping and high-resolution melting (HRM assays, were developed and compared for their ability to distinguish between avirulent (Sw-5 non-infecting, SNI and SRB biotypes. TaqMan assays proved to be more sensitive (threshold of detection in a range of 50-70 TSWV RNA copies and more reliable than HRM, assigning 25 TSWV isolates to their correct genotype with an accuracy of 100%. Moreover, the TaqMan SNP assays were further improved developing a rapid and simple protocol that included crude leaf extraction for RNA template preparations. On the other hand, HRM assays showed higher levels of sensitivity than TaqMan when used to co-detect both biotypes in different artificial mixtures. These diagnostic assays contributed to gain preliminary information on the epidemiology of TSWV isolates in open field conditions. In fact, the presented data suggest that SRB isolates are present as stable populations established year round, persisting on both winter (globe artichoke and summer (tomato crops, in the same cultivated areas of Southern Italy.

  15. High-resolution melting-curve analysis of ligation-mediated real-time PCR for rapid evaluation of an epidemiological outbreak of extended-spectrum-beta-lactamase-producing Escherichia coli.

    Science.gov (United States)

    Woksepp, Hanna; Jernberg, Cecilia; Tärnberg, Maria; Ryberg, Anna; Brolund, Alma; Nordvall, Michaela; Olsson-Liljequist, Barbro; Wisell, Karin Tegmark; Monstein, Hans-Jürg; Nilsson, Lennart E; Schön, Thomas

    2011-12-01

    Methods for the confirmation of nosocomial outbreaks of bacterial pathogens are complex, expensive, and time-consuming. Recently, a method based on ligation-mediated PCR (LM/PCR) using a low denaturation temperature which produces specific melting-profile patterns of DNA products has been described. Our objective was to further develop this method for real-time PCR and high-resolution melting analysis (HRM) in a single-tube system optimized in order to achieve results within 1 day. Following the optimization of LM/PCR for real-time PCR and HRM (LM/HRM), the method was applied for a nosocomial outbreak of extended-spectrum-beta-lactamase (ESBL)-producing and ST131-associated Escherichia coli isolates (n = 15) and control isolates (n = 29), including four previous clusters. The results from LM/HRM were compared to results from pulsed-field gel electrophoresis (PFGE), which served as the gold standard. All isolates from the nosocomial outbreak clustered by LM/HRM, which was confirmed by gel electrophoresis of the LM/PCR products and PFGE. Control isolates that clustered by LM/PCR (n = 4) but not by PFGE were resolved by confirmatory gel electrophoresis. We conclude that LM/HRM is a rapid method for the detection of nosocomial outbreaks of bacterial infections caused by ESBL-producing E. coli strains. It allows the analysis of isolates in a single-tube system within a day, and the discriminatory power is comparable to that of PFGE.

  16. High-Resolution Melting-Curve Analysis of Ligation-Mediated Real-Time PCR for Rapid Evaluation of an Epidemiological Outbreak of Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli ▿

    Science.gov (United States)

    Woksepp, Hanna; Jernberg, Cecilia; Tärnberg, Maria; Ryberg, Anna; Brolund, Alma; Nordvall, Michaela; Olsson-Liljequist, Barbro; Wisell, Karin Tegmark; Monstein, Hans-Jürg; Nilsson, Lennart E.; Schön, Thomas

    2011-01-01

    Methods for the confirmation of nosocomial outbreaks of bacterial pathogens are complex, expensive, and time-consuming. Recently, a method based on ligation-mediated PCR (LM/PCR) using a low denaturation temperature which produces specific melting-profile patterns of DNA products has been described. Our objective was to further develop this method for real-time PCR and high-resolution melting analysis (HRM) in a single-tube system optimized in order to achieve results within 1 day. Following the optimization of LM/PCR for real-time PCR and HRM (LM/HRM), the method was applied for a nosocomial outbreak of extended-spectrum-beta-lactamase (ESBL)-producing and ST131-associated Escherichia coli isolates (n = 15) and control isolates (n = 29), including four previous clusters. The results from LM/HRM were compared to results from pulsed-field gel electrophoresis (PFGE), which served as the gold standard. All isolates from the nosocomial outbreak clustered by LM/HRM, which was confirmed by gel electrophoresis of the LM/PCR products and PFGE. Control isolates that clustered by LM/PCR (n = 4) but not by PFGE were resolved by confirmatory gel electrophoresis. We conclude that LM/HRM is a rapid method for the detection of nosocomial outbreaks of bacterial infections caused by ESBL-producing E. coli strains. It allows the analysis of isolates in a single-tube system within a day, and the discriminatory power is comparable to that of PFGE. PMID:21956981

  17. An evaluation of liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization for the rapid and simultaneous measurement of carbamate pesticides and organophorus pesticides

    International Nuclear Information System (INIS)

    Kim, Byung Joo; So, Hun Young

    2000-01-01

    Liquid chromatography/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI/MS) is evaluated for the simultaneous determination of carbamate pesticides and organophosphorus pesticides in a single chromatographic analysis. APCI mass spectra of those compounds were obtained to study their ionization characteristics. APCI provided abundant ions such as protonated molecules and characteristic fragment ions for carbamate pesticides and organophosphorus pesticides. To evaluate the feasibility of the LC/APCI/MS for a routine quantitative analysis, the linearity and repeatability of LC/APCI/MS were examined by measuring standard solution mixtures of five carbamate pesticides and four organophosphorus pesticides over the range of 1 to 100 μg/mL. The peak areas in chromatograms of characteristic ions for those compounds showed less than 3% of variation from run to tun. The standard calibration curves for the nine pesticides show good linearity in the concentration range. The detection limits of the LC/APCI/MS system for those compounds range from 0.006 to 0.2 ng

  18. A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals.

    Science.gov (United States)

    Barbera, Giorgia La; Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Montone, Carmela Maria; Chiozzi, Riccardo Zenezini; Laganà, Aldo

    2017-04-21

    Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE), a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high-performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

  19. Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry for highly rapid and sensitive analysis of underivatized amino acids in functional foods.

    Science.gov (United States)

    Zhou, Guisheng; Pang, Hanqing; Tang, Yuping; Yao, Xin; Mo, Xuan; Zhu, Shaoqing; Guo, Sheng; Qian, Dawei; Qian, Yefei; Su, Shulan; Zhang, Li; Jin, Chun; Qin, Yong; Duan, Jin-ao

    2013-05-01

    This work presented a new analytical methodology based on hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry in multiple-reaction monitoring mode for analysis of 24 underivatized free amino acids (FAAs) in functional foods. The proposed method was first reported and validated by assessing the matrix effects, linearity, limit of detections and limit of quantifications, precision, repeatability, stability and recovery of all target compounds, and it was used to determine the nutritional substances of FAAs in ginkgo seeds and further elucidate the nutritional value of this functional food. The result showed that ginkgo seed turned out to be a good source of FAAs with high levels of several essential FAAs and to have a good nutritional value. Furthermore, the principal component analysis was performed to classify the ginkgo seed samples on the basis of 24 FAAs. As a result, the samples could be mainly clustered into three groups, which were similar to areas classification. Overall, the presented method would be useful for the investigation of amino acids in edible plants and agricultural products.

  20. A rapid and sensitive evaluation of nitrite content in Saudi Arabian processed meat and poultry using a novel ultra performance liquid chromatography-mass spectrometry method.

    Science.gov (United States)

    Siddiqui, Masoom Raza; Wabaidur, Saikh Mohammad; Khan, Moonis Ali; ALOthman, Zeid A; Rafiquee, M Z A; Alqadami, Ayoub Abdullah

    2018-01-01

    Quantitative assessment of nitrite (NO 2 - ) anion was performed using a newly developed high throughput ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method. The nitrite determination with the proposed method using micellar mobile phase was unknown. Selected ion reaction mode using negative electrospray ionization was adopted for the identification and quantitative analysis of nitrite. The chromatographic separation was performed using BEH C-18 column and a micellar mobile phase consisted of sodium dodecyl sulphate and acetonitrile in ratio 30:70 was used. The elution of nitrite anion was accomplished in less than 1 min. Under the optimal analysis conditions, the linearity of the developed method was checked in the concentration range of 0.5-20 mg kg -1 NO 2 - with an excellent correlation coefficient of 0.996. The precisions of the method with relative standard deviation <2% was observed when standard at concentration of 1 mg kg -1 was used. The limit of detection and limit of quantitation of the developed mass spectrometric method was found to be 0.114 and 0.346 mg kg -1 , respectively. The developed UPLC/MS method was applied to quantify this anion in processed meats and poultries from various super market of Saudi Arabia (Riyadh region). The recoveries of the nitrite in the various samples were found in the range of 100.03-103.5%.

  1. Rapid modified QuEChERS method for pesticides detection in honey by high-performance liquid chromatography UV-visible

    Directory of Open Access Journals (Sweden)

    Elisabetta Bonerba

    2014-05-01

    Full Text Available The extensive use of pesticides in agriculture plays an important role in bees die-off and allows the presence of residues in hive products, particularly in honey. An accurate and reliable analytical method, based on QuEChERS extractive technique, has been developed for the quantitative determination by high-performance liquid chromatography UV-visible detector of 5 pesticides (Deltamethrin, Dimethoate, Imidacloprid, Acetamiprid, Chlorfenvinphos in honey. The method, according to Commission Directive 2002/63/EC and Regulation 882/2004/EC, provided excellent results with respect to linearity (correlation coefficient up to 0.993, limits of detection and quantification (0.005 and 0.01 μg/mL for Dimethoate, Deltamethrin and Chlorfenvinphos; 0.02 and 0.05 μg/mL for Acetamiprid and Imidacloprid, recovery values (86.4 to 96.3%, precision and relative expanded uncertainty of a measurement, demonstrating the conformity of the this method with the European directives. The proposed method was applied to 23 samples of Apulian honey. None of the investigated pesticides was detected in these samples.

  2. Rapid trace level determination of sulfonamide residues in honey with online extraction using short C-18 column by high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Sajid, Muhammad; Na, Na; Safdar, Muhammad; Lu, Xin; Ma, Lin; He, Lan; Ouyang, Jin

    2013-11-01

    A sensitive and inexpensive quantification method with online extraction using a short C-18 column for sulfonamide residues in honey by high performance liquid chromatography with fluorescence detector was developed and validated. In sample preparation, acid hydrolysis was used to break the N-glycoside bond between the honey sugar and sulfonamide drugs and derivatization of sulfonamide residues with fluorescamine was conducted at pH 3.5 using a citrate buffer (0.5M) in the honey matrix. The chromatography was carried out on Zorbax Extended C-18 (250mm×4.6mm; 5μm) column, using a mixture of acetonitrile and an acetate buffer (pH 4.50, 20mM) as a mobile phase. A Zorbax Extended C-18 (12mm×4.6mm; 5μm) column was used for online extraction of fifteen sulfonamide residues from honey sample with the help of a two position valve. The limit of quantification of sulfonamide residues in honey was less than 3ngg(-1), and the percentage recovery of study compounds in spiked honey sample was from 80% for sulfacetamide to 100% of sulfachloropyridazine. The developed method has excellent linearity for all studied sulfonamides with a correlation coefficient 0.993. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Rapid Quantification of Four Anthocyanins in Red Grape Wine by Hydrophilic Interaction Liquid Chromatography/Triple Quadrupole Linear Ion Trap Mass Spectrometry.

    Science.gov (United States)

    Sun, Yongming; Xia, Biqi; Chen, Xiangzhun; Duanmu, Chuansong; Li, Denghao; Han, Chao

    2015-01-01

    The identification and quantification of four anthocyanins (cyanidin-3-O-glucoside, peonidin-3-O-glucoside, delphinidin-3-O-glucoside, and malvidin-3-O-glucoside) in red grape wine were carried out by hydrophilic interaction liquid chromatography/triple quadrupole linear ion trap MS (HILIC/QTrap-MS/MS). Samples were diluted directly and separated on a Merck ZIC HILIC column with 20 mM ammonium acetate solution-acetonitrile mobile phase. Quantitative data acquisition was carried out in the multiple reaction monitoring mode. Additional identification and confirmation of target compounds were performed using the enhanced product ion mode of the linear ion trap. The LOQs were in the range 0.05-1.0 ng/mL. The average recoveries were in the range 94.6 to 104.5%. The HILIC/QTrap-MS/MS platform offers the best sensitivity and specificity for characterization and quantitative determination of the four anthocyanins in red grape wines and fulfills the quality criteria for routine laboratory application.

  4. A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals

    Directory of Open Access Journals (Sweden)

    Giorgia La Barbera

    2017-04-01

    Full Text Available Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE, a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high–performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

  5. An evaluation of liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization for the rapid and simultaneous measurement of carbamate pesticides and organophorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Joo; So, Hun Young [Korea Research Institute of Standards and Sceince, Taejon (Korea, Republic of)

    2000-05-01

    Liquid chromatography/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI/MS) is evaluated for the simultaneous determination of carbamate pesticides and organophosphorus pesticides in a single chromatographic analysis. APCI mass spectra of those compounds were obtained to study their ionization characteristics. APCI provided abundant ions such as protonated molecules and characteristic fragment ions for carbamate pesticides and organophosphorus pesticides. To evaluate the feasibility of the LC/APCI/MS for a routine quantitative analysis, the linearity and repeatability of LC/APCI/MS were examined by measuring standard solution mixtures of five carbamate pesticides and four organophosphorus pesticides over the range of 1 to 100 {mu}g/mL. The peak areas in chromatograms of characteristic ions for those compounds showed less than 3% of variation from run to tun. The standard calibration curves for the nine pesticides show good linearity in the concentration range. The detection limits of the LC/APCI/MS system for those compounds range from 0.006 to 0.2 ng.

  6. Quantitative Multiclass Pesticide Residue Analysis in Apple, Pear, and Grape by Modified QuEChERS and Liquid Chromatography Coupled to High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Munaretto, Juliana S; Viera, Mariela de S; Martins, Manoel L; Adaime, Martha B; Zanella, Renato

    2016-11-01

    Most of the analytical methods currently applied in food control laboratories are focused on the determination of target compounds using LC coupled to tandem MS, which is an effective technique, but low-resolution MS is limited. Thus, a method for determination of pesticide multiresidues in fruits (pear, apple, and grape) using a modified quick, easy, cheap, effective, rugged, and safe method and LC coupled to quadrupole time-of-flight (Q-TOF) MS was developed and validated. The proposed method showed good linearity (r2 > 0.99) from 1 to 100 μg/L. Recoveries for blank samples spiked at 0.01, 0.04, and 0.10 mg/kg were between 66 and 122%, with RSDs apple, pear, and grape matrixes were 0.01 mg/kg for 112, 120, and 118 compounds, and 0.04 mg/kg for 22, 12, and 17 compounds, and average mass accuracy error was 3.2 ppm. LC with Q-TOF MS detection using protonated molecular ion and/or adducts and mass accuracy provided reliability for the method. The proposed method is effective for pesticide residue determination in apple, pear, and grape samples, proving that high-resolution MS using full scan mode can be a powerful and reliable technique for quantification purposes, being adequate for application in the surveillance of maximum residue limits set by different legislations.

  7. Wide-Scope Screening Method for Multiclass Veterinary Drug Residues in Fish, Shrimp, and Eel Using Liquid Chromatography-Quadrupole High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Turnipseed, Sherri B; Storey, Joseph M; Lohne, Jack J; Andersen, Wendy C; Burger, Robert; Johnson, Aaron S; Madson, Mark R

    2017-08-30

    A screening method for veterinary drug residues in fish, shrimp, and eel using LC with a high-resolution MS instrument has been developed and validated. The method was optimized for over 70 test compounds representing a variety of veterinary drug classes. Tissues were extracted by vortex mixing with acetonitrile acidified with 2% acetic acid and 0.2% p-toluenesulfonic acid. A centrifuged portion of the extract was passed through a novel solid phase extraction cartridge designed to remove interfering matrix components from tissue extracts. The eluent was then evaporated and reconstituted for analysis. Data were collected with a quadrupole-Orbitrap high-resolution mass spectrometer using both nontargeted and targeted acquisition methods. Residues were detected on the basis of the exact mass of the precursor and a product ion along with isotope pattern and retention time matching. Semiquantitative data analysis compared MS 1 signal to a one-point extracted matrix standard at a target testing level. The test compounds were detected and identified in salmon, tilapia, catfish, shrimp, and eel extracts fortified at the target testing levels. Fish dosed with selected analytes and aquaculture samples previously found to contain residues were also analyzed. The screening method can be expanded to monitor for an additional >260 veterinary drugs on the basis of exact mass measurements and retention times.

  8. Prospects of high-resolution resonant X-ray inelastic scattering studies on solid materials, liquids and gases at diffraction-limited storage rings

    International Nuclear Information System (INIS)

    Schmitt, Thorsten; Groot, Frank M. F. de; Rubensson, Jan-Erik

    2014-01-01

    Diffraction-limited storage rings will allow for pushing the achievable energy resolution, signal intensity and the sampled spot size in resonant inelastic X-ray scattering (RIXS) experiments to new limits. In this article the types of improved soft X-ray RIXS studies that will become possible with these instrumental improvements are envisioned. The spectroscopic technique of resonant inelastic X-ray scattering (RIXS) will particularly profit from immensely improved brilliance of diffraction-limited storage rings (DLSRs). In RIXS one measures the intensities of excitations as a function of energy and momentum transfer. DLSRs will allow for pushing the achievable energy resolution, signal intensity and the sampled spot size to new limits. With RIXS one nowadays probes a broad range of electronic systems reaching from simple molecules to complex materials displaying phenomena like peculiar magnetism, two-dimensional electron gases, superconductivity, photovoltaic energy conversion and heterogeneous catalysis. In this article the types of improved RIXS studies that will become possible with X-ray beams from DLSRs are envisioned

  9. Ultra-high-performance liquid chromatography/tandem high-resolution mass spectrometry analysis of sixteen red beverages containing carminic acid: identification of degradation products by using principal component analysis/discriminant analysis.

    Science.gov (United States)

    Gosetti, Fabio; Chiuminatto, Ugo; Mazzucco, Eleonora; Mastroianni, Rita; Marengo, Emilio

    2015-01-15

    The study investigates the sunlight photodegradation process of carminic acid, a natural red colourant used in beverages. For this purpose, both carminic acid aqueous standard solutions and sixteen different commercial beverages, ten containing carminic acid and six containing E120 dye, were subjected to photoirradiation. The results show different patterns of degradation, not only between the standard solutions and the beverages, but also from beverage to beverage. Due to the different beverage recipes, unpredictable reactions take place between the dye and the other ingredients. To identify the dye degradation products in a very complex scenario, a methodology was used, based on the combined use of principal component analysis with discriminant analysis and ultra-high-performance liquid chromatography coupled with tandem high resolution mass spectrometry. The methodology is unaffected by beverage composition and allows the degradation products of carminic acid dye to be identified for each beverage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Evaluation of the the temperature and humidity effect in the Atrazine degradation in the Saldana soil (Tolima) for liquid chromatography of high resolution

    International Nuclear Information System (INIS)

    Acevedo Buitrago Baudilio; Guerrero Jairo A; Lozano Amanda; Fuentes Cilia

    2000-01-01

    In this study was designed an experiment under laboratory conditions with temperature and soil moisture controlled. The effect of these two factors was evaluated in atrazine degradation in silty loam soil, pH 6.23 (1:1 w), and 1.48% organic carbon. The extraction process of AT and deetilatrazine (DEA), and deisopropilatrazine (DIA) metabolites of the soil was carried out with methanol followed by a clean up with dichloromethane-buffer phosphate pH 10,0.01 M. Separation and quantification of the compounds was carried out by high performance liquid chromatography (HPLC). Soil moisture was not a significant factor in atrazine degradation process, while the temperature was the factor that regulates the herbicide degradation. Atrazine degradation at 30oC was faster than at 20o C. DIA and DEA metabolites were not detected in any soil field samples

  11. A rapid quantitative analysis of bile acids, lysophosphatidylcholines and polyunsaturated fatty acids in biofluids based on ultraperformance liquid chromatography coupled with triple quadrupole tandem massspectrometry.

    Science.gov (United States)

    Peng, Zhangxiao; Zhang, Qian; Mao, Ziming; Wang, Jie; Liu, Chunying; Lin, Xuejing; Li, Xin; Ji, Weidan; Fan, Jianhui; Wang, Maorong; Su, Changqing

    2017-11-15

    Much evidence suggested that quantitative analysis of bile acids (BAs), lysophosphatidylcholines (LPCs), and polyunsaturated fatty acids (PUFAs) in biofluids may be very useful for diagnosis and prevention of hepatobiliary disease with a non-invasive manner. However, simultaneously fast analysis of these metabolites has been challenging for their huge differences of physicochemical properties and concentration levels in biofluids. In this study, we present a liquid chromatography-mass spectrometry method with a high throughput analytical cycle (10min) to fast and accurately quantify fifteen potential biomarkers (eight BAs, four LPCs and three PUFAs) of hepatobiliary disease. The accuracy for the fifteen analytes in plasma and urine matrices was 80.45%-118.99% and 84.55%-112.66%, respectively. The intra- and inter- precisions for the fifteen analytes in plasma and urine matrices were all less than 20% and the lower limit of quantification (LLOQ) of analytes is up to 0.0283-8.2172nmol/L. Therefore, this method is fast, sensitive and accurate for the quantitative analysis of BAs, LPCs and PUFAs in biofluids. Moreover, the stability and concentration differences of the analytes in plasma and serum were evaluated, and the results demonstrated that LPCs is stable, but PUFAs is very unstable in freeze and thaw cycles, and the concentrations of the analytes in serum were slightly higher than those in plasma. We suggested plasma may be a kind of better bio-sample than serum using for quantitative analysis of metabolites in blood, due to the characteristics of plasma are more close to blood than those of serum. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Rapid analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Daniele, Gaëlle; Fieu, Maëva; Joachim, Sandrine; Bado-Nilles, Anne; Baudoin, Patrick; Turies, Cyril; Porcher, Jean-Marc; Andres, Sandrine; Vulliet, Emmanuelle

    2016-06-01

    Pharmaceuticals are emerging organic contaminants ubiquitously present in the environment due to incessant input into the aquatic compartment mainly resulting from incomplete removal in wastewater treatment plants. One of the major preoccupations concerning pharmaceuticals released into surface waters is their potential for bioaccumulation in biota, possibly leading to deleterious effects on ecosystems especially as they could affect a broad variety of organisms living in or depending on the aquatic environment. Thus, the development of accurate and sensitive methods is necessary to detect these compounds in aquatic ecosystems. Considering this need, this study deals with the analytical development of a methodology to quantify traces of diclofenac together with some of its biotic and abiotic transformation products in whole-body tissue of three-spined stickleback. A simple and reliable extraction method based on a modified QuEChERS extraction is implemented on 200 mg of fish. The detection and quantification of the ten target compounds are performed using liquid chromatography-tandem mass spectrometry. The whole process was successfully validated regarding linearity, recovery, repeatability, and reproducibility. The method limits of detection and quantification do not exceed 1 ng/g. To reproduce environmental conditions, we measured the concentration of DCF and its transformation products in three-spined sticklebacks after a 6-month exposure in mesocosms at several levels of DCF ranging from 0.05 to 4.1 μg/L. The phase I metabolite 4'-hydroxydiclofenac was detected in fish samples exposed at the highest DCF concentration. Graphical abstract Analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by QuEChERS extraction followed by LC-MS/MS.

  13. Simultaneous quantification of eight organic acid components in Artemisia capillaris Thunb (Yinchen extract using high-performance liquid chromatography coupled with diode array detection and high-resolution mass spectrometry

    Directory of Open Access Journals (Sweden)

    Fangjun Yu

    2018-04-01

    Full Text Available We aim to determine the chemical constituents of Yinchen extract and Yinchen herbs using high-performance liquid chromatography coupled with diode array detection and high-resolution mass spectrometry. The method was developed to analyze of eight organic acid components of Yinchen extract (including neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, 1,3-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid. The separation was conducted using an Agilent TC-C18 column with acetonitrile – 0.2% formic acid solution as the mobile phases under gradient elution. The analytical method was fully validated in terms of linearity, sensitivity, precision, repeatability as well as recovery, and subsequently the method was performed for the quantitative assessment of Yinchen extracts and Yinchen herbs. In addition, the changes of selected markers were studied when Yinchen herbs decocting in water and isomerization occurred between the chlorogenic acids. The proposed method enables both qualitative and quantitative analyses and could be developed as a new tool for the quality evaluation of Yinchen extract and Yinchen herbs. The changes of selected markers in water decoction process could give us some novel idea when studying the link between substances and drug efficacy. Keywords: Artemisia capillaris Thunb (Yinchen extract, Quality control, Organic acid, Transformation pathways, High-performance liquid chromatography

  14. Development of an analytical strategy based on liquid chromatography-high resolution mass spectrometry for measuring perfluorinated compounds in human breast milk: application to the generation of preliminary data regarding perinatal exposure in France.

    Science.gov (United States)

    Kadar, Hanane; Veyrand, Bruno; Barbarossa, Andrea; Pagliuca, Giampiero; Legrand, Arnaud; Bosher, Cécile; Boquien, Clair-Yves; Durand, Sophie; Monteau, Fabrice; Antignac, Jean-Philippe; Le Bizec, Bruno

    2011-10-01

    Perfluorinated compounds (PFCs) are man-made chemicals for which endocrine disrupting properties and related possible side effects on human health have been reported, particularly in the case of an exposure during the early stages of development, (notably the perinatal period). Existing analytical methods dedicated to PFCs monitoring in food and/or human fluids are currently based on liquid chromatography coupled to tandem mass spectrometry, and were recently demonstrated to present some limitations in terms of sensitivity and/or specificity. An alternative strategy dedicated to the analysis of fourteen PFCs in human breast milk was proposed, based on an effective sample preparation followed by a liquid chromatography coupled to high resolution mass spectrometry measurement (LC-HRMS). This methodology confirmed the high interest for HRMS after negative ionization for such halogenated substances, and finally permitted to reach detection limits around the pg mL(-1) range with an outstanding signal specificity compared to LC-MS/MS. The proposed method was applied to a first set of 30 breast milk samples from French women. The main PFCs detected in all these samples were PFOS and PFOA with respective median values of 74 (range from 24 to 171) and 57 (range from 18 to 102) pg mL(-1), respectively. These exposure data appeared in the same range as other reported values for European countries. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Determination of bisphenol-type endocrine disrupting compounds in food-contact recycled-paper materials by focused ultrasonic solid-liquid extraction and ultra performance liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Pérez-Palacios, David; Fernández-Recio, Miguel Ángel; Moreta, Cristina; Tena, María Teresa

    2012-09-15

    Focused ultrasonic solid-liquid extraction (FUSLE) and reverse-phase ultra performance liquid chromatography (UPLC) coupled to a quadrupole-time of flight mass spectrometer (Q-TOF-MS) was applied to the determination of bisphenol-type endocrine disrupting compounds (EDCs) in food-contact recycled-paper materials. Recycled paper is a potential source of EDCs. Bisphenol A (BPA), bisphenol F (BPF) and their derivatives bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) are used for the production of epoxy resins employed in the formulation of printing inks. The FUSLE of bisphenol-type EDCs from packaging is reported for the first ti