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Sample records for chromatography method development

  1. Development of a high performance liquid chromatography method ...

    African Journals Online (AJOL)

    Development of a high performance liquid chromatography method for simultaneous ... Purpose: To develop and validate a new low-cost high performance liquid chromatography (HPLC) method for ..... Several papers have reported the use of ...

  2. Schinus terebinthifolius countercurrent chromatography (Part III): Method transfer from small countercurrent chromatography column to preparative centrifugal partition chromatography ones as a part of method development.

    Science.gov (United States)

    das Neves Costa, Fernanda; Hubert, Jane; Borie, Nicolas; Kotland, Alexis; Hewitson, Peter; Ignatova, Svetlana; Renault, Jean-Hugues

    2017-03-03

    Countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC) are support free liquid-liquid chromatography techniques sharing the same basic principles and features. Method transfer has previously been demonstrated for both techniques but never from one to another. This study aimed to show such a feasibility using fractionation of Schinus terebinthifolius berries dichloromethane extract as a case study. Heptane - ethyl acetate - methanol -water (6:1:6:1, v/v/v/v) was used as solvent system with masticadienonic and 3β-masticadienolic acids as target compounds. The optimized separation methodology previously described in Part I and II, was scaled up from an analytical hydrodynamic CCC column (17.4mL) to preparative hydrostatic CPC instruments (250mL and 303mL) as a part of method development. Flow-rate and sample loading were further optimized on CPC. Mobile phase linear velocity is suggested as a transfer invariant parameter if the CPC column contains sufficient number of partition cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Analytical chromatography. Methods, instrumentation and applications

    International Nuclear Information System (INIS)

    Yashin, Ya I; Yashin, A Ya

    2006-01-01

    The state-of-the-art and the prospects in the development of main methods of analytical chromatography, viz., gas, high performance liquid and ion chromatographic techniques, are characterised. Achievements of the past 10-15 years in the theory and general methodology of chromatography and also in the development of new sorbents, columns and chromatographic instruments are outlined. The use of chromatography in the environmental control, biology, medicine, pharmaceutics, and also for monitoring the quality of foodstuffs and products of chemical, petrochemical and gas industries, etc. is considered.

  4. Theories to support method development in comprehensive two-dimensional liquid chromatography - A review

    NARCIS (Netherlands)

    Bedani, F.; Schoenmakers, P.J.; Janssen, H.-G.

    2012-01-01

    On-line comprehensive two-dimensional liquid chromatography techniques promise to resolve samples that current one-dimensional liquid chromatography methods cannot adequately deal with. To make full use of the potential of two-dimensional liquid chromatography, optimization is required. Optimization

  5. Development of a sensitive and rapid method for rifampicin impurity analysis using supercritical fluid chromatography.

    Science.gov (United States)

    Li, Wei; Wang, Jun; Yan, Zheng-Yu

    2015-10-10

    A novel simple, fast and efficient supercritical fluid chromatography (SFC) method was developed and compared with RPLC method for the separation and determination of impurities in rifampicin. The separation was performed using a packed diol column and a mobile phase B (modifier) consisting of methanol with 0.1% ammonium formate (w/v) and 2% water (v/v). Overall satisfactory resolutions and peak shapes for rifampicin quinone (RQ), rifampicin (RF), rifamycin SV (RSV), rifampicin N-oxide (RNO) and 3-formylrifamycinSV (3-FR) were obtained by optimization of the chromatography system. With gradient elution of mobile phase, all of the impurities and the active were separated within 4 min. Taking full advantage of features of SFC (such as particular selectivity, non-sloping baseline in gradient elution, and without injection solvent effects), the method was successfully used for determination of impurities in rifampicin, with more impurity peaks detected, better resolution achieved and much less analysis time needed compared with conventional reversed-phase liquid chromatography (RPLC) methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Method Development and Validation for the Determination of Caffeine: An Alkaloid from Coffea arabica by High-performance Liquid Chromatography Method.

    Science.gov (United States)

    Naveen, P; Lingaraju, H B; Deepak, M; Medhini, B; Prasad, K Shyam

    2018-01-01

    The present study was investigated to develop and validate a reversed phase high performance liquid chromatography method for the determination of caffeine from bean material of Coffee arabica. The separation was achieved on a reversed-phase C18 column using a mobile phase composed of water: methanol (50:50) at a flow rate of 1.0 mlmin-1. The detection was carried out on a UV detector at 272 nm. The developed method was validated according to the requirements for International Conference on Harmonisation (ICH) guidelines, which includes specificity, linearity, precision, accuracy, limit of detection and limit of quantitation. The developed method validates good linearity with excellent correlation coefficient (R2 > 0.999). In repeatability and intermediate precision, the percentage relative standard deviation (% RSD) of peak area was less than 1% shows high precision of the method. The recovery rate for caffeine was within 98.78% - 101.28% indicates high accuracy of the method. The low limit of detection and limit of quantitation of caffeine enable the detection and quantitation of caffeine from C. arabica at low concentrations. The developed HPLC method is a simple, rapid, precisely, accurately and widely accepted and it is recommended for efficient assays in routine work. A simple, accurate, and sensitive high-performance liquid chromatography (HPLC) method for caffeine from Coffea arabica has been developed and validated. The developed HPLC method was validated for linearity, specificity, precision, recovery, limits of detection, and limits of quantification by the International Conference on Harmonization guidelines. The results revealed that the proposed method is highly reliable. This method could be successfully applied for routine quality work analysis. Abbreviation Used: C. arabica : Coffee arabica, ICH: International Conference on Harmonisation, % RSD: Percentage Relative Standard Deviation, R2: Correlation Coefficient, ppm: Parts per million, LOD: Limits

  7. Gradient High Performance Liquid Chromatography Method ...

    African Journals Online (AJOL)

    Purpose: To develop a gradient high performance liquid chromatography (HPLC) method for the simultaneous determination of phenylephrine (PHE) and ibuprofen (IBU) in solid ..... nimesulide, phenylephrine. Hydrochloride, chlorpheniramine maleate and caffeine anhydrous in pharmaceutical dosage form. Acta Pol.

  8. PHARMACEUTICAL AND BIOMEDICAL APPLICATIONS OF AFFINITY CHROMATOGRAPHY: RECENT TRENDS AND DEVELOPMENTS

    Science.gov (United States)

    Hage, David S.; Anguizola, Jeanethe A.; Bi, Cong; Li, Rong; Matsuda, Ryan; Papastavros, Efthimia; Pfaunmiller, Erika; Vargas, John; Zheng, Xiwei

    2012-01-01

    Affinity chromatography is a separation technique that has become increasingly important in work with biological samples and pharmaceutical agents. This method is based on the use of a biologically-related agent as a stationary phase to selectively retain analytes or to study biological interactions. This review discusses the basic principles behind affinity chromatography and examines recent developments that have occurred in the use of this method for biomedical and pharmaceutical analysis. Techniques based on traditional affinity supports are discussed, but an emphasis is placed on methods in which affinity columns are used as part of HPLC systems or in combination with other analytical methods. General formats for affinity chromatography that are considered include step elution schemes, weak affinity chromatography, affinity extraction and affinity depletion. Specific separation techniques that are examined include lectin affinity chromatography, boronate affinity chromatography, immunoaffinity chromatography, and immobilized metal ion affinity chromatography. Approaches for the study of biological interactions by affinity chromatography are also presented, such as the measurement of equilibrium constants, rate constants, or competition and displacement effects. In addition, related developments in the use of immobilized enzyme reactors, molecularly imprinted polymers, dye ligands and aptamers are briefly considered. PMID:22305083

  9. Development of an on-line mixed-mode gel liquid chromatography×reversed phase liquid chromatography method for separation of water extract from Flos Carthami.

    Science.gov (United States)

    Wang, Yu-Qing; Tang, Xu; Li, Jia-Fu; Wu, Yun-Long; Sun, Yu-Ying; Fang, Mei-Juan; Wu, Zhen; Wang, Xiu-Min; Qiu, Ying-Kun

    2017-10-13

    A novel on-line comprehensive two-dimensional liquid chromatography (2D-LC) method by coupling mixed-mode gel liquid chromatography (MMG-LC) with reversed phase liquid chromatography (RPLC) was developed. A mixture of 17 reference compounds was used to study the separation mechanism. A crude water extract of Flos Carthami was applied to evaluate the performance of the novel 2D-LC system. In the first dimension, the extract was eluted with a gradient of water/methanol over a cross-linked dextran gel Sephadex LH-20 column. Meanwhile, the advantages of size exclusion, reversed phase partition and adsorption separation mechanism were exploited before further on-line reversed phase purification on the second dimension. This novel on-line mixed-mode Sephadex LH-20×RPLC method provided higher peak resolution, sample processing ability (2.5mg) and better orthogonality (72.9%) versus RPLC×RPLC and hydrophilic interaction liquid chromatography (HILIC)×RPLC. To the best of our knowledge, this is the first report of a mixed-mode Sephadex LH-20×RPLC separation method with successful applications in on-line mode, which might be beneficial for harvesting targets from complicated medicinal plants. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    African Journals Online (AJOL)

    Purpose: To develop a simple, rapid and sensitive high performance liquid chromatography (HPLC) method for the determination of cefadroxil monohydrate in human plasma. Methods: Schimadzu HPLC with LC solution software was used with Waters Spherisorb, C18 (5 μm, 150mm × 4.5mm) column. The mobile phase ...

  11. Development of high performance liquid chromatography method for miconazole analysis in powder sample

    Science.gov (United States)

    Hermawan, D.; Suwandri; Sulaeman, U.; Istiqomah, A.; Aboul-Enein, H. Y.

    2017-02-01

    A simple high performance liquid chromatography (HPLC) method has been developed in this study for the analysis of miconazole, an antifungal drug, in powder sample. The optimized HPLC system using C8 column was achieved using mobile phase composition containing methanol:water (85:15, v/v), a flow rate of 0.8 mL/min, and UV detection at 220 nm. The calibration graph was linear in the range from 10 to 50 mg/L with r 2 of 0.9983. The limit of detection (LOD) and limit of quantitation (LOQ) obtained were 2.24 mg/L and 7.47 mg/L, respectively. The present HPLC method is applicable for the determination of miconazole in the powder sample with a recovery of 101.28 % (RSD = 0.96%, n = 3). The developed HPLC method provides short analysis time, high reproducibility and high sensitivity.

  12. Development and validation of ultra-high performance supercritical fluid chromatography method for determination of illegal dyes and comparison to ultra-high performance liquid chromatography method.

    Science.gov (United States)

    Khalikova, Maria A; Šatínský, Dalibor; Solich, Petr; Nováková, Lucie

    2015-05-18

    A novel simple, fast and efficient ultra-high performance supercritical fluid chromatography (UHPSFC) method was developed and validated for the separation and quantitative determination of eleven illegal dyes in chili-containing spices. The method involved a simple ultrasound-assisted liquid extraction of illegal compounds with tetrahydrofuran. The separation was performed using a supercritical fluid chromatography system and CSH Fluoro-Phenyl stationary phase at 70°C. The mobile phase was carbon dioxide and the mixture of methanol:acetonitrile (1:1, v/v) with 2.5% formic acid as an additive at the flow rate 2.0 mL min(-1). The UV-vis detection was accomplished at 500 nm for seven compounds and at 420 nm for Sudan Orange G, Butter Yellow, Fast Garnet GBC and Methyl Red due to their maximum of absorbance. All eleven compounds were separated in less than 5 min. The method was successfully validated and applied using three commercial samples of chili-containing spices - Chili sauce (Indonesia), Feferony sauce (Slovakia) and Mojo sauce (Spain). The linearity range of proposed method was 0.50-9.09 mg kg(-1) (r ≥ 0.995). The detection limits were determined as signal to noise ratio of 3 and were ranged from 0.15 mg kg(-1) to 0.60 mg kg(-1) (1.80 mg kg(-1) for Fast Garnet) for standard solution and from 0.25 mg kg(-1) to 1.00 mg kg(-1) (2.50 mg kg(-1) for Fast Garnet, 1.50 mg kg(-1) for Sudan Red 7B) for chili-containing samples. The recovery values were in the range of 73.5-107.2% and relative standard deviation ranging from 0.1% to 8.2% for within-day precision and from 0.5% to 8.8% for between-day precision. The method showed potential for being used to monitor forbidden dyes in food constituents. The developed UHPSFC method was compared to the UHPLC-UV method. The orthogonality of Sudan dyes separation by these two methods was demonstrated. Benefits and drawbacks were discussed showing the reliability of both methods for monitoring of studied illegal dyes in real

  13. Development and validation of high-performance liquid chromatography and high-performance thin-layer chromatography methods for the quantification of khellin in Ammi visnaga seed

    Science.gov (United States)

    Kamal, Abid; Khan, Washim; Ahmad, Sayeed; Ahmad, F. J.; Saleem, Kishwar

    2015-01-01

    Objective: The present study was used to design simple, accurate and sensitive reversed phase-high-performance liquid chromatography RP-HPLC and high-performance thin-layer chromatography (HPTLC) methods for the development of quantification of khellin present in the seeds of Ammi visnaga. Materials and Methods: RP-HPLC analysis was performed on a C18 column with methanol: Water (75: 25, v/v) as a mobile phase. The HPTLC method involved densitometric evaluation of khellin after resolving it on silica gel plate using ethyl acetate: Toluene: Formic acid (5.5:4.0:0.5, v/v/v) as a mobile phase. Results: The developed HPLC and HPTLC methods were validated for precision (interday, intraday and intersystem), robustness and accuracy, limit of detection and limit of quantification. The relationship between the concentration of standard solutions and the peak response was linear in both HPLC and HPTLC methods with the concentration range of 10–80 μg/mL in HPLC and 25–1,000 ng/spot in HPTLC for khellin. The % relative standard deviation values for method precision was found to be 0.63–1.97%, 0.62–2.05% in HPLC and HPTLC for khellin respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels and the average percentage recovery was found to be 100.53% in HPLC and 100.08% in HPTLC for khellin. Conclusions: The developed HPLC and HPTLC methods for the quantification of khellin were found simple, precise, specific, sensitive and accurate which can be used for routine analysis and quality control of A. visnaga and several formulations containing it as an ingredient. PMID:26681890

  14. 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)

  15. Development of conjugate methods with gas chromatography for inorganic compounds analysis

    International Nuclear Information System (INIS)

    Baccan, N.

    1975-01-01

    The application of gas chromatography combined with mass spectrometry or with nuclear methods for the analysis of inorganic compounds is studied. The advantages of the use of a gas chromatograph coupled with a quadrupole mass spectrometer or with a high resolution radiation detector, are discussed. We also studied the formation and solvent extraction of metal chelates; an aliquot of the organic phase was directly injected into the gas chromatograph and the eluted compounds were detected by mass spectrometry or, when radioactive, by nuclear methods. (author)

  16. Liquid chromatography method development and optimization for valsartan: pharmacokinetics of oral hydrogels in rabbits

    International Nuclear Information System (INIS)

    Sohail, M.; Minhas, M.U.

    2017-01-01

    A simple, rapid, precise, accurate high performance liquid chromatography method has been developed and subsequently validated for determination of valsartan in rabbit plasma. The method was developed employing mixture of mobile phase consisting of 0.02 M potassium dihydrogen phosphate buffer and acetonitrile (45:55), pH was adjusted to 2.7 using 50% orthophosphoric acid and pumped thorough chromatographic system at a flow rate of 1 ml/min. An isocratic elution mode was carried out at HPLC system (Agilent Technologies, 1200 series, USA) fitted with variable wavelength detector and data processing software ChemStation. For sample analysis, 20 mul sample was injected and eluate was monitored at 225nm wavelength. Pharmacokinetic evaluation was performed in rabbits after the oral administration of valsartan loaded PVA-co-poly(AA) hydrogels. The mean Cmax of valsartan was 408.439ng/ml, Tmax was 12h and half life (t1/2) was 8.812h. The extraction procedure was simple with good response even at very low drug concentration, thereby making this method suitable for pharmacokinetic application. It is concluded that developed method is simple, fast, cost effective, and reproducible for the analysis of pharmacokinetic parameters in the rabbit plasma. (author)

  17. Methods of uranium isotpic separation by chemical exchange chromatography

    International Nuclear Information System (INIS)

    Pena V, L.A.; Valle M, L.

    1985-01-01

    Chemical exchange chromatography as applied to isotope separation has undergone a constant development during the last few years. The results so far indicate that this method could eventually become commercially useful. This work presents a critical review of the experimental methods presently under study by principal research groups, and which have not get been compared. (Author)

  18. Purification of flavonoids from licorice using an off-line preparative two-dimensional normal-phase liquid chromatography/reversed-phase liquid chromatography method.

    Science.gov (United States)

    Fan, Yunpeng; Fu, Yanhui; Fu, Qing; Cai, Jianfeng; Xin, Huaxia; Dai, Mei; Jin, Yu

    2016-07-01

    An orthogonal (71.9%) off-line preparative two-dimensional normal-phase liquid chromatography/reversed-phase liquid chromatography method coupled with effective sample pretreatment was developed for separation and purification of flavonoids from licorice. Most of the nonflavonoids were firstly removed using a self-made Click TE-Cys (60 μm) solid-phase extraction. In the first dimension, an industrial grade preparative chromatography was employed to purify the crude flavonoids. Click TE-Cys (10 μm) was selected as the stationary phase that provided an excellent separation with high reproducibility. Ethyl acetate/ethanol was selected as the mobile phase owing to their excellent solubility for flavonoids. Flavonoids co-eluted in the first dimension were selected for further purification using reversed-phase liquid chromatography. Multiple compounds could be isolated from one normal-phase fraction and some compounds with bad resolution in one-dimensional liquid chromatography could be prepared in this two-dimensional system owing to the orthogonal separation. Moreover, this two-dimensional liquid chromatography method was beneficial for the preparation of relatively trace flavonoid compounds, which were enriched in the first dimension and further purified in the second dimension. Totally, 24 flavonoid compounds with high purity were obtained. The results demonstrated that the off-line two-dimensional liquid chromatography method was effective for the preparative separation and purification of flavonoids from licorice. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. COMPUTER-ASSISTED HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD DEVELOPMENT WITH APPLICATIONS TO THE ISOLATION AND ANALYSIS OF PHYTOPLANKTON PIGMENTS. (R826944)

    Science.gov (United States)

    We used chromatography modeling software to assist in HPLC method development, with the goalof enhancing separations through the exclusive use of gradient time and column temperature. Wesurveyed nine stationary phases for their utility in pigment purification and natur...

  20. Method Development for Pesticide Residue Analysis in Farmland Soil using High Perfomance Liquid Chromatography

    Science.gov (United States)

    Theresia Djue Tea, Marselina; Sabarudin, Akhmad; Sulistyarti, Hermin

    2018-01-01

    A method for the determination of diazinon and chlorantraniliprole in soil samples has been developed. The analyte was extracted with acetonitrile from farmland soil sample. Determination and quantification of diazinon and chlorantraniliprole were perfomed by high perfomance liquid chromatography (HPLC) with an UV detector. Several parameters of HPLC method were optimized with respect to sensitivity, high resolution of separation, and accurate determination of diazinon and chlorantraniliprole. Optimum conditions for the separation of two pesticides were eluent composition of acetonitrile:water ratio of 60:40, 0.4 mL/min of flow rate, and 220 nm of wavelength. Under the optimum conditions, diazinon linearity was in the range from 1-25 ppm with R2 of 0.9976, 1.19 mgL-1 LOD, and 3.98 mgL-1 LOQ; while the linearity of chlorantraniliprole was in the range from 0.2-5 mgL-1 with R2 of 0.9972, 0.39 mgL-1 LOD, and 1.29 mgL-1 LOQ. When the method was applied to the soil sample, both pesticides showed acceptable recoveries for real sample of more than 85%: thus, the developed method meets the validation requirement. Under this developed method, the concentrations of both pesticides in the soil samples were below the LOD and LOQ (0.577 mgL-1 for diazinon and 0.007 mgL-1 for chlorantraniliprole). Therefore, it can be concluded that the soil samples used in this study have neither diazinon nor chlorantraniliprole.

  1. Development and validation of a thin-layer chromatography method for stability studies of naproxen

    International Nuclear Information System (INIS)

    Rodriguez Hernandez, Yaslenis; Suarez Perez, Yania; Garcia Pulpeiro, Oscar; Rodriguez Borges, Tania

    2011-01-01

    The validation of an analytical method was carried out to be applied to the stability studies of the future formulations of naproxen suppositories for infant and adult use. The factors which mostly influenced in the naproxen stability were determined, the major degradation occurred in oxidizing acid medium and by action of light. The possible formation of esters between the free carboxyl group present in naproxen and the glyceryl monoestereate present in the base was identified as one of the degradation paths in the new formulation. The results were satisfactory. A thin-layer chromatography-based method was developed as well as the best chromatographic conditions were selected. GF 254 silica gel plates and ultraviolet developer at 254 nm were employed. Three solvent systems were evaluated of which A made up of glacial acetic: tetrahydrofurane:toluene (3:9:90 v/v/v)allowed adequate resolution between the analyte and the possible degradation products, with detection limit of 1 μg. The use of the suggested method was restricted to the identification of possible degradation products just for qualitative purposes and not as final test. The method proved to be sensitive and selective enough to be applied for the stated objective, according to the validation results

  2. Development and validation of High-performance Thin-layer Chromatography Method for Simultaneous Determination of Polyphenolic Compounds in Medicinal Plants.

    Science.gov (United States)

    Jayachandran Nair, C V; Ahamad, Sayeed; Khan, Washim; Anjum, Varisha; Mathur, Rajani

    2017-12-01

    Quantitative standardization of plant-based products is challenging albeit essential to maintain their quality. This study aims to develop and validate high-performance thin-layer chromatography (HPTLC) method for the simultaneous determination of rutin (Ru), quercetin (Qu), and gallic acid (Ga) from Psidium guajava Linn. (PG) and Aegle marmelos (L.) Correa. (AM) and correlate with antioxidant activity. The stock solution (1 mg/mL) of standard Ru, Qu, and Ga in methanol: Water (1:1) was serially diluted and spotted (5 μL) on slica gel 60 F 254 thin-layer chromatography plates. Toluene: Ethyl acetate: Formic acid: Methanol (3:4:0.8:0.7, v/v/v) was selected as mobile phase for analysis at 254 nm. Hydroalcoholic (1:1) extracts of leaves of PG and AM were fractionated and similarly analyzed. Antioxidant activity was also determined using 2, 2-diphenyl-1-picrylhydrazyl assay. The developed method was robust and resolved Ru, Qu, and Ga at R f 0.08 ± 0.02, 0.76 ± 0.01, and 0.63 ± 0.02, respectively. The intra-day, interday precision, and interanalyst were limit of detection and limit of quantification for Ru, Qu, and Ga were 4.51, 4.2, 5.27, and 13.67, 12.73, 15.98 ng/spot, respectively. Antioxidant activity (Log 50% inhibition) of PG and AM was 4.947 ± 0.322 and 6.498 ± 0.295, respectively. The developed HPTLC method was rapid, accurate, precise, reproducible, and specific for the simultaneous estimation of Ru, Qu, and Ga. HPTLC method for simultaneous determination and quantification of Rutin, Quercetin and Gallic acid, is reported for quality control of herbal drugs. Abbreviations Used: A: Aqueous fraction; AM: Aegle marmelos L. Correa; B: Butanol fraction; C: Chloroform fraction; EA: Ethyl acetate fraction; Ga: Gallic acid; H: Hexane fraction; HA: Hydroalcoholic extract; HPTLC: High-performance thin-layer chromatography; PG: Psidium guajava ; Qu: Quercetin; Ru: Rutin.

  3. Development of a Method for Rapid Determination of Morpholine in Juices and Drugs by Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Mengsi Cao

    2018-01-01

    Full Text Available A reliable derivatization method has been developed to detect and quantify morpholine in apple juices and ibuprofen with gas chromatography-mass spectrometry. Morpholine can react with sodium nitrite under acidic condition to produce stable and volatile N-nitrosomorpholine derivative. In this experiment, various factors affecting the derivatization and extraction process were optimized, including volume and concentration of hydrochloric acid, quantity of sodium nitrite, derivatization temperature, derivatization time, extraction reagents, and extraction time. The derivative was extracted with dichloromethane and determined by gas chromatography-mass spectrometry. The linearity range of morpholine was 10–500 μg·L−1 with good correlation, and limits of detection (LOD and limits of quantification (LOQ were 7.3 μg·L−1 and 24.4 μg·L−1, respectively. Low, medium, and high concentrations of morpholine were added in apple juices and ibuprofen samples to evaluate standard recovery rate and relative standard deviation. The spiked recovery rate ranged from 94.3% to 109.0%, and the intraday repeatability and interday reproducibility were 2.0%–4.4% and 3.3%–7.0%, respectively. The developed method has good accuracy and precision. This quantitative method for morpholine is simple, sensitive, rapid, and low cost and can successfully be applied to analyze the residual morpholine in apple juices and drug samples.

  4. High-performance liquid chromatography analysis methods developed for quantifying enzymatic esterification of flavonoids in ionic liquids.

    Science.gov (United States)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2008-07-11

    Methods using reversed-phase high-performance liquid chromatography (RP-HPLC) with ELSD were investigated to quantify enzymatic reactions of flavonoids with fatty acids in the presence of diverse room temperature ionic liquids (RTILs). A buffered salt (preferably triethylamine-acetate) was found essential for separation of flavonoids from strongly polar RTILs, whereby RTILs were generally visible as two major peaks identified based on an ion-pairing/exchanging hypothesis. C8 and C12 stationary phases were optimal while mobile phase pH (3-7) had only a minor influence on separation. The method developed was successfully applied for primary screening of RTILs (>20), with in depth evaluation of substrates in 10 RTILs, for their evaluation as reaction media.

  5. Development of a sample preparation method for the analysis of current-use pesticides in sediment using gas chromatography.

    Science.gov (United States)

    Wang, Dongli; Weston, Donald P; Ding, Yuping; Lydy, Michael J

    2010-02-01

    Pyrethroid insecticides have been implicated as the cause of sediment toxicity to Hyalella azteca in both agricultural and urban areas of California; however, for a subset of these toxic sediments (approximately 30%), the cause of toxicity remains unidentified. This article describes the analytical method development for seven additional pesticides that are being examined to determine if they might play a role in the unexplained toxicity. A pressurized liquid extraction method was optimized to simultaneously extract diazinon, methyl parathion, oxyfluorfen, dicofol, fenpropathrin, pyraclostrobin, and indoxacarb from sediment, and the extracts were cleaned using a two-step solid-phase extraction procedure. The final extract was analyzed for the target pesticides by gas chromatography/nitrogen-phosphorus detector (GC/NPD), and gas chromatography/electron capture detector (GC/ECD), after sulfur was removed by shaking with copper and cold crystallization. Three sediments were used as reference matrices to assess method accuracy and precision. Method detection limits were 0.23-1.8 ng/g dry sediment using seven replicates of sediment spiked at 1.0 ng/g dry sediment. Recoveries ranged from 61.6 to 118% with relative standard deviations of 2.1-17% when spiked at 5.0 and 50 ng/g dry sediment. The three reference sediments, spiked with 50 ng/g dry weight of the pesticide mixture, were aged for 0.25, 1, 4, 7, and 14 days. Recoveries of the pesticides in the sediments generally decreased with increased aging time, but the magnitude of the decline was pesticide and sediment dependent. The developed method was applied to field-collected sediments from the Central Valley of California.

  6. Determination of Urine Albumin by New Simple High-Performance Liquid Chromatography Method.

    Science.gov (United States)

    Klapkova, Eva; Fortova, Magdalena; Prusa, Richard; Moravcova, Libuse; Kotaska, Karel

    2016-11-01

    A simple high-performance liquid chromatography (HPLC) method was developed for the determination of albumin in patients' urine samples without coeluting proteins and was compared with the immunoturbidimetric determination of albumin. Urine albumin is important biomarker in diabetic patients, but part of it is immuno-nonreactive. Albumin was determined by high-performance liquid chromatography (HPLC), UV detection at 280 nm, Zorbax 300SB-C3 column. Immunoturbidimetric analysis was performed using commercial kit on automatic biochemistry analyzer COBAS INTEGRA ® 400, Roche Diagnostics GmbH, Manheim, Germany. The HLPC method was fully validated. No significant interference with other proteins (transferrin, α-1-acid glycoprotein, α-1-antichymotrypsin, antitrypsin, hemopexin) was found. The results from 301 urine samples were compared with immunochemical determination. We found a statistically significant difference between these methods (P = 0.0001, Mann-Whitney test). New simple HPLC method was developed for the determination of urine albumin without coeluting proteins. Our data indicate that the HPLC method is highly specific and more sensitive than immunoturbidimetry. © 2016 Wiley Periodicals, Inc.

  7. Development of the H-point standard additions method for coupled liquid-chromatography and UV-visible spectrophotometry

    Energy Technology Data Exchange (ETDEWEB)

    Campins-Falco, Pilar; Bosch-Reig, Francisco; Herraez-Hernandez, Rosa; Sevillano-Cabeza, Adela (Universidad de Valencia (Spain). Facultad de Quimica, Departamento de Quimica Analitica)

    1992-02-10

    This work establishes the fundamentals of the H-point standard additions method for liquid chromatography for the simultaneous analysis of binary mixtures with overlapped chromatographic peaks. The method was compared with the deconvolution method of peak suppression and the second derivative of elution profiles. Different mixtures of diuretics were satisfactorily resolved. (author). 21 refs.; 9 figs.; 2 tabs.

  8. Method development for trace and ultratrace analysis

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Method development, that is, selection of a mode of chromatography and the right column and mobile-phase combination for trace and ultratrace analysis, requires several main considerations. The method should be useful for resolving various trace and ultratrace components present in the sample. If the nature of these components is known, the choice of method may be straightforward, that is, a selection can be made from the following modes of HPLC: (1) adsorption chromatography; (2) normal-phase chromatography; (3) reversed-phase chromatography; (4) ion-pair chromatography; (5) ion-exchange chromatography; (6) ion chromatography. Unfortunately, the nature of all of the components is frequently unknown. However, several intelligent judgments can be made on the nature of impurities. This chapter deals with some basic approaches to mobile-phase selection and optimization. More detailed information may be found in basic texts. Techniques for separation of high-molecular-weight compounds (macromolecules) and chiral compounds may be found elsewhere. Mainly compounds with molecular weight lower than 2,000 are discussed here. 123 refs

  9. A high pressure liquid chromatography method for separation of prolactin forms.

    Science.gov (United States)

    Bell, Damon A; Hoad, Kirsten; Leong, Lillian; Bakar, Juwaini Abu; Sheehan, Paul; Vasikaran, Samuel D

    2012-05-01

    Prolactin has multiple forms and macroprolactin, which is thought not to be bioavailable, can cause a raised serum prolactin concentration. Gel filtration chromatography (GFC) is currently the gold standard method for separating macroprolactin, but is labour-intensive. Polyethylene glycol (PEG) precipitation is suitable for routine use but may not always be accurate. We developed a high pressure liquid chromatography (HPLC) assay for macroprolactin measurement. Chromatography was carried out using an Agilent Zorbax GF-250 (9.4 × 250 mm, 4 μm) size exclusion column and 50 mmol/L Tris buffer with 0.15 mmol/L NaCl at pH 7.2 as mobile phase, with a flow rate of 1 mL/min. Serum or plasma was diluted 1:1 with mobile phase and filtered and 100 μL injected. Fractions of 155 μL were collected for prolactin measurement and elution profile plotted. The area under the curve of each prolactin peak was calculated to quantify each prolactin form, and compared with GFC. Clear separation of monomeric-, big- and macroprolactin forms was achieved. Quantification was comparable to GFC and precision was acceptable. Total time from injection to collection of the final fraction was 16 min. We have developed an HPLC method for quantification of macroprolactin, which is rapid and easy to perform and therefore can be used for routine measurement.

  10. Liquid chromatography detection unit, system, and method

    Science.gov (United States)

    Derenzo, Stephen E.; Moses, William W.

    2015-10-27

    An embodiment of a liquid chromatography detection unit includes a fluid channel and a radiation detector. The radiation detector is operable to image a distribution of a radiolabeled compound as the distribution travels along the fluid channel. An embodiment of a liquid chromatography system includes an injector, a separation column, and a radiation detector. The injector is operable to inject a sample that includes a radiolabeled compound into a solvent stream. The position sensitive radiation detector is operable to image a distribution of the radiolabeled compound as the distribution travels along a fluid channel. An embodiment of a method of liquid chromatography includes injecting a sample that comprises radiolabeled compounds into a solvent. The radiolabeled compounds are then separated. A position sensitive radiation detector is employed to image distributions of the radiolabeled compounds as the radiolabeled compounds travel along a fluid channel.

  11. Development of a high-performance liquid chromatography method for the determination of florfenicol in animal feedstuffs.

    Science.gov (United States)

    Yang, JinJing; Sun, GuiZhi; Qian, MingRong; Huang, LingLi; Ke, XianBing; Yang, Bo

    2017-11-15

    An effective thin layer chromatography (TLC) purification procedure coupled to high-performance liquid chromatography (HPLC) method was developed for the determination of florfenicol (FF) in pig, chicken and fish feedstuffs. The feedstuff samples were extracted with ethyl acetate, defatted with n-hexane saturated with acetonitrile, and further purified by TLC. The chromatographic separation was performed on a Waters Symmetry C 18 column using an isocratic procedure with acetonitrile-water (35:65, v/v) at 0.6mL/min. The ultraviolet (UV) detector was set at a wavelength of 225nm. The FF concentrations in feedstuff samples were quantified using a standard curve. Good linear correlations (y=159075x-15054, r>0.9999) were achieved within the concentration range of 0.05-200μg/mL. The recoveries of FF spiked at levels of 1, 100 and 1000μg/g ranged from 80.6% to 105.3% with the intra-day and inter-day relative standard deviation (RSD) less than 9.3%. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.02 and 0.06mg/kg for pig feedstuffs, 0.02 and 0.07mg/kg for chicken feedstuffs, and 0.02 and 0.05mg/kg for fish feedstuffs, respectively. This reliable, simple and cost-effective method could be applied to the routine monitoring of FF in animal feedstuffs. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Method developments approaches in supercritical fluid chromatography applied to the analysis of cosmetics.

    Science.gov (United States)

    Lesellier, E; Mith, D; Dubrulle, I

    2015-12-04

    Analyses of complex samples of cosmetics, such as creams or lotions, are generally achieved by HPLC. These analyses are often multistep gradients, due to the presence of compounds with a large range of polarity. For instance, the bioactive compounds may be polar, while the matrix contains lipid components that are rather non-polar, thus cosmetic formulations are usually oil-water emulsions. Supercritical fluid chromatography (SFC) uses mobile phases composed of carbon dioxide and organic co-solvents, allowing for good solubility of both the active compounds and the matrix excipients. Moreover, the classical and well-known properties of these mobile phases yield fast analyses and ensure rapid method development. However, due to the large number of stationary phases available for SFC and to the varied additional parameters acting both on retention and separation factors (co-solvent nature and percentage, temperature, backpressure, flow rate, column dimensions and particle size), a simplified approach can be followed to ensure a fast method development. First, suited stationary phases should be carefully selected for an initial screening, and then the other operating parameters can be limited to the co-solvent nature and percentage, maintaining the oven temperature and back-pressure constant. To describe simple method development guidelines in SFC, three sample applications are discussed in this paper: UV-filters (sunscreens) in sunscreen cream, glyceryl caprylate in eye liner and caffeine in eye serum. Firstly, five stationary phases (ACQUITY UPC(2)) are screened with isocratic elution conditions (10% methanol in carbon dioxide). Complementary of the stationary phases is assessed based on our spider diagram classification which compares a large number of stationary phases based on five molecular interactions. Secondly, the one or two best stationary phases are retained for further optimization of mobile phase composition, with isocratic elution conditions or, when

  13. Lipidomic analysis of biological samples: Comparison of liquid chromatography, supercritical fluid chromatography and direct infusion mass spectrometry methods.

    Science.gov (United States)

    Lísa, Miroslav; Cífková, Eva; Khalikova, Maria; Ovčačíková, Magdaléna; Holčapek, Michal

    2017-11-24

    Lipidomic analysis of biological samples in a clinical research represents challenging task for analytical methods given by the large number of samples and their extreme complexity. In this work, we compare direct infusion (DI) and chromatography - mass spectrometry (MS) lipidomic approaches represented by three analytical methods in terms of comprehensiveness, sample throughput, and validation results for the lipidomic analysis of biological samples represented by tumor tissue, surrounding normal tissue, plasma, and erythrocytes of kidney cancer patients. Methods are compared in one laboratory using the identical analytical protocol to ensure comparable conditions. Ultrahigh-performance liquid chromatography/MS (UHPLC/MS) method in hydrophilic interaction liquid chromatography mode and DI-MS method are used for this comparison as the most widely used methods for the lipidomic analysis together with ultrahigh-performance supercritical fluid chromatography/MS (UHPSFC/MS) method showing promising results in metabolomics analyses. The nontargeted analysis of pooled samples is performed using all tested methods and 610 lipid species within 23 lipid classes are identified. DI method provides the most comprehensive results due to identification of some polar lipid classes, which are not identified by UHPLC and UHPSFC methods. On the other hand, UHPSFC method provides an excellent sensitivity for less polar lipid classes and the highest sample throughput within 10min method time. The sample consumption of DI method is 125 times higher than for other methods, while only 40μL of organic solvent is used for one sample analysis compared to 3.5mL and 4.9mL in case of UHPLC and UHPSFC methods, respectively. Methods are validated for the quantitative lipidomic analysis of plasma samples with one internal standard for each lipid class. Results show applicability of all tested methods for the lipidomic analysis of biological samples depending on the analysis requirements

  14. Qualitative and quantitative determination of ubiquinones by the method of high-efficiency liquid chromatography

    International Nuclear Information System (INIS)

    Yanotovskii, M.T.; Mogilevskaya, M.P.; Obol'nikova, E.A.; Kogan, L.M.; Samokhvalov, G.I.

    1986-01-01

    A method has been developed for the qualitative and quantitative determination of ubiquinones CoQ 6 -CoQ 10 , using high-efficiency reversed-phase liquid chromatography. Tocopherol acetate was used as the internal standard

  15. 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

  16. An optimized method for the measurement of acetaldehyde by high-performance liquid chromatography.

    Science.gov (United States)

    Guan, Xiangying; Rubin, Emanuel; Anni, Helen

    2012-03-01

    Acetaldehyde is produced during ethanol metabolism predominantly in the liver by alcohol dehydrogenase and rapidly eliminated by oxidation to acetate via aldehyde dehydrogenase. Assessment of circulating acetaldehyde levels in biological matrices is performed by headspace gas chromatography and reverse phase high-performance liquid chromatography (RP-HPLC). We have developed an optimized method for the measurement of acetaldehyde by RP-HPLC in hepatoma cell culture medium, blood, and plasma. After sample deproteinization, acetaldehyde was derivatized with 2,4-dinitrophenylhydrazine (DNPH). The reaction was optimized for pH, amount of derivatization reagent, time, and temperature. Extraction methods of the acetaldehyde-hydrazone (AcH-DNP) stable derivative and product stability studies were carried out. Acetaldehyde was identified by its retention time in comparison with AcH-DNP standard, using a new chromatography gradient program, and quantitated based on external reference standards and standard addition calibration curves in the presence and absence of ethanol. Derivatization of acetaldehyde was performed at pH 4.0 with an 80-fold molar excess of DNPH. The reaction was completed in 40 minutes at ambient temperature, and the product was stable for 2 days. A clear separation of AcH-DNP from DNPH was obtained with a new 11-minute chromatography program. Acetaldehyde detection was linear up to 80 μM. The recovery of acetaldehyde was >88% in culture media and >78% in plasma. We quantitatively determined the ethanol-derived acetaldehyde in hepatoma cells, rat blood and plasma with a detection limit around 3 μM. The accuracy of the method was volume (70 μl) plasma sampling. An optimized method for the quantitative determination of acetaldehyde in biological systems was developed using derivatization with DNPH, followed by a short RP-HPLC separation of AcH-DNP. The method has an extended linear range, is reproducible and applicable to small-volume sampling of culture

  17. Plasma chromatography

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    This book examines the fundamental theory and various applications of ion mobility spectroscopy. Plasma chromatography developed from research on the diffusion and mobility of ions. Topics considered include instrument design and description (e.g., performance, spectral interpretation, sample handling, mass spectrometry), the role of ion mobility in plasma chromatography (e.g., kinetic theory of ion transport), atmospheric pressure ionization (e.g., rate equations), the characterization of isomers by plasma chromatography (e.g., molecular ion characteristics, polynuclear aromatics), plasma chromatography as a gas chromatographic detection method (e.g., qualitative analysis, continuous mobility monitoring, quantitative analysis), the analysis of toxic vapors by plasma chromatography (e.g., plasma chromatograph calibration, instrument control and data processing), the analysis of semiconductor devices and microelectronic packages by plasma chromatography/mass spectroscopy (e.g., analysis of organic surface contaminants, analysis of water in sealed electronic packages), and instrument design and automation (hardware, software)

  18. Greening Reversed-Phase Liquid Chromatography Methods Using Alternative Solvents for Pharmaceutical Analysis

    Directory of Open Access Journals (Sweden)

    Moussa Yabré

    2018-05-01

    Full Text Available The greening of analytical methods has gained increasing interest in the field of pharmaceutical analysis to reduce environmental impacts and improve the health safety of analysts. Reversed-phase high-performance liquid chromatography (RP-HPLC is the most widely used analytical technique involved in pharmaceutical drug development and manufacturing, such as the quality control of bulk drugs and pharmaceutical formulations, as well as the analysis of drugs in biological samples. However, RP-HPLC methods commonly use large amounts of organic solvents and generate high quantities of waste to be disposed, leading to some issues in terms of ecological impact and operator safety. In this context, greening HPLC methods is becoming highly desirable. One strategy to reduce the impact of hazardous solvents is to replace classically used organic solvents (i.e., acetonitrile and methanol with greener ones. So far, ethanol has been the most often used alternative organic solvent. Others strategies have followed, such as the use of totally aqueous mobile phases, micellar liquid chromatography, and ionic liquids. These approaches have been well developed, as they do not require equipment investments and are rather economical. This review describes and critically discusses the recent advances in greening RP-HPLC methods dedicated to pharmaceutical analysis based on the use of alternative solvents.

  19. Methods of analysis-Determination of pesticides in sediment using gas chromatography/mass spectrometry

    Science.gov (United States)

    Hladik, Michelle; McWayne, Megan M.

    2012-01-01

    A method for the determination of 119 pesticides in environmental sediment samples is described. The method was developed by the U.S. Geological Survey (USGS) in support of the National Water Quality Assessment (NAWQA) Program. The pesticides included in this method were chosen through prior prioritization. Herbicides, insecticides, and fungicides along with degradates are included in this method and span a variety of chemical classes including, but not limited to, chloroacetanilides, organochlorines, organophosphates, pyrethroids, triazines, and triazoles. Sediment samples are extracted by using an accelerated solvent extraction system (ASE®, and the compounds of interest are separated from co-extracted matrix interferences (including sulfur) by passing the extracts through high performance liquid chromatography (HPLC) with gel-permeation chromatography (GPC) along with the use of either stacked graphitized carbon and alumina solid-phase extraction (SPE) cartridges or packed Florisil®. Chromatographic separation, detection, and quantification of the pesticides from the sediment-sample extracts are done by using gas chromatography with mass spectrometry (GC/MS). Recoveries in test sediment samples fortified at 10 micrograms per kilogram (μg/kg) dry weight ranged from 75 to 102 percent; relative standard deviations ranged from 3 to 13 percent. Method detection limits (MDLs), calculated by using U.S. Environmental Protection Agency procedures (40 CFR 136, Appendix B), ranged from 0.6 to 3.4 μg/kg dry weight.

  20. Development of a high performance liquid chromatography method and a liquid chromatography-tandem mass spectrometry method with pressurized liquid extraction for simultaneous quantification and confirmation of cyromazine, melamine and its metabolites in foods of animal origin

    International Nuclear Information System (INIS)

    Yu Huan; Tao Yanfei; Chen Dongmei; Wang Yulian; Liu Zhaoying; Pan Yuanhu; Huang Lingli; Peng Dapeng; Dai Menghong; Liu Zhenli; Yuan Zonghui

    2010-01-01

    Simple and sensitive methods have been developed for simultaneous detection of cyromazine, melamine and their metabolites (ammeline, ammelide and cyanuric acid) in samples of animal origins. These include a high performance liquid chromatography (HPLC) method and a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method and are useful in regular monitoring and in toxicity studies of these molecules. Representative samples used in this study include muscles and livers of swine, bovine, sheep and chicken, kidneys of swine, bovine and sheep, and milk powder. A new sample preparation procedure with pressurized liquid extraction (PLE) at 1400 psi and 70 deg. C was investigated. Quantification of these five compounds by HPLC was achieved using an APS-2 column with UV detection at 230 nm. Limit of detection (LOD) was at 10 μg kg -1 , and limit of quantification (LOQ) was at 40 μg kg -1 . Recoveries of the five analytes in spiked samples ranged from 72.2% to 115.4% with RSD less than 12%. Confirmatory analysis of the analytes was performed using LC-MS/MS in selected reaction monitoring (SRM) mode. The LOD and LOQ were 5 μg kg -1 and 15 μg kg -1 , respectively. This is the first simultaneous analysis of cyromazine, melamine, ammeline, ammelide and cyanuric acid residues in complex tissue samples using PLE and HPLC. It is expected that these methods will find many practical applications in evaluating the safety of cyromazine, melamine and their metabolites.

  1. Method development for Lawsone estimation in Trichup herbal hair powder by high-performance thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Maunang M Patel

    2013-01-01

    Full Text Available A simple, specific, accurate, precise and robust high-performance thin-layer chromatographic method has been developed and validated for estimation of Lawsone in Trichup herbal hair powder (coded as a THHP, polyherbal formulation. The chromatographic development was carried out on aluminum plates pre-coated with silica gel 60F 254 and good resolution was achieved with Toluene: Ethyl acetate: Glacial acetic acid (8:1:1 v/v/v as mobile phase. Lawsone detection was carried out densitometrically at 277 nm and obtained retardation factor value was 0.46 ± 0.02. The method was validated with respect to specificity, linearity, accuracy, precision and robustness. The calibration curve was achieved to be linear over a range of 5-60 μg/ml and regression coefficient was obtained 0.998. Accuracy of chromatographic method was evaluated by standard addition method; recovery was obtained 99.25 ± 0.61% . The peak purity of Lawsone was achieved 0.999 r. Relative standard deviation for intraday and inter-day precision was 0.37-0.56% and 0.42-0.55%, respectively. The limit of detection and limit of quantification of the Lawsone were found to be 1.08 μg/m land 3.28 μg/ml, respectively. This result shows that the method was well validated. In the present study, the Lawsone content was found 0.322 ± 0.014% in THHP. This study reveals that the proposed high performance thin layer chromatography method is accurate, fast and cost- effective for routine estimation of Lawsone in polyherbal formulation.

  2. Quality by Design in the development of hydrophilic interaction liquid chromatography method with gradient elution for the analysis of olanzapine.

    Science.gov (United States)

    Tumpa, Anja; Stajić, Ana; Jančić-Stojanović, Biljana; Medenica, Mirjana

    2017-02-05

    This paper deals with the development of hydrophilic interaction liquid chromatography (HILIC) method with gradient elution, in accordance with Analytical Quality by Design (AQbD) methodology, for the first time. The method is developed for olanzapine and its seven related substances. Following step by step AQbD methodology, firstly as critical process parameters (CPPs) temperature, starting content of aqueous phase and duration of linear gradient are recognized, and as critical quality attributes (CQAs) separation criterion S of critical pairs of substances are investigated. Rechtschaffen design is used for the creation of models that describe the dependence between CPPs and CQAs. The design space that is obtained at the end is used for choosing the optimal conditions (set point). The method is fully validated at the end to verify the adequacy of the chosen optimal conditions and applied to real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Evaluation between ultrahigh pressure liquid chromatography and high-performance liquid chromatography analytical methods for characterizing natural dyestuffs.

    Science.gov (United States)

    Serrano, Ana; van Bommel, Maarten; Hallett, Jessica

    2013-11-29

    An evaluation was undertaken of ultrahigh pressure liquid chromatography (UHPLC) in comparison to high-performance liquid chromatography (HPLC) for characterizing natural dyes in cultural heritage objects. A new UHPLC method was optimized by testing several analytical parameters adapted from prior UHPLC studies developed in diverse fields of research. Different gradient elution programs were tested on seven UHPLC columns with different dimensions and stationary phase compositions by applying several mobile phases, flow rates, temperatures, and runtimes. The UHPLC method successfully provided more improved data than that achieved by the HPLC method. Indeed, even though carminic acid has shown circa 146% higher resolution with HPLC, UHPLC resulted in an increase of 41-61% resolution and a decrease of 91-422% limit of detection, depending on the dye compound. The optimized method was subsequently assigned to analyse 59 natural reference materials, in which 85 different components were ascribed with different physicochemical properties, in order to create a spectral database for future characterization of dyes in cultural heritage objects. The majority of these reference samples could be successfully distinguished with one single method through the examination of these compounds' retention times and their spectra acquired with a photodiode array detector. These results demonstrate that UHPLC analyses are extremely valuable for the acquisition of more precise chromatographic information concerning natural dyes with complex mixtures of different and/or closely related physicochemical properties, essential for distinguishing similar species of plants and animals used to colour cultural heritage objects. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Development of a method based on on-line reversed phase liquid chromatography and gas chromatography coupled by means of an adsorption-desorption interface for the analysis of selected chiral volatile compounds in methyl jasmonate treated strawberries.

    Science.gov (United States)

    de la Peña Moreno, Fernando; Blanch, Gracia Patricia; Flores, Gema; Ruiz Del Castillo, Maria Luisa

    2010-02-12

    A method based on the use of the through oven transfer adsorption-desorption (TOTAD) interface in on-line coupling between reversed phase liquid chromatography and gas chromatography (RPLC-GC) for the determination of chiral volatile compounds was developed. In particular, the method was applied to the study of the influence of methyl jasmonate (MJ) treatment on the production and enantiomeric composition of selected aroma compounds in strawberry. The compounds studied were ethyl 2-methylbutanoate, linalool and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (i.e. furaneol), which were examined on days 3, 6 and 9 after treatment. The method developed resulted in relative standard deviations (RSDs) of 21.6%, 8.1% and 9.8% and limits of detection (LD) of 0.04, 0.07 and 0.02mg/l for ethyl 2-methylbutanoate, linalool and furaneol, respectively. The application of the RPLC-TOTAD-GC method allowed higher levels of ethyl 2-methylbutanoate, linalool and furaneol to be detected, particularly after 9 days of treatment. Besides, MJ demonstrated to affect the enantiomeric distribution of ethyl 2-methylbutanoate. On the contrary, the enantiomeric composition of linalool and furaneol kept constant in both control and MJ-treated strawberries throughout the study. These results are discussed. Copyright 2009 Elsevier B.V. All rights reserved.

  5. Supercritical fluid chromatography

    Science.gov (United States)

    Vigdergauz, M. S.; Lobachev, A. L.; Lobacheva, I. V.; Platonov, I. A.

    1992-03-01

    The characteristic features of supercritical fluid chromatography (SCFC) are examined and there is a brief historical note concerning the development of the method. Information concerning the use of supercritical fluid chromatography in the analysis of objects of different nature is presented in the form of a table. The roles of the mobile and stationary phases in the separation process and the characteristic features of the apparatus and of the use of the method in physicochemical research are discussed. The bibliography includes 364 references.

  6. Analytical method development and validation of simultaneous estimation of rabeprazole, pantoprazole, and itopride by reverse-phase high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Senthamil Selvan Perumal

    2014-12-01

    Full Text Available A simple, selective, rapid, and precise reverse-phase high-performance liquid chromatography (RP-HPLC method for the simultaneous estimation of rabeprazole (RP, pantoprazole (PP, and itopride (IP has been developed. The compounds were well separated on a Phenomenex C18 (Luna column (250 mm × 4.6 mm, dp = 5 μm with C18 guard column (4 mm × 3 mm × 5 μm with a mobile phase consisting of buffer containing 10 mM potassium dihydrogen orthophosphate (adjusted to pH 6.8: acetonitrile (70:30 v/v at a flow rate of 1.0 mL/min and ultraviolet detection at 288 nm. The retention time of RP, PP, and IP were 5.35, 7.92, and 11.16 minutes, respectively. Validation of the proposed method was carried out according to International Conference on Harmonisation (ICH guidelines. Linearity range was obtained for RP, PP, and IP over the concentration range of 2.5–25, 1–30, and 3–35 μg/mL and the r2 values were 0.994, 0.978, and 0.991, respectively. The calculated limit of detection (LOD values were 1, 0.3, and 1 μg/mL and limit of quantitation (LOQ values were 2.5, 1, and 3 μg/mL for RP, PP, and IP correspondingly. Thus, the current study showed that the developed reverse-phase liquid chromatography method is sensitive and selective for the estimation of RP, PP, and IP in combined dosage form.

  7. Analytical method development and validation of simultaneous estimation of rabeprazole, pantoprazole, and itopride by reverse-phase high-performance liquid chromatography.

    Science.gov (United States)

    Perumal, Senthamil Selvan; Ekambaram, Sanmuga Priya; Raja, Samundeswari

    2014-12-01

    A simple, selective, rapid, and precise reverse-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of rabeprazole (RP), pantoprazole (PP), and itopride (IP) has been developed. The compounds were well separated on a Phenomenex C 18 (Luna) column (250 mm × 4.6 mm, dp = 5 μm) with C 18 guard column (4 mm × 3 mm × 5 μm) with a mobile phase consisting of buffer containing 10 mM potassium dihydrogen orthophosphate (adjusted to pH 6.8): acetonitrile (70:30 v/v) at a flow rate of 1.0 mL/min and ultraviolet detection at 288 nm. The retention time of RP, PP, and IP were 5.35, 7.92, and 11.16 minutes, respectively. Validation of the proposed method was carried out according to International Conference on Harmonisation (ICH) guidelines. Linearity range was obtained for RP, PP, and IP over the concentration range of 2.5-25, 1-30, and 3-35 μg/mL and the r 2 values were 0.994, 0.978, and 0.991, respectively. The calculated limit of detection (LOD) values were 1, 0.3, and 1 μg/mL and limit of quantitation (LOQ) values were 2.5, 1, and 3 μg/mL for RP, PP, and IP correspondingly. Thus, the current study showed that the developed reverse-phase liquid chromatography method is sensitive and selective for the estimation of RP, PP, and IP in combined dosage form. Copyright © 2014. Published by Elsevier B.V.

  8. Application of partition chromatography method for separation and analysis of actinium radionuclides

    International Nuclear Information System (INIS)

    Sinitsina, G.S.; Shestakova, I.A.; Shestakov, B.I.; Plyushcheva, N.A.; Malyshev, N.A.; Belyatskij, A.F.; Tsirlin, V.A.

    1979-01-01

    The method of partition chromatography is considered with the use of different extractants for the extraction of actinium-227, actinium-225 and actinium-228. It is advisable to extract actinium-227 from the irradiated radium with the help of D2FGFK. The use of 2DEGFK allows us to separate actinium-227 from alkaline and alkaline-earth elements. Amines have a higher radiative stability. An express-method has been developed for the identification of actinium-227 with TOA by its intrinsic α-emission in nonequilibrium preparations of irradiated radium-226 of small activity. Actinium-225 is extracted from uranium-233 with due regard for the fact that U, Th, and Ac are extracted differently by TBP from HNO 3 solutions. With the help of the given procedure one can reach the purifying coefficient of 10 4 . Actinium-228 is extracted from the radiummesothorium preparations by a deposition of decay products, including polonium-210 on the iron hydroxyde. Actinium-228 extraction from the mixture of radium radionuclides is performed by the partition chromatography method on D2EGFK. All the procedures for separation of actinium isotopes by the above methods are described

  9. Development of Validated High-performance Thin-layer Chromatography Method for Simultaneous Determination of Quercetin and Kaempferol in Thespesia populnea.

    Science.gov (United States)

    Panchal, Hiteksha; Amin, Aeshna; Shah, Mamta

    2017-01-01

    Thespesia populnea L. (Family: Malvaceae) is a well-known medicinal plant distributed in tropical regions of the world and cultivated in South Gujarat and indicated to be useful in cutaneous affections, psoriasis, ringworm, and eczema. Bark and fruits are indicated in the diseases of skin, urethritis, and gonorrhea. The juice of fruits is employed in treating certain hepatic diseases. The plant is reported to contain flavonoids, quercetin, kaempferol, gossypetin, Kaempferol-3-monoglucoside, β-sitosterol, kaempferol-7-glucoside, and gossypol. T. populnea is a common component of many herbal and Ayurvedic formulation such as Kamilari and Liv-52. The present study aimed at developing validated and reliable high-performance thin layer chromatography (HPTLC) method for the analysis of quercetin and kaempferol simultaneously in T. populnea . The method employed thin-layer chromatography aluminum sheets precoated with silica gel as the stationary phase and toluene: ethyl acetate: formic acid (6:4:0.3 v/v/v) as the mobile phase, which gave compact bands of quercetin and kaempferol. Linear regression data for the calibration curves of standard quercetin and kaempferol showed a good linear relationship over a concentration range of 100-600 ng/spot and 500-3000 ng/spot with respect to the area and correlation coefficient (R2) was 0.9955 and 0.9967. The method was evaluated regarding accuracy, precision, selectivity, and robustness. Limits of detection and quantitation were recorded as 32.06 and 85.33 ng/spot and 74.055 and 243.72 ng/spot for quercetin and kaempferol, respectively. We concluded that this method employing HPTLC in the quantitative determination of quercetin and kaempferol is efficient, simple, accurate, and validated.

  10. High-performance liquid chromatography analysis methods developed for quantifying enzymatic esterification of flavonoids in ionic liquids

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, X.B.

    2008-01-01

    Methods using reversed-phase high-performance liquid chromatography (RP-HPLC) with ELSD were investigated to quantify enzymatic reactions of flavonoids with fatty acids in the presence of diverse room temperature ionic liquids (RTILs). A buffered salt (preferably triethylamine-acetate) was found...... essential for separation of flavonoids from strongly polar RTILs, whereby RTILs were generally visible as two major peaks identified based on an ion-pairing/exchanging hypothesis. C8 and C12 stationary phases were optimal while mobile phase pH (3-7) had only a minor influence on separation. The method...

  11. A fast isocratic liquid chromatography method for the quantification of xanthophylls and their stereoisomers.

    Science.gov (United States)

    Nimalaratne, Chamila; Lopes-Lutz, Daise; Schieber, Andreas; Wu, Jianping

    2015-12-01

    A fast isocratic liquid chromatography method was developed for the simultaneous quantification of eight xanthophylls (13-Z-lutein, 13'-Z-lutein, 13-Z-zeaxanthin, all-E-lutein, all-E-zeaxanthin, all-E-canthaxanthin, all-E-β-apo-8'-carotenoic acid ethyl ester and all-E-β-apo-8'-carotenal) within 12 min, compared to 90 min by the conventional high-performance liquid chromatography method. The separation was achieved on a YMC C30 reversed-phase column (100 mm x 2.0 mm; 3 μm) operated at 20°C using a methanol/tert-butyl methyl ether/water solvent system at a flow rate of 0.8 mL/min. The method was successfully applied to quantify lutein and zeaxanthin stereoisomers in egg yolk, raw and cooked spinach, and a dietary supplement. The method can be used for the rapid analysis of xanthophyll isomers in different food products and for quality control purposes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Development of an analytical method coupling cell membrane chromatography with gas chromatography-mass spectrometry via microextraction by packed sorbent and its application in the screening of volatile active compounds in natural products.

    Science.gov (United States)

    Li, Miao; Wang, Sicen; He, Langchong

    2015-01-01

    Natural products (NPs) are important sources of lead compounds in modern drug discovery. To facilitate the screening of volatile active compounds in NPs, we have developed a new biochromatography method that uses rat vascular smooth muscle cells (VSMC), which are rich in L-type calcium channels (LCC), to prepare the stationary phase. This integrated method, which couples cell membrane chromatography (CMC) with gas chromatography-mass spectrometry (GC-MS) via microextraction by packed sorbent (MEPS) technology, has been termed VSMC/CMC-MEPS-GC-MS. Methodological validation confirmed its specificity, reliability and convenience. Screening results for Radix Angelicae Dahuricae and Fructus Cnidii obtained using VSMC/CMC-MEPS-GC-MS were consistent with those obtained using VSMC/CMC-offline-GC-MS. MEPS connection plays as simplified solid-phase extraction and replaces the uncontrollable evaporation operation in reported offline connections, so our new method is supposed to be more efficient and reliable than the offline ones, especially for compounds that are volatile, thermally unstable or difficult to purify. In application, senkyunolide A and ligustilide were preliminary identified as the volatile active components in Rhizoma Chuanxiong. We have thus confirmed the suitability of VSMC/CMC-MEPS-GC-MS for volatile active compounds screening in NP. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Validation of a confirmatory method for the determination of melamine in egg by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    Xia Xi; Ding Shuangyang; Li Xiaowei; Gong Xiao; Zhang Suxia; Jiang Haiyang; Li Jiancheng; Shen Jianzhong

    2009-01-01

    A sensitive and reliable method was developed and validated for detection and confirmation of melamine in egg based on gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Trichloroacetic acid solution was used for sample extraction and precipitation of proteins. The aqueous extracts were subjected to solid-phase extraction by mixed-mode reversed-phase/strong cation-exchange cartridges. Using ultra-performance liquid chromatography and electrospray ionization in the positive ion mode, melamine was determined by LC-MS/MS, which was completed in 5 min for each injection. For the GC-MS analysis, extracted melamine was derivatized with N,O-bis(trimethylsilyl)trifluoracetamide prior to selected ion monitoring detection in electron impact mode. The average recovery of melamine from fortified samples ranged from 85.2% to 103.2%, with coefficients of variation lower than 12%. The limit of detection obtained by GC-MS and UPLC-MS/MS was 10 and 5 μg kg -1 , respectively. This validated method was successfully applied to the determination of melamine in real samples from market.

  14. Applications of extraction chromatography in the development of radionuclide generator systems for nuclear medicine

    International Nuclear Information System (INIS)

    Dietz, M.L.; Horwitz, E.P.

    2000-01-01

    Numerous methods have been described for the separation and purification of radionuclides for application in diagnostic and therapeutic nuclear medicine, among them ion exchange, solvent extraction, and various forms of chromatography. Although extraction chromatography has previously been shown to provide a means of performing a number of separations of potential use in radionuclide generator systems, the application of the technique to generator development has thus far been limited. Recent work directed at improved methods for the determination of radionuclides in biological and environmental samples has led to the development of a series of novel extraction chromatographic resins exhibiting enhanced metal ion retention from strongly acidic media and excellent selectivity, among them materials suitable for the isolation of 212 Bi, 90 Y, and 213 Bi. These resins, along with extraction chromatographic materials employing functionalized supports to improve their physical stability or metal ion retention properties, are shown to offer promise in the development of improved radionuclide generators

  15. Possibilities and limitations of the kinetic plot method in supercritical fluid chromatography.

    Science.gov (United States)

    De Pauw, Ruben; Desmet, Gert; Broeckhoven, Ken

    2013-08-30

    Although supercritical fluid chromatography (SFC) is becoming a technique of increasing importance in the field of analytical chromatography, methods to compare the performance of SFC-columns and separations in an unbiased way are not fully developed. The present study uses mathematical models to investigate the possibilities and limitations of the kinetic plot method in SFC as this easily allows to investigate a wide range of operating pressures, retention and mobile phase conditions. The variable column length (L) kinetic plot method was further investigated in this work. Since the pressure history is identical for each measurement, this method gives the true kinetic performance limit in SFC. The deviations of the traditional way of measuring the performance as a function of flow rate (fixed back pressure and column length) and the isopycnic method with respect to this variable column length method were investigated under a wide range of operational conditions. It is found that using the variable L method, extrapolations towards other pressure drops are not valid in SFC (deviation of ∼15% for extrapolation from 50 to 200bar pressure drop). The isopycnic method provides the best prediction but its use is limited when operating closer towards critical point conditions. When an organic modifier is used, the predictions are improved for both methods with respect to the variable L method (e.g. deviations decreases from 20% to 2% when 20mol% of methanol is added). Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Development of an analytical method for polycyclic aromatic hydrocarbons in coffee beverages and dark beer using novel high-sensitivity technique of supercritical fluid chromatography/mass spectrometry.

    Science.gov (United States)

    Yoshioka, Toshiaki; Nagatomi, Yasushi; Harayama, Koichi; Bamba, Takeshi

    2018-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic substances that are mainly generated during heating in food; therefore, the European Union (EU) has regulated the amount of benzo[a]pyrene and PAH4 in various types of food. In addition, the Scientific Committee on Food of the EU and the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives have recommended that 16 PAHs should be monitored. Since coffee beverages and dark beer are roasted during manufacture, monitoring these 16 PAHs is of great importance. On the other hand, supercritical fluid chromatography (SFC) is a separation method that has garnered attention in recent years as a complement for liquid and gas chromatography. Therefore, we developed a rapid high-sensitivity analytical method for the above-mentioned 16 PAHs in coffee beverages and dark beer involving supercritical fluid chromatography/atmospheric pressure chemical ionization-mass spectrometry (SFC/APCI-MS) and simple sample preparation. In this study, we developed a novel analytical technique that increased the sensitivity of MS detection by varying the back-pressure in SFC depending on the elution of PAHs. In addition, analysis of commercially available coffee and dark beer samples in Japan showed that the risk of containing the 16 PAHs may be low. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Development, validation, and application of a method for selected avermectin determination in rural waters using high performance liquid chromatography and fluorescence detection.

    Science.gov (United States)

    Lemos, Maria Augusta Travassos; Matos, Camila Alves; de Resende, Michele Fabri; Prado, Rachel Bardy; Donagemma, Raquel Andrade; Netto, Annibal Duarte Pereira

    2016-11-01

    Avermectins (AVM) are macrocyclic lactones used in livestock and agriculture. A quantitative method of high performance liquid chromatography with fluorescence detection for the determination of eprinomectin, abamectin, doramectin and ivermectin in rural water samples was developed and validated. The method was employed to study samples collected in the Pito Aceso River microbasin, located in the Bom Jardim municipality, Rio de Janeiro State, Brazil. Samples were extracted by solid phase extraction using a polymeric stationary phase, the eluted fraction was re-concentrated under a gentle N2 flow and derivatized to allow AVM determination using liquid chromatography with fluorescence detection. The excitation and emission wavelengths of the derivatives were 365 and 470nm, respectively, and a total chromatographic run of 12min was achieved. Very low limits of quantification (22-58ngL(-1)) were found after re-concentration using N2. Recovery values varied from 85.7% to 119.2% with standard deviations between 1.2% and 10.2%. The validated method was applied in the determination of AVM in 15 water samples collected in the Pito Aceso River microbasin, but most of them were free of AVM or showed only trace levels of these compounds, except for a sample that contained doramectin (9.11µgL(-1)). The method is suitable for routine analysis with satisfactory recovery, sensitivity, and selectivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Establishing the analytical procedure for acetate in water by ion chromatography method

    International Nuclear Information System (INIS)

    Nguyen Thi Hong Thinh; Ha Lan Anh; Vo Thi Anh

    2015-01-01

    In recent studies of contamination sources of arsenic, ammonium, iron, organic carbon in groundwater, acetate is measured a lot because it is the main decomposition product of organic compounds from sediment into groundwater. In order to better support for the study of the origin and mobilization mechanism of the pollutants, acetate was studied analysis method in Isotopes Hydrology Laboratory using ion chromatography technique. Project Researchers used Ion Chromatography system - DX-600 including IonPac ICE-AS1 column for separating acetate and conductivity detector CD 25 to quantify acetate in water samples. The study results showed that project team has successfully developed analytical procedures of acetate in water with acetate’s retention time is 12 minutes, limit of detection (LOD) of the method was 0.01 ppm. The accuracy of the method was established by calculating the precision and bias of 10 analysis times of a standard sample at content levels 1 ppm and 8 ppm. The results of the 10 measurements are satisfiable about precision and bias with repeated standard deviation coefficient CVR were 1.3% and 0.2% and the recoveries R were 99.92% and 101.72%. (author)

  19. Simultaneous determination of seven flavonoids in Epimedium by liquid chromatography-tandem mass spectrometry method

    Institute of Scientific and Technical Information of China (English)

    Cai Sheng Wu; Bao Lin Guo; Yu Xin Sheng; Jin Lan Zhang

    2008-01-01

    In this paper, a sensitive and specific liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS) method has been developed and validated for the identification and determination of seven flavonoids, namely epimedin A, epimedin B, epimedin C, icariin, sagittatoside B, 2"-0-rhamnosyl icariside II, and baohuoside I in Epimedium from different sources.

  20. A fast, comprehensive screening method for doping agents in urine by gas chromatography-triple quadrupole mass spectrometry.

    Science.gov (United States)

    Van Eenoo, Peter; Van Gansbeke, Wim; De Brabanter, Nik; Deventer, Koen; Delbeke, Frans T

    2011-05-27

    The use of performance enhancing drugs in sports is prohibited. For the detection of misuse of such substances gas chromatography or liquid chromatography coupled to mass spectrometry are the most frequently used detection techniques. In this work the development and validation of a fast gas chromatography tandem mass spectrometric method for the detection of a wide range of doping agents is described. The method can determine 13 endogenous steroids (the steroid profile), 19-norandrosterone, salbutamol and 11-nor-Δ9-tetrahydrocannabinol.9carboxylic acid in the applicable ranges and to detect qualitatively over 140 substances in accordance with the minimum required performance levels of the World Anti-Doping Agency in 1ml of urine. The classes of substances included in the method are anabolic steroids, β2-agonists, stimulants, narcotics, hormone antagonists and modulators and beta-blockers. Moreover, using a short capillary column and hydrogen as a carrier gas the run time of the method is less than 8min. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Use of laminar chromatographic methods for determination of separation conditions in column extraction chromatography

    International Nuclear Information System (INIS)

    Ghersini, G.; Cerrai, E.

    1978-01-01

    Possibilities of using laminar chromatographic methods (paper and thin-layer chromatography) to determine optimal separation conditions in column extraction chromatography are analysed. Most of the given laminar methods are presented as Rf-spectra, i.e. as dependences of Rf found experimentally on eluating solution component concentration. Interrelation between Rf and distribution coefficients of corresponding liquid extraction systems and retention volumes of chromatographic columns is considered. Literature data on extraction paper and thin-layer chromatography of elements with various immovable phases are presented

  2. Ion Chromatography Applications in Wastewater Analysis

    Directory of Open Access Journals (Sweden)

    Rajmund Michalski

    2018-02-01

    Full Text Available Wastewater analysis is an important area in analytical and environmental chemistry. It can be performed with both the classic wet methods and instrumental techniques. The development of new methods, and modification of the existing ones, constitute a major task for researchers. Ion chromatography plays a predominant role in ion determinations with the instrumental methods. It offers several advantages over the conventional methods, such as simultaneous determinations of alkali and alkaline earth cations and ammonia. Ammonium ions cannot be determined by spectroscopic methods. Ion chromatography has been accepted world-wide as a reference method for analyzing anions and cations in water and wastewater due to the fact that it enables the replacement of several individual wet chemistry methods for common ions with one instrumental technique. The following article describes the principles of ion chromatography, such as stationary phases, eluents, detectors, and sample preparation methods. Moreover, the applications of ion chromatography in wastewater analyses and international standards are presented.

  3. Development and validation of a spectroscopic method for the ...

    African Journals Online (AJOL)

    Development and validation of a spectroscopic method for the simultaneous analysis of ... advanced analytical methods such as high pressure liquid ..... equipment. DECLARATIONS ... high-performance liquid chromatography. J Chromatogr.

  4. Chromium Speciation Analysis by Ion Chromatography Coupled ...

    African Journals Online (AJOL)

    Two methods coupling ion chromatography with inductively coupled plasma - optical emission spectroscopy (ICP-OES) were developed for the simultaneous separation and determination of Cr(III) and Cr(VI) species. In the first method, anion chromatography with sodium bicarbonate/carbonate solution as the eluent was ...

  5. Development of a Multi-class Steroid Hormone Screening Method using Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS)

    Science.gov (United States)

    Boggs, Ashley S. P.; Bowden, John A.; Galligan, Thomas M.; Guillette, Louis J.; Kucklick, John R.

    2016-01-01

    Monitoring complex endocrine pathways is often limited by indirect measurement or measurement of a single hormone class per analysis. There is a burgeoning need to develop specific direct-detection methods capable of providing simultaneous measurement of biologically relevant concentrations of multiple classes of hormones (estrogens, androgens, progestogens, and corticosteroids). The objectives of this study were to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for multi-class steroid hormone detection using biologically relevant concentrations, then test limits of detection (LOD) in a high-background matrix by spiking charcoal-stripped fetal bovine serum (FBS) extract. Accuracy was tested with National Institute of Standards and Technology Standard Reference Materials (SRMs) with certified concentrations of cortisol, testosterone, and progesterone. 11-Deoxycorticosterone, 11-deoxycortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, adrenosterone, androstenedione, cortisol, corticosterone, dehydroepiandrosterone, dihydrotestosterone, estradiol, estriol, estrone, equilin, pregnenolone, progesterone, and testosterone were also measured using isotopic dilution. Dansyl chloride (DC) derivatization was investigated maintaining the same method to improve and expedite estrogen analysis. Biologically relevant LODs were determined for 15 hormones. DC derivatization improved estrogen response two- to eight-fold, and improved chromatographic separation. All measurements had an accuracy ≤ 14 % difference from certified values (not accounting for uncertainty) and relative standard deviation ≤ 14 %. This method chromatographically separated and quantified biologically relevant concentrations of four hormone classes using highly specific fragmentation patterns and measured certified values of hormones that were previously split into three separate chromatographic methods. PMID:27039201

  6. Determination of maduramicin in feedingstuffs and premixtures by liquid chromatography : development, validation and interlaboratory study

    NARCIS (Netherlands)

    Jong, de J.; Stoisser, B.; Wagner, K.; Tomassen, M.J.H.; Driessen, J.J.M.; Hofman, P.; Putzka, H.A.

    2004-01-01

    A reversed-phase liquid chromatography method for determination of maduramicin in feedingstuffs and premixtures was developed, validated, and interlaboratory studied. The extraction solvent was methanol. Maduramicin was detected at 520 nm after postcolumn derivatization with vanillin. Recovery was

  7. 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

  8. Development and validation of a method for detection and quantification of ochratoxin A in green coffee using liquid chromatography coupled to mass spectrometry

    Directory of Open Access Journals (Sweden)

    Raquel Duarte da Costa Cunha Bandeira

    2012-12-01

    Full Text Available A method using Liquid Chromatography Tanden Mass Spectrometry (LC-MS/MS with matrix-matched calibration curve was developed and validated for determining ochratoxin A (OTA in green coffee. Linearity was found between 3.0 and 23.0 ng.g-1. Mean recoveries ranged between 90.45% and 108.81%; the relative standard deviation under repeatability and intermediate precision conditions ranged from 5.39% to 9.94% and from 2.20% to 14.34%, respectively. The limits of detection and quantification were 1.2 ng.g-1 and 3.0 ng.g-¹, respectively. The method developed was suitable and contributed to the field of mycotoxin analysis, and it will be used for future production of the Certified Reference Material (CRM for OTA in coffee.

  9. Multiple responses optimization in the development of a headspace gas chromatography method for the determination of residual solvents in pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Carla M. Teglia

    2015-10-01

    Full Text Available An efficient generic static headspace gas chromatography (HSGC method was developed, optimized and validated for the routine determination of several residual solvents (RS in drug substance, using a strategy with two sets of calibration. Dimethylsulfoxide (DMSO was selected as the sample diluent and internal standards were used to minimize signal variations due to the preparative step. A gas chromatograph from Agilent Model 6890 equipped with flame ionization detector (FID and a DB-624 (30 m×0.53 mm i.d., 3.00 µm film thickness column was used. The inlet split ratio was 5:1. The influencing factors in the chromatographic separation of the analytes were determined through a fractional factorial experimental design. Significant variables: the initial temperature (IT, the final temperature (FT of the oven and the carrier gas flow rate (F were optimized using a central composite design. Response transformation and desirability function were applied to find out the optimal combination of the chromatographic variables to achieve an adequate resolution of the analytes and short analysis time. These conditions were 30 °C for IT, 158 °C for FT and 1.90 mL/min for F. The method was proven to be accurate, linear in a wide range and very sensitive for the analyzed solvents through a comprehensive validation according to the ICH guidelines. Keywords: Headspace gas chromatography, Residual solvents, Pharmaceuticals, Surface response methodology, Desirability function

  10. Development of an analytical method to quantify total isoflavones in phytotherapic capsules using high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Liliane C. C. Auwerter

    2012-12-01

    Full Text Available Isoflavones can be found in grains and leaves of soybean. Currently, these are sold in pharmacies as phytotherapic capsules. Isoflavones have been recommended by doctors, especially for women, due to their ability to relieve menopause symptoms, among other benefits. However, no method exists for the official control of isoflavone content in capsules sold in the Brazilian market. This study aims to develop an appropriate analytical method to determine the total isoflavone content (daidzin, glycitin, and genistin, and their respective aglycone forms in phytotherapic capsules purchased in pharmacies in Curitiba, Parana State, Brazil, using the technique of high-performance liquid chromatography with UV detection (UV-HPLC. The HPLC system consisted of a quaternary pump, an autosampler, and Waters reversed-phase C18 column (5 μm × 300 mm. Analyses were carried out at 40 °C, using a flow rate of 1.0 mL/min (acetonitrile and acetic acid 0.1%, and detection was performed at 254 nm. The method was validated as required by ANVISA and showed to be reliable for the following parameters: linearity (r² >0.99, selectivity (correlation between 0.99 and 1.00, precision (relative standard derivation <1.59%, accuracy (from 80% to 111.63% intraday and from 80% to 117.88% interday recovery, and robustness.

  11. Development of an analytical method to quantify total isoflavones in phytotherapic capsules using high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Liliane C. C. Auwerter

    2012-10-01

    Full Text Available Isoflavones can be found in grains and leaves of soybean. Currently, these are sold in pharmacies as phytotherapic capsules. Isoflavones have been recommended by doctors, especially for women, due to their ability to relieve menopause symptoms, among other benefits. However, no method exists for the official control of isoflavone content in capsules sold in the Brazilian market. This study aims to develop an appropriate analytical method to determine the total isoflavone content (daidzin, glycitin, and genistin, and their respective aglycone forms in phytotherapic capsules purchased in pharmacies in Curitiba, Parana State, Brazil, using the technique of high-performance liquid chromatography with UV detection (UV-HPLC. The HPLC system consisted of a quaternary pump, an autosampler, and Waters reversed-phase C18 column (5 μm × 300 mm. Analyses were carried out at 40 °C, using a flow rate of 1.0 mL/min (acetonitrile and acetic acid 0.1%, and detection was performed at 254 nm. The method was validated as required by ANVISA and showed to be reliable for the following parameters: linearity (r² >0.99, selectivity (correlation between 0.99 and 1.00, precision (relative standard derivation <1.59%, accuracy (from 80% to 111.63% intraday and from 80% to 117.88% interday recovery, and robustness.

  12. 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.

  13. Simultaneous analysis for water- and fat-soluble vitamins by a novel single chromatography technique unifying supercritical fluid chromatography and liquid chromatography.

    Science.gov (United States)

    Taguchi, Kaori; Fukusaki, Eiichiro; Bamba, Takeshi

    2014-10-03

    Chromatography techniques usually use a single state in the mobile phase, such as liquid, gas, or supercritical fluid. Chromatographers manage one of these techniques for their purpose but are sometimes required to use multiple methods, or even worse, multiple techniques when the target compounds have a wide range of chemical properties. To overcome this challenge, we developed a single method covering a diverse compound range by means of a "unified" chromatography which completely bridges supercritical fluid chromatography and liquid chromatography. In our method, the phase state was continuously changed in the following order; supercritical, subcritical and liquid. Moreover, the gradient of the mobile phase starting at almost 100% CO2 was replaced with 100% methanol at the end completely. As a result, this approach achieved further extension of the polarity range of the mobile phase in a single run, and successfully enabled the simultaneous analysis of fat- and water-soluble vitamins with a wide logP range of -2.11 to 10.12. Furthermore, the 17 vitamins were exceptionally separated in 4min. Our results indicated that the use of dense CO2 and the replacement of CO2 by methanol are practical approaches in unified chromatography covering diverse compounds. Additionally, this is a first report to apply the novel approach to unified chromatography, and can open another door for diverse compound analysis in a single chromatographic technique with single injection, single column and single system. Copyright © 2014. Published by Elsevier B.V.

  14. Analytical method development for the determination of emerging contaminants in water using supercritical-fluid chromatography coupled with diode-array detection.

    Science.gov (United States)

    Del Carmen Salvatierra-Stamp, Vilma; Ceballos-Magaña, Silvia G; Gonzalez, Jorge; Ibarra-Galván, Valentin; Muñiz-Valencia, Roberto

    2015-05-01

    An analytical method using supercritical-fluid chromatography coupled with diode-array detection for the determination of seven emerging contaminants-two pharmaceuticals (carbamazepine and glyburide), three endocrine disruptors (17α-ethinyl estradiol, bisphenol A, and 17β-estradiol), one bactericide (triclosan), and one pesticide (diuron)-was developed and validated. These contaminants were chosen because of their frequency of use and their toxic effects on both humans and the environment. The optimized chromatographic separation on a Viridis BEH 2-EP column achieved baseline resolution for all compounds in less than 10 min. This separation was applied to environmental water samples after sample preparation. The optimized sample treatment involved a preconcentration step by means of solid-phase extraction using C18-OH cartridges. The proposed method was validated, finding recoveries higher than 94 % and limits of detection and limits of quantification in the range of 0.10-1.59 μg L(-1) and 0.31-4.83 μg L(-1), respectively. Method validation established the proposed method to be selective, linear, accurate, and precise. Finally, the method was successfully applied to environmental water samples.

  15. Two-step Purification Method for Aging Pigments A2E and Iso-A2E Using Medium Pressure Liquid Chromatography

    International Nuclear Information System (INIS)

    Park, Sang Il; Park, Sang Cheol; Kim, So Ra; Jang, Young Pyo

    2016-01-01

    A newly modified method for the efficient purification of A2E and iso-A2E using reverse phase silica gel resin with medium pressure liquid chromatography (MPLC) was suggested. MPLC is one of the various preparative column chromatography techniques and separation under pressure renders the use of smaller particle size resins possible and increases the diversity of available stationary phases. A simplified two-step purification method was developed for the purification of aging pigments in eye, A2E and iso-A2E. With simple two-step elution of mobile phase in reverse phase MPLC, A2E and iso-A2E were successfully purified with great efficiency compare with previous column chromatography and HPLC method. This method provides more simple, convenient, cost-effective, and less time-consuming procedure for mass purification of aging pigments A2E and iso-A2E

  16. Two-step Purification Method for Aging Pigments A2E and Iso-A2E Using Medium Pressure Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Il; Park, Sang Cheol [Kyunghee Univ., Seoul (Korea, Republic of); Kim, So Ra; Jang, Young Pyo [Seoul National Univ., Seoul (Korea, Republic of)

    2016-09-15

    A newly modified method for the efficient purification of A2E and iso-A2E using reverse phase silica gel resin with medium pressure liquid chromatography (MPLC) was suggested. MPLC is one of the various preparative column chromatography techniques and separation under pressure renders the use of smaller particle size resins possible and increases the diversity of available stationary phases. A simplified two-step purification method was developed for the purification of aging pigments in eye, A2E and iso-A2E. With simple two-step elution of mobile phase in reverse phase MPLC, A2E and iso-A2E were successfully purified with great efficiency compare with previous column chromatography and HPLC method. This method provides more simple, convenient, cost-effective, and less time-consuming procedure for mass purification of aging pigments A2E and iso-A2E.

  17. Constructing a LabVIEW-Controlled High-Performance Liquid Chromatography (HPLC) System: An Undergraduate Instrumental Methods Exercise

    Science.gov (United States)

    Smith, Eugene T.; Hill, Marc

    2011-01-01

    In this laboratory exercise, students develop a LabVIEW-controlled high-performance liquid chromatography system utilizing a data acquisition device, two pumps, a detector, and fraction collector. The programming experience involves a variety of methods for interface communication, including serial control, analog-to-digital conversion, and…

  18. Analytical Method Development and Validation for the Simultaneous Estimation of Abacavir and Lamivudine by Reversed-phase High-performance Liquid Chromatography in Bulk and Tablet Dosage Forms.

    Science.gov (United States)

    Raees Ahmad, Sufiyan Ahmad; Patil, Lalit; Mohammed Usman, Mohammed Rageeb; Imran, Mohammad; Akhtar, Rashid

    2018-01-01

    A simple rapid, accurate, precise, and reproducible validated reverse phase high performance liquid chromatography (HPLC) method was developed for the determination of Abacavir (ABAC) and Lamivudine (LAMI) in bulk and tablet dosage forms. The quantification was carried out using Symmetry Premsil C18 (250 mm × 4.6 mm, 5 μm) column run in isocratic way using mobile phase comprising methanol: water (0.05% orthophosphoric acid with pH 3) 83:17 v/v and a detection wavelength of 245 nm and injection volume of 20 μl, with a flow rate of 1 ml/min. In the developed method, the retention times of ABAC and LAMI were found to be 3.5 min and 7.4 min, respectively. The method was validated in terms of linearity, precision, accuracy, limits of detection, limits of quantitation, and robustness in accordance with the International Conference on Harmonization guidelines. The assay of the proposed method was found to be 99% - 101%. The recovery studies were also carried out and mean % recovery was found to be 99% - 101%. The % relative standard deviation from reproducibility was found to be performance liquid chromatography, UV: Ultraviolet, ICH: International Conference on Harmonization, ABAC: Abacavir, LAMI: Lamivudine, HIV: Human immunodeficiency virus, AIDS: Acquired immunodeficiency syndrome, NRTI: Nucleoside reverse transcriptase inhibitors, ARV: Antiretroviral, RSD: Relative standard deviation, RT: Retention time, SD: Standard deviation.

  19. Method development and validation for the determination of pesticides in green coffee by gas chromatography

    International Nuclear Information System (INIS)

    Dallos Corredor, David; Guerrero Dallos, Jairo Arturo

    2005-01-01

    This study describes the implementation and validation of a multiresidue methodology for the determination of organochlorine, organophosphorus and pyrethroids pesticides in green coffee. Pesticides residues were extracted from green samples with an acetone-water (2:1) mixture followed by ethyl acetate cyclohexane (1:1) partitioning. The clean up steps include gel permeation chromatography and mini column chromatography using silica gel. Final determination was carried out by high-resolution gas chromatography with a pulsed split less injection mode and simultaneous detection by μ-ECD and NPD coupled in parallel. The methodology is specific, selective precise and accurate. Recoveries of majority of pesticides from spiked samples range from 70 to 110% at fortification levels of 0.038 mg/kg-1.536 mg/kg with limit of quantitation between 0.011 mg/kg and 0.100 mg/kg

  20. Development of a multiresidue method for the determination of endocrine disrupters in fish fillet using gas chromatography-triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Munaretto, Juliana S; Ferronato, Giovana; Ribeiro, Lucila C; Martins, Manoel L; Adaime, Martha B; Zanella, Renato

    2013-11-15

    Endocrine Disrupter Compounds (EDCs) are responsible for alterations in the endocrine system functions. Aquatic organisms are able to accumulate EDCs residues, being the major source of contamination for top predators and human consumers. This study aimed to develop and validate a method for the determination of 40 EDCs in fish fillet using modified QuEChERS and Gas Chromatography coupled with Mass Spectrometry in tandem (GC-MS/MS). A factorial design was used to optimize the extraction procedure. Method validation presented recoveries from 70.1% to 120.0% with RSDfish fillet from different species and residues of bisphenol A, chlorpyrifos and bifenthrin were detected. The proposed method proved to be effective for the determination of EDCs in fish fillet at very low concentration levels. © 2013 Elsevier B.V. All rights reserved.

  1. Amphenicols stability in medicated feed – development and validation of liquid chromatography method

    Directory of Open Access Journals (Sweden)

    Pietro Wojciech Jerzy

    2014-12-01

    Full Text Available A liquid chromatography-ultraviolet detection method for the determination of florfenicol (FF and thiamphenicol (TAP in feeds is presented. The method comprises the extraction of analytes from the matrix with a mixture of methanol and acetonitrile, drying of the extract, and its dissolution in phosphate buffer. The analysis was performed with a gradient programme of the mobile phase composed of acetonitrile and buffer (pH = 7.3 on a Zorbax Eclipse Plus C18 (150 × 4.6 mm, 5 μm analytical column with UV (λ = 220 nm detection. The analytical procedure has been successfully adopted and validated for quantitative determination of florfenicol and thiamphenicol in feed samples. Sensitivity, specificity, linearity, repeatability, and intralaboratory reproducibility were included in the validation. The mean recovery of amphenicols was 93.5% within the working range of 50-4000 mg/kg. Simultaneous determination of chloramphenicol, which is banned in the feed, was also included within the same procedure of FF and TAP stability studies. Storing the medicated feed at room temperature for up to one month decreased concentration in the investigated drugs even by 45%. These findings are relevant to successful provision of therapy to animals.

  2. Development of Extraction Methods for the Analysis of Perfluorinated Compounds in Leather with High Performance Liquid Chromatography Tandem Mass Spectrometry

    Science.gov (United States)

    Zhang, Yan; Wang, Youchao; Tang, Chuanjiang; Nie, Jingmei; Xu, Chengtao

    2018-01-01

    Perfluorinated compounds (PFCs), used to provide water, oil, grease, heat and stain repellency to a range of textile and other products, have been found to be persistent in the environment and are associated with adverse effects on humans and wildlife. This study presents the development and validation of an analytical method to determine the simultaneous presence of eleven PFCs in leather using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The perfluorinated compounds were primarily extracted from the samples by a liquid extraction procedure by ultrasonic, in which the parameters were optimized. Then the solid-phase extraction (SPE) is the most important advantages of the developed methodology. The sample volume and elution conditions were optimized by means of an experimental design. The proposed method was applied to determine the PFCs in leather, where the detection limits of the eleven compounds were 0.09-0.96 ng/L, and the recoveries of all compounds spiked at 5 ng/L concentration level were in the range of 65-96%, with a better RSD lower than 19% (n = 7).

  3. Development of QuEChERS-based extraction and liquid chromatography-tandem mass spectrometry method for quantifying flumethasone residues in beef muscle.

    Science.gov (United States)

    Park, Ki Hun; Choi, Jeong-Heui; Abd El-Aty, A M; Cho, Soon-Kil; Park, Jong-Hyouk; Kwon, Ki Sung; Park, Hee Ra; Kim, Hyung Soo; Shin, Ho-Chul; Kim, Mi Ra; Shim, Jae-Han

    2012-12-01

    A rapid, specific, and sensitive method based on liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) in the positive ion mode using multiple reaction monitoring (MRM) was developed and validated to quantify flumethasone residues in beef muscle. Methods were compared between the original as well as the EN quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based extraction. Good linearity was achieved at concentration levels of 5-30 μg/kg. Estimated recovery rates at spiking levels of 5 and 10 μg/kg ranged from 72.1 to 84.6%, with relative standard deviations (RSDs)noise ratios (S/Ns) of 3 and 10, respectively. The method was successfully applied to analyze real samples obtained from large markets throughout the Korean Peninsula. The method proved to be sensitive and reliable and, thus, rendered an appropriate means for residue analysis studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Main Achievements 2003-2004 - Interdisciplinary Research - Radiation detection methods for health, earth and environmental sciences - Detection methods in gas chromatography

    International Nuclear Information System (INIS)

    2005-01-01

    Detection methods in gas chromatography are under development, especially ultra-sensitive gas chromatography detection methods to monitor the atmosphere (with respect to gases active in the destruction of the Earth ozone layer). A new chromatographic method has been elaborated for Ne determination, and technique for determination of Ar and N 2 in groundwater has been significantly improved. Measurements of neon are performed by means of a chromatographic system equipped with a helium ionization detector (PD-HID) doped with neon pulse discharge, working with a modified sample introduction system. The Ar and N 2 contents are determined by a thermal-conductivity detector (TCD). The problem of separation of Ar from O 2 has been solved by catalytic removal of the latter from the sample. The measurement reproducibility is 1%, 2% and 0.5% for Ar, Ne and N 2 , respectively. Both methods were successfully applied in measurements of groundwaters in the Cracow area. The excess air contents are in the range of about 1 to 3 cm 3 STP L-1. The values of recharge temperatures for Holocen water agree reasonably well with the yearly mean long-term surface air temperature (8.2 o C)

  5. Development of multi-residue method for the determination of pesticides in cereal matrices by isotopic dilution associated to liquid chromatography coupled to tandem mass spectrometry after pressurized liquid extraction

    International Nuclear Information System (INIS)

    El Mrabet, Khadija

    2008-01-01

    Pesticides are nowadays considered as toxic for human health. The maximal residues levels authorized in water and foodstuff are more and more strict. Therefore, selective analytical techniques are necessary for their identification and their quantification. The aim of this thesis was to develop a multi-residue method for the determination of pesticides by isotopic dilution associated to liquid chromatography (LC) coupled with tandem mass spectrometry (MS"2) after pressurized liquid extraction. In a first step, an analysis method of phenyl-ureas and triazines in groundwater by isotopic dilution associated to LC/MS"2 after solid phase extraction has been developed. The method has been validated and evaluated by participating to an inter-laboratory study. Concerning cereals, an extraction method of pesticides associated to an analysis by LC/MS"2 has been developed for thirty-eight pesticides representative of twenty-six chemicals families and fourteen labeled compounds in wheat. The analysis has been carried out in reversed phase chromatography. Separation and detection conditions have been optimized. A global analytical protocol consisting of a pressurized liquid extraction step using acetonitrile at 100 deg. C and at 100 bars and followed by purification step of the resulting extract on a polymeric sorbent was developed. The developed method enables to extract thirty-eight pesticides and fourteen labeled compounds from wheat with recovery yield about 85% (RSD =4%, n=3). Moreover, the results show that the application of isotopic dilution can be complex. Although some improvements need to be added regarding experimentation of aged matrices or contaminated samples, the potential of the method has been demonstrated. (author) [fr

  6. Development of a method to extract and purify target compounds from medicinal plants in a single step: online hyphenation of expanded bed adsorption chromatography and countercurrent chromatography.

    Science.gov (United States)

    Li, Yang; Wang, Nan; Zhang, Min; Ito, Yoichiro; Zhang, Hongyang; Wang, Yuerong; Guo, Xin; Hu, Ping

    2014-04-01

    Pure compounds extracted and purified from natural sources are crucial to lead discovery and drug screening. This study presents a novel two-dimensional hyphenation of expanded bed adsorption chromatography (EBAC) and high-speed countercurrent chromatography (HSCCC) for extraction and purification of target compounds from medicinal plants in a single step. The EBAC and HSCCC were hyphenated via a six-port injection valve as an interface. Fractionation of ingredients of Salvia miltiorrhiza and Rhizoma coptidis was performed on the hyphenated system to verify its efficacy. Two compounds were harvested from Salvia miltiorrhiza, one was 52.9 mg of salvianolic acid B with an over 95% purity and the other was 2.1 mg of rosmarinic acid with a 74% purity. Another two components were purified from Rhizoma coptidis, one was 4.6 mg of coptisine with a 98% purity and one was 4.1 mg of berberine with a 82% purity. The processing time was nearly 50% that of the multistep method. The results indicate that the present method is a rapid and green way to harvest targets from medicinal plants in a single step.

  7. Osteoblast cell membrane chromatography coupled with liquid chromatography and time-of-flight mass spectrometry for screening specific active components from traditional Chinese medicines.

    Science.gov (United States)

    Wang, Nani; Zhang, Qiaoyan; Xin, Hailiang; Shou, Dan; Qin, Luping

    2017-11-01

    A method using osteoblast membrane chromatography coupled with liquid chromatography and time-of-flight mass spectrometry was developed to recognize and identify the specific active components from traditional Chinese medicines. Primary rat osteoblasts were used for the preparation of the stationary phase in the cell chromatography method. Retention components from the cell chromatography were collected and analyzed by liquid chromatography with time-of-flight mass spectrometry. This method was applied in screening active components from extracts of four traditional Chinese medicines. In total, 24 potentially active components with different structures were retained by osteoblast cell chromatography. There were five phenolic glucosides and one triterpenoid saponin from Curculigo orchioides Gaertn, two organic acids and ten flavonoids from Epimedium sagittatum Maxim, one phthalide compound and one organic acid from Angelica sinensis Diels, and two flavonoids and two saponins from Anemarrhena asphodeloides Bunge. Among those, four components (icariin, curculigoside, ferulaic acid, and timosaponin BII) were used for in vitro pharmacodynamics validation. They significantly increased the osteoblast proliferation, alkaline phosphatase activity, levels of bone gla protein and collagen type 1, and promoted mineralized nodule formation. The developed method was an effective screening method for finding active components from complex medicines that act on bone diseases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Analysis of lignans in Magnoliae Flos by turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Xuan; Chen, Cen; Ye, Xiaolan; Song, Fenyun; Fan, Guorong; Wu, Fuhai

    2016-04-01

    In this study, a method coupling turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry was developed for analyzing the lignans in Magnoliae Flos. By the online pretreatment of turbulent flow chromatography solid-phase extraction, the impurities removal and analytes concentration were automatically processed, and the lignans were separated rapidly and well. Seven lignans of Magnoliae Flos including epieudesmin, magnolin, 1-irioresinol-B-dimethyl ether, epi-magnolin, fargesin aschantin, and demethoxyaschantin were identified by comparing their retention behavior, UV spectra, and mass spectra with those of reference substances or literature data. The developed method was validated, and the good results showed that the method was not only automatic and rapid, but also accurate and reliable. The turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry method holds a high potential to become an effective method for the quality control of lignans in Magnoliae Flos and a useful tool for the analysis of other complex mixtures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Development of liquid chromatography-tandem mass spectrometry methods for the quantitation of Anisakis simplex proteins in fish.

    Science.gov (United States)

    Fæste, Christiane Kruse; Moen, Anders; Schniedewind, Björn; Haug Anonsen, Jan; Klawitter, Jelena; Christians, Uwe

    2016-02-05

    The parasite Anisakis simplex is present in many marine fish species that are directly used as food or in processed products. The anisakid larvae infect mostly the gut and inner organs of fish but have also been shown to penetrate into the fillet. Thus, human health can be at risk, either by contracting anisakiasis through the consumption of raw or under-cooked fish, or by sensitisation to anisakid proteins in processed food. A number of different methods for the detection of A. simplex in fish and products thereof have been developed, including visual techniques and PCR for larvae tracing, and immunological assays for the determination of proteins. The recent identification of a number of anisakid proteins by mass spectrometry-based proteomics has laid the groundwork for the development of two quantitative liquid chromatography-tandem mass spectrometry methods for the detection of A. simplex in fish that are described in the present study. Both, the label-free semi-quantitative nLC-nESI-Orbitrap-MS/MS (MS1) and the heavy peptide-applying absolute-quantitative (AQUA) LC-TripleQ-MS/MS (MS2) use unique reporter peptides derived from anisakid hemoglobin and SXP/RAL-2 protein as analytes. Standard curves in buffer and in salmon matrix showed limits of detection at 1μg/mL and 10μg/mL for MS1 and 0.1μg/mL and 2μg/mL for MS2. Preliminary method validation included the assessment of sensitivity, repeatability, reproducibility, and applicability to incurred and naturally-contaminated samples for both assays. By further optimization and full validation in accordance with current recommendations the LC-MS/MS methods could be standardized and used generally as confirmative techniques for the detection of A. simplex protein in fish. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Determination of 2-naphthylamine in urine by a novel reversed-phase high-performance liquid chromatography method

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Poulsen, O M; Christensen, J M

    1992-01-01

    A high-performance liquid chromatographic method for the determination of 2-naphthylamine in urine using fluorescence detection was developed. The method validation analysis showed the method to be in analytical control, i.e. the distribution of the difference between the observed and true values...... of the method evaluation samples did not deviate significantly from the normal distribution. The recovery of the method was 85%. The entire run time of chromatography was 10 min using isocratic elution (acetonitrile-water, 35:65), and the retention time for 2-naphthylamine was 5.8 min. The relative short time...

  11. A reversed-phase high-performance liquid chromatography method for the determination of cotrimoxazole (trimethoprim/ sulphamethoxazole) in children treated for malaria

    DEFF Research Database (Denmark)

    Rønn, A M; Mutabingwa, T K; Kreisby, S

    1999-01-01

    A high-performance liquid chromatography (HPLC) method was developed for the simultaneous analysis of trimethoprim (TMP), sulphamethoxazole (SMX), and acetylsulphamethoxazole (AcSMX) in small amounts of blood. The method involved precipitation with 50 microL trichloracetic acid (1M) to 125 micro...

  12. Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

    International Nuclear Information System (INIS)

    Mihucz, Victor G.; Moricz, Agnes M.; Kroepfl, Krisztina; Szikora, Szilvia; Tatar, Eniko; Parra, Lue Meru Marco; Zaray, Gyula

    2006-01-01

    Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods

  13. Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

    Energy Technology Data Exchange (ETDEWEB)

    Mihucz, Victor G. [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); Moricz, Agnes M. [L. Eoetvoes University, Department of Chemical Technology and Environmental Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Kroepfl, Krisztina [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Szikora, Szilvia [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Tatar, Eniko [Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Parra, Lue Meru Marco [Universidad Centro-occidental Lisandro Alvarado, Decanato de Agronomia, Departamento de Quimica y Suelos Unidad de Analisis Instrumental, Apartado Postal 4076, Cabudare 3023 (Venezuela); Zaray, Gyula [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary) and Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary) and L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary)]. E-mail: zaray@ludens.elte.hu

    2006-11-15

    Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods.

  14. DETERMINATION OF RUTIN IN LEAVES OF SALIX TRIANDRA USING THE METHOD OF PLANAR CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    E. G. Sannikova

    2016-01-01

    Full Text Available The aim of the study is to develop new methods of identification and quantitative determination of rutin in the leaves of Salix triandra L. with thin-layer chromatography. The digital processing of the chromatograms was performed using «Sorbfil Videodensitometer» computer program (Krasnodar. For the chromatography analysis we used plates «Sorbfil» PTSH-P-A-UV, mobile phase: n-butanol-glacial acetic acid-water (4:1:1, detecting reagent – ammonia vapors. The rutin is detected as yellow spots with Rf 0.64±0.02. The detection limit is 0.5 μg/μl. The regression equation has the form: S=4.75×103 m. With the use of this method we found that the composition of rutin in leaves of Salix triandra was in the range 1.81±0.06% on the air-dry raw material (relative standard deviation RSD%=2.5%; the measurement error E=3.12%. The method is sensitive, linear, has a small error, and does not require expensive equipment.

  15. Method development for the analysis of 1,4-dioxane in drinking water using solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Grimmett, Paul E; Munch, Jean W

    2009-01-01

    1,4-Dioxane has been identified as a probable human carcinogen and an emerging contaminant in drinking water. The United States Environmental Protection Agency's (U.S. EPA) National Exposure Research Laboratory (NERL) has developed a method for the analysis of 1,4-dioxane in drinking water at ng/L concentrations. The method consists of an activated carbon solid-phase extraction of 500-mL or 100-mL water samples using dichloromethane as the elution solvent. The extracts are analyzed by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. In the NERL laboratory, recovery of 1,4-dioxane ranged from 94-110% in fortified laboratory reagent water and recoveries of 96-102% were demonstrated for fortified drinking water samples. The relative standard deviations for replicate analyses were less than 6% at concentrations exceeding the minimum reporting level.

  16. Quantitative bioanalytical and analytical method development of dibenzazepine derivative, carbamazepine: A review

    Directory of Open Access Journals (Sweden)

    Prasanna A. Datar

    2015-08-01

    Full Text Available Bioanalytical methods are widely used for quantitative estimation of drugs and their metabolites in physiological matrices. These methods could be applied to studies in areas of human clinical pharmacology and toxicology. The major bioanalytical services are method development, method validation and sample analysis (method application. Various methods such as GC, LC–MS/MS, HPLC, HPTLC, micellar electrokinetic chromatography, and UFLC have been used in laboratories for the qualitative and quantitative analysis of carbamazepine in biological samples throughout all phases of clinical research and quality control. The article incorporates various reported methods developed to help analysts in choosing crucial parameters for new method development of carbamazepine and its derivatives and also enumerates metabolites, and impurities reported so far. Keywords: Carbamazepine, HPLC, LC–MS/MS, HPTLC, RP-UFLC, Micellar electrokinetic chromatography

  17. Purification of lignans from Fructus Arctii using off-line two-dimensional supercritical fluid chromatography/reversed-phase liquid chromatography.

    Science.gov (United States)

    Yang, Bichao; Xin, Huaxia; Wang, Feier; Cai, Jianfeng; Liu, Yanfang; Fu, Qing; Jin, Yu; Liang, Xinmiao

    2017-08-01

    As a common traditional Chinese medicine, Fructus Arctii has important clinical medical values. Its main components are lignans, which are difficult to separate and analyze because of the complex composition, similar chemical structures, and close properties. In this study, an off-line two-dimensional supercritical fluid chromatography/reversed-phase liquid chromatography method, as well as an effective sample pretreatment method based on hydrophilic interaction chromatography material, was developed to enrich the minor lignan fractions and obtain high-purity compounds. In total, 12 high-purity compounds were isolated from Fructus Arctii. Their structures were identified by using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy, which showed that all were lignans and that most of them were isomers. The results demonstrated the effective off-line two-dimensional supercritical fluid chromatography/reversed-phase liquid chromatography method for the purification of lignans from Fructus Arctii. The separation protocol established here will be beneficial for the separation of complex samples from other kinds of natural products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Q Sepharose micro-column chromatography: A simple screening method for identifying beta thalassemia traits and hemoglobin E carriers.

    Science.gov (United States)

    Wong, Peerapon; Sritippayawan, Suchila; Suwannakhon, Narutchala; Tapprom, Akamon; Deoisares, Rawisut; Sanguansermsri, Torpong

    2016-11-01

    For beta thalassemia control program in pregnancy, mass screening of the carrier state by determination of the hemoglobin (Hb) A 2 and Hb E proportions and mutation analysis is a preferred method for making prenatal diagnoses. Q Sepharose micro-column chromatography, developed for the determination of Hb A 2 and Hb E for screening purposes, was compared with high performance liquid chromatography (HPLC) to ascertain its relative accuracy and reliability. Results using Q Sepharose micro-column chromatography in 350 blood specimens, including 50 samples genetically proven to be beta thalassemia heterozygotes, were compared to HPLC for validation. An additional study was conducted to test a clinical application on a large-scale survey for beta thalassemia in 1581 pregnant women and their spouses. The mean (±SD) Hb A 2 proportions in the normal and genetically proven beta thalassemia heterozygotes were 2.70±0.40% and 6.30±1.23%, respectively, as determined by Q-Sepharose micro-column chromatography, and 2.65±0.31% and 5.37±0.96%, respectively, as determined by HPLC. The mean Hb E proportions in the Hb E heterozygotes were 23.25±4.13% and 24.72±3.5% as determined by Q Sepharose micro-column chromatography and HPLC, respectively. In the large-scale survey for beta thalassemia, 23 at risk couples were detected. Seven affected fetuses were identified by prenatal diagnosis. Q Sepharose micro-column chromatography was found to be reliable, reproducible and well-suited for large-scale surveys. Additionally, by being reusable and convenient, this simple and economical chromatography method may be an alternative means to screen for beta thalassemia and Hb E carriers in the mass population. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  19. A simple high performance liquid chromatography method for analyzing paraquat in soil solution samples.

    Science.gov (United States)

    Ouyang, Ying; Mansell, Robert S; Nkedi-Kizza, Peter

    2004-01-01

    A high performance liquid chromatography (HPLC) method with UV detection was developed to analyze paraquat (1,1'-dimethyl-4,4'-dipyridinium dichloride) herbicide content in soil solution samples. The analytical method was compared with the liquid scintillation counting (LSC) method using 14C-paraquat. Agreement obtained between the two methods was reasonable. However, the detection limit for paraquat analysis was 0.5 mg L(-1) by the HPLC method and 0.05 mg L(-1) by the LSC method. The LSC method was, therefore, 10 times more precise than the HPLC method for solution concentrations less than 1 mg L(-1). In spite of the high detection limit, the UC (nonradioactive) HPLC method provides an inexpensive and environmentally safe means for determining paraquat concentration in soil solution compared with the 14C-LSC method.

  20. Validation of a high-performance liquid chromatography/fluorescence detection method for the simultaneous quantification of fifteen polycyclic aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Olsen, I L; Holst, E

    1991-01-01

    A high-performance liquid chromatography/fluorescence method using multiple wavelength shift for simultaneous quantification of different PAH compounds was developed. The new method was superior to the methods of DONG and GREENBERG [J. Liquid Chromatogr. 11, 1887-1905 (1988)] and WISE et al...... that no systematic errors, and only small unsystematic errors, could be demonstrated. Furthermore, the method had a good reproducibility and a high sensitivity....

  1. Airtight miniaturized chromatography: a safer method for radiopharmaceutical quality control

    International Nuclear Information System (INIS)

    Coupal, J.J.; Shih, W.J.; Ryo, U.Y.

    1988-01-01

    Miniaturized chromatography is widely used for quality control of radiopharmaceuticals. Recently, published chromatography procedures have illustrated or described chromatography chambers open to the air in use, suggesting that volatile toxic mobile phases are harmless to people in the vicinity. The authors describe the results of their search for an inexpensive closed chromatography chamber that can be used to derive safely the benefits from conventional miniaturized chromatography

  2. Sensitive method for the analysis of carbohydrates by gas chromatography of 3H-labeled alditol acetates

    International Nuclear Information System (INIS)

    Prehm, P.; Scheid, A.

    1978-01-01

    A highly sensitive method has been developed for the analysis of carbohydrates from glycoproteins or lipopolysaccharides. The method is based on labeling the carbohydrates with [ 3 H] sodium borohydride, acetylating the resulting alditols and separating them by gas chromatography. The gas effluent is fractionated by trapping on silicone-coated glass beads and the amount of radioactivity is determined. This permits the quantitation of as little as 0.2 nmoles monosaccharide with an accuracy of 10 to 15%. (Auth)

  3. The analysis of carbohydrates in milk powder by a new "heart-cutting" two-dimensional liquid chromatography method.

    Science.gov (United States)

    Ma, Jing; Hou, Xiaofang; Zhang, Bing; Wang, Yunan; He, Langchong

    2014-03-01

    In this study, a new"heart-cutting" two-dimensional liquid chromatography method for the simultaneous determination of carbohydrate contents in milk powder was presented. In this two dimensional liquid chromatography system, a Venusil XBP-C4 analysis column was used in the first dimension ((1)D) as a pre-separation column, a ZORBAX carbohydrates analysis column was used in the second dimension ((2)D) as a final-analysis column. The whole process was completed in less than 35min without a particular sample preparation procedure. The capability of the new two dimensional HPLC method was demonstrated in the determination of carbohydrates in various brands of milk powder samples. A conventional one dimensional chromatography method was also proposed. The two proposed methods were both validated in terms of linearity, limits of detection, accuracy and precision. The comparison between the results obtained with the two methods showed that the new and completely automated two dimensional liquid chromatography method is more suitable for milk powder sample because of its online cleanup effect involved. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  4. A method for fast determination of psoralens in oral solutions of phytomedicines using liquid chromatography.

    Science.gov (United States)

    Pires, Adriana Elias; Honda, Neli Kiko; Cardoso, Cláudia Andréa Lima

    2004-10-29

    A method for sample preparation and analysis by high performance liquid chromatography with UV detection (HPLC-UV) has been developed for routine analysis of psoralen and bergapten, photosensitizing compounds, in oral solutions of phytomedicines employed in Brazil for some illnesses. The linearity, accuracy, the inter- and intra-day precision of the procedure were evaluated. Calibration curves for psoralen and bergapten were linear in the range of 1.0-600.0 microg ml(-1) and 1.0-400.0 microg ml(-1) respectively. The recoveries of the psoralens in the oral solutions analysed were 94.43-99.97%. The percentage coefficient of variation (CV) of the quantitative analysis of the psoralens in the products analysis was within 5%. In inter-equipment study was employed gas chromatography-flame ionization (CG-FID) detection.

  5. Development of a Supercritical Fluid Chromatography-Tandem Mass Spectrometry Method for the Determination of Azacitidine in Rat Plasma and Its Application to a Bioavailability Study

    Directory of Open Access Journals (Sweden)

    Dongpo Li

    2013-12-01

    Full Text Available Azacitidine is widely used for the treatment of myelodysplastic syndromes (MDS and acute myelogenous leukaemia (AML. The analysis of azacitidine in biological samples is subject to interference by endogenous compounds. Previously reported high-performance liquid chromatography/tandem mass spectrometric (HPLC-MS/MS bioanalytical assays for azacitidine suffer from expensive sample preparation procedures or from long separation times to achieve the required selectivity. Herein, supercritical fluid chromatography with tandem mass spectrometry (SFC-MS/MS was explored as a more promising technique for the selective analysis of structure-like or chiral drugs in biological matrices. In this study, a simple, rapid and specific SFC/MS/MS analytical method was developed for the determination of azacitidine levels in rat plasma. Azacitidine was completely separated from the endogenous compounds on an ACQUITY UPLC™ BEH C18 column (100 mm × 3.0 mm, 1.7 μm; Waters Corp., Milford, MA, USA using isocratic elution with CO2/methanol as the mobile phase. The single-run analysis time was as short as 3.5 min. The sample preparation for protein removal was accomplished using a simple methanol precipitation method. The lower limit of quantification (LLOQ of azacitidine was 20 ng/mL. The intra-day and inter-day precisions were less than 15%, and the relative error (RE was within ±15% for the medium- and high-concentration quality control (QC samples and within ±20% for the low-concentration QC samples. Finally, the developed method was successfully applied to a pharmacokinetic study in rats following the intravenous administration of azacitidine.

  6. Development of headspace solid-phase microextraction method for ...

    African Journals Online (AJOL)

    A headspace solid-phase microextraction (HS-SPME) method was developed as a preliminary investigation using univariate approach for the analysis of 14 multiclass pesticide residues in fruits and vegetable samples. The gas chromatography mass spectrometry parameters (desorption temperature and time, column flow ...

  7. Novel method for measurement of glutathione kinetics in neonates using liquid chromatography coupled to isotope ratio mass spectrometry

    NARCIS (Netherlands)

    Schierbeek, Henk; te Braake, Frans; Godin, Jean-Philippe; Fay, Laurent-Bernard; van Goudoever, Johannes B.

    2007-01-01

    A novel analytical method using liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS) was developed for measuring the fractional synthesis rate (FSR) of glutathione (GSH) in neonates after infusion of [1-(13)C]-glycine as a tracer. After transformation of GSH into GSSG, its

  8. Development of anion-exchange/reversed-phase high performance liquid chromatography-inductively coupled plasma-mass spectrometry methods for the speciation of bio-available iodine and bromine from edible seaweed.

    Science.gov (United States)

    Romarís-Hortas, Vanessa; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2012-05-04

    Anion exchange high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry has been novelly applied to assess inorganic (iodide and iodate) and organic (3-iodotyrosine - MIT, and 3,5-diiodotyrosine - DIT) iodine species in a single chromatographic run. The optimized operating conditions (Dionex IonPac AS7, gradient elution with 175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase and flow rates within the 0.5-1.5 mL min(-1) range) have also been used to perform inorganic bromine speciation analysis (bromide and bromate). The developed method has been applied for determining the bio-available contents of iodine and bromine species in dialyzates from edible seaweed. Reverse phase high performance liquid chromatography (Zorbax Eclipse XDB-C8, gradient elution with 0.2% (m/m) acetic acid, and 0.2% (m/m) acetic acid in methanol, as mobile phases, and a constant flow rate of 0.75 mL min(-1)) also hyphenated with inductively coupled plasma-mass spectrometry was used to confirm the presence of organic iodine species (MIT and DIT) in the dialyzates. The verification of the presence of iodinated amino acids (MIT and DIT) in the extracts was also performed by reverse phase high performance liquid chromatography-electrospray ionization-mass spectrometry (LTQ Orbitrap). The developed methods have provided good repeatability (RSD values lower than 10% for both anion exchange and reverse phase separations) and analytical recoveries within the 90-105% range for all cases. The in vitro bio-availability method consisted of a simulated gastric and an intestinal digestion/dialysis (10 kDa molecular weight cut-off - MWCO) two-stage procedure. Iodide and MIT were the main bio-available species quantified, whereas bromide was the major bromine species found in the extracts. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Comparative determination of phenytoin by spectrophotometry, gas chromatography, liquid chromatography, enzyme immunoassay, and radioimmunoassay

    International Nuclear Information System (INIS)

    Castro, A.; Ibanez, J.; DiCesare, J.L.; Adams, R.F.; Malkus, H.

    1978-01-01

    Sera from patients being treated with phenytoin were analyzed for the drug by spectrophotometry, gas chromatography, radioimmunoasay, enzyme immunoassay, and liquid chromatography. The assay values obtained were intercompared statistically. Enzyme immunoassay and liquid chromatography appear to be attractive alternatives to the more traditional methods of spectrophotometry and gas chromatography. Our radioimmunoassay data correlated poorly with results by the four other methods

  10. 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...

  11. Capillary gas-solid chromatography

    International Nuclear Information System (INIS)

    Berezkin, V.G.

    1996-01-01

    Modern state of gas adsorption chromatography in open capillary columns has been analyzed. The history of the method development and its role in gas chromatography, ways to construct open adsorptional capillary columns, foundations of the theory of retention and washing of chromatographic regions in gas adsorption capillary columns have been considered. The fields is extensively and for analyzing volatile compounds of different isotopic composition, inorganic and organic gases, volatile organic polar compounds, aqueous solutions of organic compounds. Separation of nuclear-spin isomers and isotopes of hydrogen is the first illustrative example of practical application of the adsorption capillary chromatography. It is shown that duration of protium and deuterium nuclear isomers may be reduced if the column temperature is brought to 47 K

  12. Development of a fast liquid chromatography-tandem mass spectrometry method for the determination of endocrine-disrupting compounds in waters.

    Science.gov (United States)

    Di Carro, Marina; Scapolla, Carlo; Liscio, Camilla; Magi, Emanuele

    2010-09-01

    A fast liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS) method was developed to study five endocrine-disrupting compounds (4-n-nonylphenol, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol) in water. Different columns were tested; the chromatographic separation of the analytes was optimized on a Pinnacle DB biphenylic column with a water-acetonitrile gradient elution, which allowed the separation of the selected endocrine-disrupting compounds (EDCs) in less than 6 min. Quantitative analysis was performed in selected reaction monitoring (SRM) mode; two transitions were chosen for each compound, using the most abundant for quantitation. Calibration curves using bisphenol A-d (16) as internal standard were drawn, showing good correlation coefficients (0.9993-0.9998). All figures of merit of the method were satisfactory; limits of detection were in the low pg range for all analytes. The method was then applied to the determination of the analytes in real water samples: to this aim, polar organic chemical integrative samplers (POCIS) were deployed in the influent and in the effluent of a drinking water treatment plant in Liguria (Italy). The EDC level was rather low in the influent and negligible in the outlet, reflecting the expected function of the treatment plant.

  13. Development and application of liquid chromatography coupled to isotope ratio mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lijun

    2014-02-19

    evaluated for, isotope ratio mass spectrometry (HT-RPLC/IRMS). The effect of column bleed on measured isotope ratios was investigated at high temperature in isothermal mode and in temperature gradient mode. Four different revised-phase columns were proven to be compatible with IRMS for compound-specific isotope analysis. The developed method was applied to measure caffeine in different drinks. Naturally occurring and industrially synthesized caffeine was observed to have two distinct δ{sup 13}C-ranges, from -25 to -32% circle and from -33 to -38% circle, respectively. On the basis of two different δ{sup 13}C-ranges, four out of 38 drinks were suspected of being mislabelled due to added but non-labelled synthetic caffeine with δ{sup 13}C-values falling in the range of synthetic caffeine. Furthermore, HTLC/IRMS was applied to measure non-polar and water-insoluble compounds, here steroids, for the first time. The use of steroid isotope analysis for pharmaceutical product control by HTLC/IRMS was demonstrated. The major advantage is that steroids can be analysed without derivatization. By overcoming current limitations in sample preparation, the method might become applicable for doping control purposes. Another potential application of LC/IRMS in doping control is the isotope analysis of 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR), a gene doping drug. Here, the first method for compound-specific isotope analysis of AICAR has been presented. The endogenous AICAR in urine and industrially synthesized AICAR were observed to have significantly different isotope signature. It shows that isotope analysis of LC/IRMS could potentially be used for the detection of AICAR abuse. The methodological developments presented in the thesis will lead to new applications of LC/IRMS.

  14. Development and application of liquid chromatography coupled to isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Zhang, Lijun

    2014-01-01

    evaluated for, isotope ratio mass spectrometry (HT-RPLC/IRMS). The effect of column bleed on measured isotope ratios was investigated at high temperature in isothermal mode and in temperature gradient mode. Four different revised-phase columns were proven to be compatible with IRMS for compound-specific isotope analysis. The developed method was applied to measure caffeine in different drinks. Naturally occurring and industrially synthesized caffeine was observed to have two distinct δ 13 C-ranges, from -25 to -32% circle and from -33 to -38% circle, respectively. On the basis of two different δ 13 C-ranges, four out of 38 drinks were suspected of being mislabelled due to added but non-labelled synthetic caffeine with δ 13 C-values falling in the range of synthetic caffeine. Furthermore, HTLC/IRMS was applied to measure non-polar and water-insoluble compounds, here steroids, for the first time. The use of steroid isotope analysis for pharmaceutical product control by HTLC/IRMS was demonstrated. The major advantage is that steroids can be analysed without derivatization. By overcoming current limitations in sample preparation, the method might become applicable for doping control purposes. Another potential application of LC/IRMS in doping control is the isotope analysis of 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR), a gene doping drug. Here, the first method for compound-specific isotope analysis of AICAR has been presented. The endogenous AICAR in urine and industrially synthesized AICAR were observed to have significantly different isotope signature. It shows that isotope analysis of LC/IRMS could potentially be used for the detection of AICAR abuse. The methodological developments presented in the thesis will lead to new applications of LC/IRMS.

  15. Chiral liquid chromatography-mass spectrometry (LC-MS/MS) method development for the detection of salbutamol in urine samples.

    Science.gov (United States)

    Chan, Sue Hay; Lee, Warren; Asmawi, Mohd Zaini; Tan, Soo Choon

    2016-07-01

    A sequential solid-phase extraction (SPE) method was developed and validated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the detection and quantification of salbutamol enantiomers in porcine urine. Porcine urine samples were hydrolysed with β-glucuronidase/arylsulfatase from Helix pomatia and then subjected to a double solid-phase extraction (SPE) first using the Abs-Elut Nexus SPE and then followed by the Bond Elut Phenylboronic Acid (PBA) SPE. The salbutamol enantiomers were separated using the Astec CHIROBIOTIC™ T HPLC column (3.0mm×100mm; 5μm) maintained at 15°C with a 15min isocratic run at a flow rate of 0.4mL/min. The mobile phase constituted of 5mM ammonium formate in methanol. Salbutamol and salbutamol-tert-butyl-d9 (internal standard, IS) was monitored and quantified with the multiple reaction monitoring (MRM) mode. The method showed good linearity for the range of 0.1-10ng/mL with limit of quantification at 0.3ng/mL. Analysis of the QC samples showed intra- and inter-assay precisions to be less than 5.04%, and recovery ranging from 83.82 to 102.33%. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Development, optimization, validation and application of faster gas chromatography - flame ionization detector method for the analysis of total petroleum hydrocarbons in contaminated soils.

    Science.gov (United States)

    Zubair, Abdulrazaq; Pappoe, Michael; James, Lesley A; Hawboldt, Kelly

    2015-12-18

    This paper presents an important new approach to improving the timeliness of Total Petroleum Hydrocarbon (TPH) analysis in the soil by Gas Chromatography - Flame Ionization Detector (GC-FID) using the CCME Canada-Wide Standard reference method. The Canada-Wide Standard (CWS) method is used for the analysis of petroleum hydrocarbon compounds across Canada. However, inter-laboratory application of this method for the analysis of TPH in the soil has often shown considerable variability in the results. This could be due, in part, to the different gas chromatography (GC) conditions, other steps involved in the method, as well as the soil properties. In addition, there are differences in the interpretation of the GC results, which impacts the determination of the effectiveness of remediation at hydrocarbon-contaminated sites. In this work, multivariate experimental design approach was used to develop and validate the analytical method for a faster quantitative analysis of TPH in (contaminated) soil. A fractional factorial design (fFD) was used to screen six factors to identify the most significant factors impacting the analysis. These factors included: injection volume (μL), injection temperature (°C), oven program (°C/min), detector temperature (°C), carrier gas flow rate (mL/min) and solvent ratio (v/v hexane/dichloromethane). The most important factors (carrier gas flow rate and oven program) were then optimized using a central composite response surface design. Robustness testing and validation of model compares favourably with the experimental results with percentage difference of 2.78% for the analysis time. This research successfully reduced the method's standard analytical time from 20 to 8min with all the carbon fractions eluting. The method was successfully applied for fast TPH analysis of Bunker C oil contaminated soil. A reduced analytical time would offer many benefits including an improved laboratory reporting times, and overall improved clean up

  17. High-performance liquid chromatography method with radiochemical detection for measurement of nitric oxide synthase, arginase, and arginine decarboxylase activities

    DEFF Research Database (Denmark)

    Volke, A; Wegener, Gregers; Vasar, E

    2006-01-01

    regulate NOS activity. We aimed to develop a HPLC-based method to measure simultaneously the products of these three enzymes. Traditionally, the separation of amino acids and related compounds with HPLC has been carried out with precolumn derivatization and reverse phase chromatography. We describe here...

  18. Chromatography in Industry

    Science.gov (United States)

    Schoenmakers, Peter

    2009-07-01

    This review focuses on the chromatography research that has been carried out within industry or in close cooperation with industry and that has been reported in the scientific literature between 2006 and mid-2008. Companies in the health care sector, such as pharmaceutical and biotechnology companies, are the largest contributors. Industrial research seems to take place in an open environment in cooperation with academia, peer companies, and institutions. Industry appears ready to embrace new technologies as they emerge, but they focus strongly on making chromatography work robustly, reliably, rapidly, and automatically. “Hyphenated” systems that incorporate on-line sample-preparation techniques and mass-spectrometric detection are the rule rather than the exception. Various multidimensional separation methods are finding numerous applications. Strategies aimed at speeding up the development of new chromatographic methods remain the focus of attention. Also, there is a clear trend toward exploring chromatographic methods for parallel processing along with other strategies for high-throughput analysis.

  19. Determination of telmisartan in human blood plasma: Part II: Liquid chromatography-tandem mass spectrometry method development, comparison to immunoassay and pharmacokinetic study

    NARCIS (Netherlands)

    Hempen, C.M.; Gläsle-Schwarz, Liane; Kunz, Ulrich; Karst, U.

    2006-01-01

    A new liquid chromatography/atmospheric pressure chemical ionization-tandem mass spectrometry (LC/APCI-MS/MS) method with on-line sample clean-up for the determination of telmisartan in human blood plasma is presented. This technique is compared to a previously introduced enzyme-linked immunosorbent

  20. A simplified method for rapid quantification of intracellular nucleoside triphosphates by one-dimensional thin-layer chromatography

    DEFF Research Database (Denmark)

    Jendresen, Christian Bille; Kilstrup, Mogens; Martinussen, Jan

    2011-01-01

    -pyrophosphate (PRPP), and inorganic pyrophosphate (PPi) in cell extracts. The method uses one-dimensional thin-layer chromatography (TLC) and radiolabeled biological samples. Nucleotides are resolved at the level of ionic charge in an optimized acidic ammonium formate and chloride solvent, permitting...... quantification of NTPs. The method is significantly simpler and faster than both current two-dimensional methods and high-performance liquid chromatography (HPLC)-based procedures, allowing a higher throughput while common sources of inaccuracies and technical problems are avoided. For determination of PPi...

  1. A liquid chromatography-mass spectrometry method for the quantification of bioavailability and bioconversion of beta-carotene to retinol in humans

    NARCIS (Netherlands)

    Yan Wang,; Xiaoying Xu,; Lieshout, van M.; West, C.E.; Lugtenburg, J.; Verhoeven, M.A.; Creemers, A.F.L.

    2000-01-01

    A method based on high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (APCI LC-MS) was developed for the quantification of the bioavailability of retinyl palmitate and -carotene and the bioconversion of -carotene to retinol in humans. Following oral

  2. Recent applications of gas chromatography with high-resolution mass spectrometry.

    Science.gov (United States)

    Špánik, Ivan; Machyňáková, Andrea

    2018-01-01

    Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high-resolution time-of-flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi-target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high-resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high-resolution mass spectrometry for non-target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high-resolution mass spectrometry over the currently used methods is expected, will be discussed as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Establishment of analysis method for methane detection by gas chromatography

    Science.gov (United States)

    Liu, Xinyuan; Yang, Jie; Ye, Tianyi; Han, Zeyu

    2018-02-01

    The study focused on the establishment of analysis method for methane determination by gas chromatography. Methane was detected by hydrogen flame ionization detector, and the quantitative relationship was determined by working curve of y=2041.2x+2187 with correlation coefficient of 0.9979. The relative standard deviation of 2.60-6.33% and the recovery rate of 96.36%∼105.89% were obtained during the parallel determination of standard gas. This method was not quite suitable for biogas content analysis because methane content in biogas would be over the measurement range in this method.

  4. Ion counting method and it's operational characteristics in gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Fujii, Toshihiro

    1976-01-01

    Ion counting method with continuous channel electron multiplier which affords the direct detection of very small ion currents and it's operational characteristics were studied in gas chromatography-mass spectrometry. Then this method was applied to the single ion detection technique of GC-MS. A detection limit was measured, using various standard samples of low level concentration. (auth.)

  5. Hydroxylapatite chromatography.

    Science.gov (United States)

    Broadhurst, A V

    2001-05-01

    Hydroxylapatite (also called hydroxyapatite), a form of calcium phosphate, can be used as a matrix for the chromatography of both proteins and nucleic acids. Protocols are provided for both standard low-pressure chromatography of a protein mixture using a hydroxylapatite column prepared in the laboratory, and an HPLC method, applicable to proteins and nucleic acids, that uses a commercially available column. Alternate protocols describe column chromatography using a step gradient or batch binding and step-gradient elution.

  6. Development of a Microemulsion High Performance Liquid Chromatography (MELC Method for Determination of Salbutamol in Metered-Dose Inhalers (MDIS

    Directory of Open Access Journals (Sweden)

    J Hanaee

    2013-02-01

    Full Text Available Introduction: A sensitive and rapid oil-in-water (O/W microemulsion high performance liquid chromatography (MELC method has been developed. The water-in-oil (w/o microemulsion was used as a mobile phase in the determination of salbutamol in aqueous solutions. In addition, the influence of operating parameters on the separation performance was examined. Methods: The samples were injected into C18, (250mm×4.6mm analytical columns maintained at 25oC with a flow rate 1 ml/min. The mobile phase was 95.5% v/v aqueous orthophosphate buffer 20 mM (adjusted to pH 3 with orthophosphoric acid, 0.5% ethyl acetate, 1.5% Brij35, and 2.5% 1-butanol, all w/w. The salbutamol and internal standard peaks were detected by fluorescence detection at the excitation and emission wavelengths of 267 and 313 nm respectively. Results: The method had an accuracy of > 97.78% and the calibration curve was linear (r2 = 0.99 over salbutamol concentrations ranging from 25 to 500 ng/mL. The intra-day and inter-day precisions (CV % were <1.6 and <1.8, respectively. The limit of detection (LOD and limit of quantitation (LOQ were 9.61ng/ml and 29.13ng/ml, respectively. Conclusion: The method reported is simple, precise and accurate, and has the capacity to be used for determination of salbutamol in the pharmaceutical preparation.

  7. Instrumental liquid chromatography: a practical manual on high-performance liquid chromatographic methods

    National Research Council Canada - National Science Library

    Parris, N. A

    1976-01-01

    Available texts on liquid chromatography have tended to emphasize the developments in the theoretical understanding of the technique and methodology or to list numerous applications, complete with experimental details...

  8. Efficient methods for isolating five phytochemicals from Gentiana macrophylla using high-performance countercurrent chromatography.

    Science.gov (United States)

    Rho, Taewoong; Jung, Mila; Lee, Min Won; Chin, Young-Won; Yoon, Kee Dong

    2016-12-01

    Efficient high-performance countercurrent chromatography methods were developed to isolate five typical compounds from the extracts of Gentiana macrophylla. n-Butanol-soluble extract of G. macrophylla contained three hydrophilic iridoids, loganic acid (1), swertiamarin (2) and gentiopicroside (3), and a chromene derivative, macrophylloside D (4) which were successfully isolated by flow rate gradient (1.5 mL/min in 0-60 min, 5.0 mL/min in 60-120 min), and consecutive flow rate gradient HPCCC using n-butanol/0.1% aqueous trifluoroacetic acid (1:1, v/v, normal phase mode) system. The yields of 1-4 were 22, 16, 122, and 6 mg, respectively, with purities over 97% in a flow rate gradient high-performance countercurrent chromatography, and consecutive flow rate gradient high-performance countercurrent chromatography gave 1, 2, 3 (54, 41, 348 mg, respectively, purities over 97%) and 4 (13 mg, purity at 95%) from 750 mg of sample. The main compound in methylene chloride soluble extract, 2-methoxyanofinic acid, was successfully separated by n-hexane/ethyl acetate/methanol/water (4:6:4:6, v/v/v/v, flow-rate: 4 mL/min, reversed phase mode) condition. The structures of five isolates were elucidated by 1 H, 13 C NMR and ESI-Q-TOF-MS spectroscopic data which were compared with previously reported values. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. 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.

  10. Development and validation of automatic HS-SPME with a gas chromatography-ion trap/mass spectrometry method for analysis of volatiles in wines.

    Science.gov (United States)

    Paula Barros, Elisabete; Moreira, Nathalie; Elias Pereira, Giuliano; Leite, Selma Gomes Ferreira; Moraes Rezende, Claudia; Guedes de Pinho, Paula

    2012-11-15

    An automated headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-ion trap/mass spectrometry (GC-IT/MS) was developed in order to quantify a large number of volatile compounds in wines such as alcohols, ester, norisoprenoids and terpenes. The procedures were optimized for SPME fiber selection, pre-incubation temperature and time, extraction temperature and time, and salt addition. A central composite experimental design was used in the optimization of the extraction conditions. The volatile compounds showed optimal extraction using a DVB/CAR/PDMS fiber, incubation of 5 ml of wine with 2g NaCl at 45 °C during 5 min, and subsequent extraction of 30 min at the same temperature. The method allowed the identification of 64 volatile compounds. Afterwards, the method was validated successfully for the most significant compounds and was applied to study the volatile composition of different white wines. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Multiresidue screening method for detection of benzimidazoles and their metabolites in liver and muscle by high-performance liquid chromatography: method development and validation according to Commission Decision 2002/657/EC

    Directory of Open Access Journals (Sweden)

    Marilena Gili

    2014-02-01

    Full Text Available The use of veterinary drugs may cause the presence of residues in food of animal origin if appropriate withdrawal periods are not respected. A high-performance liquid chromatography (HPLC method has been developed for the simultaneous detection of 11 benzimidazole residues, including metabolites – albendazole, albendazole sulphoxide, albendazole sulphone, fenbendazole, fenbendazole sulphoxide (oxfendazole, fenbendazole sulphone, flubendazole, mebendazole, oxibendazole, thiabendazole, 5-hydroxythiabendazole – in bovine, ovine, equine, swine, rabbit and poultry liver and in bovine, swine and fish muscle. After extraction with a dicloromethane/acetonitrile solution (35/65 v/v containing 5% ammonium hydroxide, the solvent was evaporated to dryness, the residue was dissolved in HCl 0.1 M, defatted with hexane, purified on a strong cation exchange solid-phase extraction cartridge and analysed in HPLC with diode array and fluorescence detectors. The method was validated as screening qualitative method evaluating, according to Commission Decision 2002/657/EC criteria, specificity, CCb and b error at cut off level of 25 mg/kg and ruggedness.

  12. Chromatography resin support

    Science.gov (United States)

    Dobos, James G.

    2002-01-01

    An apparatus and method of using an improved chromatography resin support is disclosed. The chromatography support platform is provided by a stainless steel hollow cylinder adapted for being inserted into a chromatography column. An exterior wall of the stainless steel cylinder defines a groove for carrying therein an "O"-ring. The upper surface of the stainless steel column is covered by a fine stainless steel mesh welded to the edges of the stainless steel cylinder. When placed upon a receiving ledge defined within a chromatography column, the "O"-ring provides a fluid tight seal with the inner edge wall of the chromatography cylinder. The stainless steel mesh supports the chromatography matrix and provides a back flushable support which is economical and simple to construct.

  13. New EDTA determination method based on ion chromatography with suppressed conductimetric detection

    International Nuclear Information System (INIS)

    Gyoergy Patzay; Yahya Ramadan; Csilla Tonko

    2014-01-01

    A novel direct method for the determination of EDTA in alkaline radioactive evaporator residue solution was developed and validated based on ion chromatography with suppressed conductimetric detection and anion exchange columns (A Supp 4, 4 mm × 250 mm and A Supp 5, 4 mm × 150 mm). The yttrium-EDTA complex resulted one single chromatographic peak in the eluent and allowed the correct determination of EDTA in an alkaline, high concentration radioactive waste water. Depending on coexisting substances, suitable eluent is 10.0 mM carbonate buffer/pH 10.6 or 10.75 (t R ,Y-EDTA = 7.01 and 6.4 min, respectively). For 10.0 mM carbonate buffer/pH 10.6 and isocratic flow rate of 1.0 cm 3 /min, a linear calibration curve was obtained from 5 to 40 mg/dm 3 (r > 0.999) EDTA. Good resolution was achieved from commonly coexisting anions (chloride, nitrite, nitrate, sulphate, phosphate, bromide and citrate). The developed simple ion chromatographic method was applied for the assay of EDTA in various radioactive alkaline solutions. (author)

  14. Report: Affinity Chromatography.

    Science.gov (United States)

    Walters, Rodney R.

    1985-01-01

    Supports, affinity ligands, immobilization, elution methods, and a number of applications are among the topics considered in this discussion of affinity chromatography. An outline of the basic principles of affinity chromatography is included. (JN)

  15. Analytical method development of nifedipine and its degradants binary mixture using high performance liquid chromatography through a quality by design approach

    Science.gov (United States)

    Choiri, S.; Ainurofiq, A.; Ratri, R.; Zulmi, M. U.

    2018-03-01

    Nifedipin (NIF) is a photo-labile drug that easily degrades when it exposures a sunlight. This research aimed to develop of an analytical method using a high-performance liquid chromatography and implemented a quality by design approach to obtain effective, efficient, and validated analytical methods of NIF and its degradants. A 22 full factorial design approach with a curvature as a center point was applied to optimize of the analytical condition of NIF and its degradants. Mobile phase composition (MPC) and flow rate (FR) as factors determined on the system suitability parameters. The selected condition was validated by cross-validation using a leave one out technique. Alteration of MPC affected on time retention significantly. Furthermore, an increase of FR reduced the tailing factor. In addition, the interaction of both factors affected on an increase of the theoretical plates and resolution of NIF and its degradants. The selected analytical condition of NIF and its degradants has been validated at range 1 – 16 µg/mL that had good linearity, precision, accuration and efficient due to an analysis time within 10 min.

  16. Development and validation of a high-performance liquid chromatography method with post-column derivatization for the detection of aflatoxins in cereals and grains.

    Science.gov (United States)

    Asghar, Muhammad Asif; Iqbal, Javed; Ahmed, Aftab; Khan, Mobeen Ahmed; Shamsuddin, Zuzzer Ali; Jamil, Khalid

    2016-06-01

    A novel, reliable and rapid high-performance liquid chromatography (HPLC) method with post-column derivatization was developed and validated. The HPLC method was used for the simultaneous determination of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) in various cereals and grains. Samples were extracted with 80:20 (v/v) methanol:water and purified using C18 (40-63 μm) solid-phase extraction cartridges. AFs were separated using a LiChroCART-RP-18 (5 μm, 250 × 4.0 mm(2)) column. The mobile phase consisted of methanol:acetonitrile:buffer (17.5:17.5:65 v/v) (pH 7.4) delivered at the flow rate of 1.0 mL min(-1) The fluorescence of each AF was detected at λex = 365 nm and λem = 435 nm. All four AFs were properly resolved within the total run time of 20 min. The established method was extensively validated as a final verification of the method development by the evaluation of selectivity (AFB1, AFB2, AFG1 and AFG2), linearity (R(2) ≥ 0.9994), precision (average SD ≤ 2.79), accuracy (relative mean error ≤ -5.51), robustness (p HPLC method could be effectively applied for the routine analysis of the AFs in different cereals and grains. © The Author(s) 2014.

  17. 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.

  18. Ionic liquid stationary phases for gas chromatography.

    Science.gov (United States)

    Poole, Colin F; Poole, Salwa K

    2011-04-01

    This article provides a summary of the development of ionic liquids as stationary phases for gas chromatography beginning with early work on packed columns that established details of the retention mechanism and established working methods to characterize selectivity differences compared with molecular stationary phases through the modern development of multi-centered cation and cross-linked ionic liquids for high-temperature applications in capillary gas chromatography. Since there are many reviews on ionic liquids dealing with all aspects of their chemical and physical properties, the emphasis in this article is placed on the role of gas chromatography played in the design of ionic liquids of low melting point, high thermal stability, high viscosity, and variable selectivity for separations. Ionic liquids provide unprecedented opportunities for extending the selectivity range and temperature-operating range of columns for gas chromatography, an area of separation science that has otherwise been almost stagnant for over a decade. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Multi-residue analysis method for analysis of pharmaceuticals using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS) in water sample

    Science.gov (United States)

    Al-Qaim, Fouad Fadhil; Abdullah, Md Pauzi; Othman, Mohamed Rozali

    2013-11-01

    In this work, a developed method using solid - phase extraction (SPE) followed by liquid chromatography - time of flight mass spectrometry (LC-ESI-TOF/MS) was developed and validated for quantification and confirmation of eleven pharmaceuticals with different therapeutic classes in water samples, Malaysia. These compounds are caffeine (CAF), prazosin (PRZ), enalapril (ENL), carbamazepine (CBZ), nifedipine (NFD), levonorgestrel (LNG), simvastatin (SMV), hydrochlorothiazide (HYD), gliclazide (GLIC), diclofenac-Na (DIC-Na) and mefenamic acid (MEF). LC was performed on a Dionex Ultimate 3000/LC 09115047 (USA) system. Chromatography was performed on a Thermo Scientific C18 (250 mm × 2.1 mm, i.d.: 5μm) column. Several parameters were optimised such as; mobile phase, gradient elution, collision energy and solvent elution for extraction of compounds from water. The recoveries obtained ranged from 30-148 % in river water. Five pharmaceutical compounds were detected in the surface water samples: caffeine, prazosin, enalpril, diclofenac-Na and mefenamic acid. The developed method is precise and accepted recoveries were got. In addition, this method is suitable to identify and quantify trace concentrations of pharmaceuticals in surface water.

  20. Determination of thyroid hormones in mouse tissues by isotope-dilution microflow liquid chromatography-mass spectrometry method.

    Science.gov (United States)

    De Angelis, Meri; Giesert, Florian; Finan, Brian; Clemmensen, Christoffer; Müller, Timo D; Vogt-Weisenhorn, Daniela; Tschöp, Matthias H; Schramm, Karl-Werner

    2016-10-15

    Thyroid hormones (THs) play a critical role in the regulation of many biological processes such as growth, metabolism and development both in humans and wildlife. In general, TH levels are measured by immunoassay (IA) methods but the specificity of the antibodies used in these assays limits selectivity. In the last decade, several analytical methods using liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS) have been developed to measure THs. These new techniques proved to be more accurate than the IA analysis and they were widely used for the determination of TH level in different human and animal tissues. A large part of LC-MS/MS methods described in literature employed between 200 and 500mg of sample, however this quantity can be considered too high especially when preclinical studies are conducted using mice as test subjects. Thus an analytical method that reduces the amount of tissue is essential. In this study, we developed a procedure for the analysis of six THs; L-thyroxine (T4), 3,3',5-triiodo-l-thyronine (T3), 3,3',5'-triiodo-l-thyronine (rT3), 3,5-diiodo-l-thyronine (rT2), 3,3'-diiodo-l-thyronine (T2), 3-iodo-l-thyronine (T1) using isotope ((13)C6-T4, (13)C6-T3, (13)C6-rT3, (13)C6-T2) dilution liquid chromatography-mass spectrometry. The major difference with previously described methods lies in the utilization of a nano-UPLC (Ultra Performance Liquid Chromatography) system in micro configuration. This approach leads to a reduction compared to the published methods, of column internal diameter, flow rate, and injected volume. The result of all these improvements is a decrease in the amount of sample necessary for the analysis. The method was tested on six different mouse tissues: liver, heart, kidney, muscle, lung and brown adipose tissue (BAT). The nano-UPLC system was interfaced with a quadrupole time-of-flight mass spectrometer (Q-TOF2-MS) using the positive ion mode electrospray ionization. In our analytical method

  1. Calibration of shahid's analytical method for adulterated Zn-edta fertilizers by ion chromatography and atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Khan, M.S.A.; Akram, M.; Qazi, M.A.

    2010-01-01

    Chelated zinc fertilizers are usually recommended in calcareous alkaline soils to provide Zn nutrition in order to prevent possible Zn precipitation. In Punjab (Pakistan), Zn EDTA products are being manufactured, and marketed to meet the zinc requirement of various crops grown in Zn deficient soils. Under fertilizer control order, 1973 (amended), their quality has to be monitored by the Agriculture Department, Government of the Punjab. None of the traditional method was found suitable which can separate the mineral fraction from that of chelated adulterated fertilizer except for those methods based on ion chromatography. Calibration of ion chromatography method was carried out by determining the mineral Zn fraction leading to estimate remaining Zn EDTA fraction in fertilizer samples of adulterated nature i.e. mixture of chelated and mineral fraction. In order to achieve the objective atomic absorption spectroscopy was coupled with ion chromatography. The method offers a specific, reliable technique for determination of chelated zinc in fertilizers. In the first step chelation was broken down with concentrated sulphuric acid treatment and total zinc contents were determined by atomic absorption spectroscopy. In second step, non-chelated (mineral) portion of zinc was determined by ion chromatography using cation column and conductivity detector. Chelated zinc was calculated by subtracting non-chelated (mineral) fraction from total zinc contents. (author)

  2. Isolation and HPLC method development of azafrin from Alectra parasitica var. chitrakutensis.

    Science.gov (United States)

    Agrawal, Poonam; Laddha, Kirti; Tiwari, Ashok

    2014-01-01

    This study was undertaken to isolate and quantify azafrin in Alectra parasitica (Scrophulariaceae) rhizomes. A simple method for the isolation of carotenoid, azafrin, involves solvent extraction of the dried rhizome powder using a single solvent and further purification by recrystallisation. The structure of the compound was elucidated and confirmed by thin-layer chromatography, infrared spectroscopy, mass spectroscopy and nuclear magnetic resonance spectral analysis. A specific and rapid reversed-phase high-performance liquid chromatography (HPLC) method was developed for the analysis of azafrin. The method was validated for accuracy, precision, linearity and specificity. Validation revealed that the method is specific, accurate, precise, reliable and reproducible. The proposed HPLC method can be used for the identification and quantitative analysis of azafrin in A. parasitica rhizomes.

  3. Gel chromatography of sup(99m)Tc-labelled compounds

    International Nuclear Information System (INIS)

    Vilcek, S.; Machan, V.; Kalincak, M.

    1976-01-01

    The present state of gel chromatography of sup(99m)Tc-labelled compounds is reviewed. Examples are given of gel chromatography for preparing labelled compounds and for quality control analysis and the development of new types of sup(99m)Tc-labelled compounds. The factors which influence the gel chromatography of these compounds are discussed, i.e., the nature of the elution agent, the duration of the contact of the gel and the preparation the gel type, the nature of the labelled compound. The GCS method (gel chromatography scanning) is briefly described. The advantages of gel chromatography as compared with other chromatographic techniques for sup(99m)Tc-labelled compounds are summarized. (author)

  4. Separation techniques: Chromatography

    Science.gov (United States)

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorption, partition, and size exclusion. Other chromatography techniques are based on the stationary bed, including column, thin layer, and paper chromatography. Column chromatography is one of the most common methods of protein purification. PMID:28058406

  5. Purification of human albumin by the combination of the method of Cohn with liquid chromatography

    Directory of Open Access Journals (Sweden)

    Tanaka K.

    1998-01-01

    Full Text Available Large volumes of plasma can be fractionated by the method of Cohn at low cost. However, liquid chromatography is superior in terms of the quality of the product obtained. In order to combine the advantages of each method, we developed an integrated method for the production of human albumin and immunoglobulin G (IgG. The cryoprecipitate was first removed from plasma for the production of factor VIII and the supernatant of the cryoprecipitate was fractionated by the method of Cohn. The first precipitate, containing fractions (F-I + II + III, was used for the production of IgG by the chromatographic method (see Tanaka K et al. (1998 Brazilian Journal of Medical and Biological Research, 31: 1375-1381. The supernatant of F-I + II + III was submitted to a second precipitation and F-IV was obtained and discarded. Albumin was obtained from the supernatant of the precipitate F-IV by liquid chromatography, ion-exchange on DEAE-Sepharose FF, filtration through Sephacryl S-200 HR and introduction of heat treatment for fatty acid precipitation. Viral inactivation was performed by pasteurization at 60ºC for 10 h. The albumin product obtained by the proposed procedure was more than 99% pure for the 15 lots of albumin produced, with a mean yield of 25.0 ± 0.5 g/l plasma, containing 99.0 to 99.3% monomer, 0.7 to 1.0% dimers, and no polymers. Prekallikrein activator levels were <=5 IU/ml. This product satisfies the requirements of the 1997 Pharmacopée Européenne.

  6. Simplified and rapid method for extraction of ergosterol from natural samples and detection with quantitative and semi-quantitative methods using thin-layer chromatography

    OpenAIRE

    Larsen, Cand.scient Thomas; Ravn, Senior scientist Helle; Axelsen, Senior Scientist Jørgen

    2004-01-01

    A new and simplified method for extraction of ergosterol (ergoste-5,7,22-trien-3-beta-ol) from fungi in soil and litter was developed using pre-soaking extraction and paraffin oil for recovery. Recoveries of ergosterol were in the range of 94 - 100% depending on the solvent to oil ratio. Extraction efficiencies equal to heat-assisted extraction treatments were obtained with pre-soaked extraction. Ergosterol was detected with thin-layer chromatography (TLC) using fluorodensitometry with a quan...

  7. An optimized method for fatty acid analysis, including quantification of trans fatty acids, in human adipose tissue by gas-liquid chromatography

    DEFF Research Database (Denmark)

    Bysted, Anette; Cold, S; Hølmer, Gunhild Kofoed

    1999-01-01

    Considering the need for a quick direct method for measurement of the fatty acid composition including trans isomers ofhuman adipose tissue we have developed a procedure using gas-liquid chromatography (GLC) alone, which is thussuitable for validation of fatty acid status in epidemiological studies...... for 25 min, and finally raised at 25 degrees C/min to 225 degrees C. The trans and cis isomers of18:1 were well separated from each other, as shown by silver-ion thin-layer chromatography. Verification by standardsshowed that the trans 18:1 isomers with a double bond in position 12 or lower were...

  8. A high-throughput method for liquid chromatography-tandem mass spectrometry determination of plasma alkylresorcinols, biomarkers of whole grain wheat and rye intake

    DEFF Research Database (Denmark)

    Ross, Alastair B; Svelander, Cecilia; Savolainen, Otto I

    2016-01-01

    supported extraction methods for extracting alkylresorcinols from plasma and improved a normal-phase liquid chromatography coupled to a tandem mass spectrometer method to reduce sample analysis time. The method was validated and compared with gas chromatography-mass spectrometry analysis. Sample preparation...

  9. Simultaneous determination of niacin and pyridoxine at trace levels by using diode array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Sel, Sabriye; Öztürk Er, Elif; Bakırdere, Sezgin

    2017-12-01

    A highly sensitive and simple diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method was developed for the simultaneous determination of niacin and pyridoxine in pharmaceutical drugs, tap water, and wastewater samples. To determine the in vivo behavior of niacin and pyridoxine, analytes were subjected to simulated gastric conditions. The calibration plots of the diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method showed good linearity over a wide concentration range with close to 1.0 correlation coefficients for both analytes. The limit of detection/limit of quantitation values for liquid chromatography quadrupole time-of-flight tandem mass spectrometry analysis were 1.98/6.59 and 1.3/4.4 μg/L for niacin and pyridoxine, respectively, while limit of detection/limit of quantitation values for niacin and pyridoxine in high-performance liquid chromatography analysis were 3.7/12.3 and 5.7/18.9 μg/L, respectively. Recovery studies were also performed to show the applicability of the developed methods, and percentage recovery values were found to be 90-105% in tap water and 94-97% in wastewater for both analytes. The method was also successfully applied for the qualitative and quantitative determination of niacin and pyridoxine in drug samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A validated high performance thin layer chromatography method for determination of yohimbine hydrochloride in pharmaceutical preparations.

    Science.gov (United States)

    Badr, Jihan M

    2013-01-01

    Yohimbine is an indole alkaloid used as a promising therapy for erectile dysfunction. A number of methods were reported for the analysis of yohimbine in the bark or in pharmaceutical preparations. In the present work, a simple and sensitive high performance thin layer chromatographic method is developed for determination of yohimbine (occurring as yohimbine hydrochloride) in pharmaceutical preparations and validated according to International Conference of Harmonization (ICH) guidelines. The method employed thin layer chromatography aluminum sheets precoated with silica gel as the stationary phase and the mobile phase consisted of chloroform:methanol:ammonia (97:3:0.2), which gave compact bands of yohimbine hydrochloride. Linear regression data for the calibration curves of standard yohimbine hydrochloride showed a good linear relationship over a concentration range of 80-1000 ng/spot with respect to the area and correlation coefficient (R(2)) was 0.9965. The method was evaluated regarding accuracy, precision, selectivity, and robustness. Limits of detection and quantitation were recorded as 5 and 40 ng/spot, respectively. The proposed method efficiently separated yohimbine hydrochloride from other components even in complex mixture containing powdered plants. The amount of yohimbine hydrochloride ranged from 2.3 to 5.2 mg/tablet or capsule in preparations containing the pure alkaloid, while it varied from zero (0) to 1.5-1.8 mg/capsule in dietary supplements containing powdered yohimbe bark. We concluded that this method employing high performance thin layer chromatography (HPTLC) in quantitative determination of yohimbine hydrochloride in pharmaceutical preparations is efficient, simple, accurate, and validated.

  11. Study of comportment of trioctylphosphine oxide by coat slight chromatography

    International Nuclear Information System (INIS)

    Meddour, Laaldja; Azzouz Abdelkrim

    1996-04-01

    The synthesis and characterisation process of the extractant agent 'Trioctylphosphine oxide' (TOPO) are not very developped in the literature. However, in order to identify this agent (TOPO) in its synthesis process, we attempt several analysis methods. The coat slight chromatography proves the simple and accessible method, that explains the choice of this study. In the present work, we have analysed the TOPO by coat slight chromatography with the intention of finding a better solvent

  12. Liquid chromatography/tandem mass spectrometry method for quantitative estimation of solutol HS15 and its applications

    OpenAIRE

    Bhaskar, V. Vijaya; Middha, Anil; Srivastava, Pratima; Rajagopal, Sriram

    2015-01-01

    A rapid, sensitive and selective pseudoMRM (pMRM)-based method for the determination of solutol HS15 (SHS15) in rat plasma was developed using liquid chromatography/tandem mass spectrometry (LCâMS/MS). The most abundant ions corresponding to SHS15 free polyethyleneglycol (PEG) oligomers at m/z 481, 525, 569, 613, 657, 701, 745, 789, 833, 877, 921 and 965 were selected for pMRM in electrospray mode of ionization. Purity of the lipophilic and hydrophilic components of SHS15 was estimated using ...

  13. Hydrophilic Interaction Liquid Chromatography/Mass Spectrometry: An Attractive and Prospective Method for the Quantitative Bioanalysis in Drug Metabolism.

    Science.gov (United States)

    Li, Zheng; Han, Jie; Sun, Shi-an; Chen, Kai; Tang, Dao-quan

    2016-01-01

    During the development, dosage optimization and safety evaluation of a drug, rapid and precise monitoring of administered drug and/or its metabolites in biological samples including blood, plasma, serum, tissues and saliva are vital. As drug biotransformation produces more hydrophilic metabolites for the enhancement of drug elimination, which is often a challenge for traditional reversed-phase liquid chromatography (RPLC) separation. Because hydrophilic interaction liquid chromatography (HILIC) is capable of retaining polar compounds and readily compatible with mass spectrometry (MS), HILIC has been used as a complementary separation technique to RPLC for analysis of polar metabolites, especially polar drugs and their metabolites. This review covers core aspects of HILIC-MS/MS method and overall profile of its application in analysis of drug and/or its metabolites. The emphasis of this paper has been placed on the applications of HILIC-MS/MS method in quantitative bioanalysis of drugs alone or along with their metabolites in drug metabolism studies in recent years. As a fundamental and critical step of bioanalytical method, conventional sample preparation techniques of biological matrices for the HILIC-MS/MS analysis of drugs and/or their metabolites are also briefly featured.

  14. Development of a supercritical fluid chromatography method with ultraviolet and mass spectrometry detection for the characterization of biomass fast pyrolysis bio oils.

    Science.gov (United States)

    Crepier, Julien; Le Masle, Agnès; Charon, Nadège; Albrieux, Florian; Heinisch, Sabine

    2017-08-11

    The characterization of complex mixtures is a challenging issue for the development of innovative processes dedicated to biofuels and bio-products production. The huge number of compounds present in biomass fast pyrolysis oils combined with the large diversity of chemical functions represent a bottleneck as regards analytical technique development. For the extensive characterization of complex samples, supercritical fluid chromatography (SFC) can be alternative to usual separation techniques such as gas (GC) or liquid chromatography (LC). In this study, an approach is proposed to define the best conditions for the SFC separation of a fast pyrolysis bio-oil. This approach was based on SFC data obtained directly from the bio-oil itself instead of selecting model compounds as usually done. SFC conditions were optimized by using three specific, easy-to-use and quantitative criteria aiming at maximizing the separation power. Polar stationary phases (ethylpyridine bonded silica) associated to a mix of acetonitrile and water as polarity modifier provided the best results, with more than 120 peaks detected in SFC-UV. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A rapid method for the separation and estimation of uranium in geological materials using ion chromatography

    International Nuclear Information System (INIS)

    Prakash, Satya; Bangroo, P.N.

    2013-01-01

    Ion Chromatography is an elegant analytical technique which was primarily developed for the analysis of anionic species and over the years it has been used successfully to analyse various elements in different matrices. In this work the potential of Ion Chromatography has been used for the rapid separation and estimation of uranium in hydrogeochemical and other geological materials

  16. A review on development of analytical methods to determine monitorable drugs in serum and urine by micellar liquid chromatography using direct injection.

    Science.gov (United States)

    Esteve-Romero, Josep; Albiol-Chiva, Jaume; Peris-Vicente, Juan

    2016-07-05

    Therapeutic drug monitoring is a common practice in clinical studies. It requires the quantification of drugs in biological fluids. Micellar liquid chromatography (MLC), a well-established branch of Reverse Phase-High Performance Liquid Chromatography (RP-HPLC), has been proven by many researchers as a useful tool for the analysis of these matrices. This review presents several analytical methods, taken from the literature, devoted to the determination of several monitorable drugs in serum and urine by micellar liquid chromatography. The studied groups are: anticonvulsants, antiarrhythmics, tricyclic antidepressants, selective serotonin reuptake inhibitors, analgesics and bronchodilators. We detail the optimization strategy of the sample preparation and the main chromatographic conditions, such as the type of column, mobile phase composition (surfactant, organic solvent and pH), and detection. The finally selected experimental parameters, the validation, and some applications have also been described. In addition, their performances and advantages have been discussed. The main ones were the possibility of direct injection, and the efficient chromatographic elution, in spite of the complexity of the biological fluids. For each substance, the measured concentrations were accurate and precise at their respective therapeutic range. It was found that the MLC-procedures are fast, simple, inexpensive, ecofriendly, safe, selective, enough sensitive and reliable. Therefore, they represent an excellent alternative for the determination of drugs in serum and urine for monitoring purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. DEVELOPMENT OF SAMPLING AND ANALYTICAL METHODS FOR THE MEASUREMENT OF NITROUS OXIDE FROM FOSSIL FUEL COMBUSTION SOURCES

    Science.gov (United States)

    The report documents the technical approach and results achieved while developing a grab sampling method and an automated, on-line gas chromatography method suitable to characterize nitrous oxide (N2O) emissions from fossil fuel combustion sources. The two methods developed have...

  18. Column Liquid Chromatography.

    Science.gov (United States)

    Majors, Ronald E.; And Others

    1984-01-01

    Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

  19. Interlaboratory study of a liquid chromatography method for erythromycin: determination of uncertainty.

    Science.gov (United States)

    Dehouck, P; Vander Heyden, Y; Smeyers-Verbeke, J; Massart, D L; Marini, R D; Chiap, P; Hubert, Ph; Crommen, J; Van de Wauw, W; De Beer, J; Cox, R; Mathieu, G; Reepmeyer, J C; Voigt, B; Estevenon, O; Nicolas, A; Van Schepdael, A; Adams, E; Hoogmartens, J

    2003-08-22

    Erythromycin is a mixture of macrolide antibiotics produced by Saccharopolyspora erythreas during fermentation. A new method for the analysis of erythromycin by liquid chromatography has previously been developed. It makes use of an Astec C18 polymeric column. After validation in one laboratory, the method was now validated in an interlaboratory study. Validation studies are commonly used to test the fitness of the analytical method prior to its use for routine quality testing. The data derived in the interlaboratory study can be used to make an uncertainty statement as well. The relationship between validation and uncertainty statement is not clear for many analysts and there is a need to show how the existing data, derived during validation, can be used in practice. Eight laboratories participated in this interlaboratory study. The set-up allowed the determination of the repeatability variance, s(2)r and the between-laboratory variance, s(2)L. Combination of s(2)r and s(2)L results in the reproducibility variance s(2)R. It has been shown how these data can be used in future by a single laboratory that wants to make an uncertainty statement concerning the same analysis.

  20. Method for 236U Determination in Seawater Using Flow Injection Extraction Chromatography and Accelerator Mass Spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter

    2015-01-01

    An automated analytical method implemented in a flow injection (FI) system was developed for rapid determination of 236U in 10 L seawater samples. 238U was used as a chemical yield tracer for the whole procedure, in which extraction chromatography (UTEVA) was exploited to purify uranium, after...... experimental parameters affecting the analytical effectiveness were investigated and optimized in order to achieve high chemical yields and simple and rapid analysis as well as low procedure background. Besides, the operational conditions for the target preparation prior to the AMS measurement were optimized......, on the basis of studying the coprecipitation behavior of uranium with iron hydroxide. The analytical results indicate that the developed method is simple and robust, providing satisfactory chemical yields (80−100%) and high analysis speed (4 h/sample), which could be an appealing alternative to conventional...

  1. Bio-analytical method development and validation of Rasagiline by high performance liquid chromatography tandem mass spectrometry detection and its application to pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Ravi Kumar Konda

    2012-10-01

    Full Text Available The most suitable bio-analytical method based on liquid–liquid extraction has been developed and validated for quantification of Rasagiline in human plasma. Rasagiline-13C3 mesylate was used as an internal standard for Rasagiline. Zorbax Eclipse Plus C18 (2.1 mm×50 mm, 3.5 μm column provided chromatographic separation of analyte followed by detection with mass spectrometry. The method involved simple isocratic chromatographic condition and mass spectrometric detection in the positive ionization mode using an API-4000 system. The total run time was 3.0 min. The proposed method has been validated with the linear range of 5–12000 pg/mL for Rasagiline. The intra-run and inter-run precision values were within 1.3%–2.9% and 1.6%–2.2% respectively for Rasagiline. The overall recovery for Rasagiline and Rasagiline-13C3 mesylate analog was 96.9% and 96.7% respectively. This validated method was successfully applied to the bioequivalence and pharmacokinetic study of human volunteers under fasting condition. Keywords: High performance liquid chromatography, Mass spectrometry, Rasagiline, Liquid–liquid extraction

  2. Development of a method for the simultaneous determination of multi-class pesticides in earthworms by liquid chromatography coupled to tandem electrospray mass spectrometry.

    Science.gov (United States)

    Daniele, Gaëlle; Lafay, Florent; Pelosi, Céline; Fritsch, Clémentine; Vulliet, Emmanuelle

    2018-06-04

    Agricultural intensification, and in particular the use of pesticides, leads over the years to a loss of biodiversity and a decline of ecosystem services in cultivated zones and agricultural landscapes. Among the animal communities involved in the functioning of agro-ecosystems, earthworms are ubiquitous and recognized as indicators of land uses and cultural practices. However, little data is available on the levels of pesticides in such organisms in natura, which would allow estimating their actual exposure and the potentially resulting impacts. Thus, the objective of this study was to develop a sensitive analytical methodology to detect and quantify 27 currently used pesticides in earthworms (Allolobophora chlorotica). A modified QuEChERS extraction was implemented on individual earthworms. This step was followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The whole analytical method was validated on spiked earthworm blank samples, with regard to linearity (from 1 to 100 method limit of quantification, r 2  > 0.95), intra-day precision (relative standard deviation (RSD) Graphical abstract.

  3. Technical note: development and validation of a method using ultra performance liquid chromatography coupled with tandem mass spectrometry for determination of vitamin B12 concentrations in milk and dairy products.

    Science.gov (United States)

    Zironi, E; Gazzotti, T; Barbarossa, A; Devicienti, C; Scardilli, M; Pagliuca, G

    2013-05-01

    A method using ultra performance liquid chromatography coupled with tandem mass spectrometry was developed to measure cobalamins in naturally enriched raw milk and to evaluate their fate during thermal treatments and along the process of cheese making. After addition of methotrexate as internal standard, samples were submitted to heat treatment in the presence of cyanide, which converts all the less-stable cobalamins into cyanocobalamin; then, purification was performed by a solid-phase extraction step. Reverse-phase ultra performance liquid chromatography separation coupled with tandem mass spectrometry provided a fast and reliable determination. Mass spectrometric analysis was carried out in multiple reaction monitoring mode. The monitored transitions were m/z 678.36 → 147.10 and 678.36 → 359.30 for vitamin B12 and m/z 455.22 → 175.13 and 455.22 → 308.22 for methotrexate (internal standard). The limit of quantification was 2 ng/g. The method showed good linearity from 2 to 20 ng/g (R(2) ≥ 0.98) and intra- and interday precisions were always less than 19%. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Quality by design approach in the development of an ultra-high-performance liquid chromatography method for Bexsero meningococcal group B vaccine.

    Science.gov (United States)

    Nompari, Luca; Orlandini, Serena; Pasquini, Benedetta; Campa, Cristiana; Rovini, Michele; Del Bubba, Massimo; Furlanetto, Sandra

    2018-02-01

    Bexsero is the first approved vaccine for active immunization of individuals from 2 months of age and older to prevent invasive disease caused by Neisseria meningitidis serogroup B. The active components of the vaccine are Neisseria Heparin Binding Antigen, factor H binding protein, Neisseria adhesin A, produced in Escherichia coli cells by recombinant DNA technology, and Outer Membrane Vesicles (expressing Porin A and Porin B), produced by fermentation of Neisseria meningitidis strain NZ98/254. All the Bexsero active components are adsorbed on aluminum hydroxide and the unadsorbed antigens content is a product critical quality attribute. In this paper the development of a fast, selective and sensitive ultra-high-performance liquid chromatography (UHPLC) method for the determination of the Bexsero antigens in the vaccine supernatant is presented. For the first time in the literature, the Quality by Design (QbD) principles were applied to the development of an analytical method aimed to the quality control of a vaccine product. The UHPLC method was fully developed within the QbD framework, the new paradigm of quality outlined in International Conference on Harmonisation guidelines. Critical method attributes (CMAs) were identified with the capacity factor of Neisseria Heparin Binding Antigen, antigens resolution and peak areas. After a scouting phase, aimed at selecting a suitable and fast UHPLC operative mode for the vaccine antigens separation, risk assessment tools were employed to define the critical method parameters to be considered in the screening phase. Screening designs were applied for investigating at first the effects of vial type and sample concentration, and then the effects of injection volume, column type, organic phase starting concentration, ramp time and temperature. Response Surface Methodology pointed out the presence of several significant interaction effects, and with the support of Monte-Carlo simulations led to map out the design space, at

  5. Chromatography of phosphorus oxoacids

    International Nuclear Information System (INIS)

    Ohashi, S.

    1975-01-01

    The present state of studies on the chromatographic separation of phosphorus oxoacids is surveyed. In this paper, chromatographic techniques are divided into four groups, i.e. paper and thin-layer chromatography, paper electrophoresis, ion-exchange chromatography, and gel chromatography. The separation mechanisms and characteristics for these chromatographic methods are discussed and some examples for the separation of phosphorus oxoacids are described. As examples of the application of ion-exchange and gel chromatography, studies on the hot atom chemistry of 32 P in solid inorganic phosphates and those on the substitution reactions between diphosphonate (diphosphite) and polyphosphates are reported. (author)

  6. Recent developments in methods for analysis of perfluorinated persistent pollutants

    International Nuclear Information System (INIS)

    Trojanowicz, Marek; Koc, Mariusz

    2013-01-01

    Perfluoroalkyl substances (PFASs) are proliferated into the environment on a global scale and present in the organisms of animals and humans even in remote locations. Persistent organic pollutants of that kind therefore have stimulated substantial improvement in analytical methods. The aim of this review is to present recent achievements in PFASs determination in various matrices with different methods and its comparison to measurements of Total Organic Fluorine (TOF). Analytical methods used for PFASs determinations are dominated by chromatography, mostly in combination with mass spectrometric detection. However, HPLC may be also hyphenated with conductivity or fluorimetric detection, and gas chromatography may be combined with flame ionization or electron capture detection. The presence of a large number of PFASs species in environmental and biological samples necessitates parallel attempts to develop a total PFASs index that reflects the total content of PFASs in various matrices. Increasing attention is currently paid to the determination of branched isomers of PFASs, and their determination in food. (author)

  7. Development of a magnetic solid-phase extraction coupled with high-performance liquid chromatography method for the analysis of polyaromatic hydrocarbons.

    Science.gov (United States)

    Ma, Yan; Xie, Jiawen; Jin, Jing; Wang, Wei; Yao, Zhijian; Zhou, Qing; Li, Aimin; Liang, Ying

    2015-07-01

    A novel magnetic solid phase extraction coupled with high-performance liquid chromatography method was established to analyze polyaromatic hydrocarbons in environmental water samples. The extraction conditions, including the amount of extraction agent, extraction time, pH and the surface structure of the magnetic extraction agent, were optimized. The results showed that the amount of extraction agent and extraction time significantly influenced the extraction performance. The increase in the specific surface area, the enlargement of pore size, and the reduction of particle size could enhance the extraction performance of the magnetic microsphere. The optimized magnetic extraction agent possessed a high surface area of 1311 m(2) /g, a large pore size of 6-9 nm, and a small particle size of 6-9 μm. The limit of detection for phenanthrene and benzo[g,h,i]perylene in the developed analysis method was 3.2 and 10.5 ng/L, respectively. When applied to river water samples, the spiked recovery of phenanthrene and benzo[g,h,i]perylene ranged from 89.5-98.6% and 82.9-89.1%, respectively. Phenanthrene was detected over a concentration range of 89-117 ng/L in three water samples withdrawn from the midstream of the Huai River, and benzo[g,h,i]perylene was below the detection limit. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Counter-current motion in counter-current chromatography.

    Science.gov (United States)

    Ito, Yoichiro

    2014-12-12

    After the CCC2012 meeting, I have received an e-mail regarding the terminology of "Countercurrent Chromatography". It stated that the term "Countercurrent" is a misnomer, because its stationary phase is motionless in the column and that the method should be renamed as liquid-liquid separations or centrifugal separations. However, it was found that these names are already used for various other techniques as found via Google search. The term "Countercurrent Chromatography" was originally made after two preparative methods of Countercurrent distribution and liquid Chromatography, both having no countercurrent motion in the column. However, it is surprising to find that this F1 hybrid method "Countercurrent Chromatography" can clearly exhibit countercurrent motion within the separation column in both hydrodynamic and hydrostatic equilibrium systems. This justifies that "Countercurrent Chromatography" is a proper term for this chromatographic method. Published by Elsevier B.V.

  9. 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

  10. Flow Rates in Liquid Chromatography, Gas Chromatography and Supercritical Fluid Chromatography: A Tool for Optimization

    Directory of Open Access Journals (Sweden)

    Joris Meurs

    2016-08-01

    Full Text Available This paper aimed to develop a standalone application for optimizing flow rates in liquid chromatography (LC, gas chromatography (GC and supercritical fluid chromatography (SFC. To do so, Van Deemter’s equation, Knox’ equation and Golay’s equation were implemented in a MATLAB script and subsequently a graphical user interface (GUI was created. The application will show the optimal flow rate or linear velocity and the corresponding plate height for the set input parameters. Furthermore, a plot will be shown in which the plate height is plotted against the linear flow velocity. Hence, this application will give optimized flow rates for any set conditions with minimal effort.

  11. Identification of Hepatoprotective Constituents in Limonium tetragonum and Development of Simultaneous Analysis Method using High-performance Liquid Chromatography

    Science.gov (United States)

    Lee, Jae Sun; Kim, Yun Na; Kim, Na-Hyun; Heo, Jeong-Doo; Yang, Min Hye; Rho, Jung-Rae; Jeong, Eun Ju

    2017-01-01

    Background: Limonium tetragonum, a naturally salt-tolerant halophyte, has been studied recently and is of much interest to researchers due to its potent antioxidant and hepatoprotective activities. Objective: In the present study, we attempted to elucidate bioactive compounds from ethyl acetate (EtOAc) soluble fraction of L. tetragonum extract. Furthermore, the simultaneous analysis method of bioactive EtOAc fraction of L. tetragonum has been developed using high-performance liquid chromatography (HPLC). Materials and Methods: Thirteen compounds have been successfully isolated from EtOAc fraction of L. tetragonum, and the structures of 1–13 were elucidated by extensive one-dimensional and two-dimensional spectroscopic methods including 1H-NMR, 13C-NMR, 1H-1H COSY, heteronuclear single quantum coherence, heteronuclear multiple bond correlation, and nuclear Overhauser effect spectroscopy. Hepatoprotection of the isolated compounds against liver fibrosis was evaluated by measuring inhibition on hepatic stellate cells (HSCs) undergoing proliferation. Results: Compounds 1–13 were identified as gallincin (1), apigenin-3-O-β-D-galactopyranoside (2), quercetin (3), quercetin-3-O-β-D-galactopyranoside (4), (−)-epigallocatechin (5), (−)-epigallocatechin-3-gallate (6), (−)-epigallocatechin-3-(3″-O-methyl) gallate (7), myricetin-3-O-β-D-galactopyranoside (8), myricetin-3-O-(6″-O-galloyl)-β-D-galactopyranoside (9), myricetin-3-O-α-L-rhamnopyranoside (10), myricetin-3-O-(2″-O-galloyl)-α-L-rhamnopyranoside (11), myricetin-3-O-(3″-O-galloyl)-α-L-rhamnopyranoside (12), and myricetin-3-O-α-L-arabinopyranoside (13), respectively. All compounds except for 4, 8, and 10 are reported for the first time from this plant. Conclusion: Myricetin glycosides which possess galloyl substituent (9, 11, and 12) showed most potent inhibitory effects on the proliferation of HSCs. SUMMARY In the present study, we have successfully isolated 13 compounds from bioactive fraction

  12. Application of liquid column chromatography to preconcentration, separation and determination of platinum metals

    International Nuclear Information System (INIS)

    Alimarin, I.P.; Basova, E.M.; Bol'shova, T.A.; Ivanov, V.M.

    1986-01-01

    Separation and determination of platimum metals using the methods of adsorption, ion-pair, ion-exchange, distributing and sieve chromatography are discussed in the review of literature in 1971-1984. Separation and determination of metals as chelates using the method of adsorption and ion-pair chromatograpy are noted to be most perspective directions of developing highly effective liquid chromatography of inorganic systems

  13. A single-run liquid chromatography mass spectrometry method to quantify neuroactive kynurenine pathway metabolites in rat plasma.

    Science.gov (United States)

    Orsatti, Laura; Speziale, Roberto; Orsale, Maria Vittoria; Caretti, Fulvia; Veneziano, Maria; Zini, Matteo; Monteagudo, Edith; Lyons, Kathryn; Beconi, Maria; Chan, Kelvin; Herbst, Todd; Toledo-Sherman, Leticia; Munoz-Sanjuan, Ignacio; Bonelli, Fabio; Dominguez, Celia

    2015-03-25

    Neuroactive metabolites in the kynurenine pathway of tryptophan catabolism are associated with neurodegenerative disorders. Tryptophan is transported across the blood-brain barrier and converted via the kynurenine pathway to N-formyl-L-kynurenine, which is further degraded to L-kynurenine. This metabolite can then generate a group of metabolites called kynurenines, most of which have neuroactive properties. The association of tryptophan catabolic pathway alterations with various central nervous system (CNS) pathologies has raised interest in analytical methods to accurately quantify kynurenines in body fluids. We here describe a rapid and sensitive reverse-phase HPLC-MS/MS method to quantify L-kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxy-L-kynurenine (3HK) and anthranilic acid (AA) in rat plasma. Our goal was to quantify these metabolites in a single run; given their different physico-chemical properties, major efforts were devoted to develop a chromatography suitable for all metabolites that involves plasma protein precipitation with acetonitrile followed by chromatographic separation by C18 RP chromatography, detected by electrospray mass spectrometry. Quantitation range was 0.098-100 ng/ml for 3HK, 9.8-20,000 ng/ml for KYN, 0.49-1000 ng/ml for KYNA and AA. The method was linear (r>0.9963) and validation parameters were within acceptance range (calibration standards and QC accuracy within ±30%). Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Quantitative bioanalytical and analytical method development of dibenzazepine derivative, carbamazepine: A review ☆

    OpenAIRE

    Datar, Prasanna A.

    2015-01-01

    Bioanalytical methods are widely used for quantitative estimation of drugs and their metabolites in physiological matrices. These methods could be applied to studies in areas of human clinical pharmacology and toxicology. The major bioanalytical services are method development, method validation and sample analysis (method application). Various methods such as GC, LC–MS/MS, HPLC, HPTLC, micellar electrokinetic chromatography, and UFLC have been used in laboratories for the qualitative and qua...

  15. Analysis of Biological Interactions by Affinity Chromatography: Clinical and Pharmaceutical Applications.

    Science.gov (United States)

    Hage, David S

    2017-06-01

    The interactions between biochemical and chemical agents in the body are important in many clinical processes. Affinity chromatography and high-performance affinity chromatography (HPAC), in which a column contains an immobilized biologically related binding agent, are 2 methods that can be used to study these interactions. This review presents various approaches that can be used in affinity chromatography and HPAC to characterize the strength or rate of a biological interaction, the number and types of sites that are involved in this process, and the interactions between multiple solutes for the same binding agent. A number of applications for these methods are examined, with an emphasis on recent developments and high-performance affinity methods. These applications include the use of these techniques for fundamental studies of biological interactions, high-throughput screening of drugs, work with modified proteins, tools for personalized medicine, and studies of drug-drug competition for a common binding agent. The wide range of formats and detection methods that can be used with affinity chromatography and HPAC for examining biological interactions makes these tools attractive for various clinical and pharmaceutical applications. Future directions in the development of small-scale columns and the coupling of these methods with other techniques, such as mass spectrometry or other separation methods, should continue to increase the flexibility and ease with which these approaches can be used in work involving clinical or pharmaceutical samples. © 2016 American Association for Clinical Chemistry.

  16. Optimization and validation of liquid chromatography and headspace-gas chromatography based methods for the quantitative determination of capsaicinoids, salicylic acid, glycol monosalicylate, methyl salicylate, ethyl salicylate, camphor and l-menthol in a topical formulation.

    Science.gov (United States)

    Pauwels, Jochen; D'Autry, Ward; Van den Bossche, Larissa; Dewever, Cédric; Forier, Michel; Vandenwaeyenberg, Stephanie; Wolfs, Kris; Hoogmartens, Jos; Van Schepdael, Ann; Adams, Erwin

    2012-02-23

    Capsaicinoids, salicylic acid, methyl and ethyl salicylate, glycol monosalicylate, camphor and l-menthol are widely used in topical formulations to relieve local pain. For each separate compound or simple mixtures, quantitative analysis methods are reported. However, for a mixture containing all above mentioned active compounds, no assay methods were found. Due to the differing physicochemical characteristics, two methods were developed and optimized simultaneously. The non-volatile capsaicinoids, salicylic acid and glycol monosalicylate were analyzed with liquid chromatography following liquid-liquid extraction, whereas the volatile compounds were analyzed with static headspace-gas chromatography. For the latter method, liquid paraffin was selected as compatible dilution solvent. The optimized methods were validated in terms of specificity, linearity, accuracy and precision in a range of 80% to 120% of the expected concentrations. For both methods, peaks were well separated without interference of other compounds. Linear relationships were demonstrated with R² values higher than 0.996 for all compounds. Accuracy was assessed by performing replicate recovery experiments with spiked blank samples. Mean recovery values were all between 98% and 102%. Precision was checked at three levels: system repeatability, method precision and intermediate precision. Both methods were found to be acceptably precise at all three levels. Finally, the method was successfully applied to the analysis of some real samples (cutaneous sticks). Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Development of a gas chromatography-mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere.

    Science.gov (United States)

    Borrás, E; Sánchez, P; Muñoz, A; Tortajada-Genaro, L A

    2011-08-05

    A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography-mass spectrometry (GC-MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1). Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5±1%, a reproducibility of 13±3% and detection limits of 0.05-0.18 pg m(-3) for the particulate phase and 26-88 pg m(-3) for the gaseous phase. Finally, the methodology was successfully applied to rural and agricultural samples in the Mediterranean area. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Fast methods for screening of trichothecenes in fungal cultures using gas chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Kristian Fog; Thrane, Ulf

    2001-01-01

    The paper presents a fast method for trichothecene profiling and chemotaxonomic studies in species of Fusarium, Stachybotrys, Trichoderma and Memnoniella. Micro scale extracted crude Fusarium extracts were derivatised using pentafluoropropionic anhydride and analysed by gas chromatography...

  19. Development and validation of an ultra-high performance liquid chromatography-tandem mass spectrometry method to measure creatinine in human urine.

    Science.gov (United States)

    Fraselle, S; De Cremer, K; Coucke, W; Glorieux, G; Vanmassenhove, J; Schepers, E; Neirynck, N; Van Overmeire, I; Van Loco, J; Van Biesen, W; Vanholder, R

    2015-04-15

    Despite decades of creatinine measurement in biological fluids using a large variety of analytical methods, an accurate determination of this compound remains challenging. Especially with the novel trend to assess biomarkers on large sample sets preserved in biobanks, a simple and fast method that could cope with both a high sample throughput and a low volume of sample is still of interest. In answer to these challenges, a fast and accurate ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to measure creatinine in small volumes of human urine. In this method, urine samples are simply diluted with a basic mobile phase and injected directly under positive electrospray ionization (ESI) conditions, without further purification steps. The combination of an important diluting factor (10(4) times) due to the use of a very sensitive triple quadrupole mass spectrometer (XEVO TQ) and the addition of creatinine-d3 as internal standard completely eliminates matrix effects coming from the urine. The method was validated in-house in 2012 according to the EMA guideline on bioanalytical method validation using Certified Reference samples from the German External Quality Assessment Scheme (G-Equas) proficiency test. All obtained results for accuracy and recovery are within the authorized tolerance ranges defined by G-Equas. The method is linear between 0 and 5 g/L, with LOD and LOQ of 5 × 10(-3) g/L and 10(-2) g/L, respectively. The repeatability (CV(r) = 1.03-2.07%) and intra-laboratory reproducibility (CV(RW) = 1.97-2.40%) satisfy the EMA 2012 guideline. The validated method was firstly applied to perform the German G-Equas proficiency test rounds 51 and 53, in 2013 and 2014, respectively. The obtained results were again all within the accepted tolerance ranges and very close to the reference values defined by the organizers of the proficiency test scheme, demonstrating an excellent accuracy of the developed method. The

  20. A new liquid chromatography - tandem mass spectrometry method using atmospheric pressure photo ionization for the simultaneous determination of azaarenes and azaarones in Dutch river sediments

    NARCIS (Netherlands)

    Brulik, J.; Simek, Z.; de Voogt, P.

    2013-01-01

    A new method for the analysis of azaarenes and their degradation products (azaarones) was developed, optimized and validated using liquid chromatography coupled with atmospheric pressure photo ionization tandem mass spectrometric detection (LC-APPI/MS/MS). Seventeen compounds including 4 PAHs

  1. Determination of Alternaria mycotoxins in wine and juice using ionic liquid modified countercurrent chromatography as a pretreatment method followed by high-performance liquid chromatography.

    Science.gov (United States)

    Fan, Chen; Cao, Xueli; Liu, Man; Wang, Wei

    2016-03-04

    Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants in food materials. The objective of this study was to develop a pretreatment method with countercurrent chromatography (CCC) for enrichment and cleanup of trace Alternaria mycotoxins in food samples prior to high-performance liquid chromatography (HPLC) analysis. An Analytical CCC instrument with a column volume 22.5mL was used, and a two-phase solvent system composed of ethyl acetate and water modified with 6% [HOOMIM][Cl] in mass to volume ratio was selected. Under the optimized CCC operation conditions, trace amounts of AOH, AME, and TeA in large volume of liquid sample were efficiently extracted and enriched in the stationary phase, and then eluted out just by reversing the stationary phase as mobile phase in the opposite flowing direction tail-to-head. The enrichment and elution strategies are unique and can be fulfilled online with high enrichment factors (87-114) and high recoveries (81.14-110.94%). The method has been successively applied to the determination of Alternaria mycotoxins in real apple juice and wine samples with the limits of detection (LOD) in the range of 0.03-0.14μgL(-1). Totally 12 wine samples and 15 apple juice samples from the local market were analyzed. The detection rate of AOH and AME in both kinds of the samples were more than 50%, while TeA was found in relatively high level of 1.75-49.61μgL(-1) in some of the apple juice samples. The proposed method is simple, rapid, and sensitive and could also be used for the analysis and monitoring of Alternaria mycotoxin in other food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A novel liquid chromatography method using diode-array detector for the determination of oleuropein in dietary supplements.

    Science.gov (United States)

    Bertolini, Tiziana; Vicentini, Lorenza; Boschetti, Silvia; Andreatta, Paolo; Gatti, Rita

    2016-09-10

    A simple and fast chromatographic method using ultraviolet diode-array detector (UV-DAD) was developed for the automatic high performance liquid chromatography (HPLC) determination of the title of oleuropein in a new dietary supplements in form of effervescent granules. The chromatographic separations were performed on a C18 core-shell column with detection at λ=232nm. The mobile phase consisted of deionized water with 0.1% TFA and acetonitrile under gradient conditions at a flow-rate of 0.8mL/min. Oleuropein and oleuroside present in the raw material were characterized by high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The validation of the analytical procedure has been performed determining the following parameters: specificity, linearity, repeatability, reproducibility, accuracy, limit of quantification (LOQ), stability of the standard and sample solutions. Linear response was observed in fortified placebo solutions (determination coefficient: 0.9998). Intra-day precision (relative standard deviation, RSD) was ≤5.0% for peak area and for retention times (tR) without significant differences between intra- and inter-day data. The limits of quantitation (LOQ) was about 5μg/mL and 9pmol/inject. Oleuropein recovery studies gave good results (99.9%) with a R.S.D. of 0.5%. The speed of analysis and the stability of the solutions with a fluctuation Δ (%) ≤2.0 at room temperature means an undoubted advantage of the method allowing the simultaneous preparation of many samples and consecutive chromatographic analyses by using an autosampler. The developed method is suitable for the quality control of oleuropein in raw material and industrial products. The method can be applied in any analytical laboratory not requiring a sophisticated instrumentation. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. The effect of improved chromatography on GDGT-based palaeoproxies

    NARCIS (Netherlands)

    Hopmans, E.C.; Schouten, S.; Sinninghe Damsté, J.S.

    2016-01-01

    The development of methods using liquid chromatography coupled to mass spectrometry to analyze glycerol dialkyl glycerol tetraethers (GDGTs) has substantially expanded the biomarker tool box and led to the development of several new proxies. Recent studies have shown that new high performance liquid

  4. Quality evaluation of moluodan concentrated pill using high-performance liquid chromatography fingerprinting coupled with chemometrics.

    Science.gov (United States)

    Tao, Lingyan; Zhang, Qing; Wu, Yongjiang; Liu, Xuesong

    2016-12-01

    In this study, a fast and effective high-performance liquid chromatography method was developed to obtain a fingerprint chromatogram and quantitative analysis simultaneously of four indexes including gallic acid, chlorogenic acid, albiflorin and paeoniflorin of the traditional Chinese medicine Moluodan Concentrated Pill. The method was performed by using a Waters X-bridge C 18 reversed phase column on an Agilent 1200S high-performance liquid chromatography system coupled with diode array detection. The mobile phase of the high-performance liquid chromatography method was composed of 20 mmol/L phosphate solution and acetonitrile with a 1 mL/min eluent velocity, under a detection temperature of 30°C and a UV detection wavelength of 254 nm. After the methodology validation, 16 batches of Moluodan Concentrated Pill were analyzed by this high-performance liquid chromatography method and both qualitative and quantitative evaluation results were achieved by similarity analysis, principal component analysis and hierarchical cluster analysis. The results of these three chemometrics were in good agreement and all indicated that batch 10 and batch 16 showed significant differences with the other 14 batches. This suggested that the developed high-performance liquid chromatography method could be applied in the quality evaluation of Moluodan Concentrated Pill. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Methods in endogenous steroid profiling - A comparison of gas chromatography mass spectrometry (GC-MS) with supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS).

    Science.gov (United States)

    Teubel, Juliane; Wüst, Bernhard; Schipke, Carola G; Peters, Oliver; Parr, Maria Kristina

    2018-06-15

    In various fields of endocrinology, the determination of steroid hormones synthesised by the human body plays an important role. Research on central neurosteroids has been intensified within the last years, as they are discussed as biomarkers for various cognitive disorders. Their concentrations in cerebrospinal fluid (CSF) are considered to be regulated independently from peripheral fluids. For that reason, the challenging matrix CSF becomes a very interesting specimen for analysis. Concentrations are expected to be very low and available amount of CSF is limited. Thus, a comprehensive method for very sensitive quantification of a set of analytes as large as possible in one analytical aliquot is desired. However, high structural similarities of the selected panel of 51 steroids and steroid sulfates, including numerous isomers, challenges achievement of chromatographic selectivity. Since decades the analysis of endogenous steroids in various body fluids is mainly performed by gas chromatography (GC) coupled to (tandem) mass spectrometry (MS(/MS)). Due to the structure of the steroids of interest, derivatisation is performed to meet the analytical requirements for GC-MS(/MS). Most of the laboratories use a two-step derivatisation in multi-analyte assays that was already published in the 1980s. However, for some steroids this elaborate procedure yields multiple isomeric derivatives. Thus, some laboratories utilize (ultra) high performance liquid chromatography ((U)HPLC)-MS/MS as alternative but, even UHPLC is not able to separate some of the isomeric pairs. Supercritical fluid chromatography (SFC) as an orthogonal separation technique to GC and (U)HPLC may help to overcome these issues. Within this project the two most promising methods for endogenous steroid profiling were investigated and compared: the "gold standard" GC-MS and the orthogonal separation technique SFC-MS/MS. Different derivatisation procedures for gas chromatographic detection were explored and the

  6. Analysis of residual toluene in food packaging via headspace extraction method using gas chromatography

    International Nuclear Information System (INIS)

    Lim, Ying Chin; Mohd Marsin Sanagi

    2008-01-01

    Polymeric materials are used in many food contact applications as packaging material. The presence of residual toluene in this food packaging material can migrate into food and thus affect the quality of food. In this study, a manual headspace analysis was successfully designed and developed. The determination of residual toluene was carried out with standard addition method and multiple headspace extraction, MHE) method using gas chromatography-flame ionization detector, GC-FID). Identification of toluene was performed by comparison of its retention time with standard toluene and GC-MS. It was found that the suitable heating temperature was 180 degree Celsius with an optimum heating time of 10 minutes. The study also found that the concentration of residual toluene in multicolored sample was higher compared to mono colored sample whereas residual toluene in sample analyzed using standard addition method was higher compared to MHE method. However, comparison with the results obtained from De Paris laboratory, France found that MHE method gave higher accuracy for sample with low analyte concentration. On the other hand, lower accuracy was obtained for sample with high concentration of residual toluene due to systematic errors. Comparison between determination methods showed that MHE method is more precise compared to standard addition method. (author)

  7. Method development and validation of liquid chromatography-tandem/mass spectrometry for aldosterone in human plasma: Application to drug interaction study of atorvastatin and olmesartan combination

    Directory of Open Access Journals (Sweden)

    Rakesh Das

    2014-01-01

    Full Text Available In the present investigation, a simple and sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS method was developed for the quantification of aldosterone (ALD a hormone responsible for blood pressure in human plasma. The developed method was validated and extended for application on human subjects to study drug interaction of atorvastatin (ATSV and olmesartan (OLM on levels of ALD. The ALD in plasma was extracted by liquid-liquid extraction with 5 mL dichloromethane/ethyl ether (60/40% v/v. The chromatographic separation of ALD was carried on Xterra, RP-Column C18 (150 mm× 4.6 mm × 3.5 μm at 30°C followed by four-step gradient program composed of methanol and water. Step 1 started with 35% methanol for first 1 min and changed linearly to 90% in next 1.5 min in Step 2. Step 3 lasted for next 2 min with 90% methanol. The method finally concluded with Step 4 to achieve initial concentration of methanol that is, 35% thus contributing the total method run time of 17.5 min. The flow rate was 0.25 mL/min throughout the process. The developed method was validated for specificity, accuracy, precision, stability, linearity, sensitivity, and recovery. The method was linear and found to be acceptable over the range of 50-800 ng/mL. The method was successfully applied for the drug interaction study of ATSV + OLM in combination against OLM treatment on blood pressure by quantifying changes in levels of ALD in hypertensive patients. The study revealed levels of ALD were significantly higher in ATSV + OLM treatment condition when compared to OLM as single treated condition. This reflects the reason of low effectiveness of ATSV + OLM in combination instead of synergistic activity.

  8. A method for screening active components from Chinese herbs by cell membrane chromatography-offline-high performance liquid chromatography/mass spectrometry and an online statistical tool for data processing.

    Science.gov (United States)

    Cao, Yan; Wang, Shaozhan; Li, Yinghua; Chen, Xiaofei; Chen, Langdong; Wang, Dongyao; Zhu, Zhenyu; Yuan, Yongfang; Lv, Diya

    2018-03-09

    Cell membrane chromatography (CMC) has been successfully applied to screen bioactive compounds from Chinese herbs for many years, and some offline and online two-dimensional (2D) CMC-high performance liquid chromatography (HPLC) hyphenated systems have been established to perform screening assays. However, the requirement of sample preparation steps for the second-dimensional analysis in offline systems and the need for an interface device and technical expertise in the online system limit their extensive use. In the present study, an offline 2D CMC-HPLC analysis combined with the XCMS (various forms of chromatography coupled to mass spectrometry) Online statistical tool for data processing was established. First, our previously reported online 2D screening system was used to analyze three Chinese herbs that were reported to have potential anti-inflammatory effects, and two binding components were identified. By contrast, the proposed offline 2D screening method with XCMS Online analysis was applied, and three more ingredients were discovered in addition to the two compounds revealed by the online system. Then, cross-validation of the three compounds was performed, and they were confirmed to be included in the online data as well, but were not identified there because of their low concentrations and lack of credible statistical approaches. Last, pharmacological experiments showed that these five ingredients could inhibit IL-6 release and IL-6 gene expression on LPS-induced RAW cells in a dose-dependent manner. Compared with previous 2D CMC screening systems, this newly developed offline 2D method needs no sample preparation steps for the second-dimensional analysis, and it is sensitive, efficient, and convenient. It will be applicable in identifying active components from Chinese herbs and practical in discovery of lead compounds derived from herbs. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. 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.

  10. Use of micro gas chromatography in the fuel cycle of fusion reactors

    International Nuclear Information System (INIS)

    Laesser, R.; Gruenhagen, S.; Kawamura, Y.

    2003-01-01

    Various analytical techniques exist to determine the compositions of gases handled in the fuel cycle of future fusion machines. Gas chromatography was found to be the most appropriate method. The main disadvantages of conventional gas chromatography were the long retention times for the heavy hydrogen species of >30 min. Recent progress in the development of micro-gas chromatography has reduced these retention times to ∼3 min. The usefulness of micro-gas chromatography for the analysis of hydrogen and impurity gas mixtures in the fuel cycle of future fusion machines is presented and the advantages and drawbacks are discussed

  11. The contribution of photosynthetic pigments to the development of biochemical separation methods: 1900-1980.

    Science.gov (United States)

    Albertsson, Per-Ake

    2003-01-01

    The role of photosynthetic pigments in the development of separation methods in biochemistry during the period 1900-1980 is described beginning with M. Tswett who introduced separation of chlorophylls and carotenoids on columns and coined the term chromatography in 1906. In Uppsala, T. Svedberg developed the ultracentrifuge in the 1920s. A. Tiselius improved electrophoresis in the 1930s and developed chromatography of proteins in the 1940s and 1950s. Others of 'The Uppsala school in separation science' include J. Porath, P. Flodin and S. Hjertén who further developed various gel chromatographic methods. Hjertén introduced free zone electrophoresis in narrow tubes, a forerunner of capillary electrophoresis. Two proteins, phycoerythrin and phycocyanin, were used as test substances in all these methodological studies. Aqueous two-phase partitioning as a separation method was introduced in 1956 by the author. In this work, chloroplast particles were used, and the method was applied for the separation and purification of intact chloroplasts, inside-out thylakoid vesicles and plasma membranes. My research was carried out in cooperation with G. Blomquist, G. Johansson, C. Larsson, B. Andersson and H.-E. Akerlund during a 20-year period, 1960-1980.

  12. Affinity monolith chromatography: A review of principles and recent analytical applications

    Science.gov (United States)

    Pfaunmiller, Erika L.; Paulemond, Marie Laura; Dupper, Courtney M.; Hage, David S.

    2012-01-01

    Affinity monolith chromatography (AMC) is a type of liquid chromatography that uses a monolithic support and a biologically-related binding agent as a stationary phase. AMC is a powerful method for the selective separation, analysis or studies of specific target compounds in a sample. This review discusses the basic principles of AMC and recent developments or applications of this method, with particular emphasis being given to work that has appeared in the last five years. Various materials that have been used to prepare columns for AMC are examined, including organic monoliths, silica monoliths, agarose monoliths and cryogels. These supports have been used in AMC for formats that have ranged from traditional columns to disks, microcolumns and capillaries. Many binding agents have also been employed in AMC, such as antibodies, enzymes, proteins, lectins, immobilized metal-ions and dyes. Some applications that have been reported with these binding agents in AMC are bioaffinity chromatography, immunoaffinity chromatography or immunoextraction, immobilized metal-ion affinity chromatography, dye-ligand affinity chromatography, chiral separations and biointeraction studies. Examples are presented from fields that include analytical chemistry, pharmaceutical analysis, clinical testing and biotechnology. Current trends and possible future directions in AMC are also discussed. PMID:23187827

  13. A Study of Method Development, Validation, and Forced Degradation for Simultaneous Quantification of Paracetamol and Ibuprofen in Pharmaceutical Dosage Form by RP-HPLC Method

    OpenAIRE

    Jahan, Md. Sarowar; Islam, Md. Jahirul; Begum, Rehana; Kayesh, Ruhul; Rahman, Asma

    2014-01-01

    A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP) guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and...

  14. Analytical Method Validation of High-Performance Liquid Chromatography and Stability-Indicating Study of Medroxyprogesterone Acetate Intravaginal Sponges

    Directory of Open Access Journals (Sweden)

    Nidal Batrawi

    2017-02-01

    Full Text Available Medroxyprogesterone acetate is widely used in veterinary medicine as intravaginal dosage for the synchronization of breeding cycle in ewes and goats. The main goal of this study was to develop reverse-phase high-performance liquid chromatography method for the quantification of medroxyprogesterone acetate in veterinary vaginal sponges. A single high-performance liquid chromatography/UV isocratic run was used for the analytical assay of the active ingredient medroxyprogesterone. The chromatographic system consisted of a reverse-phase C18 column as the stationary phase and a mixture of 60% acetonitrile and 40% potassium dihydrogen phosphate buffer as the mobile phase; the pH was adjusted to 5.6. The method was validated according to the International Council for Harmonisation (ICH guidelines. Forced degradation studies were also performed to evaluate the stability-indicating properties and specificity of the method. Medroxyprogesterone was eluted at 5.9 minutes. The linearity of the method was confirmed in the range of 0.0576 to 0.1134 mg/mL ( R 2 > 0.999. The limit of quantification was shown to be 3.9 µg/mL. Precision and accuracy ranges were found to be %RSD <0.2 and 98% to 102%, respectively. Medroxyprogesterone capacity factor value of 2.1, tailing factor value of 1.03, and resolution value of 3.9 were obtained in accordance with ICH guidelines. Based on the obtained results, a rapid, precise, accurate, sensitive, and cost-effective analysis procedure was proposed for quantitative determination of medroxyprogesterone in vaginal sponges. This analytical method is the only available method to analyse medroxyprogesterone in veterinary intravaginal dosage form.

  15. Determination of Oxidized Phosphatidylcholines by Hydrophilic Interaction Liquid Chromatography Coupled to Fourier Transform Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Pia Sala

    2015-04-01

    Full Text Available A novel liquid chromatography-mass spectrometry (LC-MS approach for analysis of oxidized phosphatidylcholines by an Orbitrap Fourier Transform mass spectrometer in positive electrospray ionization (ESI coupled to hydrophilic interaction liquid chromatography (HILIC was developed. This method depends on three selectivity criteria for separation and identification: retention time, exact mass at a resolution of 100,000 and collision induced dissociation (CID fragment spectra in a linear ion trap. The process of chromatography development showed the best separation properties with a silica-based Kinetex column. This type of chromatography was able to separate all major lipid classes expected in mammalian samples, yielding increased sensitivity of oxidized phosphatidylcholines over reversed phase chromatography. Identification of molecular species was achieved by exact mass on intact molecular ions and CID tandem mass spectra containing characteristic fragments. Due to a lack of commercially available standards, method development was performed with copper induced oxidation products of palmitoyl-arachidonoyl-phosphatidylcholine, which resulted in a plethora of lipid species oxidized at the arachidonoyl moiety. Validation of the method was done with copper oxidized human low-density lipoprotein (LDL prepared by ultracentrifugation. In these LDL samples we could identify 46 oxidized molecular phosphatidylcholine species out of 99 possible candidates.

  16. Development and validation of a high-performance liquid chromatography method for determination of lisinopril in human plasma by magnetic solid-phase extraction and pre-column derivatization.

    Science.gov (United States)

    Rastkari, Noushin; Ahmadkhaniha, Reza

    2018-03-01

    A sensitive, reliable and simple HPLC method was developed for the determination of lisinopril in human plasma. The method consists of extraction and clean-up steps based on magnetic solid-phase extraction and pre-column derivatization with a fluorescent reagent. The mobile phase consisted of a mixture of methanol-sodium dihydrogen phosphate (pH 3.0; 0.005 m; 75:25, v/v). The flow rate was set at 0.7 mL/min. Fluorescence detection was performed at 470nm excitation and 530nm emission wavelengths. Total chromatography run time was 5 min. The average extraction recovery of lisinopril and fluvoxamine (internal standard) was ≥82.8%. The limits of detection and quantification were determined as 1 and 3 ng/mL respectively. The method exhibited a linear calibration line over the concentration range of 3-1000 ng/mL with coefficient of determination (r 2 ) of ≥0.98. The within-run and between-run precisions were satisfactory with values of CV of 1.8-12.8% (accuracy from 99.2 to 94.7%) and 2.4-13.7% (accuracy from 99.5 to 92.2%), respectively. These developments led to considerable improvement in method sensitivity and reliability. The method was validated according to the US Food and Drug Administration guidelines. Therefore, it can be considered as a suitable method for determination of lisinopril in plasma samples. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Application of coupled affinity-sizing chromatography for the detection of proteolyzed HSA-tagged proteins.

    Science.gov (United States)

    London, Anne Serdakowski; Patel, Kunal; Quinn, Lisa; Lemmerer, Martin

    2015-04-01

    Coupled affinity liquid chromatography and size exclusion chromatography (ALC-SEC) is a technique that has been shown to successfully report product quality of proteins during cell expression and prior to the commencement of downstream processing chromatography steps. This method was applied to monitoring the degradation and subsequent partial remediation of a HSA-tagged protein which showed proteolysis, allowing for rapid cell line development to address this product quality dilemma. This paper outlines the novel application of this method for measuring and addressing protease-induced proteolysis. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Contribution of chromatography and hyphenated technology to production process development for pharma chemicals

    International Nuclear Information System (INIS)

    Ueda, Masafumi; Fujii, Yoshimi; Nakamura, Tomokazu

    2010-01-01

    'Chromatography' is an indispensable technique for treating small organic molecules, and 'Hyphenated Technology', which means a combination of two different techniques (in this case, chromatography and mass spectrometry, etc.), is a powerful tool for quick on-line identification of trace amount impurities in processes. During production process development for active pharmaceutical ingredients (APIs) and reactive intermediates, these techniques are mainly utilized for confirmation of synthesized target molecules, by-products and impurities, and also for their identification. This paper describes the contribution of these techniques to process study acceleration and product quality improvement, while showing some examples. (author)

  19. A high performance liquid chromatography method for determination of furfural in crude palm oil.

    Science.gov (United States)

    Loi, Chia Chun; Boo, Huey Chern; Mohammed, Abdulkarim Sabo; Ariffin, Abdul Azis

    2011-09-01

    A modified steam distillation method was developed to extract furfural from crude palm oil (CPO). The collected distillates were analysed using high performance liquid chromatography (HPLC) coupled with an ultraviolet diode detector at 284nm. The HPLC method allowed identification and quantification of furfural in CPO. The unique thermal extraction of CPO whereby the fresh fruit bunches (FFB) are first subjected to steam treatment, distinguishes itself from other solvent-extracted or cold-pressed vegetable oils. The presence of furfural was also determined in the fresh palm oil from FFB (without undergoing the normal extraction process), palm olein, palm stearin, olive oil, coconut oil, sunflower oil, soya oil and corn oil. The chromatograms of the extracts were compared to that of standard furfural. Furfural was only detected in CPO. The CPO consignments obtained from four mills were shown to contain 7.54 to 20.60mg/kg furfural. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Integration of gas chromatography mass spectrometry methods for differentiating ricin preparation methods.

    Science.gov (United States)

    Wunschel, David S; Melville, Angela M; Ehrhardt, Christopher J; Colburn, Heather A; Victry, Kristin D; Antolick, Kathryn C; Wahl, Jon H; Wahl, Karen L

    2012-05-07

    The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of Ricinus communis, commonly known as the castor plant. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatography-mass spectrometry (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid, as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods, starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid, or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method, independent of the seed source. In particular, the abundance of mannose, arabinose, fucose, ricinoleic acid, and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation than would be possible using a single analytical method.

  1. Analysis of Fluconazole in Human Urine Sample by High Performance Liquid Chromatography Method

    International Nuclear Information System (INIS)

    Hermawan, D; Ali, N A Md; Ibrahim, W A Wan; Sanagi, M M

    2013-01-01

    A method for determination of fluconazole, antifungal drug in human urine by using reversed-phased high performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detector was developed. Optimization HPLC conditions were carried out by changing the flow rate and composition of mobile phase. The optimum separation conditions at a flow rate 0.85 mL/min with a composition of mobile phase containing methanol:water (70:30, v/v) with UV detection at a wavelength 254 nm was able to analyze fluconazole within 3 min. The excellent linearity was obtained in the range of concentration 1 to 10 μg/mL with r 2 = 0.998. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.39 μg/mL and 1.28 μg/mL, respectively. Solid phase extraction (SPE) method using octadecylsilane (C18) as a sorbent was used to clean-up and pre-concentrated of the urine sample prior to HPLC analysis. The average recoveries of fluconazole in spiked urine sample was 72.4% with RSD of 3.21% (n=3).

  2. Electrochemical Detectors in HPLC and Ion Chromatography.

    Science.gov (United States)

    Horvai, George; Pungor, ErnÕ

    1989-01-01

    Back in 1952, the renowned Polish electrochemist Wiktor Kemula introduced chromato-polarography, 1 i.e., polaro-graphic detection for liquid chromatography. This technique continued to develop slowly until the early 1970s (for a review see Reference 2) when modem high-performance liquid chromatography (HPLC) emerged. This new, highly efficient chromatographc method could only be. used with detectors ensuring low dispersion. It was not easy to modify the dropping mercury electrode cells to satisfy this requirement. However, at the same time, electroanalytical chemists, who already had much experience in using carbon-based electrodes for oxidative detection in flow analysis, put forward the idea of oxidative amperometric detection in liquid chromatography. 3,4 In this technique, solid or quasi-solid (paste) electrodes were used and this made possible the construction of miniaturized cells with just a few microliter volume.

  3. XII All-Russian conference on gas chromatography. Program. Summary of reports

    International Nuclear Information System (INIS)

    2002-01-01

    Program and summary of reports of the XII All-Russian conference on gas chromatography are performed. The conference took place in Samara, 10-14 June, 2002. Reports on physicochemical regularities of gas chromatography, application of chromatographic methods in atomic energetics are included in the program of the conference. Part of the reports are deleted to the analytical application of the gas chromatography. Adsorbents for the gas chromatography, complex methods, mathematic methods in chromatography, ecological aspects of the gas chromatography [ru

  4. Thin-layer and paper chromatography

    International Nuclear Information System (INIS)

    Sherma, J.

    1986-01-01

    This selective review covers the literature of thin-layer chromatography (TLC) and paper chromatography (PC) cited in Chemical Abstracts from December 5, 1983, through November 25, 1985, and Analytical Abstracts from November 1983 to November 1985. Also researched directly were the following important journals publishing papers on TLC and PC: the Journal of Chromatography (including its bibliography issues), Journal of High Resolution Chromatography and Chromatography Communications, Journal of Chromatographic Science, Chromatographia, Analytical Chemistry, JAOAC, and the special TLC issues of the Journal of Liquid Chromatography. Many of the inherent advantages of TLC that are obvious to workers familiar with high performance, quantitative theory and practice still are not appreciated adequately by the majority of people using chromatography. These include unrestricted access to the separation process; introducing magnetic, thermal, electrical, and other physical forces to improve resolution; high sample throughput; truly multidimensional separations; and the use of controlled multiple gradients. Many advantages of TLC relative to column chromatography were discussed in the Introductions to our 1982 and 1984 reviews of TLC in this Journal. No complete commercial robotics system specifically for TLC has been developed, but all necessary modules are available for such a system. The combination of robotics, with the continued development of theory, practice, and instrumentation will lead eventually to TLC systems that are unrivaled for speed, versatility, accuracy, precision, and sensitivity. 573 references

  5. Analysis of moniliformin in maize plants using hydrophilic interaction chromatography

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Nielsen, Kristian Fog; Thrane, Ulf

    2007-01-01

    A novel HPLC method was developed for detection of the Fusarium mycotoxin, moniliformin in whole maize plants. The method is based on hydrophilic interaction chromatography (HILIC) on a ZIC zwitterion column combined with diode array detection and negative electrospray mass spectrometry (ESI...

  6. A candidate liquid chromatography mass spectrometry reference method for the quantification of the cardiac marker 1-32 B-type natriuretic peptide.

    Science.gov (United States)

    Torma, Attila F; Groves, Kate; Biesenbruch, Sabine; Mussell, Chris; Reid, Alan; Ellison, Steve; Cramer, Rainer; Quaglia, Milena

    2017-08-28

    B-type natriuretic peptide (BNP) is a 32 amino acid cardiac hormone routinely measured by immunoassays to diagnose heart failure. While it is reported that immunoassay results can vary up to 45%, no attempt of standardization and/or harmonization through the development of certified reference materials (CRMs) or reference measurement procedures (RMPs) has yet been carried out. B-type natriuretic peptide primary calibrator was quantified traceably to the International System of Units (SI) by both amino acid analysis and tryptic digestion. A method for the stabilization of BNP in plasma followed by protein precipitation, solid phase extraction (SPE) and liquid chromatography (LC) mass spectrometry (MS) was then developed and validated for the quantification of BNP at clinically relevant concentrations (15-150 fmol/g). The candidate reference method was applied to the quantification of BNP in a number of samples from the UK NEQAS Cardiac Markers Scheme to demonstrate its applicability to generate reference values and to preliminary evaluate the commutability of a potential CRM. The results from the reference method were consistently lower than the immunoassay results and discrepancy between the immunoassays was observed confirming previous data. The application of the liquid chromatography-mass spectrometry (LC-MS) method to the UK NEQAS samples and the correlation of the results with the immunoassay results shows the potential of the method to support external quality assessment schemes, to improve understanding of the bias of the assays and to establish RMPs for BNP measurements. Furthermore, the method has the potential to be multiplexed for monitoring circulating truncated forms of BNP.

  7. Simultaneous separation of antihyperlipidemic drugs by green ultrahigh-performance liquid chromatography-diode array detector method: Improving the health of liquid chromatography.

    Science.gov (United States)

    Alghazi, Mansoor; Alanazi, Fars; Mohsin, Kazi; Siddiqui, Nasir Ali; Shakeel, Faiyaz; Haq, Nazrul

    2017-04-01

    Statins in combination with fibrates show beneficial effects on the lipoprotein profile of patients because they have positive complimentary effects on lipid profile. A new green ultrahigh-performance liquid chromatography-diode array detector method for simultaneous analysis of simvastatin (SMV) and fenofibrate (FNF) in standard form, marketed formulations, and self-emulsifying drug delivery system formulations was developed and validated in the present investigation. The method utilized C 18 as stationary phase and a combination of methanol:water (8:2) as an eluent. It was found that selected eluent provided short run time (2.5 minutes), better peak symmetry and satisfactory values of other chromatographic parameters such as resolution (Rs=2.325), capacity factor (k, 3.0 and 4.2 for SMV and FNF, respectively), selectivity (α =1.4), and number of theoretical plates (N, 4265 and 5285 for SMV and FNF, respectively). An excellent linear relationship (r 2 0.998 and 0.997 for SMV and FNF, respectively) was observed for linear regression data for the calibration plots. The developed system was validated for accuracy, precision, robustness (˃ 2% for both drugs) and recovery (98-102% for both drugs). Results obtained from the statistical treatment of the values obtained for different parameters proved that the method is suitable, reproducible, and selective for the simultaneous analysis of SMV and FNF in bulk, marketed, and self-emulsifying drug delivery system formulations. The replacement of commonly applied toxic solvents with innocuous and environmentally benign solvents provides a better option than the more toxic processes in drug analysis. Copyright © 2016. Published by Elsevier B.V.

  8. Chromatography.

    Science.gov (United States)

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities on chromatography. Directions for preparing leaf pigment extracts using alcohol are given, and paper chromatography and thin-layer chromatography are described as modifications of the basic principles of chromatography. (KHR)

  9. Study of Separation and Identification of the Active Ingredients in Gardenia jasminoides Ellis Based on a Two-Dimensional Liquid Chromatography by Coupling Reversed Phase Liquid Chromatography and Hydrophilic Interaction Liquid Chromatography.

    Science.gov (United States)

    Zhou, Xuan; Chen, Cen; Ye, Xiaolan; Song, Fenyun; Fan, Guorong; Wu, Fuhai

    2017-01-01

    In this paper, by coupling reversed phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC), a two-dimensional liquid chromatography system was developed for separation and identification of the active ingredients in Gardenia jasminoides Ellis (GJE). By applying the semi-preparative C18 column as the first dimension and the core-shell column as the second dimension, a total of 896 peaks of GJE were separated. Among the 896 peaks, 16 active ingredients including geniposide, gardenoside, gardoside, etc. were identified by mass spectrometry analysis. The results indicated that the proposed two-dimensional RPLC/HILIC system was an effective method for the analysis of GJE and might hold a high potential to become a useful tool for analysis of other complex mixtures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Nanomaterials as stationary phases and supports in liquid chromatography.

    Science.gov (United States)

    Beeram, Sandya R; Rodriguez, Elliott; Doddavenkatanna, Suresh; Li, Zhao; Pekarek, Allegra; Peev, Darin; Goerl, Kathryn; Trovato, Gianfranco; Hofmann, Tino; Hage, David S

    2017-10-01

    The development of various nanomaterials over the last few decades has led to many applications for these materials in liquid chromatography (LC). This review will look at the types of nanomaterials that have been incorporated into LC systems and the applications that have been explored for such systems. A number of carbon-based nanomaterials and inorganic nanomaterials have been considered for use in LC, ranging from carbon nanotubes, fullerenes and nanodiamonds to metal nanoparticles and nanostructures based on silica, alumina, zirconia and titanium dioxide. Many ways have been described for incorporating these nanomaterials into LC systems. These methods have included covalent immobilization, adsorption, entrapment, and the synthesis or direct development of nanomaterials as part of a chromatographic support. Nanomaterials have been used in many types of LC. These applications have included the reversed-phase, normal-phase, ion-exchange, and affinity modes of LC, as well as related methods such as chiral separations, ion-pair chromatography and hydrophilic interaction liquid chromatography. Both small and large analytes (e.g., dyes, drugs, amino acids, peptides and proteins) have been used to evaluate possible applications for these nanomaterial-based methods. The use of nanomaterials in columns, capillaries and planar chromatography has been considered as part of these efforts. Potential advantages of nanomaterials in these applications have included their good chemical and physical stabilities, the variety of interactions many nanomaterials can have with analytes, and their unique retention properties in some separation formats. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones.

    Science.gov (United States)

    Carnes, Stephanie; O'Brien, Stacey; Szewczak, Angelica; Tremeau-Cayel, Lauriane; Rowe, Walter F; McCord, Bruce; Lurie, Ira S

    2017-09-01

    A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite-5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Sensitive method for the quantitative determination of bromocriptine in human plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Salvador, Arnaud; Dubreuil, Didier; Denouel, Jannick; Millerioux, L

    2005-06-25

    A sensitive LC-MS-MS assay for the quantitative determination of bromocriptine has been developed and validated and is described in this work. The assay involved the extraction of the analyte from 1 ml of human plasma using a solid phase extraction on Oasis MCX cartridges. Chromatography was performed on a Symmetry C18 (2.1 mm x 100 mm, 3.5 microm) column using a mobile phase consisting of 25:75:01 acetonitrile-water-formic acid with a flow rate of 250 microl/min. The linearity was within the concentration range of 2-500 pg/ml. The lower limit of quantification was 2 pg/ml. This method has been demonstrated to be an improvement over existing methods due to its greater sensitivity and specificity.

  13. Development and Application of Immunoaffinity Chromatography for Coplanar PCBs in Soil and Sediment

    Science.gov (United States)

    An immunoaffinity chromatography (IAC) column was developed as a simple cleanup procedure for preparing environmental samples for analysis of polychlorinated biphenyls (PCBs). Soil and sediment samples were prepared using pressurized liquid extraction (PLE), followed by the IAC c...

  14. High-throughput micro-scale cultivations and chromatography modeling: Powerful tools for integrated process development.

    Science.gov (United States)

    Baumann, Pascal; Hahn, Tobias; Hubbuch, Jürgen

    2015-10-01

    Upstream processes are rather complex to design and the productivity of cells under suitable cultivation conditions is hard to predict. The method of choice for examining the design space is to execute high-throughput cultivation screenings in micro-scale format. Various predictive in silico models have been developed for many downstream processes, leading to a reduction of time and material costs. This paper presents a combined optimization approach based on high-throughput micro-scale cultivation experiments and chromatography modeling. The overall optimized system must not necessarily be the one with highest product titers, but the one resulting in an overall superior process performance in up- and downstream. The methodology is presented in a case study for the Cherry-tagged enzyme Glutathione-S-Transferase from Escherichia coli SE1. The Cherry-Tag™ (Delphi Genetics, Belgium) which can be fused to any target protein allows for direct product analytics by simple VIS absorption measurements. High-throughput cultivations were carried out in a 48-well format in a BioLector micro-scale cultivation system (m2p-Labs, Germany). The downstream process optimization for a set of randomly picked upstream conditions producing high yields was performed in silico using a chromatography modeling software developed in-house (ChromX). The suggested in silico-optimized operational modes for product capturing were validated subsequently. The overall best system was chosen based on a combination of excellent up- and downstream performance. © 2015 Wiley Periodicals, Inc.

  15. Determination of nucleosides in Cordyceps sinensis and Ganoderma lucidum by high performance liquid chromatography method

    Directory of Open Access Journals (Sweden)

    Masood Shah Khan

    2015-01-01

    Full Text Available Background: Nucleosides are supportive in the regulation and modulation of various physiological processes in body, they acts as precursors in nucleic acid synthesis, enhance immune response, help in absorption of iron and influence the metabolism of fatty acids. Cordyceps sinensis and Ganoderma lucidum are well-known for its use in traditional medicine of China, Nepal and India. They are rich in nucleosides such as adenine, adenosine, cordycepin, etc. Hence, a simple, economic and accurate high-performance liquid chromatography (HPLC analytical method was proposed for determination of adenine and adenosine for the quality control of plants. Materials and Methods: Chromatographic experiments were conducted on YL9100 HPLC system (South Korea. Reversed-phase chromatography was performed on a C18 column with methanol and dihydrogen phosphate as the mobile phase in isocratic elution method at a flow rate of 1.0 mL/min. Detection was carried out at 254 nm, which gives a sharp peak of adenine and adenosine at a retention time of 6.53 ± 0.02 min and 12.41 ± 0.02, respectively. Results and Discussion: Linear regression analysis data for the calibration plot showed a good linear relationship between response and concentration in the range of 25–200 µg/mL for adenosine and 100–800 µg/mL for adenine with regression coefficient of 0.999 and 0.996, respectively. The adenine was found 0.16% and 0.71% w/w in G. lucidum and in C. sinensis, respectively, and adenosine was found to be 0.14% w/w in G. lucidum whereas absent in C. sinensis. Conclusion: The developed HPLC method for the quantification of adenosine and adenine can be used for the quality control and standardization of crude drug and for the different herbal formulations, in which adenine and adenosine are present as major constituents. The wide linearity range, sensitivity, accuracy, and simple mobile phase imply the method is suitable for routine quantification of adenosine and adenine with

  16. Development of a new ultra-high performance liquid chromatography - tandem mass spectrometry method for determination of ambroxol hydrochloride in serum with pharmacokinetic application

    Directory of Open Access Journals (Sweden)

    Vujović Maja M.

    2016-01-01

    Full Text Available Ambroxol hydrochloride is an expectorant agent, successfully applied in mucolytic therapy for acute and chronic bronchopulmonary diseases. The drug regulates not only mucus secretion but also showed antioxidant, anti-inflammatory and local anesthetic properties. To supplement the pharmacokinetic and toxicological studies of ambroxol, a rapid ultra-high performance liquid chromatography-tandem mass spectrometry method for the quantitation of ambroxol in rabbit serum was developed. A validation of the method was performed as per the ICH guidelines for the validation of bioanalytical methods. The chromatographic separation was achieved in a submicron Kinetex RP - C18 - column (2.1 mm x 50 mm, 1.3μm using the no buffer mobile phase. The ESI mass spectrometry in the MRM mode was used with a typical transitions m/z 378.9→263.8 for ambroxol and m/z 455.2→165.0 for IS. Linearity was determined with an average coefficient of determination >0.999 over the dynamic range from 0.5 - 200 ng/mL with LOD and LOQ of 0.25 ng/mL and 0.5 ng/mL, respectively. The results of the intra- and inter-day precision and accuracy determined in different days were all found to be within the acceptable limits ±15%. The present method was successfully applied to pharmacokinetic study in the rabbits after a single oral dose administration. [Projekat Ministarstva nauke Republike Srbije, br. 175045

  17. Development of On-Line High Performance Liquid Chromatography (HPLC)-Biochemical Detection Methods as Tools in the Identification of Bioactives

    Science.gov (United States)

    Malherbe, Christiaan J.; de Beer, Dalene; Joubert, Elizabeth

    2012-01-01

    Biochemical detection (BCD) methods are commonly used to screen plant extracts for specific biological activities in batch assays. Traditionally, bioactives in the most active extracts were identified through time-consuming bio-assay guided fractionation until single active compounds could be isolated. Not only are isolation procedures often tedious, but they could also lead to artifact formation. On-line coupling of BCD assays to high performance liquid chromatography (HPLC) is gaining ground as a high resolution screening technique to overcome problems associated with pre-isolation by measuring the effects of compounds post-column directly after separation. To date, several on-line HPLC-BCD assays, applied to whole plant extracts and mixtures, have been published. In this review the focus will fall on enzyme-based, receptor-based and antioxidant assays. PMID:22489144

  18. Downstream processing and chromatography based analytical methods for production of vaccines, gene therapy vectors, and bacteriophages

    Science.gov (United States)

    Kramberger, Petra; Urbas, Lidija; Štrancar, Aleš

    2015-01-01

    Downstream processing of nanoplexes (viruses, virus-like particles, bacteriophages) is characterized by complexity of the starting material, number of purification methods to choose from, regulations that are setting the frame for the final product and analytical methods for upstream and downstream monitoring. This review gives an overview on the nanoplex downstream challenges and chromatography based analytical methods for efficient monitoring of the nanoplex production. PMID:25751122

  19. Collaborative trial validation study of two methods, one based on high performance liquid chromatography-tandem mass spectrometry and on gas chromatography-mass spectrometry for the determination of acrylamide in bakery and potato products.

    Science.gov (United States)

    Wenzl, Thomas; Karasek, Lubomir; Rosen, Johan; Hellenaes, Karl-Erik; Crews, Colin; Castle, Laurence; Anklam, Elke

    2006-11-03

    A European inter-laboratory study was conducted to validate two analytical procedures for the determination of acrylamide in bakery ware (crispbreads, biscuits) and potato products (chips), within a concentration range from about 20 microg/kg to about 9000 microgg/kg. The methods are based on gas chromatography-mass spectrometry (GC-MS) of the derivatised analyte and on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) of native acrylamide. Isotope dilution with isotopically labelled acrylamide was an integral part of both methods. The study was evaluated according to internationally accepted guidelines. The performance of the HPLC-MS/MS method was found to be superior to that of the GC-MS method and to be fit-for-the-purpose.

  20. Extraction chromatography of fission products

    International Nuclear Information System (INIS)

    Bonnevie-Svendsen, M.; Goon, K.

    1978-01-01

    Various cases of using extraction chromatography during analysis of fission products are reviewed. The use of the extraction chromatography method is considered while analysing reprocessed products of nuclear fuel for quantitative radiochemical analysis and control of fission product and actinoide separation during extraction and their chemical state in production solutions. The method is used to obtain pure fractions of typical burnup monitors (neodymium, molybdenum, cerium, cesium, europium, lanthanides) during determination of nuclear fuel burnup degree. While studying the nature of nuclear reactions the method is used to separate quickly short-life isotopes, to purify β-radiator fractions before measuring their half-life periods, to enrich isotopes forming with low output during fission. Examples of using extraction chromatography are given to separate long half-life or stable fission products from spent solutions, to control environment object contamination

  1. Ion chromatography for the precise analysis of chloride and sodium in sweat for the diagnosis of cystic fibrosis

    NARCIS (Netherlands)

    Doorn, J.; Storteboom, T. T. R.; Mulder, A. M.; de Jong, W. H. A.; Rottier, B. L.; Kema, I. P.

    BACKGROUND: Measurement of chloride in sweat is an essential part of the diagnostic algorithm for cystic fibrosis. The lack in sensitivity and reproducibility of current methods led us to develop an ion chromatography/high-performance liquid chromatography (IC/HPLC) method, suitable for the analysis

  2. A high-performance liquid chromatography-electronic circular dichroism online method for assessing the absolute enantiomeric excess and conversion ratio of asymmetric reactions

    Science.gov (United States)

    Zhang, Xiang; Wang, Mingchao; Li, Li; Yin, Dali

    2017-03-01

    Asymmetric reactions often need to be evaluated during the synthesis of chiral compounds. However, traditional evaluation methods require the isolation of the individual enantiomer, which is tedious and time-consuming. Thus, it is desirable to develop simple, practical online detection methods. We developed a method based on high-performance liquid chromatography-electronic circular dichroism (HPLC-ECD) that simultaneously analyzes the material conversion ratio and absolute optical purity of each enantiomer. In particular, only a reverse-phase C18 column instead of a chiral column is required in our method because the ECD measurement provides a g-factor that describes the ratio of each enantiomer in the mixtures. We used our method to analyze the asymmetric hydrosilylation of β-enamino esters, and we discussed the advantage, feasibility, and effectiveness of this new methodology.

  3. Chemistry and liquid chromatography methods for the analyses of primary oxidation products of triacylglycerols.

    Science.gov (United States)

    Zeb, A

    2015-05-01

    Triacylglycerols (TAGs) are one of the major components of the cells in higher biological systems, which can act as an energy reservoir in the living cells. The unsaturated fatty acid moiety is the key site of oxidation and formation of oxidation compounds. The TAG free radical generates several primary oxidation compounds. These include hydroperoxides, hydroxides, epidioxides, hydroperoxy epidioxides, hydroxyl epidioxides, and epoxides. The presence of these oxidized TAGs in the cell increases the chances of several detrimental processes. For this purpose, several liquid chromatography (LC) methods were reported in their analyses. This review is therefore focused on the chemistry, oxidation, extraction, and the LC methods reported in the analyses of oxidized TAGs. The studies on thin-layer chromatography were mostly focused on the total oxidized TAGs separation and employ hexane as major solvent. High-performance LC (HPLC) methods were discussed in details along with their merits and demerits. It was found that most of the HPLC methods employed isocratic elution with methanol and acetonitrile as major solvents with an ultraviolet detector. The coupling of HPLC with mass spectrometry (MS) highly increases the efficiency of analysis as well as enables reliable structural elucidation. The use of MS was found to be helpful in studying the oxidation chemistry of TAGs and needs to be extended to the complex biological systems.

  4. Simultaneous analysis of fourteen tertiary amine stimulants in human urine for doping control purposes by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Lu Jianghai; Wang San; Dong Ying; Wang Xiaobing; Yang Shuming; Zhang Jianli; Deng Jing; Qin Yang; Xu Youxuan; Wu Moutian; Ouyang Gangfeng

    2010-01-01

    A method for the simultaneous screening and confirmation of the presence of fourteen tertiary amine stimulants in human urine by gas chromatography-mass spectrometry (GC-MS) in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed and validated. Solid phase extraction (SPE) and liquid-liquid extraction (LLE) approaches were utilized for the pre-treatment of the urine samples. The study indicated that the capillary temperature played a significant role in the signal abundances of the protonated molecules of cropropamide and crotethamide under positive ion electrospray ionization (ESI) conditions. In addition, comparison studies of two different pre-treatment approaches as well as the two ionization modes were conducted. The LODs of the developed method for all the analytes were lower than the minimum required performance limit (MRPL) as set forth in the World Anti-Doping Agency (WADA) technical document for laboratories. The human urine sample obtained after oral administration of prolintane.HCl was successfully analyzed by the developed method, which demonstrated the applicability and reliability of the method for routine doping control analysis.

  5. Preparative supercritical fluid chromatography: A powerful tool for chiral separations.

    Science.gov (United States)

    Speybrouck, David; Lipka, Emmanuelle

    2016-10-07

    In 2012, the 4 biggest pharmaceutical blockbusters were pure enantiomers and separating racemic mixtures is now frequently a key step in the development of a new drug. For a long time, preparative liquid chromatography was the technique of choice for the separation of chiral compounds either during the drug discovery process to get up to a hundred grams of a pure enantiomer or during the clinical trial phases needing kilograms of material. However the advent of supercritical Fluid Chromatography (SFC) in the 1990s has changed things. Indeed, the use of carbon dioxide as the mobile phase in SFC offers many advantages including high flow rate, short equilibration time as well as low solvent consumption. Despite some initial teething troubles, SFC is becoming the primary method for preparative chiral chromatography. This article will cover recent developments in preparative SFC for the separation of enantiomers, reviewing several aspects such as instrumentation, chiral stationary phases, mobile phases or purely preparative considerations including overloading, productivity or large scale chromatography. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Application of gas chromatography in hydrogen isotope separation

    International Nuclear Information System (INIS)

    Ye Xiaoqiu; Sang Ge; Peng Lixia; Xue Yan; Cao Wei

    2008-01-01

    The principle of gas chromatographic separation of hydrogen isotopes was briefly introduced. The main technology and their development of separating hydrogen isotopes, including elution chromatography, hydrogen-displacement chromatography, self-displacement chromatography and frontal chromatography were discussed in detail. The prospect of hydrogen isotope separation by gas chromatography was presented. (authors)

  7. Determination of methyldibromoglutaronitrile in cosmetic products by high-performance liquid chromatography with electrochemical detection. Method validation

    DEFF Research Database (Denmark)

    Rastogi, Suresh Chandra; Zachariae, Claus; Johansen, Jeanne D

    2004-01-01

    An increased frequency of contact allergy to methyldibromoglutaronitrile (MDBGN), a commonly used preservative in cosmetics and other consumer products, has been reported in recent years. A high-performance liquid chromatography (HPLC) method for the determination of MDBGN in cosmetic products has...

  8. Determination of methyldibromoglutaronitrile in cosmetic products by high-performance liquid chromatography with electrochemical detection. Method validation

    DEFF Research Database (Denmark)

    Rastogi, Suresh Chandra; Zachariae, Claus; Johansen, Jeanne D

    2004-01-01

    An increased frequency of contact allergy to methyldibromoglutaronitrile (MDBGN), a commonly used preservative in cosmetics and other consumer products, has been reported in recent years. A high-performance liquid chromatography (HPLC) method for the determination of MDBGN in cosmetic products ha...

  9. Development and validation of confirmatory method for analysis of nitrofuran metabolites in milk, honey, poultry meat and fish by liquid chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Fatih Alkan

    2016-03-01

    Full Text Available In this study we have devoloped and validated a confirmatory analysis method for nitrofuran metabolites, which is in accordance with European Commission Decision 2002/657/EC requirements. Nitrofuran metabolites in honey, milk, poultry meat and fish samples were acidic hydrolised followed by derivatisation with nitrobenzaldehyde and liquid-liquid extracted with ethylacetate. The quantitative and confirmative determination of nitrofuran metbolites was performed by liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS in the positive ion mode. In-house method validation was performed and reported data of validation (specificity, linearity, recovery, CCα and CCβ. The advantage of this method is that it avoids the use of clean-up by Solid-Phase Extraction (SPE. Furthermore, low levels of nitrofuran metabolites are detectable and quantitatively confirmed at a rapid rate in all samples.

  10. 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)

  11. Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

    International Nuclear Information System (INIS)

    Shu, Xikai; Wang, Mei; Liu, Daicheng; Wang, Daijie; Lin, Xiaojing; Liu, Jianhua; Wang, Xiao; Huang, Luqi

    2013-01-01

    An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-β-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-β-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). (author)

  12. Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Xikai; Wang, Mei; Liu, Daicheng [College of Life Science, Shandong Normal University, Jinan, Shandong (China); Wang, Daijie; Lin, Xiaojing; Liu, Jianhua; Wang, Xiao; Huang, Luqi, E-mail: wxjn1998@126.com [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China)

    2013-09-01

    An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-{beta}-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-{beta}-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). (author)

  13. Development and Validation of High Performance Liquid Chromatography Method for Determination Atorvastatin in Tablet

    Science.gov (United States)

    Yugatama, A.; Rohmani, S.; Dewangga, A.

    2018-03-01

    Atorvastatin is the primary choice for dyslipidemia treatment. Due to patent expiration of atorvastatin, the pharmaceutical industry makes copy of the drug. Therefore, the development methods for tablet quality tests involving atorvastatin concentration on tablets needs to be performed. The purpose of this research was to develop and validate the simple atorvastatin tablet analytical method by HPLC. HPLC system used in this experiment consisted of column Cosmosil C18 (150 x 4,6 mm, 5 µm) as the stationary reverse phase chomatography, a mixture of methanol-water at pH 3 (80:20 v/v) as the mobile phase, flow rate of 1 mL/min, and UV detector at wavelength of 245 nm. Validation methods were including: selectivity, linearity, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ). The results of this study indicate that the developed method had good validation including selectivity, linearity, accuracy, precision, LOD, and LOQ for analysis of atorvastatin tablet content. LOD and LOQ were 0.2 and 0.7 ng/mL, and the linearity range were 20 - 120 ng/mL.

  14. Development of a gas chromatography-mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Borras, E.; Sanchez, P.; Munoz, A. [Instituto Universitario Centro de Estudios Ambientales del Mediterraneo CEAM-UMH (Fundacion CEAM-UMH), 46980 Paterna, Valencia (Spain); Tortajada-Genaro, L.A., E-mail: luitorge@qim.upv.es [Instituto IDM, Departamento de Quimica, Universitat Politecnica de Valencia, Cami de Vera s/n 46022 Valencia (Spain)

    2011-08-05

    Highlights: {yields} An efficient method for the determination of sixteen pesticides in atmospheric samples. {yields} XAD-4 is an interesting support for collecting gas-phase pesticides, with similar performances than the conventional XAD-2. {yields} The ultrasonic extraction is cheaper, less aggressive and time-consuming with excellent analytical parameters. {yields} The method has been successfully tested by using high volume atmospheric simulation chamber and field campaigns. - Abstract: A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography-mass spectrometry (GC-MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1). Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5 {+-} 1%, a

  15. Development of a gas chromatography-mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere

    International Nuclear Information System (INIS)

    Borras, E.; Sanchez, P.; Munoz, A.; Tortajada-Genaro, L.A.

    2011-01-01

    Highlights: → An efficient method for the determination of sixteen pesticides in atmospheric samples. → XAD-4 is an interesting support for collecting gas-phase pesticides, with similar performances than the conventional XAD-2. → The ultrasonic extraction is cheaper, less aggressive and time-consuming with excellent analytical parameters. → The method has been successfully tested by using high volume atmospheric simulation chamber and field campaigns. - Abstract: A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography-mass spectrometry (GC-MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1). Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5 ± 1%, a reproducibility of 13

  16. Comprehensive two-dimensional liquid chromatography and hyphenated liquid chromatography to study the degradation of poly(bisphenol A)carbonate

    NARCIS (Netherlands)

    Coulier, L.; Kaal, E.R.; Hankemeier, T.

    2005-01-01

    Size exclusion chromatography (SEC), gradient polymer elution chromatography (GPEC) and liquid chromatography at critical conditions (LC-CC) have been developed and applied to observe chemical changes in poly(bisphenol A)carbonate (PC) due to hydrolytic degradation. Especially LC-CC appeared to be

  17. 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.

  18. Method of determining of polybrominated diphenyl ethers in fish and fish products by the method of liquid chromatography

    Directory of Open Access Journals (Sweden)

    O.N. Timofeeva

    2016-09-01

    Full Text Available The aim of the work was to develop a methodology for determining of polybrominated diphenyl ethers (PBDE in fish and fish products for the control of impurities content in the food and environmental objects in general. The conditions of chromatography (temperature conditions, the impact of the speed and magnitude of dividing of the gas-carrier stream using a HP-1 capillary columns, the DB-5, HP-50 +, DB-1; and lipids destructive and non-destructive cleaning methods of extract during the determination of PBDEs. The method of determination of 2,2,4,4-Tetrabromodiphenyl ether (BDE-47, 2,2,4,4,5-pentabromodiphenyl ether (BDE-99 and decabromodiphenyl ether (BDE-209 in fish and fish products by the liquid chromatography with electron detector was suggested. The method of PBDE is based on the extraction of samples with hexane-acetone (3:1, purification of the extract with concentrated sulfuric acid (phase ratio hexane-sulfuric acid – 5:1. The second purification step is carried out by using solid phase extraction cartridges «SiOH-H2SO4/SA» and hexane as the eluent. Gas chromatographic analysis of the determination of BDE-47 and BDE-99 is carried out on low-polar capillary column DB-5 (30 m x0.25 mm x0.25 mum with the programming of the column temperature. In determining the BDE-209 a DB-1 nonpolar capillary column was used (15 m x 0.25 mm x 0.1 mum with the column temperature programming. Calculation of the content of BDE-47 and BDE-99 is carried out with the internal standard (2,2, 3,4,4-pentabromodiphenyl ether (BDE-85, BDE-209 by absolute calibration. In determining the BDE-209 the calibration matrix was used. The range of concentrations of the calibration solutions for the determination of BDE-47 and BDE-99 is 0.005–0.05 g/cm 3 , for BDE-209 0.05–0.3 g/cm 3 . The technique allows the measurement of BDE-47 and BDE-99 in the range of 0.0002–0.05 mg/kg of the product concerned; BDE-209 – in the range of 0.002–0.3 mg/kg. The metrological

  19. Thin-layer chromatography coupled with high performance liquid chromatography for determining tetrabromobisphenol A/S and their derivatives in soils.

    Science.gov (United States)

    Liu, Aifeng; Shen, Zhaoshuang; Tian, Yong; Shi, Rongguang; Liu, Yi; Zhao, Zongshan; Xian, Mo

    2017-12-01

    As brominated flame retardants (BFRs), tetrabromobisphenol A/S (TBBPA/S) and their derivatives have raised wide concerns owing to their widely usage, distributions and adverse effects on human health, thus monitoring these BFRs was urgently needed. In this study, a rapid and cost-effective method based on thin-layer chromatography (TLC) sample pre-treatment coupled with high performance liquid chromatography-diode array detector (HPLC-DAD) (UV=214nm) was developed for determining TBBPA/S and their derivatives in soils, including TBBPA, TBBPA bis(allyl ether) (TBBPA-BAE), TBBPA bis(2,3-dibromopropyl ether) (TBBPA-BDBPE), TBBPS bis(allyl ether) (TBBPS-BAE) and TBBPS bis(2,3-dibromopropyl ether) (TBBPS-BDBPE). The method detection limits (MDLs) and the method quantification limits (MQLs) for these BFRs ranged from 0.023 to 0.087μgg -1 dw and 0.076-0.29μgg -1 dw, respectively. The recoveries were 41-108% and both RSD of repeatability and intermediate precision were less than 11%. The developed method presented good performance for analyzing natural soil samples collected from BFRs industrial park, suggesting its great application potential for monitoring environmental TBBPA/S and their derivatives. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Development of analytical methods for the separation of plutonium, americium, curium and neptunium from environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Salminen, S.

    2009-07-01

    In this work, separation methods have been developed for the analysis of anthropogenic transuranium elements plutonium, americium, curium and neptunium from environmental samples contaminated by global nuclear weapons testing and the Chernobyl accident. The analytical methods utilized in this study are based on extraction chromatography. Highly varying atmospheric plutonium isotope concentrations and activity ratios were found at both Kurchatov (Kazakhstan), near the former Semipalatinsk test site, and Sodankylae (Finland). The origin of plutonium is almost impossible to identify at Kurchatov, since hundreds of nuclear tests were performed at the Semipalatinsk test site. In Sodankylae, plutonium in the surface air originated from nuclear weapons testing, conducted mostly by USSR and USA before the sampling year 1963. The variation in americium, curium and neptunium concentrations was great as well in peat samples collected in southern and central Finland in 1986 immediately after the Chernobyl accident. The main source of transuranium contamination in peats was from global nuclear test fallout, although there are wide regional differences in the fraction of Chernobyl-originated activity (of the total activity) for americium, curium and neptunium. The separation methods developed in this study yielded good chemical recovery for the elements investigated and adequately pure fractions for radiometric activity determination. The extraction chromatographic methods were faster compared to older methods based on ion exchange chromatography. In addition, extraction chromatography is a more environmentally friendly separation method than ion exchange, because less acidic waste solutions are produced during the analytical procedures. (orig.)

  1. Liquid chromatography tandem mass spectrometry method for simultaneous determination of metoprolol tartrate and ramipril in human plasma.

    Science.gov (United States)

    Gowda, K Veeran; Mandal, Uttam; Senthamil Selvan, P; Sam Solomon, W D; Ghosh, Animesh; Sarkar, Amlan Kanti; Agarwal, Sangita; Nageswar Rao, T; Pal, Tapan Kumar

    2007-10-15

    A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of metoprolol tartrate (MT) and ramipril, in human plasma. Both the drugs were extracted by liquid-liquid extraction with diethyl ether-dichloromethane (70:30, v/v). The chromatographic separation was performed on a reversed-phase C8 column with a mobile phase of 10 mM ammonium formate-methanol (3:97, v/v). The protonated analyte was quantitated in positive ionization by multiple reaction monitoring with a mass spectrometer. The method was validated over the concentration range of 5-500 ng/ml for metoprolol and ramipril in human plasma. The precursor to product ion transitions of m/z 268.0-103.10 and m/z 417.20-117.20 were used to measure metoprolol and ramipril, respectively.

  2. Comparative urine analysis by liquid chromatography-mass spectrometry and multivariate statistics : Method development, evaluation, and application to proteinuria

    NARCIS (Netherlands)

    Kemperman, Ramses F. J.; Horvatovich, Peter L.; Hoekman, Berend; Reijmers, Theo H.; Muskiet, Frits A. J.; Bischoff, Rainer

    2007-01-01

    We describe a platform for the comparative profiling of urine using reversed-phase liquid chromatography-mass spectrometry (LC-MS) and multivariate statistical data analysis. Urinary compounds were separated by gradient elution and subsequently detected by electrospray Ion-Trap MS. The lower limit

  3. Validation of a method to determine methylmercury in fish tissues using gas chromatography

    International Nuclear Information System (INIS)

    Vega Bolannos, Luisa O.; Arias Verdes, Jose A.; Beltran Llerandi, Gilberto; Castro Diaz, Odalys; Moreno Tellez, Olga L.

    2000-01-01

    We validated a method to determine methylmercury in fish tissues using gas chromatography with an electron capture detector as described by the Association of Official Analytical Chemist (AOAC) International. The linear curve range was 0.02 to 1 g/ml and linear correlation coefficient was 0.9979. A 1 mg/kg methylmercury-contaminated fish sample was analyzed 20 times to determine repeatability of the method. The quantification limit was 0.16 mg/kg and detection limit was 0.06 ppm. Fish samples contaminated with 0.2 to 10 mg/kg methylmercury showed recovery indexes from 94.66 to 108.8%

  4. Gas chromatography at the Tritium Laboratory Karlsruhe

    International Nuclear Information System (INIS)

    Laesser, R.; Gruenhagen, S.

    2003-08-01

    Among the analytical techniques (mass spectrometry, laser Raman spectroscopy, gas chromatography, use of ionisation chambers) employed at the Tritium Laboratory Karlsruhe (TLK), gas chromatography plays a prominent role. The main reasons for that are the simplicity of the gas chromatographic separation process, the small space required for the equipment, the low investment costs in comparison to other methods, the robustness of the equipment, the simple and straightforward analysis and the fact that all gas species of interest (with the exception of water) can easily be detected by gas chromatographic means. The conventional gas chromatographs GC1 and GC2 used in the Tritium Measurement Techniques (TMT) System of the TLK and the gas chromatograph GC3 of the experiment CAPER are presented in detail, by discussing their flow diagrams, their major components, the chromatograms measured by means of various detectors, shortcomings and possible improvements. One of the main disadvantages of the conventional gas chromatography is the long retention times required for the analysis of hydrogen gas mixtures. To overcome this disadvantage, micro gas chromatography for hydrogen analysis was developed. Reduction of the retention times by one order of magnitude was achieved. (orig.)

  5. Validating a High Performance Liquid Chromatography-Ion Chromatography (HPLC-IC) Method with Conductivity Detection After Chemical Suppression for Water Fluoride Estimation.

    Science.gov (United States)

    Bondu, Joseph Dian; Selvakumar, R; Fleming, Jude Joseph

    2018-01-01

    A variety of methods, including the Ion Selective Electrode (ISE), have been used for estimation of fluoride levels in drinking water. But as these methods suffer many drawbacks, the newer method of IC has replaced many of these methods. The study aimed at (1) validating IC for estimation of fluoride levels in drinking water and (2) to assess drinking water fluoride levels of villages in and around Vellore district using IC. Forty nine paired drinking water samples were measured using ISE and IC method (Metrohm). Water samples from 165 randomly selected villages in and around Vellore district were collected for fluoride estimation over 1 year. Standardization of IC method showed good within run precision, linearity and coefficient of variance with correlation coefficient R 2  = 0.998. The limit of detection was 0.027 ppm and limit of quantification was 0.083 ppm. Among 165 villages, 46.1% of the villages recorded water fluoride levels >1.00 ppm from which 19.4% had levels ranging from 1 to 1.5 ppm, 10.9% had recorded levels 1.5-2 ppm and about 12.7% had levels of 2.0-3.0 ppm. Three percent of villages had more than 3.0 ppm fluoride in the water tested. Most (44.42%) of these villages belonged to Jolarpet taluk with moderate to high (0.86-3.56 ppm) water fluoride levels. Ion Chromatography method has been validated and is therefore a reliable method in assessment of fluoride levels in the drinking water. While the residents of Jolarpet taluk (Vellore distict) are found to be at a high risk of developing dental and skeletal fluorosis.

  6. Column Chromatography To Obtain Organic Cation Sorption Isotherms.

    Science.gov (United States)

    Jolin, William C; Sullivan, James; Vasudevan, Dharni; MacKay, Allison A

    2016-08-02

    Column chromatography was evaluated as a method to obtain organic cation sorption isotherms for environmental solids while using the peak skewness to identify the linear range of the sorption isotherm. Custom packed HPLC columns and standard batch sorption techniques were used to intercompare sorption isotherms and solid-water sorption coefficients (Kd) for four organic cations (benzylamine, 2,4-dichlorobenzylamine, phenyltrimethylammonium, oxytetracycline) with two aluminosilicate clay minerals and one soil. A comparison of Freundlich isotherm parameters revealed isotherm linearity or nonlinearity was not significantly different between column chromatography and traditional batch experiments. Importantly, skewness (a metric of eluting peak symmetry) analysis of eluting peaks can establish isotherm linearity, thereby enabling a less labor intensive means to generate the extensive data sets of linear Kd values required for the development of predictive sorption models. Our findings clearly show that column chromatography can reproduce sorption measures from conventional batch experiments with the benefit of lower labor-intensity, faster analysis times, and allow for consistent sorption measures across laboratories with distinct chromatography instrumentation.

  7. Comparison of photoacoustic radiometry to gas chromatography/mass spectrometry methods for monitoring chlorinated hydrocarbons

    International Nuclear Information System (INIS)

    Sollid, J.E.; Trujillo, V.L.; Limback, S.P.; Woloshun, K.A.

    1996-01-01

    A comparison of two methods of gas chromatography mass spectrometry (GCMS) and a nondispersive infrared technique, photoacoustic radiometry (PAR), is presented in the context of field monitoring a disposal site. First is presented an historical account describing the site and early monitoring to provide an overview. The intent and nature of the monitoring program changed when it was proposed to expand the Radiological Waste Site close to the Hazardous Waste Site. Both the sampling methods and analysis techniques were refined in the course of this exercise

  8. Centrifugal partition chromatography enables selective enrichment of trimeric and tetrameric proanthocyanidins for biomaterial development.

    Science.gov (United States)

    Phansalkar, Rasika S; Nam, Joo-Won; Chen, Shao-Nong; McAlpine, James B; Leme, Ariene A; Aydin, Berdan; Bedran-Russo, Ana-Karina; Pauli, Guido F

    2018-02-02

    Proanthocyanidins (PACs) find wide applications for human use including food, cosmetics, dietary supplements, and pharmaceuticals. The chemical complexity associated with PACs has triggered the development of various chromatographic techniques, with countercurrent separation (CCS) gaining in popularity. This study applied the recently developed DESIGNER (Depletion and Enrichment of Select Ingredients Generating Normalized Extract Resources) approach for the selective enrichment of trimeric and tetrameric PACs using centrifugal partition chromatography (CPC). This CPC method aims at developing PAC based biomaterials, particularly for their application in restoring and repairing dental hard tissue. A general separation scheme beginning with the depletion of polymeric PACs, followed by the removal of monomeric flavan-3-ols and a final enrichment step produced PAC trimer and tetramer enriched fractions. A successful application of this separation scheme is demonstrated for four polyphenol rich plant sources: grape seeds, pine bark, cinnamon bark, and cocoa seeds. Minor modifications to the generic DESIGNER CCS method were sufficient to accommodate the varying chemical complexities of the individual source materials. The step-wise enrichment of PAC trimers and tetramers was monitored using normal phase TLC and Diol-HPLC-UV analyses. CPC proved to be a reliable tool for the selective enrichment of medium size oligomeric PACs (OPACs). This method plays a key role in the development of dental biomaterials considering its reliability and reproducibility, as well as its scale-up capabilities for possible larger-scale manufacturing. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Fractionation of lithium isotopes in cation-exchange chromatography

    International Nuclear Information System (INIS)

    Oi, Takao; Kawada, Kazuhiko; Kakihana, Hidetake; Hosoe, Morikazu

    1991-01-01

    Various methods for lithium isotope separation have been developed, and their applicability to large-scale enriched lithium isotope production has been assessed. Ion-exchange chromatography is one such method. Cation-exchange chromatography of lithium was carried out to investigate the lithium isotope effect in aqueous ion-exchange systems. The heavier isotope. 7 Li, was preferentially fractionated into the resin phase in every experiment conducted, and this result is consistent with the results of previous work. The value of the separation factor was 1.00089-1.00171 at 25C. A comparison of lithium isotope effect with those of potassium and rubidium indicated that the isotope effect originating from hydration is larger than the effect due to phase change for lithium, while the opposite is the case with potassium and rubidium

  10. Validation of a liquid chromatography method for the simultaneous determination of sulfadimethoxine and trimethoprim and application to a stability study.

    Science.gov (United States)

    Louati, K; Mistiri, F; Kallel, M; Safta, F

    2010-03-01

    A liquid chromatography method is described for the simultaneous determination of sulfadimetoxine and trimethoprim from a veterinary formulation at the proportion of 187 mg and 40 mg respectively in presence of some excipient. The solution was subjected to different International Conference On Harmonisation prescribed stress conditions (hydrolysis, oxidation and photolysis). A stability-indicating high-performance liquid chromatography method was developed for the analysis of active substances in presence of their major degradation products. It involved a Knauer Eurospher C18 thermostated column at 25 degrees C, and 9.57 mM phosphate buffer (pH adjusted to 2.0 with orthophosphoric acid)-acetonitrile (70:30 v/v) as mobile phase. The mobile phase flow rate and sample volume injected were 1.2 mL/min and 20 microL, respectively. The selected wavelength for the determination was 248 nm. The method was validated for linearity, precision, accuracy and specificity, and then applied to a stability study of sulfadimetoxine and trimethoprim in the veterinary solution packaged in high density polyethylene plastic bottles of 1 L and 100 mL thermosealed and no thermosealed and corked by a white cap, at both accelerated and long-term conditions required by the International Conference On Harmonisation. The method developed, which separates all of the most degradation products formed under variety of conditions, proved to be simple, accurate, precise and specific. The results of the stress degradation show that the solution is more sensitive to hydrolysis. The stability studies carried out on three batches of each presentation show that the finished product remains stable for six months. Copyright 2010 Elsevier Masson SAS. All rights reserved.

  11. A novel fast gas chromatography method for higher time resolution measurements of speciated monoterpenes in air

    Science.gov (United States)

    Jones, C. E.; Kato, S.; Nakashima, Y.; Kajii, Y.

    2014-05-01

    Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9-C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in ambient air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C9-C15 BVOC composition of single plant emissions may be characterised within a 14.5 min analysis time. Moreover, in-situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an 11.7 min chromatographic separation time (increasing to 19.7 min when simultaneous quantification of multiple oxygenated C9-C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). These analysis times potentially allow for a twofold to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in-situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC (OBVOC) linalool in ambient air. During this field deployment within a suburban forest

  12. Sensitive, automatic method for the determination of diazepam and its five metabolites in human oral fluid by online solid-phase extraction and liquid chromatography with tandem mass spectrometry

    DEFF Research Database (Denmark)

    Jiang, Fengli; Rao, Yulan; Wang, Rong

    2016-01-01

    A novel and simple online solid-phase extraction liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of diazepam and its five metabolites including nordazepam, oxazepam, temazepam, oxazepam glucuronide, and temazepam glucuronide...... in human oral fluid. Human oral fluid was obtained using the Salivette(®) collection device, and 100 μL of oral fluid samples were loaded onto HySphere Resin GP cartridge for extraction. Analytes were separated on a Waters Xterra C18 column and quantified by liquid chromatography with tandem mass...

  13. A fast and sensitive method for the separation of carotenoids using ultra-high performance supercritical fluid chromatography-mass spectrometry.

    Science.gov (United States)

    Jumaah, Firas; Plaza, Merichel; Abrahamsson, Victor; Turner, Charlotta; Sandahl, Margareta

    2016-08-01

    In this study, a rapid and sensitive ultra-high performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS) method has been developed and partially validated for the separation of carotenoids within less than 6 min. Six columns of orthogonal selectivity were examined, and the best separation was obtained by using a 1-aminoanthracene (1-AA) column. The length of polyene chain as well as the number of hydroxyl groups in the structure of the studied carotenoids determines their differences in the physiochemical properties and thus the separation that is achieved on this column. All of the investigated carotenoids were baseline separated with resolution values greater than 1.5. The effects of gradient program, back pressure, and column temperature were studied with respect to chromatographic properties such as retention and selectivity. Electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) were compared in both positive and negative mode, using both direct infusion and hyphenated with UHPSFC. The ESI in positive mode provided the highest response. The coefficient of determination (R (2)) for all calibration curves were greater than 0.998. Limit of detection (LOD) was in the range of 2.6 and 25.2 ng/mL for α-carotene and astaxanthin, respectively, whereas limit of quantification (LOQ) was in the range of 7.8 and 58.0 ng/mL for α-carotene and astaxanthin, respectively. Repeatability and intermediate precision of the developed UHPSFC-MS method were determined and found to be RSD supercritical fluid extracts of microalgae and rosehip. Graphical Abstract Ultra-high performance supercritical fluid chromatography-a rapid separation method for the analysis of carotenoids in rosehip and microalgae samples.

  14. A high-performance liquid chromatography method for the serotonin release assay is equivalent to the radioactive method.

    Science.gov (United States)

    Sono-Koree, N K; Crist, R A; Frank, E L; Rodgers, G M; Smock, K J

    2016-02-01

    The serotonin release assay (SRA) is considered the gold standard laboratory test for heparin-induced thrombocytopenia (HIT). The historic SRA method uses platelets loaded with radiolabeled serotonin to evaluate platelet activation by HIT immune complexes. However, a nonradioactive method is desirable. We report the performance characteristics of a high-performance liquid chromatography (HPLC) SRA method. We validated the performance characteristics of an HPLC-SRA method, including correlation with a reference laboratory using the radioactive method. Serotonin released from reagent platelets was quantified by HPLC using fluorescent detection. Results were expressed as % release and classified as positive, negative, or indeterminate based on previously published cutoffs. Serum samples from 250 subjects with suspected HIT were tested in the HPLC-SRA and with the radioactive method. Concordant classifications were observed in 230 samples (92%). Sera from 41 healthy individuals tested negative. Between-run imprecision studies showed standard deviation of performance characteristics, equivalent to the historic radioactive method, but avoids the complexities of working with radioactivity. © 2015 John Wiley & Sons Ltd.

  15. Development and Validation of a GC-FID Method for Diagnosis of Methylmalonic Acidemia

    Directory of Open Access Journals (Sweden)

    Fatemeh Keyfi

    2016-05-01

    Full Text Available Background: Urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. In the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. Gas chromatography is the most commonly-used technology to separate and identify these metabolites. In this report the analytical conditions for the determination of methylmalonic acid using a gas chromatography/flame ionization detector (GC-FID are studied with the aim to establish a method to analyze organic acids in human urine. Methods: Studies included the GC-FID method development, the conditions of the derivatization (trimethylsilylation reaction, and the stability of the methylmalonic acid standard solution and trimethylsilyl derivatives during storage. Also, a systematic comparison between GC-FID and gas chromatography/mass spectrometry (GC-MS was performed. Results: The highest resolution and sensitivity were obtained at 60 oC with a 30 min reaction time. Standard solutions and derivatized samples were stable for 7 days at 4-8 oC. Relative standard deviations of within-day and day-to-day assay results were less than 5%. Methylmalonic acid was detected in thirty human urine samples by the proposed GC-FID, and the results were compared with gold standard technique GC-MS. The correlation coefficient between GC-MS and GC-FID was obtained with R2= 0.997. Conclusions: The developed method was applied to the quantitative analysis of methylmalonic acid in urine from hospitalized children with methylmalonic acidemia. With this method we aim to support pediatric clinics in Iran and assist in clinical diagnostics.

  16. An efficient hydrophilic interaction liquid chromatography separation of 7 phospholipid classes based on a diol column

    NARCIS (Netherlands)

    Zhu, C.; Dane, A.; Spijksma, G.; Wang, M.; Greef, J. van der; Luo, G.; Hankemeier, T.; Vreeken, R.J.

    2012-01-01

    A hydrophilic interaction liquid chromatography (HILIC) - ion trap mass spectrometry method was developed for separation of a wide range of phospholipids. A diol column which is often used with normal phase chromatography was adapted to separate different phospholipid classes in HILIC mode using a

  17. Analysis of Trace Pharmaceuticals and Related Compounds in Municipal Wastewaters by Preconcentration, Chromatography, Derivatization, and Separation Methods

    Directory of Open Access Journals (Sweden)

    Petra Camilla Lindholm

    2014-05-01

    Full Text Available A significant portion of pharmaceuticals and other organic chemicals consumed by people and animals are released into municipal wastewater treatment plants. Most of them are degraded during the wastewater treatment processes, but some of them degrade only partially and may be widely transported and dispersed into the aquatic environment. This is why efficient and fast analytical methods are needed for detection of organic compounds in wastewaters at trace levels. Because wastewaters often consist of complex matrices and high-molecular mass materials, e.g., lignocellulosic biomass, which may bring challenges to the sample preparation procedures, efficient pre-concentration methods such as solid phase extraction (SPE solid phase microextraction (SPME, or single drop microextraction (SDME are needed. The most common analysis methods are gas chromatography (GC and liquid chromatography (LC coupled with tandem mass spectrometry (MS/MS. The aim of this review is to give an overview of chromatographic and spectroscopic methods when characterizing low- and medium-molecular weight organic pollutants, mainly focusing on pharmaceuticals, biocides, and personal care products in environmental matrices.

  18. Development and Validation of a Reversed-Phase Liquid Chromatography Method for the Simultaneous Determination of Indole-3-Acetic Acid, Indole-3-Pyruvic Acid, and Abscisic Acid in Barley (Hordeum vulgare L.).

    Science.gov (United States)

    Nakurte, Ilva; Keisa, Anete; Rostoks, Nils

    2012-01-01

    A simple, sensitive, precise, and specific reverse HPLC method was developed and validated for the determination of plant hormones in barley (Hordeum vulgare L.). The method includes extraction in aqueous organic solvent followed by solid-phase extraction, sample evaporation, and reversed-phase HPLC analysis in a general purpose UV-visible (abscisic acid (ABA)) and fluorescence detection (indole-3-acetic acid (IAA) and indole-3-pyruvic acid (IPA)), high-performance liquid chromatography system. The separation was carried out on Zorbax Eclipse XDB C8 column (150  ×  4.6  mm I.D) with a mobile phase composed of methanol and 1% acetic acid (60 : 40 v/v) in isocratic mode at a flow rate of 1 ml min(-1). The detection was monitored at 270 nm (ABA) and at 282 nm (Ex) and 360 nm (Em) (IAA, IPA). The developed method was validated in terms of accuracy, precision, linearity, limit of detection, limit of quantification, and robustness. The determined validation parameters are in the commonly acceptable ranges for that kind of analysis.

  19. The weight of flash chromatography: A tool to predict its mass intensity from thin-layer chromatography

    Directory of Open Access Journals (Sweden)

    Freddy Pessel

    2016-11-01

    Full Text Available Purification by flash chromatography strongly impacts the greenness of a process. Unfortunately, due to the lack of the relevant literature data, very often this impact cannot be assessed thus preventing the comparison of the environmental factors affecting the syntheses. We developed a simple mathematical approach to evaluate the minimum mass intensity of flash chromatography from the retention factor values determined by thin-layer chromatography.

  20. Ion-pairing reversed-phased chromatography/mass spectrometry of heparin

    DEFF Research Database (Denmark)

    Henriksen, Jens; Roepstorff, Peter; Ringborg, Lene H.

    2006-01-01

    not well characterised. In order to further characterise such mixtures, two on-line ion-pairing reverse-phased chromatography electrospray ionisation (ESI) mass spectrometry methods have been developed. One of the systems allows the determination of more than 200 components in a medium molecular weight...

  1. A general screening method for doping agents in human urine by solid phase extraction and liquid chromatography/time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kolmonen, Marjo [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland) and Doping Control Laboratory, United Laboratories Ltd., Helsinki (Finland)]. E-mail: marjo.kolmonen@helsinki.fi; Leinonen, Antti [Doping Control Laboratory, United Laboratories Ltd., Helsinki (Finland); Pelander, Anna [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland); Ojanperae, Ilkka [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland)

    2007-02-28

    A general screening method based on solid phase extraction (SPE) and liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) was developed and investigated with 124 different doping agents, including stimulants, {beta}-blockers, narcotics, {beta}{sub 2}-adrenergic agonists, agents with anti-estrogenic activity, diuretics and cannabinoids. Mixed mode cation exchange/C8 cartridges were applied to SPE, and chromatography was based on gradient elution on a C18 column. Ionization of the analytes was achieved with electrospray ionization in the positive mode. Identification by LC/TOFMS was based on retention time, accurate mass and isotopic pattern. Validation of the method consisted of analysis of specificity, analytical recovery, limit of detection and repeatability. The minimum required performance limit (MRPL), established by World Anti-Doping Agency (WADA), was attained to 97 doping agents. The extraction recoveries varied between 33 and 98% and the median was 58%. Mass accuracy was always better than 5 ppm, corresponding to a maximum mass error of 0.7 mDa. The repeatability of the method for spiked urine samples, expressed as median of relative standard deviations (RSD%) at concentrations of MRPL and 10 times MRPL, were 14% and 9%, respectively. The suitability of the LC/TOFMS method for doping control was demonstrated with authentic urine samples.

  2. Development of a perfusion reversed-phase high performance liquid chromatography method for the characterisation of maize products using multivariate analysis.

    Science.gov (United States)

    Rodriguez-Nogales, J M; Garcia, M C; Marina, M L

    2006-02-03

    A perfusion reversed-phase high performance liquid chromatography (RP-HPLC) method has been designed to allow rapid (3.4 min) separations of maize proteins with high resolution. Several factors, such as extraction conditions, temperature, detection wavelength and type and concentration of ion-pairing agent were optimised. A fine optimisation of the gradient elution was also performed by applying experimental design. Commercial maize products for human consumption (flours, precocked flours, fried snacks and extruded snacks) were characterised for the first time by perfusion RP-HPLC and their chromatographic profiles allowed a differentiation among products relating the different technological process used for their preparation. Furthermore, applying discriminant analysis makes it possible to group the samples according with the technological process suffered by maize products, obtaining a good prediction in 92% of the samples.

  3. High perfomance liquid chromatography in pharmaceutical analyses.

    Science.gov (United States)

    Nikolin, Branko; Imamović, Belma; Medanhodzić-Vuk, Saira; Sober, Miroslav

    2004-05-01

    electrochemical detection is nearly always associated with a major frontal peak than tails considerably. To date, the most sensitive method has been the reductive electrochemical detection and giving the excellent results in the investigation on some classes of drugs. Several high performance liquid chromatography oxidative electrochemical methods have been developed for the analyses of drugs and metabolites in body fluids. Mass spectrometer as specific detector with all variation of ionisation and interface (thermo spray, moving belt etc. ) or liquid chromatography-tandem mass spectrometry2,3,4,5). NMR as selective and specific detector in high performance liquid chromatography today is also in used. The development of a non-aqueous eluent for ion-exchange separation on silica has provided an excellent system which, when used in conjugation with an electrochemical detector, permits the analyses of an extensive range of especially basic drugs and metabolites. New packing materials such as polymeric, base deactivated silica's, pyrolysed carbon and the internal surface packing should offer the improved stability and higher efficiencies for certain classes of the compounds such as basic drugs. Microbore columns should become more accepted since they offer not only improved sensitivity but also a lower solvent consumption and consequently the reduced needs to dispose of noxious solvents. Many analyses of basic drugs are still performed by the same method of the ion-exchange chromatography on unmodified silica columns with an eluent buffered to about pH 9. Neutral or weakly acidic drugs for instance barbiturates can be chromatographed on a reversed phase system whilst acidic drugs for example paracetamol, cannabis are separated either by ion suppression or ion-pair chromatography on a reversed-phase packing material. In micelar liquid chromatography micelar mobile phases in reversed-phase instead of conventional hydro organic mobile phase is used. In micelar liquid chromatography

  4. Development of a supercritical fluid chromatography-tandem mass spectrometry method for the determination of lacidipine in beagle dog plasma and its application to a bioavailability study.

    Science.gov (United States)

    Geng, Yajie; Zhao, Longshan; Zhao, Juanhang; Guo, Bei; Ma, Panqin; Li, Yuanyuan; Zhang, Tianhong

    2014-01-15

    A simple, novel, rapid and sensitive supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) method was developed and validated for the determination of lacidipine in beagle dog plasma with nimodipine as internal standard. The method involved a simple liquid-liquid extraction method with tert-butyl methyl ether. The analytes were analyzed on an Acquity UPC(2) with a HSS C18 SB column (3mm×100mm, 1.8μm) set at 50°C. The mobile phase was carbon dioxide (≥99.99%) and methanol (92:8, v/v) at a flow rate of 2ml/min, the compensation solvent was methanol with 2% formic acid at a flow rate of 0.2ml/min and a total analysis time of 1.5min for each sample. The multiple reaction-monitoring mode was used for quantification of ion transitions at m/z 473.32→354.10 and 419.00→343.10 for lacidipine and internal standard, respectively. The linearity range of proposed method was 0.10-100ng/ml) (r(2)≥0.9990). The intra- and inter-day precision values were less than 15% and accuracy was from -0.83% to 3.27% at all quality control levels. The proposed method was successfully applied to a pharmacokinetic study of lacidipine in beagle dogs. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Gas chromatography of β-diketonates

    International Nuclear Information System (INIS)

    Burgett, C.A.

    1976-01-01

    The history of separation of metal complexes by gas chromatography is reviewed. The greatest success has been achieved with metal halides or metal β-diketonates, particularly with chelates of the small elements, Be and Al, and the extremely inert chromium diketonates. Many problems still remain concerning the development of suitable chromatographic techniques for many chelates; however, the technique of synergic solvent extraction, mixed-ligand complex chromatography, the synthesis of new heteroatomic ligands, and the advent of new liquid phases are discussed as means to increase the number of unique techniques for separation and analysis of metals. Methods are suggested and references are cited for chromatographic analysis of elements in the following groups: alkali metals, alkaline earths, Group IIIA, IVB, VB, VIB, VIIB, VIII, IB, and IIB. Special attention is given to separation of the volatile complexes of Sc, Y, the lanthanides, the actinides, and Pb. 156 references

  6. Cross validation of gas chromatography-flame photometric detection and gas chromatography-mass spectrometry methods for measuring dialkylphosphate metabolites of organophosphate pesticides in human urine.

    Science.gov (United States)

    Prapamontol, Tippawan; Sutan, Kunrunya; Laoyang, Sompong; Hongsibsong, Surat; Lee, Grace; Yano, Yukiko; Hunter, Ronald Elton; Ryan, P Barry; Barr, Dana Boyd; Panuwet, Parinya

    2014-01-01

    We report two analytical methods for the measurement of dialkylphosphate (DAP) metabolites of organophosphate pesticides in human urine. These methods were independently developed/modified and implemented in two separate laboratories and cross validated. The aim was to develop simple, cost effective, and reliable methods that could use available resources and sample matrices in Thailand and the United States. While several methods already exist, we found that direct application of these methods required modification of sample preparation and chromatographic conditions to render accurate, reliable data. The problems encountered with existing methods were attributable to urinary matrix interferences, and differences in the pH of urine samples and reagents used during the extraction and derivatization processes. Thus, we provide information on key parameters that require attention during method modification and execution that affect the ruggedness of the methods. The methods presented here employ gas chromatography (GC) coupled with either flame photometric detection (FPD) or electron impact ionization-mass spectrometry (EI-MS) with isotopic dilution quantification. The limits of detection were reported from 0.10ng/mL urine to 2.5ng/mL urine (for GC-FPD), while the limits of quantification were reported from 0.25ng/mL urine to 2.5ng/mL urine (for GC-MS), for all six common DAP metabolites (i.e., dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate, and diethyldithiophosphate). Each method showed a relative recovery range of 94-119% (for GC-FPD) and 92-103% (for GC-MS), and relative standard deviations (RSD) of less than 20%. Cross-validation was performed on the same set of urine samples (n=46) collected from pregnant women residing in the agricultural areas of northern Thailand. The results from split sample analysis from both laboratories agreed well for each metabolite, suggesting that each method can produce

  7. Liquid chromatography-tandem mass spectrometry method for determination of panel of neurotransmitters in cerebrospinal fluid from the rat model for tauopathy.

    Science.gov (United States)

    Kovac, Andrej; Somikova, Zuzana; Zilka, Norbert; Novak, Michal

    2014-02-01

    Alzheimer's disease (AD) is still being recognized today as an unmet medical need. Currently, there is no cure and early preclinical diagnostic assay available for AD. Therefore much attention is now being directed at the development of novel methods for quantitative determination of AD biomarkers in the cerebrospinal fluid (CSF). Here, we describe the liquid chromatography-tandem mass spectrometry method for determination of 5-hydroxytryptamine (SER), 5-hydroxyindoleacetic acid (5-HIAA), homovanilic acid (HVA), noradrenaline (NADR), adrenaline (ADR), dopamine (DA), glutamic acid (Glu), γ-aminobutyric acid (GABA), 3,4-dihydroxyphenylacetic acid (DOPAC) and histamine (HIS) in cerebrospinal fluid (CSF) from the rat model for human tauopathy. The benzoyl chloride was used as pre-column derivatization reagents. Neurotransmitters and metabolites were analysed on ultra performance liquid chromatography (UPLC) on C18 column in combination with tandem mass spectrometry. The method is simple, highly sensitive and showed excellent linearity with regression coefficients higher than 0.99. The accuracy was in a range of 93-113% for all analytes. The inter-day precision (n=5 days), expressed as %RSD, was in a range 2-10% for all analytes. Using this method we detected significant changes of CSF levels of two important neurotransmitters/metabolites, ADR and 5-HIAA, which correlates with progression of neurodegeneration in our animal model. © 2013 Published by Elsevier B.V.

  8. Liquid chromatography method to determine polyamines in thermosetting polymers

    International Nuclear Information System (INIS)

    Dopico-Garcia, M.S.; Lopez-Vilarino, J.M.; Fernandez-Martinez, G.; Gonzalez-Rodriguez, M.V.

    2010-01-01

    A simple, robust and sensitive analytical method to determine three polyamines commonly used as hardeners in epoxy resin systems and in the manufacture of polyurethane is reported. The studied polyamines are: one tetramine, TETA (triethylenetetramine), and two diamines, IPDA (Isophorone diamine) and TCD-diamine (4,7-methano-1H-indene-5,?-dimethanamine, octahydro-). The latter has an incompletely defined structure, and, as far as we know, has not been previously determined by other methods. All three polyamines contain primary amines; TETA also contains secondary amines. The analytical method involves derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, used for the first time for these compounds, followed by high performance liquid chromatography (HPLC) analysis with a fluorescence (FL) detector (λ excitation 248 nm, λ emision 395 nm). The HPLC-DAD-LTQ Orbitrap MS was used in order to provide structural information about the obtained derivatized compounds. The hybrid linear ion trap LTQ Orbitrap mass spectrometer has been introduced in recent years and provides a high mass accuracy. The structures of the derivatized analytes were identified from the protonated molecular ions [M+H] + and corresponded to the fully labelled analytes. The following analytical parameters were determined for the method using the HPLC-FL: linearity, precision (2.5-10%), instrumental precision intraday (0.8-1.5%) and interday (2.9-6.3%), and detection limits (0.02-0.14 mg L -1 ). The stability of stock solutions and derivatized compounds was also investigated. The method was applied to determine the amine free content in epoxy resin dust collected in workplaces.

  9. Liquid chromatography method to determine polyamines in thermosetting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Dopico-Garcia, M.S. [Laboratorio de Quimica - Centro de Investigacions Tecnoloxicas, Universidade da Coruna, Campus de Esteiro s/n, 15403 Ferrol (Spain); Centro Galego do Plastico, A Cabana s/n, 15590 Ferrol (Spain); Lopez-Vilarino, J.M. [Laboratorio de Quimica - Centro de Investigacions Tecnoloxicas, Universidade da Coruna, Campus de Esteiro s/n, 15403 Ferrol (Spain); Fernandez-Martinez, G. [Unidad de Tecnicas Cromatograficas, Servizos de Apoio a Investigacion, Edificio Servizos Centrais de Investigacion, Universidade da Coruna, Campus de Elvina s/n, 15071 A Coruna (Spain); Gonzalez-Rodriguez, M.V., E-mail: victoria@udc.es [Dpto. de Quimica Analitica - E.U. Politecnica, Universidade da Coruna, Avda. 19 de Febrero s/n, 15405 Ferrol (Spain)

    2010-05-14

    A simple, robust and sensitive analytical method to determine three polyamines commonly used as hardeners in epoxy resin systems and in the manufacture of polyurethane is reported. The studied polyamines are: one tetramine, TETA (triethylenetetramine), and two diamines, IPDA (Isophorone diamine) and TCD-diamine (4,7-methano-1H-indene-5,?-dimethanamine, octahydro-). The latter has an incompletely defined structure, and, as far as we know, has not been previously determined by other methods. All three polyamines contain primary amines; TETA also contains secondary amines. The analytical method involves derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, used for the first time for these compounds, followed by high performance liquid chromatography (HPLC) analysis with a fluorescence (FL) detector ({lambda} excitation 248 nm, {lambda} emision 395 nm). The HPLC-DAD-LTQ Orbitrap MS was used in order to provide structural information about the obtained derivatized compounds. The hybrid linear ion trap LTQ Orbitrap mass spectrometer has been introduced in recent years and provides a high mass accuracy. The structures of the derivatized analytes were identified from the protonated molecular ions [M+H]{sup +} and corresponded to the fully labelled analytes. The following analytical parameters were determined for the method using the HPLC-FL: linearity, precision (2.5-10%), instrumental precision intraday (0.8-1.5%) and interday (2.9-6.3%), and detection limits (0.02-0.14 mg L{sup -1}). The stability of stock solutions and derivatized compounds was also investigated. The method was applied to determine the amine free content in epoxy resin dust collected in workplaces.

  10. Detection of radiation-induced hydrocarbons in Camembert irradiated before and after the maturing process-comparison of florisil column chromatography and on-line coupled liquid chromatography-gas chromatography

    International Nuclear Information System (INIS)

    Schulzki, G.; Spiegelberg, A.; Bögl, K.W.; Schreiber, G.A.

    1995-01-01

    The influence of the maturing process on the detection of radiation-induced volatile hydrocarbons in the fat of Camembert has been investigated. Two analytical methods for separation of the hydrocarbon fraction from the lipid were applied: Florisil column chromatography with subsequent gas chromatographic-mass spectrometric (GC-MS) determination as well as on-line coupled liquid chromatography-GC-MS. The maturing process had no influence on the detection of radiation-induced volatiles. Comparable results were achieved with both analytical methods. However, preference is given to the more effective on-line coupled LC-GC method

  11. Screening anti-tumor compounds from Ligusticum wallichii using cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Zhang, Tao; Ding, Yuanyuan; An, Hongli; Feng, Liuxin; Wang, Sicen

    2015-07-14

    Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry was developed. Tyrosine 367 Cysteine-HEK293 cells were used as cell membrane stationary phase. Specificity and reproducibility of the cell membrane chromatography was evaluated using 1-tert-butyl-3-{2-[4-(diethylamino)butylamino]-6-(3,5-dimethoxyphenyl)pyrido[2,3-d]pyrimidin-7-yl}urea, Nimodipine and dexamethasone acetate. Then, anti-tumor components acting on Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 were screened and identified from extracts of Ligusticum wallichii. Components from the extract were retained on the cell membrane chromatographic column. The retained fraction was directly eluted into high-performance liquid chromatography with mass spectrometry system for separation and identification. Finally, Levistolide A was identified as an active component from Ligusticum wallichii extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan colorimetric assay revealed that Levistolide A inhibits proliferation of overexpressing the mutated receptor cells with dose-dependent manner. Phosphorylation of fibroblast growth factor receptor 4 was also decrease under Levistolide A treatment. Flex dock simulation verified that Levistolide A could bind with the tyrosine kinase domain of fibroblast growth factor receptor 4. Therefore, Levistolide A screened by the cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry can arrest cell growth. In conclusion, the two-dimensional high-performance liquid chromatography method can screen and identify potential anti-tumor ingredients which specifically act on the tyrosine kinase domain of the mutated fibroblast growth factor receptor 4. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. Determination of chlormequat in pears by liquid chromatography/mass spectrometry

    NARCIS (Netherlands)

    Mol, H.G.J.; Dam, R.C.J. van; Vreeken, R.J.; Steijger, O.M.

    2000-01-01

    A straightforward and reliable method was developed for the determination of chlormequat in pears by liquid chromatography/mass spectrometry (LC/MS). Water and methanol were compared as extraction solvents. Because no significant differences in extraction efficiency or repeatability were found,

  13. A novel high-performance thin layer chromatography method for quantification of long chain aliphatic hydrocarbons from Cissus quadrangularis

    Directory of Open Access Journals (Sweden)

    Vandana Jain

    2016-08-01

    Full Text Available Context: A high-performance thin layer chromatography (HPTLC is an analytical technique, which can be used for the determination of constituents or marker components in various parts of the plants. Earlier studies have estimated phytoconstituents from the stem and other aerial plant parts of Cissus quadrangularis Linn. Estimation of hydrocarbons can also be successfully done using HPTLC technique using suitable derivatization. Aims: To develop and validate a simple and rapid method for the estimation of long chain aliphatic hydrocarbons from the leaves of C. quadrangularis using HPTLC technique. Methods: Precoated silica gel 60 F254 plates were used as stationary phase. The mobile phase used was hexane (100 %. The detection of spots was carried out using berberine sulphate as detecting reagent. Results: The method was validated in terms of linearity, sensitivity, accuracy, and precision. Linearity range was found to be 2-10 µg/mL, limit of detection 0.127 µg/mL, and limit of quantification 0.384 µg/mL. Conclusions: A novel, simple, accurate, precise and sensitive HPTLC method has been developed and validated for the estimation of long chain aliphatic hydrocarbons obtained from the leaves of C. quadrangularis Linn.

  14. Supercritical fluid chromatography for GMP analysis in support of pharmaceutical development and manufacturing activities.

    Science.gov (United States)

    Hicks, Michael B; Regalado, Erik L; Tan, Feng; Gong, Xiaoyi; Welch, Christopher J

    2016-01-05

    Supercritical fluid chromatography (SFC) has long been a preferred method for enantiopurity analysis in support of pharmaceutical discovery and development, but implementation of the technique in regulated GMP laboratories has been somewhat slow, owing to limitations in instrument sensitivity, reproducibility, accuracy and robustness. In recent years, commercialization of next generation analytical SFC instrumentation has addressed previous shortcomings, making the technique better suited for GMP analysis. In this study we investigate the use of modern SFC for enantiopurity analysis of several pharmaceutical intermediates and compare the results with the conventional HPLC approaches historically used for analysis in a GMP setting. The findings clearly illustrate that modern SFC now exhibits improved precision, reproducibility, accuracy and robustness; also providing superior resolution and peak capacity compared to HPLC. Based on these findings, the use of modern chiral SFC is recommended for GMP studies of stereochemistry in pharmaceutical development and manufacturing. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Optimization of ultra-performance liquid chromatography (UPLC) with fluorescence detector (FLD) method for the quantitative determination of selected neurotransmitters in rat brain.

    Science.gov (United States)

    Stragierowicz, Joanna; Daragó, Adam; Brzeźnicki, Sławomir; Kilanowicz, Anna

    2017-07-26

    Glutamate (Glu) and γ-aminobutyric acid (GABA) are the main neurotransmitters in the central nervous system for excitatory and inhibitory processes, respectively. Monitoring these neurotransmitters is an essential tool in establishing pathological functions, among others in terms of occupational exposure to toxic substances. We present modification of the HPLC (high-performance liquid chromatography) to the UPLC (ultra-performance liquid chromatography) method for the simultaneous determination of glutamate and γ-aminobutyric acid in a single injection. The isocratic separation of these neurotransmitter derivatives was performed on Waters Acquity BEH (ethylene bridged hybrid) C18 column with particle size of 1.7 μm at 35°C using a mobile phase consisting of 0.1 M acetate buffer (pH 6.0) and methanol (60:40, v/v) at a flow rate of 0.3 ml/min. The analytes were detected with the fluorescence detector (FLD) using derivatization with o-phthaldialdehyde (OPA), resulting in excitation at 340 nm and emission at 455 nm. Several validation parameters including linearity (0.999), accuracy (101.1%), intra-day precision (1.52-1.84%), inter-day precision (2.47-3.12%), limit of detection (5-30 ng/ml) and quantification (100 ng/ml) were examined. The developed method was also used for the determination of these neurotransmitters in homogenates of selected rat brain structures. The presented UPLC-FLD is characterized by shorter separation time (3.5 min), which is an adaptation of the similar HPLC methods and is an alternative for more expensive references techniques such as liquid chromatography coupled with tandem mass-spectrometry (LC-MS/MS) methods. Med Pr 2017;68(5):583-591. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  16. High performance liquid chromatography in pharmaceutical analyses

    Directory of Open Access Journals (Sweden)

    Branko Nikolin

    2004-05-01

    components observed in plasma extract whereas electrochemical detection is nearly always associated with a major frontal peak than tails considerably. To date, the most sensitive method has been the reductive electrochemical detection and giving the excellent results in the investigation on some classes of drugs. Several high performance liquid chromatography oxidative electrochemical methods have been developed for the analyses of drugs and metabolites in body fluids. Mass spectrometer as specific detector with all variation of ionisation and interface (thermo spray, moving belt etc. or liquid chromatography-tandem mass spectrometry2,3,4,5. NMR as selective and specific detector in high performance liquid chromatography today is also in used. The development of a non-aqueous eluent for ion-exchange separation on silica has provided an excellent system which, when used in conjugation with an electrochemical detector, permits the analyses of an extensive range of especially basic drugs and metabolites. New packing materials such as polymeric, base deactivated silica's, pyrolysed carbon and the internal surface packing should offer the improved stability and higher efficiencies for certain classes of the compounds such as basic drugs. Microbore columns should become more accepted since they offer not only improved sensitivity but also a lower solvent consumption and consequently the reduced needs to dispose of noxious solvents. Many analyses of basic drugs are still performed by the same method of the ion-exchange chromatography on unmodified silica columns with an eluent buffered to about pH 9. Neutral or weakly acidic drugs for instance barbiturates can be chromatographed on a reversed phase system whilst acidic drugs for example paracetamol, cannabis are separated either by ion suppression or ion-pair chromatography on a reversed-phase packing material. In micelar liquid chromatography micelar mobile phases in reversed-phase instead of conventional hydro

  17. Simple column-switching ion chromatography method for determining eight monosaccharides and oligosaccharides in honeydew and nectar.

    Science.gov (United States)

    Ni, Chengzhu; Zhu, Binhe; Wang, Nani; Wang, Muhua; Chen, Suqing; Zhang, Jiajie; Zhu, Yan

    2016-03-01

    Honeydew is excreted by aphids as a sweet waste and nectar is floral honey. Honeydew and nectar are complicated samples which consist of various sugars and amino acids. In this work, a simple ion chromatography with column-switching method was developed for the simultaneous analysis of 8 monosaccharides and oligosaccharides in honeydew and nectar. A reversed-phase column was used as a pretreatment column to eliminate organics on-line and sugars were eluted from a collection loop to analytical column by using column-switching technique. This method showed good linearity (r⩾0.9994) and afforded low limits of detection ranging from 1.55 to 10.17μgL(-1) for all the analytes. Recoveries ranged from 95% to 105% and repeatability results were acceptable with relative standard deviation of less than 3.21% (n=6). This method was successfully applied to quantification of these sugars in honeydew and nectar. These results showed honeydew had much more oligosaccharides than nectar. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. 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)

  19. Determination of petroleum fractions as contaminants in the waters by gas chromatography

    International Nuclear Information System (INIS)

    Kubinec, R.; Mracnova, R.; Kuran, P.; Ostrovsky, I.; Sojak, L.

    1995-01-01

    The method of micro-extraction of petroleum fractions from water and analysis using gas chromatography was developed. This method can be used for the analysis of gaseous oil and mineral oil in the water wit the detection limit 12 ppb and 18 ppb, respectively

  20. Isotope dilution liquid chromatography - mass spectrometry methods for fat- and water-soluble vitamins in nutritional formulations.

    Science.gov (United States)

    Phinney, Karen W; Rimmer, Catherine A; Thomas, Jeanice Brown; Sander, Lane C; Sharpless, Katherine E; Wise, Stephen A

    2011-01-01

    Vitamins are essential to human health, and dietary supplements containing vitamins are widely used by individuals hoping to ensure they have adequate intake of these important nutrients. Measurement of vitamins in nutritional formulations is necessary to monitor regulatory compliance and in studies examining the nutrient intake of specific populations. Liquid chromatographic methods, primarily with UV absorbance detection, are well established for both fat- and water-soluble measurements, but they do have limitations for certain analytes and may suffer from a lack of specificity in complex matrices. Liquid chromatography-mass spectrometry (LC-MS) provides both sensitivity and specificity for the determination of vitamins in these matrices, and simultaneous analysis of multiple vitamins in a single analysis is often possible. In this work, LC-MS methods were developed for both fat- and water-soluble vitamins and applied to the measurement of these analytes in two NIST Standard Reference Materials. When possible, stable isotope labeled internal standards were employed for quantification.

  1. Screening of extraction methods for glycoproteins from jellyfish ( Rhopilema esculentum) oral-arms by high performance liquid chromatography

    Science.gov (United States)

    Ren, Guoyan; Li, Bafang; Zhao, Xue; Zhuang, Yongliang; Yan, Mingyan; Hou, Hu; Zhang, Xiukun; Chen, Li

    2009-03-01

    In order to select an optimum extraction method for the target glycoprotein (TGP) from jellyfish ( Rhopilema esculentum) oral-arms, a high performance liquid chromatography (HPLC)-assay for the determination of the TGP was developed. Purified target glycoprotein was taken as a standard glycoprotein. The results showed that the calibration curves for peak area plotted against concentration for TGP were linear ( r = 0.9984, y = 4.5895 x+47.601) over concentrations ranging from 50 to 400 mgL-1. The mean extraction recovery was 97.84% (CV2.60%). The fractions containing TGP were isolated from jellyfish ( R. esculentum) oral-arms by four extraction methods: 1) water extraction (WE), 2) phosphate buffer solution (PBS) extraction (PE), 3) ultrasound-assisted water extraction (UA-WE), 4) ultrasound-assisted PBS extraction (UA-PE). The lyophilized extract was dissolved in Milli-Q water and analyzed directly on a short TSK-GEL G4000PWXL (7.8 mm×300 mm) column. Our results indicated that the UA-PE method was the optimum extraction method selected by HPLC.

  2. Hydrophilic interaction liquid chromatography method for measuring the composition of aquatic humic substances

    KAUST Repository

    Wang, Renqi; Gutié rrez, Leonardo A.; Ng, Siuchoon; Croue, Jean-Philippe

    2015-01-01

    A hydrophilic interaction liquid chromatography (HILIC) method was developed to measure the composition of humic substances from river, reservoir, and treated wastewater based on their physicochemical properties. The current method fractionates the humic substances into four well-defined groups based on parallel analyses with a neutral and a cationic HILIC column, using mobile phases of varied compositions and pH. The results indicate that: (i) the proportion of carboxylic acids in the humic substances from terrestrial origins is less than half of that from treated wastewater (Jeddah, KSA), (ii) a higher content of basic compounds was observed in the humic substances from treated wastewater and Ribou Reservoir (Cholet, France) than in the sample from Loire River (France), (iii) a higher percentage of hydrophobic macromolecules were found in the humic substances from Loire River than in the other samples, and (iv) humic substances of treated wastewater contained less ionic neutral compounds (i.e., pKa 5-9) than the waters from terrestrial origins. The physicochemical property disparity amongst the compounds in each humic substances sample was also evaluated. The humic substances from the lightly humic Loire river displayed the highest disparity, whereas the highly humic Suwannee river (Georgia, USA) showed the most homogeneous humic substances.

  3. A simple method for the measurement of radioactivity of samples separated by gas chromatography

    International Nuclear Information System (INIS)

    Farkas, T.

    1981-01-01

    Gas chromatographs with flame ionization detector can be used to determine the radioactivity ( 14 C) of separated peaks. After a suitable change in the detector output the combustion product 14 CO 2 can be trapped by hyamine hydroxyde and measured by liquid scintigraphy. 90% of peak activity can be collected and measured, thus the method can be applied to determine the distribution and specific radioactivity of the components separated by gas chromatography. (author)

  4. Development of a method for comprehensive and quantitative analysis of plant hormones by highly sensitive nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry

    International Nuclear Information System (INIS)

    Izumi, Yoshihiro; Okazawa, Atsushi; Bamba, Takeshi; Kobayashi, Akio; Fukusaki, Eiichiro

    2009-01-01

    In recent plant hormone research, there is an increased demand for a highly sensitive and comprehensive analytical approach to elucidate the hormonal signaling networks, functions, and dynamics. We have demonstrated the high sensitivity of a comprehensive and quantitative analytical method developed with nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS/MS) under multiple-reaction monitoring (MRM) in plant hormone profiling. Unlabeled and deuterium-labeled isotopomers of four classes of plant hormones and their derivatives, auxins, cytokinins (CK), abscisic acid (ABA), and gibberellins (GA), were analyzed by this method. The optimized nanoflow-LC-ESI-IT-MS/MS method showed ca. 5-10-fold greater sensitivity than capillary-LC-ESI-IT-MS/MS, and the detection limits (S/N = 3) of several plant hormones were in the sub-fmol range. The results showed excellent linearity (R 2 values of 0.9937-1.0000) and reproducibility of elution times (relative standard deviations, RSDs, <1.1%) and peak areas (RSDs, <10.7%) for all target compounds. Further, sample purification using Oasis HLB and Oasis MCX cartridges significantly decreased the ion-suppressing effects of biological matrix as compared to the purification using only Oasis HLB cartridge. The optimized nanoflow-LC-ESI-IT-MS/MS method was successfully used to analyze endogenous plant hormones in Arabidopsis and tobacco samples. The samples used in this analysis were extracted from only 17 tobacco dry seeds (1 mg DW), indicating that the efficiency of analysis of endogenous plant hormones strongly depends on the detection sensitivity of the method. Our analytical approach will be useful for in-depth studies on complex plant hormonal metabolism.

  5. Development of a method for comprehensive and quantitative analysis of plant hormones by highly sensitive nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, Yoshihiro; Okazawa, Atsushi; Bamba, Takeshi; Kobayashi, Akio [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Fukusaki, Eiichiro, E-mail: fukusaki@bio.eng.osaka-u.ac.jp [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2009-08-26

    In recent plant hormone research, there is an increased demand for a highly sensitive and comprehensive analytical approach to elucidate the hormonal signaling networks, functions, and dynamics. We have demonstrated the high sensitivity of a comprehensive and quantitative analytical method developed with nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS/MS) under multiple-reaction monitoring (MRM) in plant hormone profiling. Unlabeled and deuterium-labeled isotopomers of four classes of plant hormones and their derivatives, auxins, cytokinins (CK), abscisic acid (ABA), and gibberellins (GA), were analyzed by this method. The optimized nanoflow-LC-ESI-IT-MS/MS method showed ca. 5-10-fold greater sensitivity than capillary-LC-ESI-IT-MS/MS, and the detection limits (S/N = 3) of several plant hormones were in the sub-fmol range. The results showed excellent linearity (R{sup 2} values of 0.9937-1.0000) and reproducibility of elution times (relative standard deviations, RSDs, <1.1%) and peak areas (RSDs, <10.7%) for all target compounds. Further, sample purification using Oasis HLB and Oasis MCX cartridges significantly decreased the ion-suppressing effects of biological matrix as compared to the purification using only Oasis HLB cartridge. The optimized nanoflow-LC-ESI-IT-MS/MS method was successfully used to analyze endogenous plant hormones in Arabidopsis and tobacco samples. The samples used in this analysis were extracted from only 17 tobacco dry seeds (1 mg DW), indicating that the efficiency of analysis of endogenous plant hormones strongly depends on the detection sensitivity of the method. Our analytical approach will be useful for in-depth studies on complex plant hormonal metabolism.

  6. Liquid chromatography method to determine polyamines in thermosetting polymers.

    Science.gov (United States)

    Dopico-García, M S; López-Vilariño, J M; Fernández-Martínez, G; González-Rodríguez, M V

    2010-05-14

    A simple, robust and sensitive analytical method to determine three polyamines commonly used as hardeners in epoxy resin systems and in the manufacture of polyurethane is reported. The studied polyamines are: one tetramine, TETA (triethylenetetramine), and two diamines, IPDA (Isophorone diamine) and TCD-diamine (4,7-methano-1H-indene-5,?-dimethanamine, octahydro-). The latter has an incompletely defined structure, and, as far as we know, has not been previously determined by other methods. All three polyamines contain primary amines; TETA also contains secondary amines. The analytical method involves derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, used for the first time for these compounds, followed by high performance liquid chromatography (HPLC) analysis with a fluorescence (FL) detector (lambda excitation 248nm, lambda emision 395nm). The HPLC-DAD-LTQ Orbitrap MS was used in order to provide structural information about the obtained derivatized compounds. The hybrid linear ion trap LTQ Orbitrap mass spectrometer has been introduced in recent years and provides a high mass accuracy. The structures of the derivatized analytes were identified from the protonated molecular ions [M+H](+) and corresponded to the fully labelled analytes. The following analytical parameters were determined for the method using the HPLC-FL: linearity, precision (2.5-10%), instrumental precision intraday (0.8-1.5%) and interday (2.9-6.3%), and detection limits (0.02-0.14mgL(-1)). The stability of stock solutions and derivatized compounds was also investigated. The method was applied to determine the amine free content in epoxy resin dust collected in workplaces. Copyright 2010 Elsevier B.V. All rights reserved.

  7. Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments.

    Science.gov (United States)

    Chiappini, L; Perraudin, E; Durand-Jolibois, R; Doussin, J F

    2006-11-01

    A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m3 Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91method were both good and detection limits ranged from 1.2 to 6.4 ng for the investigated compounds.

  8. Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chiappini, L.; Perraudin, E.; Durand-Jolibois, R.; Doussin, J.F. [Universites Paris, Laboratoire Interuniversitaire des Systemes Atmospheriques, UMR CNRS 7583, Creteil (France)

    2006-11-15

    A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m{sup 3} Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91 < R < 0.98) of the method were both good and detection limits ranged from 1.2 to 6.4 ng for the investigated compounds. (orig.)

  9. Development of a high performance liquid chromatography method for quantification of isomers β-caryophyllene and α-humulene in copaiba oleoresin using the Box-Behnken design.

    Science.gov (United States)

    de Almeida Borges, Vinícius Raphael; Ribeiro, Ana Ferreira; de Souza Anselmo, Carina; Cabral, Lúcio Mendes; de Sousa, Valéria Pereira

    2013-12-01

    The sesquiterpene isomers, β-Cariofileno (CAR) and α-Humuleno (HUM) are the primary constituents of the copaiba oleoresin species. These natural products are primarily used by the Amazonian population and marketed as phytotherapies and cosmetics. The aim of this study was to develop and validate a method that simultaneously assays the isomers present in copaiba oleoresins by high performance liquid chromatography using the Box-Behnken design. After preliminary studies, the reverse phase chromatographic system was selected using a cyano column and a mobile phase consisting of acetonitrile and phosphate buffer. The Box-Behnken design was applied at three levels and with four independent variables: flow rate (X1), gradient slope time (X2), proportion of organic compounds at the end of the gradient (X3) and at the beginning of the gradient (X4). Also, the responses of the dependent variables: CAR retention time (Y1) and the resolution between the CAR and HUM peaks (Y2) was assessed. The mathematical model obtained from the regression results was satisfactory (R(2)>0.98, n=27) and showed a quadratic relationship where the effects of interactions between the variables, was observed by response surface graphs. The simultaneous optimization method was used to establish the best compromise of the resolution between the CAR and HUM isomers while adjusting the retention time of CAR. This method was successfully optimized by BBD obtaining chromatographic peaks with good symmetry, resolution and separation efficiency. The validation of the developed method confirmed its specificity, precision, accuracy and linearity in the range of 5.0-11.0 and 0.4-1.0μg/mL for CAR and HUM, respectively, and is considered suitable for routine applications which assure quality control. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Development of an isotope labeling ultra-high performance liquid chromatography mass spectrometric method for quantification of acylglycines in human urine

    Energy Technology Data Exchange (ETDEWEB)

    Stanislaus, Avalyn; Guo, Kevin [Department of Chemistry, University of Alberta, Edmonton, Alberta (Canada); Li Liang, E-mail: Liang.Li@ualberta.ca [Department of Chemistry, University of Alberta, Edmonton, Alberta (Canada)

    2012-10-31

    Graphical abstract: - Abstract: Acylglycines play a crucial regulatory and detoxification role in the accumulation of the corresponding acyl CoA esters and are an important class of metabolites in the diagnoses of inborn errors of metabolism. Sensitive quantification of a large number of acylglycines not only improves diagnosis but also enables the discovery of potential new biomarkers of diseases. We report an ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS) method for quantifying acylglycines in human urine with high sensitivity. This method is based on the use of a newly developed isotope labeling reagent, p-dimethylaminophenacyl (DmPA) bromide, to label acylglycines to improve detection sensitivity. Eighteen acylglycines, namely acetylglycine, propionylglycine, isobutyrylglycine, butyrylglycine, 4-hydroxyphenylacetylglycine, 2-furoylglycine, tiglylglycine, 2-methybutyrylglycine, 3-methylcrotonylglycine, isovalerylglycine, valerylglycine, hexanoylglycine, phenylacetylglycine, phenylpropionylglycine, glutarylglycine, heptanoylglycine, octanoylglycine and suberylglycine, were measured. This method uses calibration standards prepared in surrogate matrix (un-derivatized urine) and stable-isotope labeled analytes as the internal standards. The analysis was carried out in the positive ion detection mode using multiple reaction monitoring (MRM) survey scans. The calibration curves were validated over the range of 1.0-500 nM. The method achieved a lower limit of quantitation (LLOQ) of 1-5 nM for all analytes, as measured by the standard derivations associated with calibration curves and confirmed in surrogate matrix; the signal-to-noise ratio at LLOQ ranged from 12.50 to 156.70. Both accuracy (% RE or relative error) and precision (% CV) were <15%. Matrix effects were minimized using the surrogate matrix. All eighteen analytes were stable in urine for at least 5 h at room temperature, autosampler (4 Degree-Sign C) for 24 h, 7 weeks at -20

  11. 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.

  12. Development of a liquid chromatography-electrospray chemical ionization tandem mass spectrometry analytical method for analysis of eleven hydroxylated polybrominated diphenyl ethers.

    Science.gov (United States)

    Feo, Maria Luisa; Barón, Enrique; Aga, Diana S; Eljarrat, Ethel; Barceló, Damià

    2013-08-02

    Recently, hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have emerged as environmentally relevant pollutants due to recent reports of their natural production and metabolism. Recent mechanistic studies in human and rats have shown that some OH-PBDEs are more potent than parent compounds (PBDEs) and may contribute substantially to neurodevelopmental disorders by direct neurotoxicity, or indirectly through altered thyroid disruption. However, analytical methodologies for determination of OH-PBDEs are currently limited. In this study a robust liquid chromatography-electrospray tandem triple quadrupole-linear ion trap mass spectrometer (LC-ESI-QqLIT-MS-MS) in negative mode method was developed for the determination of eleven OH-tri- to OH-hexa-PBDEs. Two different columns were tested and compared for chromatographic separation: a C18 BetaBasic and a Purospher STAR RP 18, working at pH 8 and 10, respectively. Mobile phase (acetonitrile:water) was optimized by changing the pH of the aqueous phase and the concentration of the organic modifier (methanol). The MS-MS parameters (declustering potential (DP), collision energy (CE) and cell exit potential (CXP)) were optimized. Selected reaction monitoring (SRM) was used in order to increase sensitivity. Two SRM transitions ([M-H](-)>[Br](-)) were selected for each OH-PBDE, one for quantification and the second one for confirmation. Under the optimized conditions, the instrumental limits of detection were between 0.17 and 0.72injectedpg. The method provided good linearity (r>0.99 for a concentration range of 0.30-100ng/mL), accuracy and precision (%Dev and %RSD≤20% for intra- and inter-assays). Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Method for the direct determination of available carbohydrates in low-carbohydrate products using high-performance anion exchange chromatography.

    Science.gov (United States)

    Ellingson, David; Potts, Brian; Anderson, Phillip; Burkhardt, Greg; Ellefson, Wayne; Sullivan, Darryl; Jacobs, Wesley; Ragan, Robert

    2010-01-01

    An improved method for direct determination of available carbohydrates in low-level products has been developed and validated for a low-carbohydrate soy infant formula. The method involves modification of an existing direct determination method to improve specificity, accuracy, detection levels, and run times through a more extensive enzymatic digestion to capture all available (or potentially available) carbohydrates. The digestion hydrolyzes all common sugars, starch, and starch derivatives down to their monosaccharide components, glucose, fructose, and galactose, which are then quantitated by high-performance anion-exchange chromatography with photodiode array detection. Method validation consisted of specificity testing and 10 days of analyzing various spike levels of mixed sugars, maltodextrin, and corn starch. The overall RSD was 4.0% across all sample types, which contained within-day and day-to-day components of 3.6 and 3.4%, respectively. Overall average recovery was 99.4% (n = 10). Average recovery for individual spiked samples ranged from 94.1 to 106% (n = 10). It is expected that the method could be applied to a variety of low-carbohydrate foods and beverages.

  14. Fingerprint analysis of Resina Draconis by ultra-performance liquid chromatography

    OpenAIRE

    Xue, Yudi; Zhu, Lin; Yi, Tao

    2017-01-01

    Background Resina Draconis, a bright red resin derived from Dracaena cochinchinensis, is a traditional medicine used in China. To improve its quality control approach, an ultra-performance liquid chromatography (UPLC) fingerprint method was developed for rapidly evaluating the quality of Resina Draconis. Methods The precision, repeatability and stability of the proposed UPLC method were validated in the study. Twelve batches of Resina Draconis samples from various sources were analyzed by the...

  15. Extraction chromatography of actinides

    International Nuclear Information System (INIS)

    Muller, W.

    1978-01-01

    Extraction chromatography of actinides in the oxidation state from 2 to 6 is reviewed. Data on using neutral (tbp), basic (substituted ammonium salts) and acidic [di-(2-ethylhexyl)-phosphoric acid (D2EHPA)] extracting agents ketones, esters, alcohols and β-diketones in this method are given. Using the example of actinide separation using D2EHPA, discussed are factors influencing the efficiency of their chromatography separation (nature and particle size of the carrier materials, extracting agents amount on the carrier, temperature and elution rate)

  16. Pressurised liquid extraction of flavonoids in onions. Method development and validation

    DEFF Research Database (Denmark)

    Søltoft, Malene; Christensen, J.H.; Nielsen, J.

    2009-01-01

    A rapid and reliable analytical method for quantification of flavonoids in onions was developed and validated. Five extraction methods were tested on freeze-dried onions and subsequently high performance liquid chromatography (HPLC) with UV detection was used for quantification of seven flavonoids...... extraction methods. However. PLE was the preferred extraction method because the method can be highly automated, use only small amounts of solvents, provide the cleanest extracts, and allow the extraction of light and oxygen-sensitive flavonoids to be carried out in an inert atmosphere protected from light......-step PLE method showed good selectivity, precision (RSDs = 3.1-11%) and recovery of the extractable flavonoids (98-99%). The method also appeared to be a multi-method, i.e. generally applicable to, e.g. phenolic acids in potatoes and carrots....

  17. Pre-staining thin layer chromatography method for amino acid ...

    African Journals Online (AJOL)

    Jane

    2010-12-13

    Dec 13, 2010 ... inexpensive and the results obtained were clean and reproducible. However, it is suitable for the high throughput screening of amino acid-producing strains. Key words: Thin layer chromatography, pre-staining, amino acid detection. INTRODUCTION. Several analytical techniques have been often used for.

  18. 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.

  19. Csaba Horváth and preparative liquid chromatography.

    Science.gov (United States)

    Guiochon, Georges

    2005-06-24

    Few chromatographers have been interested in furthering preparative liquid chromatography. The pioneers, Tswett, Kuhn and Lederer, A.J.P. Martin, Tiselius, isolated fractions but as an intermediate step in the analysis of their samples. The progress in electronics and sensors, and in their miniaturization has lead to the paradoxical situation that the analysts never see the transient pure fractions that their detector quantitates. Yet, over the last 25 years, preparative liquid chromatography has become an important industrial process for the separation, the extraction, and/or the purification of many pharmaceuticals or pharmaceutical intermediates, including pure enantiomers, purified peptides and proteins, compounds that are manufactured at the relatively large industrial scale of a few kilograms to several hundred tons per year. This development that has strongly affected the modem pharmaceutical industry is mainly due to the pioneering work of Csaba Horváth. His work in preparative HPLC was critical at both the practical and the theoretical levels. He was the first scientist in modem times to pay serious attention to the relationships between the curvature of the equilibrium isotherms, the competitive nature of nonlinear isotherms, and the chromatographic band profiles of complex mixtures. The thermodynamics of multi-component phase equilibria and mass transfer kinetics in chromatography attracted his interest and were the focus of ground-breaking contributions. He investigated displacement chromatography, an old method invented by Tiselius that Csaba was first to implement in HPLC. This choice was explained by the essential characteristic of displacement chromatography, in that it delivers fractions that can be far more concentrated than the feed. Remarkably, once the basics of nonlinear chromatography had been mastered in his group, most of the applications that were studied by his coworkers dealt with peptides of various sizes and with proteins. Thus, all

  20. Thin-layer chromatography and colorimetric analysis of multi-component explosive mixtures

    Science.gov (United States)

    Pagoria, Philip F.; Mitchell, Alexander R.; Whipple, Richard E.; Carman, M. Leslie

    2014-08-26

    A thin-layer chromatography method for detection and identification of common military and peroxide explosives in samples includes the steps of provide a reverse-phase thin-layer chromatography plate; prepare the plate by marking spots on which to deposit the samples by touching the plate with a marker; spot one micro liter of a first standard onto one of the spots, spot one micro liter of a second standard onto another of the spots, and spot samples onto other of spots producing a spotted plate; add eluent to a developing chamber; add the spotted plate to the developing chamber; remove the spotted plate from the developing chamber producing a developed plate; place the developed plate in an ultraviolet light box; add a visualization agent to a dip tank; dip the developed plate in the dip tank and remove the developed plate quickly; and detect explosives by viewing said developed plate.

  1. Development of a simple and rapid solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry method for the analysis of dopamine, serotonin and norepinephrine in human urine.

    Science.gov (United States)

    Naccarato, Attilio; Gionfriddo, Emanuela; Sindona, Giovanni; Tagarelli, Antonio

    2014-01-31

    The work aims at developing a simple and rapid method for the quantification of dopamine (DA), serotonin (5-HT) and norepinephrine (NE) in human urine. The urinary levels of these biogenic amines can be correlated with several pathological conditions concerning heart disease, stress, neurological disorders and cancerous tumors. The proposed analytical approach is based on the use of solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) after a fast derivatization of both aliphatic amino and phenolic moieties by propyl chloroformate. The variables influencing the derivatization reaction were reliably optimized by the multivariate approach of "Experimental design". The optimal conditions were obtained by performing derivatization with 100μL of propyl chloroformate and 100μL of pyridine. The extraction ability of five commercially available SPME fibers was evaluated in univariate mode and the best results were obtained using the polyacrylate fiber. The variables affecting the efficiency of SPME analysis were again optimized by the multivariate approach of "Experimental design" and, in particular, a central composite design (CCD) was applied. The optimal values were extraction in 45min at room temperature, desorption temperature at 300°C, no addition of NaCl. Assay of derivatized analytes was performed by using a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) system in selected reaction monitoring (SRM) acquisition. An evaluation of all analytical parameters demonstrates that the developed method provides satisfactory results. Indeed, very good linearities were achieved in the tested calibration range with correlation coefficient values of 0.9995, 0.9999 and 0.9997 for DA, 5-HT and NE, respectively. Accuracies and RSDs calculated for between-run and tested at concentrations of 30, 200, and 800μg L(-1) were in the range from 92.8% to 103.0%, and from 0.67 to 4.5%, respectively. Finally

  2. Laboratory and field based evaluation of chromatography ...

    Science.gov (United States)

    The Monitor for AeRosols and GAses in ambient air (MARGA) is an on-line ion-chromatography-based instrument designed for speciation of the inorganic gas and aerosol ammonium-nitrate-sulfate system. Previous work to characterize the performance of the MARGA has been primarily based on field comparison to other measurement methods to evaluate accuracy. While such studies are useful, the underlying reasons for disagreement among methods are not always clear. This study examines aspects of MARGA accuracy and precision specifically related to automated chromatography analysis. Using laboratory standards, analytical accuracy, precision, and method detection limits derived from the MARGA chromatography software are compared to an alternative software package (Chromeleon, Thermo Scientific Dionex). Field measurements are used to further evaluate instrument performance, including the MARGA’s use of an internal LiBr standard to control accuracy. Using gas/aerosol ratios and aerosol neutralization state as a case study, the impact of chromatography on measurement error is assessed. The new generation of on-line chromatography-based gas and particle measurement systems have many advantages, including simultaneous analysis of multiple pollutants. The Monitor for Aerosols and Gases in Ambient Air (MARGA) is such an instrument that is used in North America, Europe, and Asia for atmospheric process studies as well as routine monitoring. While the instrument has been evaluat

  3. Feasibility of correlating separation of ternary mixtures of neutral analytes via thin layer chromatography with supercritical fluid chromatography in support of green flash separations.

    Science.gov (United States)

    Ashraf-Khorassani, M; Yan, Q; Akin, A; Riley, F; Aurigemma, C; Taylor, L T

    2015-10-30

    Method development for normal phase flash liquid chromatography traditionally employs preliminary screening using thin layer chromatography (TLC) with conventional solvents on bare silica. Extension to green flash chromatography via correlation of TLC migration results, with conventional polar/nonpolar liquid mixtures, and packed column supercritical fluid chromatography (SFC) retention times, via gradient elution on bare silica with a suite of carbon dioxide mobile phase modifiers, is reported. Feasibility of TLC/SFC correlation is individually described for eight ternary mixtures for a total of 24 neutral analytes. The experimental criteria for TLC/SFC correlation was assumed to be as follows: SFC/UV/MS retention (tR) increases among each of the three resolved mixture components; while, TLC migration (Rf) decreases among the same resolved mixture components. Successful correlation of TLC to SFC was observed for most of the polar organic solvents tested, with the best results observed via SFC on bare silica with methanol as the CO2 modifier and TLC on bare silica with a methanol/dichloromethane mixture. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Rapid and Convenient Separation of Chitooligosaccharides by Ion-Exchange Chromatography

    Science.gov (United States)

    Wu, Yuxiao; Lu, Wei-Peng; Wang, Jianing; Gao, Yunhua; Guo, Yanchuan

    2017-12-01

    Pervious methods for separation of highly purified chitooligosaccharides was time-consuming and labor-intensive, which limited the large-scale production. This study developed a convenient ion-exchange chromatography using the ÄKTA™ avant 150 chromatographic system. Five fractions were automatically collected under detecting the absorption at 210 nm. The fractions were analyzed by high-performance liquid chromatography. It proved that they primarily comprised chitobiose, chitotriose, chitotetraose, chitopentaose, and chitohexaose, respectively, with chromatographic purities over 90%. The separation process was rapid, convenient and could be monitored on-line, which would be benefit for the mass production of chitooligosaccharides.

  5. Phytochemical analysis of ethanolic extract of Dichrostachys Cinerea W and Arn leaves by a thin layer chromatography, high performance thin layer chromatography and column chromatography

    OpenAIRE

    M Vijayalakshmi; K Periyanayagam; K Kavitha; K Akilandeshwari

    2013-01-01

    Background: The leaves of Dichrostachys cinerea are used as laxative, diuretic, painkiller. It is also used in the treatment of gonorrhoea, boils, oedema, gout, veneral diseases and nasopharyngeal affections, etc. Materials and Methods: The Phytochemical investigation of ethanolic extract of D. cinerea leaves were performed by standard chemical tests, thin layer chromatography (TLC) by using various solvent systems, and by high performance liquid chromatography (HPTLC). Two compounds were...

  6. Hyphenated and comprehensive liquid chromatography × gas chromatography-mass spectrometry for the identification of Mycobacterium tuberculosis.

    Science.gov (United States)

    Mourão, Marta P B; Denekamp, Ilse; Kuijper, Sjoukje; Kolk, Arend H J; Janssen, Hans-Gerd

    2016-03-25

    Tuberculosis is one of the world's most emerging public health problems, particularly in developing countries. Chromatography based methods have been used to tackle this epidemic by focusing on biomarker detection. Unfortunately, interferences from lipids in the sputum matrix, particularly cholesterol, adversely affect the identification and detection of the marker compounds. The present contribution describes the serial combination of normal phase liquid chromatography (NPLC) with thermally assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) to overcome the difficulties of biomarker evaluation. The in-series combination consists of an LC analysis where fractions are collected and then transferred to the THM-GC-MS system. This was either done with comprehensive coupling, transferring all the fractions, or with hyphenated interfacing, i.e. off-line multi heart-cutting, transferring only selected fractions. Owing to the high sensitivity and selectivity of LC as a sample pre-treatment method, and to the high specificity of the MS as a detector, this analytical approach, NPLC × THM-GC-MS, is extremely sensitive. The results obtained indicate that this analytical set-up is able to detect down to 1 × 10(3) mycobacteria/mL of Mycobacterium tuberculosis strain 124, spiked in blank sputum samples. It is a powerful analytical tool and also has great potential for full automation. If further studies demonstrate its usefulness when applied blind in real sputum specimens, this technique could compete with the current smear microscopy in the early diagnosis of tuberculosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Trace Level Determination of Mesityl Oxide and Diacetone Alcohol in Atazanavir Sulfate Drug Substance by a Gas Chromatography Method.

    Science.gov (United States)

    Raju, K V S N; Pavan Kumar, K S R; Siva Krishna, N; Madhava Reddy, P; Sreenivas, N; Kumar Sharma, Hemant; Himabindu, G; Annapurna, N

    2016-01-01

    A capillary gas chromatography method with a short run time, using a flame ionization detector, has been developed for the quantitative determination of trace level analysis of mesityl oxide and diacetone alcohol in the atazanavir sulfate drug substance. The chromatographic method was achieved on a fused silica capillary column coated with 5% diphenyl and 95% dimethyl polysiloxane stationary phase (Rtx-5, 30 m x 0.53 mm x 5.0 µm). The run time was 20 min employing programmed temperature with a split mode (1:5) and was validated for specificity, sensitivity, precision, linearity, and accuracy. The detection and quantitation limits obtained for mesityl oxide and diacetone alcohol were 5 µg/g and 10 µg/g, respectively, for both of the analytes. The method was found to be linear in the range between 10 µg/g and 150 µg/g with a correlation coefficient greater than 0.999, and the average recoveries obtained in atazanavir sulfate were between 102.0% and 103.7%, respectively, for mesityl oxide and diacetone alcohol. The developed method was found to be robust and rugged. The detailed experimental results are discussed in this research paper.

  8. Determination of haloacetic acids in water by ion chromatography--method development.

    Science.gov (United States)

    Lopez-Avila, V; Liu, Y; Charan, C

    1999-01-01

    The microextraction/ion chromatographic (IC) method developed in this study involves extraction of 9 haloacetic acids (HAAs) from aqueous samples (acidified with sulfuric acid to a pH of copper sulfate pentahydrate and sodium sulfate) with methyl tert-butyl ether (MTBE), back extraction into reagent water, and analysis by IC with conductivity detection. The separation column consists of an Ion Pac AG-11 (2 mm id x 50 mm length) guard column and an Ion Pac AS-11 (2 mm id x 250 mm length) analytical column, and the concentration column is a 4 mm id x 35 mm length Dionex TAC-LP column. Use of the 2 mm id Dionex AS-11 column improved detection limits especially for trichloracetic acid (TCAA), bromodichloroacetic acid (BDCAA), dibromochloroacetic acid (DBCAA), and tribromoacetic acid (TBAA). The peak interfering with BCAA elutes at the same retention time as nitrate; however, we have not confirmed the presence of nitrate. Stability studies indicate that HAAs are stable in water for at least 8 days when preserved with ammonium chloride at 100 mg/L and stored at 4 degrees C in the dark. At day 30, recoveries were still high (e.g., 92.1-106%) for dichloroacetic acid (DCAA), BCAA, dibromoacetic acid (DBAA), trichloroacetic acid (TCAA), BDCAA, and DBCAA. However, recoveries of monochloroacetic acid (MCAA), monobromoacetic acid (MBAA), and TBAA were only 54.6, 56.8, and 66.8%, respectively. Stability studies of HAAs in H2SO4-saturated MTBE indicate that all compounds except TBAA are stable for 48 h when stored at 4 degrees C in the dark. TBAA recoveries dropped to 47.1% after 6 h of storage and no TBAA was detected after 48 h of storage. The method described here is only preliminary and was tested in only one laboratory. Additional research is needed to improve method performance.

  9. Validation of a High-Performance Liquid Chromatography method for the determination of vitamin A, vitamin D3, vitamin E and benzyl alcohol in a veterinary oily injectable solution

    OpenAIRE

    Maria Neagu; Georgiana Soceanu; Ana Caterina Bucur

    2015-01-01

    A new simple, rapid, accurate and precise high – performance liquid chromatography (HPLC) method for determination of vitamin A, vitamin D3, vitamin E and benzyl alcohol in oily injectable solution was developed and validated. The method can be used for the detection and quantification of known and unknown impurities and degradants in the drug substance during routine analysis and also for stability studies in view of its capability to separate degradation products. The method was validate...

  10. Detection of Stimulants and Narcotics by Liquid Chromatography-Tandem Mass Spectrometry and Gas Chromatography-Mass Spectrometry for Sports Doping Control.

    Science.gov (United States)

    Ahrens, Brian D; Kucherova, Yulia; Butch, Anthony W

    2016-01-01

    Sports drug testing laboratories are required to detect several classes of compounds that are prohibited at all times, which include anabolic agents, peptide hormones, growth factors, beta-2 agonists, hormones and metabolic modulators, and diuretics/masking agents. Other classes of compounds such as stimulants, narcotics, cannabinoids, and glucocorticoids are also prohibited, but only when an athlete is in competition. A single class of compounds can contain a large number of prohibited substances and all of the compounds should be detected by the testing procedure. Since there are almost 70 stimulants on the prohibited list it can be a challenge to develop a single screening method that will optimally detect all the compounds. We describe a combined liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) testing method for detection of all the stimulants and narcotics on the World Anti-Doping Agency prohibited list. Urine for LC-MS/MS testing does not require sample pretreatment and is a direct dilute and shoot method. Urine samples for the GC-MS method require a liquid-liquid extraction followed by derivatization with trifluoroacetic anhydride.

  11. Integrated Graduate and Continuing Education in Protein Chromatography for Bioprocess Development and Scale-Up

    Science.gov (United States)

    Carta, Jungbauer

    2011-01-01

    We describe an intensive course that integrates graduate and continuing education focused on the development and scale-up of chromatography processes used for the recovery and purification of proteins with special emphasis on biotherapeutics. The course includes lectures, laboratories, teamwork, and a design exercise and offers a complete view of…

  12. Frontal affinity chromatography: A unique research tool for biospecific interaction that promotes glycobiology

    Science.gov (United States)

    KASAI, Kenichi

    2014-01-01

    Combination of bioaffinity and chromatography gave birth to affinity chromatography. A further combination with frontal analysis resulted in creation of frontal affinity chromatography (FAC). This new versatile research tool enabled detailed analysis of weak interactions that play essential roles in living systems, especially those between complex saccharides and saccharide-binding proteins. FAC now becomes the best method for the investigation of saccharide-binding proteins (lectins) from viewpoints of sensitivity, accuracy, and efficiency, and is contributing greatly to the development of glycobiology. It opened a door leading to deeper understanding of the significance of saccharide recognition in life. The theory is also concisely described. PMID:25169774

  13. Comparison of high-performance liquid chromatography and supercritical fluid chromatography using evaporative light scattering detection for the determination of plasticizers in medical devices.

    Science.gov (United States)

    Lecoeur, Marie; Decaudin, Bertrand; Guillotin, Yoann; Sautou, Valérie; Vaccher, Claude

    2015-10-23

    Recently, interest in supercritical fluid chromatography (SFC) has increased due to its high throughput and the development of new system improving chromatographic performances. However, most papers dealt with fundamental studies and chiral applications and only few works described validation process of SFC method. Likewise, evaporative light scattering detection (ELSD) has been widely employed in liquid chromatography but only a few recent works presented its quantitative performances hyphenated with SFC apparatus. The present paper discusses about the quantitative performances of SFC-ELSD compared to HPLC-ELSD, for the determination of plasticizers (ATBC, DEHA, DEHT and TOTM) in PVC tubing used as medical devices. After the development of HPLC-ELSD, both methods were evaluated based on the total error approach using accuracy profile. The results show that HPLC-ELSD was more precise than SFC-ELSD but lower limits of quantitation were obtained by SFC. Hence, HPLC was validated in the ± 10% acceptance limits whereas SFC lacks of accuracy to quantify plasticizers. Finally, both methods were used to determine the composition of plasticized-PVC medical devices. Results demonstrated that SFC and HPLC both hyphenated with ELSD provided similar results. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Screening antiallergic components from Carthamus tinctorius using rat basophilic leukemia 2H3 cell membrane chromatography combined with high-performance liquid chromatography and tandem mass spectrometry.

    Science.gov (United States)

    Han, Shengli; Huang, Jing; Cui, Ronghua; Zhang, Tao

    2015-02-01

    Carthamus tinctorius, used in traditional Chinese medicine, has many pharmacological effects, such as anticoagulant effects, antioxidant effects, antiaging effects, regulation of gene expression, and antitumor effects. However, there is no report on the antiallergic effects of the components in C. tinctorius. In the present study, we investigated the antiallergic components of C. tinctorius and its mechanism of action. A rat basophilic leukemia 2H3/cell membrane chromatography coupled online with high-performance liquid chromatography and tandem mass spectrometry method was developed to screen antiallergic components from C. tinctorius. The screening results showed that Hydroxysafflor yellow A, from C. tinctorius, was the targeted component that retained on the rat basophilic leukemia 2H3/cell membrane chromatography column. We measured the amount of β-hexosaminidase and histamine released in mast cells and the key markers of degranulation. The release assays showed that Hydroxysafflor yellow A could attenuate the immunoglobulin E induced release of allergic cytokines without affecting cell viability from 1.0 to 50.0 μM. In conclusion, the established rat basophilic leukemia 2H3 cell membrane chromatography coupled with online high-performance liquid chromatography and tandem mass spectrometry method successfully screened and identified Hydroxysafflor yellow A from C. tinctorius as a potential antiallergic component. Pharmacological analysis elucidated that Hydroxysafflor yellow A is an effective natural component for inhibiting immunoglobulin E-antigen-mediated degranulation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. New method for determination of epichlorohydrin in epoxy-coated cans by oxolane derivatization and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Sung, Jun Hyun; Lee, Young Ja; Park, Hyun Jin

    2008-08-01

    A new method was developed for the determination of epichlorohydrin (ECH) in food contact surface of epoxy-coated cans. The oxolane derivative, which produced by reaction of epoxy moiety in ECH with cyclopentanone in the presence of borontrifluoride-diethyletherate, was analyzed by gas chromatography (GC)/mass spectrometry (MS). 1,2-Epoxyhexane was used as internal standard (IS), which produced an oxolane derivative under the same reaction mechanism as ECH. The developed method was validated with 1 ng ml(-1) of limit of detection (LOD, surface area related 20 ng dm(-2)), >0.999 of linearity. Good precision, which was tested both in terms of intra-day repeatability and inter-day reproducibility, and 97.3-102.7% of good recoveries were obtained on three spiked levels of 5.2, 40.3 and 149.1 ng ml(-1). The excellent validation data suggests that this method is more simple, quick and effective than the official method in European Committee for Standardization (CEN) to determine the residual amount of ECH in food contact materials for food law compliance test. The residual amount of ECH for 13 epoxy-coated can samples was analyzed, and none of the samples was found to be detectable levels of ECH in epoxy-coated cans.

  16. Clinical applications of fast liquid chromatography: a review on the analysis of cardiovascular drugs and their metabolites.

    Science.gov (United States)

    Baranowska, Irena; Magiera, Sylwia; Baranowski, Jacek

    2013-05-15

    One of the major challenges facing the medicine today is developing new therapies that enhance human health. To help address these challenges the utilization of analytical technologies and high-throughput automated platforms has been employed; in order to perform more experiments in a shorter time frame with increased data quality. In the last decade various analytical strategies have been established to enhance separation speed and efficiency in liquid chromatography applications. Liquid chromatography is an increasingly important tool for monitoring drugs and their metabolites. Furthermore, liquid chromatography has played an important role in pharmacokinetics and metabolism studies at these drug development stages since its introduction. This paper provides an overview of current trends in fast chromatography for the analysis of cardiovascular drugs and their metabolites in clinical applications. Current trends in fast liquid chromatographic separations involve monolith technologies, fused-core columns, high-temperature liquid chromatography (HTLC) and ultra-high performance liquid chromatography (UHPLC). The high specificity in combination with high sensitivity makes it an attractive complementary method to traditional methodology used for routine applications. The practical aspects of, recent developments in and the present status of fast chromatography for the analysis of biological fluids for therapeutic drug and metabolite monitoring, pharmacokinetic studies and bioequivalence studies are presented. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Comparison of extraction chromatography and a procedure based on the molecular recognition method as separation methods in the determination of neptunium and plutonium radionuclides

    International Nuclear Information System (INIS)

    Strisovska, Jana; Galanda, Dusan; Drabova, Veronika; Kuruc, Jozef

    2012-01-01

    The potential of various types of sorbents for separation of radionuclides of plutonium and neptunium were examined. Extraction chromatography and a procedure based on the molecular recognition method were used for the separation. The suitability of the various sorbent types and brands for this purpose was determined. (orig.)

  18. Optimization and validation of high-performance liquid chromatography method for analyzing 25-desacetyl rifampicin in human urine

    Science.gov (United States)

    Lily; Laila, L.; Prasetyo, B. E.

    2018-03-01

    A selective, reproducibility, effective, sensitive, simple and fast High-Performance Liquid Chromatography (HPLC) was developed, optimized and validated to analyze 25-Desacetyl Rifampicin (25-DR) in human urine which is from tuberculosis patient. The separation was performed by HPLC Agilent Technologies with column Agilent Eclipse XDB- Ci8 and amobile phase of 65:35 v/v methanol: 0.01 M sodium phosphate buffer pH 5.2, at 254 nm and flow rate of 0.8ml/min. The mean retention time was 3.016minutes. The method was linear from 2–10μg/ml 25-DR with a correlation coefficient of 0.9978. Standard deviation, relative standard deviation and coefficient variation of 2, 6, 10μg/ml 25-DR were 0-0.0829, 03.1752, 0-0.0317%, respectively. The recovery of 5, 7, 9μg/ml25-DR was 80.8661, 91.3480 and 111.1457%, respectively. Limits of detection (LoD) and quantification (LoQ) were 0.51 and 1.7μg/ml, respectively. The method has fulfilled the validity guidelines of the International Conference on Harmonization (ICH) bioanalytical method which includes parameters of specificity, linearity, precision, accuracy, LoD, and LoQ. The developed method is suitable for pharmacokinetic analysis of various concentrations of 25-DR in human urine.

  19. Analytical FcRn affinity chromatography for functional characterization of monoclonal antibodies

    Science.gov (United States)

    Schlothauer, Tilman; Rueger, Petra; Stracke, Jan Olaf; Hertenberger, Hubert; Fingas, Felix; Kling, Lothar; Emrich, Thomas; Drabner, Georg; Seeber, Stefan; Auer, Johannes; Koch, Stefan; Papadimitriou, Apollon

    2013-01-01

    The neonatal Fc receptor (FcRn) is important for the metabolic fate of IgG antibodies in vivo. Analysis of the interaction between FcRn and IgG in vitro might provide insight into the structural and functional integrity of therapeutic IgG that may affect pharmacokinetics (PK) in vivo. We developed a standardized pH gradient FcRn affinity liquid chromatography method with conditions closely resembling the physiological mechanism of interaction between IgG and FcRn. This method allows the separation of molecular IgG isoforms, degradation products and engineered molecules based on their affinity to FcRn. Human FcRn was immobilized on the column and a linear pH gradient from pH 5.5 to 8.8 was applied. FcRn chromatography was used in comparison to surface plasmon resonance to characterize different monoclonal IgG preparations, e.g., oxidized or aggregated species. Wild-type and engineered IgGs were compared in vitro by FcRn chromatography and in vivo by PK studies in huFcRn transgenic mice. Analytical FcRn chromatography allows differentiation of IgG samples and variants by peak pattern and retention time profile. The method can distinguish: 1) IgGs with different Fabs, 2) oxidized from native IgG, 3) aggregates from monomer and 4) antibodies with mutations in the Fc part from wild-type IgGs. Changes in the FcRn chromatographic behavior of mutant IgGs relative to the wild-type IgG correlate to changes in the PK profile in the FcRn transgenic mice. These results demonstrate that FcRn affinity chromatography is a useful new method for the assessment of IgG integrity. PMID:23765230

  20. Glucose and glycerol concentrations and their tracer enrichment measurements using liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bornø, Andreas; Foged, Lene; van Hall, Gerrit

    2014-01-01

    The present study describes a new liquid chromatography tandem mass spectrometry method for high-throughput quantification of glucose and glycerol in human plasma using stable isotopically labeled internal standards and is suitable for simultaneous measurements of glucose and glycerol enrichments...... of variation were 2.0% and 9.7%, respectively. After derivatization, plasma samples were stable for at least 14 days. In conclusion, we have developed and validated a novel, accurate, and sensitive high-throughput liquid chromatography tandem mass spectrometry method for simultaneous determination of glucose...

  1. Gas chromatography in space

    Science.gov (United States)

    Akapo, S. O.; Dimandja, J. M.; Kojiro, D. R.; Valentin, J. R.; Carle, G. C.

    1999-01-01

    Gas chromatography has proven to be a very useful analytical technique for in situ analysis of extraterrestrial environments as demonstrated by its successful operation on spacecraft missions to Mars and Venus. The technique is also one of the six scientific instruments aboard the Huygens probe to explore Titan's atmosphere and surface. A review of gas chromatography in previous space missions and some recent developments in the current environment of fiscal constraints and payload size limitations are presented.

  2. 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.

  3. 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.

  4. Chromatography methods and chemometrics for determination of milk fat adulterants

    Science.gov (United States)

    Trbović, D.; Petronijević, R.; Đorđević, V.

    2017-09-01

    Milk and milk-based products are among the leading food categories according to reported cases of food adulteration. Although many authentication problems exist in all areas of the food industry, adequate control methods are required to evaluate the authenticity of milk and milk products in the dairy industry. Moreover, gas chromatography (GC) analysis of triacylglycerols (TAGs) or fatty acid (FA) profiles of milk fat (MF) in combination with multivariate statistical data processing have been used to detect adulterations of milk and dairy products with foreign fats. The adulteration of milk and butter is a major issue for the dairy industry. The major adulterants of MF are vegetable oils (soybean, sunflower, groundnut, coconut, palm and peanut oil) and animal fat (cow tallow and pork lard). Multivariate analysis enables adulterated MF to be distinguished from authentic MF, while taking into account many analytical factors. Various multivariate analysis methods have been proposed to quantitatively detect levels of adulterant non-MFs, with multiple linear regression (MLR) seemingly the most suitable. There is a need for increased use of chemometric data analyses to detect adulterated MF in foods and for their expanded use in routine quality assurance testing.

  5. 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

  6. Determination of dibutylphosphate and monobutylphosphate in TBP by ion chromatography

    International Nuclear Information System (INIS)

    Siva Kumar, B.; Vijayalakshmi, S.; Sankaran, K.; Ganesan, V.

    2012-01-01

    Tri-n-butyl phosphate (TBP) is used as solvent in the PUREX (Plutonium Uranium Refining by Extraction) process of nuclear fuel reprocessing. TBP undergoes chemical and radiological degradation to give DBP and MBP which in turn extracts the heavy metal such as U, Pu thereby affecting the performance of the extraction process. Analytical method using ion chromatography (IC) was developed for the determination of dibutyl phosphate (DBP) and monobutyl phosphate (MBP) in TBP. In this method, DBP and MBP were extracted from tri-n-butyl phosphate using carbonate-bicarbonate mixture of eluent composition and the aqueous phase was analyzed using suppressed ion chromatography employing carbonate as eluent. Standardization of extraction was carried out by standard addition studies. The detection limits for both DBP and MBP are found to be in sub ppm level. This method was applied to the analysis of TBP supplied by different suppliers

  7. Sample displacement chromatography as a method for purification of proteins and peptides from complex mixtures

    Science.gov (United States)

    Gajdosik, Martina Srajer; Clifton, James; Josic, Djuro

    2012-01-01

    Sample displacement chromatography (SDC) in reversed-phase and ion-exchange modes was introduced approximately twenty years ago. This method takes advantage of relative binding affinities of components in a sample mixture. During loading, there is a competition among different sample components for the sorption on the surface of the stationary phase. SDC was first used for the preparative purification of proteins. Later, it was demonstrated that this kind of chromatography can also be performed in ion-exchange, affinity and hydrophobic-interaction mode. It has also been shown that SDC can be performed on monoliths and membrane-based supports in both analytical and preparative scale. Recently, SDC in ion-exchange and hydrophobic interaction mode was also employed successfully for the removal of trace proteins from monoclonal antibody preparations and for the enrichment of low abundance proteins from human plasma. In this review, the principals of SDC are introduced, and the potential for separation of proteins and peptides in micro-analytical, analytical and preparative scale is discussed. PMID:22520159

  8. Determination of chloride and sulphur in sodium by ion chromatography and its application to PFBR sodium samples

    International Nuclear Information System (INIS)

    Vijayalakshmi, S.; Ushalakshmi, K.

    2011-01-01

    Analytical method using ion chromatography was developed for the determination of chloride and sulphur in sodium. In this method, sodium was dissolved in water and various sulphur species present in the sample was oxidized to sulphate using hydrogen peroxide. Carbon dioxide gas was passed through the solution to convert sodium hydroxide to carbonate solution. The resulting sample solution was analysed using suppressed Ion chromatography employing carbonate eluent. This method was applied to the analysis of sodium samples procured for prototype fast breeder reactor. (author)

  9. Study of radiolysis products of natural organic materials by means of gas chromatography

    International Nuclear Information System (INIS)

    Pogocki, D.

    1994-01-01

    Analytical methods based on gas chromatography for identification determination of products arising during food irradiation have been presented. Behind the classics version of the methods one has shown also combined methods being the on-line connection of gas chromatography with mass spectroscopy as well as gas chromatography with liquid chromatography and mass spectroscopy. The applicability as well as weakness and advantages of each version have been discussed on the context of food irradiation. 11 refs, 7 figs

  10. High-throughput oxidation screen of antibody-drug conjugates by analytical protein A chromatography following IdeS digest.

    Science.gov (United States)

    Buecheler, Jakob W; Winzer, Matthias; Weber, Christian; Gieseler, Henning

    2018-05-01

    Oxidation of protein therapeutics is a major chemical degradation pathway which may impact bioactivity, serum half-life and stability. Therefore, oxidation is a relevant parameter which has to be monitored throughout formulation development. Methods such as HIC, RPLC and LC/MS achieve a separation of oxidized and non-oxidized species by differences in hydrophobicity. Antibody-drug conjugates (ADC) although are highly more complex due to the heterogeneity in linker, drug, drug-to-antibody ratio (DAR) and conjugation site. The analytical protein A chromatography can provide a simple and fast alternative to these common methods. A miniature analytical protein A chromatography method in combination with an IdeS digest was developed to analyse ADCs. The IdeS digest efficiency of an IgG1 was monitored using SEC-HPLC and non-reducing SDS-PAGE. An antibody-fluorescent dye conjugate was conjugated at different dye-to-antibody ratios as model construct to mimic an ADC. With IdeS, an almost complete digest of a model IgG1 can be achieved (digested protein amount >98%). This enables subsequent analytical protein A chromatography, which consequently eliminates any interference of payload with the stationary phase. A novel high-throughput method for an interchain cysteine-linked ADC oxidation screens during formulation development was developed. © 2018 Royal Pharmaceutical Society.

  11. DETECTION AND QUANTIFICATION OF PHYTOCHEMICAL MARKERS OF Ilex paraguariensis BY LIQUID CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    Rodrigo M. C. Pinto

    2015-11-01

    Full Text Available Ilex paraguariensis (yerba-mate is used as a beverage, and its extract requires adequate quality control methods in order to guarantee quality and safe use. Strategies to develop and optimize a chromatographic method to quantify theobromine, caffeine, and chlorogenic acid in I. paraguariensis extracts were evaluated by applying a quality by design (QbD model and ultra high-performance liquid chromatography (UHPLC. The presence of these three phytochemical markers in the extracts was evaluated using UHPLC-MS and was confirmed by the chromatographic bands in the total ion current traces (m/z of 181.1 [M+H]+, 195.0 [M+H]+, and 353.0 [M−H]−, respectively. The developed method was then transferred to a high-performance liquid chromatography (HPLC platform, and the three phytochemical markers were used as external standards in the validation of a method for analyses of these compounds in extracts using a diode array detector (DAD. The validated method was applied to quantify the chlorogenic acid, caffeine, and theobromine in the samples. HPLC-DAD chromatographic fingerprinting was also used in a multivariate approach to process the entire data and to separate the I. paraguariensis extracts into two groups. The developed method is very useful for qualifying and quantifying I. paraguariensis extracts.

  12. New ultra-performance liquid chromatography-tandem mass spectrometry method for the determination of irbesartan in human plasma

    Directory of Open Access Journals (Sweden)

    Tanveer A. Wani

    2015-09-01

    Full Text Available With the objective of reducing analysis time and maintaining good efficiency, there has been substantial focus on high-speed chromatographic separations and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS is a preeminent analytical tool for rapid biomedical analysis. In this study a simple, rapid, sensitive, and specific ultra-performance liquid chromatography-MS/MS method was developed and validated for quantification of the angiotensin II receptor antagonist, irbesartan (IRB, in human plasma. After a simple protein precipitation using methanol and acetonitrile, IRB and internal standard (IS telmisartan were separated on Acquity UPLC BEH C18 column (50 mm × 2.1 mm, i.d. 1.7 μm, Waters, Milford, MA, USA using a mobile phase consisted of acetonitrile: methanol: 10 mM ammonium acetate (70: 15: 15 v/v/v with a flow rate of 0.4 mL/min and detected MS/MS in negative ion mode. The ion transitions recorded in multiple reaction monitoring mode were m/z 427.2→193.08 for IRB and m/z 513.2→469.3 for IS. The assay exhibited a linear dynamic range of 2–500 ng/mL for IRB in human plasma with good correlation coefficient of (0.995 and with a lower limit of quantitation of 2 ng/mL. The intra- and interassay precisions were satisfactory; the relative standard deviations did not exceed 9.91%. The proposed UPLC-MS/MS method is simple, rapid, and highly sensitive, and hence it could be reliable for pharmacokinetic and toxicokinetic study in both animals and humans.

  13. Development of a comprehensive screening method for more than 300 organic chemicals in water samples using a combination of solid-phase extraction and liquid chromatography-time-of-flight-mass spectrometry.

    Science.gov (United States)

    Chau, Hong Thi Cam; Kadokami, Kiwao; Ifuku, Tomomi; Yoshida, Yusuke

    2017-12-01

    A comprehensive screening method for 311 organic compounds with a wide range of physicochemical properties (log Pow -2.2-8.53) in water samples was developed by combining solid-phase extraction with liquid chromatography-high-resolution time-of-flight mass spectrometry. Method optimization using 128 pesticides revealed that tandem extraction with styrene-divinylbenzene polymer and activated carbon solid-phase extraction cartridges at pH 7.0 was optimal. The developed screening method was able to extract 190 model compounds with average recovery of 80.8% and average relative standard deviations (RSD) of 13.5% from spiked reagent water at 0.20 μg L -1 , and 87.1% recovery and 10.8% RSD at 0.05 μg L -1 . Spike-recovery testing (0.20 μg L -1 ) using real sewage treatment plant effluents resulted in an average recovery and average RSD of 190 model compounds of 77.4 and 13.1%, respectively. The method was applied to the influent and effluent of five sewage treatment plants in Kitakyushu, Japan, with 29 out of 311 analytes being observed at least once. The results showed that this method can screen for a large number of chemicals with a wide range of physicochemical properties quickly and at low operational cost, something that is difficult to achieve using conventional analytical methods. This method will find utility in target screening of hazardous chemicals with a high risk in environmental waters, and for confirming the safety of water after environmental incidents.

  14. Instant thin layer chromatography (ITLC) - the most true and convenient method for the determination of radiochemical purity of Tc-99m Labeled radiopharmaceuticals

    International Nuclear Information System (INIS)

    Anwar-Ul-Azim, M.; Ansari, M.I.H.

    2007-01-01

    Full text: Determination of radiochemical purity usually involves paper chromatography method or some column chromatography such as ion exchange or gel filtration technique. In this study, a modified chromatography method with thin-layer support called instant thin Layer chromatography (ITLC) was used for the measurement of radiochemical purity. The aim of the study was to present instant thin layer chromatography-Silica-Gel (ITLC-SG) technique as a fairly rapid , convenient and inexpensive system for the screening of radiochemical impurities of 99mTc-labeled radiopharmaceuticals resulting from physical , chemical and/or radiation decomposition. Materials and Methods: The experiment was carried out at the Institute of Nuclear Medicine and Ultrasound, Dhaka for a period of 10 months from August '05 to May '06. Radiochemical purity of seven types of 99mTc-labeled radiopharmaceuticals, namely 99mTc-DTPA,99mTc- MI I, 99m Tc - HDP, 99m Tc - DMSA, 99m Tc - Tetofosmin, 99mTc-Fyton and 99mTc-ECD were measured by the use of two solvent dual-instant thin layer chromatography systems. Commercially available instant thin layer chromatography plate ( 20cm x20cm) impregnated with silica gel (ITLC-SG: Merck, Germany) was used as a stationary phase for the measurement of radiochemical impurities.Acetone, Ethyl methyl ketone, chloroform and methanol were used to measure the amount of free pertechnetate in the labelled radiopharmaceuticals and 0.9% saline was used in all cases as solvent (Mobile phase) to measure the amount of the hydrolyzed-reduced technetium colloid. Results: The results showed that the measured radiochemical purity of 99mTc-DTPA, 99mTc-MIBI, 99mTc-HDP, 99mTc-DMSA, 99mTc-Tetofosmin, 99mTc-Fyton and 99mTc-ECD were acceptable for all the studied samples except two samples of 99mTc-MIBI, one sample of 99mTc-Fyton and two samples of 99mTc-ECD, where the measured radiochemical purity were not within the acceptable RCP limits of commonly used radiopharmaceuticals (RCP

  15. Quantitative analysis of abused drugs in physiological fluids by gas chromatography/chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Foltz, R.L.

    1978-01-01

    Methods have been developed for quantitative analysis of commonly abused drugs in physiological fluids using gas chromatography/chemical ionization mass spectrometry. The methods are being evaluated in volunteer analytical and toxicological laboratories, and analytical manuals describing the methods are being prepared. The specific drug and metabolites included in this program are: Δ 9 -tetrahydrocannabinol, methadone, phencyclidine, methaqualone, morphine, amphetamine, methamphetamine, mescaline, 2,5-dimethoxy-4-methyl amphetamine, cocaine, benzoylecgonine, diazepam, and N-desmethyldiazepam. The current analytical methods utilize relatively conventional instrumentation and procedures, and are capable of measuring drug concentrations as low as 1 ng/ml. Various newer techniques such as sample clean-up by high performance liquid chromatography, separation by glass capillary chromatography, and ionization by negative ion chemical ionization are being investigated with respect to their potential for achieving higher sensitivity and specificity, as well as their ability to facilitate simultaneous analysis of more than one drug and metabolite. (Auth.)

  16. Affinity chromatography: A versatile technique for antibody purification.

    Science.gov (United States)

    Arora, Sushrut; Saxena, Vikas; Ayyar, B Vijayalakshmi

    2017-03-01

    Antibodies continue to be extremely utilized entities in myriad applications including basic research, imaging, targeted delivery, chromatography, diagnostics, and therapeutics. At production stage, antibodies are generally present in complex matrices and most of their intended applications necessitate purification. Antibody purification has always been a major bottleneck in downstream processing of antibodies, due to the need of high quality products and associated high costs. Over the years, extensive research has focused on finding better purification methodologies to overcome this holdup. Among a plethora of different techniques, affinity chromatography is one of the most selective, rapid and easy method for antibody purification. This review aims to provide a detailed overview on affinity chromatography and the components involved in purification. An array of support matrices along with various classes of affinity ligands detailing their underlying working principles, together with the advantages and limitations of each system in purifying different types of antibodies, accompanying recent developments and important practical methodological considerations to optimize purification procedure are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. NONLINEAR-REGRESSION METHODS FOR MODELING OF HETEROSCEDASTIC RETENTION DATA IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

    NARCIS (Netherlands)

    HENDRIKS, MMWB; COENEGRACHT, PMJ; DOORNBOS, DA

    1994-01-01

    New models have been developed that accurately describe the response surfaces of capacity factors that are a function of changes in the pH and the fraction of organic modifier in reversed-phase high-performance liquid chromatography (RP-HPLC). The purpose of this article is to illustrate one of the

  18. Isotope-dilution gas chromatography-mass spectrometry method for the analysis of hydroxyurea.

    Science.gov (United States)

    Garg, Uttam; Scott, David; Frazee, Clint; Kearns, Gregory; Neville, Kathleen

    2015-06-01

    Hydroxyurea is used in the treatment of various malignancies and sickle cell disease. There are limited studies on the pharmacokinetics of hydroxyurea, particularly in pediatric patients. An accurate, precise, and sensitive method is needed to support such studies and to monitor therapeutic adherence. We describe a novel gas chromatography-mass spectrometry (GC-MS) method for the determination of hydroxyurea concentration in plasma using stable labeled hydroxyurea C N2 as an internal standard. The method involved an organic extraction followed by the preparation of trimethylsilyl (TMS) derivatives of hydroxyurea for GC-MS selected ion-monitoring analysis. The following mass-to-charge (m/z) ratio ions for silated hydroxyurea and hydroxyurea C N2 were monitored: hydroxyurea-quantitative ion 277, qualifier ions 292 and 249; hydroxyurea C N2-quantitative ion 280, qualifier ion 295. This method was evaluated for reportable range, accuracy, within-run and between-run imprecisions, and limits of quantification. The reportable range for the method was 0.1-100 mcg/mL. All results were accurate within an allowable error of 15%. Within-run and between-run imprecisions were hydroxyurea described here is accurate, sensitive, precise, and robust. Its characteristics make the method suitable for supporting pharmacokinetic studies and/or clinical therapeutic monitoring.

  19. Development and validation of a multi-residue method for the detection of a wide range of hormonal anabolic compounds in hair using gas chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    Rambaud, Lauriane; Monteau, Fabrice; Deceuninck, Yoann; Bichon, Emmanuelle; Andre, Francois; Le Bizec, Bruno

    2007-01-01

    The monitoring of anabolic steroid residues in hair is undoubtedly one of the most efficient strategies to demonstrate the long-term administration of these molecules in meat production animals. A multi-residue sample preparation procedure was developed and validated for 28 steroids. A 100 mg hair sample was grinded into powder and extracted at 50 deg. C with methanol. After acidic hydrolysis and extraction with ethyl acetate, phenolsteroids, such as estrogens, resorcyclic acid lactones and stilbens in one hand, are separated from androgens and progestagens in the other hand. Solid phase extractions were performed before applying a specific derivatisation for each compound sub-group. Detection and identification were achieved using gas chromatography-tandem mass spectrometry with acquisition in the selected reaction monitoring mode after electron ionisation. The method was validated according to the 2002/657/EC guideline. Decision limits (CCα) for main steroids were in the 0.1-10 μg kg -1 range

  20. Development and validation of a multi-residue method for the detection of a wide range of hormonal anabolic compounds in hair using gas chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rambaud, Lauriane [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Monteau, Fabrice [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Deceuninck, Yoann [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Bichon, Emmanuelle [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Andre, Francois [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Le Bizec, Bruno [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France)]. E-mail: lebizec@vet-nantes.fr

    2007-03-14

    The monitoring of anabolic steroid residues in hair is undoubtedly one of the most efficient strategies to demonstrate the long-term administration of these molecules in meat production animals. A multi-residue sample preparation procedure was developed and validated for 28 steroids. A 100 mg hair sample was grinded into powder and extracted at 50 deg. C with methanol. After acidic hydrolysis and extraction with ethyl acetate, phenolsteroids, such as estrogens, resorcyclic acid lactones and stilbens in one hand, are separated from androgens and progestagens in the other hand. Solid phase extractions were performed before applying a specific derivatisation for each compound sub-group. Detection and identification were achieved using gas chromatography-tandem mass spectrometry with acquisition in the selected reaction monitoring mode after electron ionisation. The method was validated according to the 2002/657/EC guideline. Decision limits (CC{alpha}) for main steroids were in the 0.1-10 {mu}g kg{sup -1} range.

  1. Magnetic solid phase extraction and static headspace gas chromatography-mass spectrometry method for the analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cai, Ying; Yan, Zhihong; Wang, Lijia; NguyenVan, Manh; Cai, Qingyun

    2016-01-15

    A magnetic solid phase extraction (MSPE) protocol combining a static headspace gas chromatography coupled to mass spectrometry (HS-GC-MS) method has been developed for extraction, and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in drinking water samples. Magnetic nanoparticles (MNPs) were coated with 3-aminopropyltriethoxysilane and modified by cholesterol chloroformate. Transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy were used to characterize the cholesterol-functionalized sorbents, and the main parameters affecting the extraction as well as HS sampling, such as sorbent amount, extraction time, oven temperature and equilibration time have been investigated and established. Combination with HS sampling, the MSPE procedure was simple, fast and environmentally friendly, without need of any organic solvent. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels obtaining the limit of detection (S/N=3) ranging from 0.20 to 7.8 ng/L. Good values for intra and inter-day precision were obtained (RSDs ≤ 9.9%). The proposed method was successfully applied to drinking water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Ion mobility: its role in plasma chromatography

    International Nuclear Information System (INIS)

    Mason, E.A.

    1984-01-01

    This paper is a review of the basic physical theory underlying plasma chromatography. Essentially, plasma chromatography simply measures ion mobility. The new feature of plasma chromatography, as compared to aqueous electrophoresis, is the existence of a highly-developed and accurate body of theory that connects gaseous ion mobility and diffusion to the ion molecule interactions in the drift tube. Attention is restricted to phenomena occurring in the drift tube portion of the apparatus

  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. Addressing the need for biomarker liquid chromatography/mass spectrometry assays: a protocol for effective method development for the bioanalysis of endogenous compounds in cerebrospinal fluid.

    Science.gov (United States)

    Benitex, Yulia; McNaney, Colleen A; Luchetti, David; Schaeffer, Eric; Olah, Timothy V; Morgan, Daniel G; Drexler, Dieter M

    2013-08-30

    Research on disorders of the central nervous system (CNS) has shown that an imbalance in the levels of specific endogenous neurotransmitters may underlie certain CNS diseases. These alterations in neurotransmitter levels may provide insight into pathophysiology, but can also serve as disease and pharmacodynamic biomarkers. To measure these potential biomarkers in vivo, the relevant sample matrix is cerebrospinal fluid (CSF), which is in equilibrium with the brain's interstitial fluid and circulates through the ventricular system of the brain and spinal cord. Accurate analysis of these potential biomarkers can be challenging due to low CSF sample volume, low analyte levels, and potential interferences from other endogenous compounds. A protocol has been established for effective method development of bioanalytical assays for endogenous compounds in CSF. Database searches and standard-addition experiments are employed to qualify sample preparation and specificity of the detection thus evaluating accuracy and precision. This protocol was applied to the study of the histaminergic neurotransmitter system and the analysis of histamine and its metabolite 1-methylhistamine in rat CSF. The protocol resulted in a specific and sensitive novel method utilizing pre-column derivatization ultra high performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS), which is also capable of separating an endogenous interfering compound, identified as taurine, from the analytes of interest. Copyright © 2013 John Wiley & Sons, Ltd.

  5. Quantification of imatinib in human serum: validation of a high-performance liquid chromatography-mass spectrometry method for therapeutic drug monitoring and pharmacokinetic assays

    Directory of Open Access Journals (Sweden)

    Rezende VM

    2013-08-01

    Full Text Available Vinicius Marcondes Rezende,1 Ariane Rivellis,1 Mafalda Megumi Yoshinaga Novaes,1 Dalton de Alencar Fisher Chamone,2 Israel Bendit1,21Laboratory of Tumor Biology, 2Department of Hematology, School of Medicine, University of São Paulo, São Paulo, BrazilBackground: Imatinib mesylate has been a breakthrough treatment for chronic myeloid leukemia. It has become the ideal tyrosine kinase inhibitor and the standard treatment for chronic-phase leukemia. Striking results have recently been reported, but intolerance to imatinib and noncompliance with treatment remain to be solved. Molecular monitoring by quantitative real-time polymerase chain reaction is the gold standard for monitoring patients, and imatinib blood levels have also become an important tool for monitoring.Methods: A fast and cheap method was developed and validated using high-performance liquid chromatography-mass spectrometry for quantification of imatinib in human serum and tamsulosin as the internal standard. Remarkable advantages of the method includes use of serum instead of plasma, less time spent on processing and analysis, simpler procedures, and requiring reduced amounts of biological material, solvents, and reagents. Stability of the analyte was also studied. This research also intended to drive the validation scheme in clinical centers. The method was validated according to the requirements of the US Food and Drug Administration and Brazilian National Health Surveillance Agency within the range of 0.500–10.0 µg/mL with a limit of detection of 0.155 µg/mL. Stability data for the analyte are also presented.Conclusion: Given that the validated method has proved to be linear, accurate, precise, and robust, it is suitable for pharmacokinetic assays, such as bioavailability and bioequivalence, and is being successfully applied in routine therapeutic drug monitoring in the hospital service.Keywords: imatinib, high-performance liquid chromatography-mass spectrometry, therapeutic

  6. Column chromatography isolation of nicotine from tobacco leaf extract (Nicotiana tabaccum L.)

    Science.gov (United States)

    Fathi, Raden Muhammad; Fauzantoro, Ahmad; Rahman, Siti Fauziyah; Gozan, Misri

    2018-02-01

    Restrictions on the use of dried tobacco leaf for cigarette production must be accompanied by the development of non-cigarette alternative products that are made from tobacco leaves. One of the alternative that can be done is to use the nicotine compound in tobacco leaf extract as medical product, such as Parkinson's medication or to be used as active substance in biopesticide. Nicotine was isolated using column chromatography method with the variation of mobile phase mixture ratio (petroleum ether and ethanol), started from 8:2, 6:4, 4:6, 2:8, to 0:10. All of the chromatographic fraction from each mobile phase's ratio was then tested qualitatively using thin layer chromatography (TLC) and also quantitatively using HPLC instrument. The column chromatography process could isolate 4.006% of nicotine compound from 4.19% tobacco leaf extract's nicotine. It is also known that ethanol is a good solution to be used as chromatography's mobile phase for nicotine isolation from tobacco leaf extract.

  7. Simultaneous Determination of Perfluorinated Compounds in Edible Oil by Gel-Permeation Chromatography Combined with Dispersive Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Yang, Lili; Jin, Fen; Zhang, Peng; Zhang, Yanxin; Wang, Jian; Shao, Hua; Jin, Maojun; Wang, Shanshan; Zheng, Lufei; Wang, Jing

    2015-09-30

    A simple analytical method was developed for the simultaneous analysis of 18 perfluorinated compounds (PFCs) in edible oil. The target compounds were extracted by acetonitrile, purified by gel permeation chromatography (GPC) and dispersive solid-phase extraction (DSPE) using graphitized carbon black (GCB) and octadecyl (C18), and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ES-MS/MS) in negative ion mode. Recovery studies were performed at three fortification levels. The average recoveries of all target PFCs ranged from 60 to 129%, with an acceptable relative standard deviation (RSD) (1-20%, n = 3). The method detection limits (MDLs) ranged from 0.004 to 0.4 μg/kg, which was significantly improved compared with the existing liquid-liquid extraction and cleanup method. The method was successfully applied for the analysis of all target PFCs in edible oil samples collected from markets in Beijing, China, and the results revealed that C6-C10 perfluorocarboxylic acid (PFCAs) and C7 perfluorosulfonic acid PFSAs were the major PFCs detected in oil samples.

  8. Determination of 1-hydroxypyrene in human urine by high-performance liquid chromatography

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Poulsen, O M; Christensen, J M

    1993-01-01

    A high-performance liquid chromatography (HPLC)/fluorescence method for quantitative analysis of 1-hydroxypyrene in urine was developed. The method validation analysis showed the method to be in analytical control. No significant systematical errors could be demonstrated. The entire run time....... The developed method is presently used for measurement of 1-hydroxypyrene in urine samples from workers exposed to a low airborne level of polycyclic aromatic hydrocarbons, generally less than 25 micrograms/m3. The urine samples of exposed workers (n = 122) showed a range of 1-hydroxypyrene from the limit...

  9. METHOD 332.0: DETERMINATION OF PERCHLORATE IN DRINKING WATER BY ION CHROMATOGRAPHY WITH SUPPRESSED CONDUCTIVITY AND ELECTROSPRAY IONIZATION MASS SPECTROMETRY

    Science.gov (United States)

    This method is applicable to the identification and quantitation of perchlorate in raw and finished drinking waters. The approach used is ion chromatography with suppressed conductivity and electrospray ionization mass spectrometry (IC-ESI/MS)

  10. Microcystin Detection Characteristics of Fluorescence Immunochromatography and High Performance Liquid Chromatography

    International Nuclear Information System (INIS)

    Pyo, Dong Jin; Park, Geun Young; Choi, Jong Chon; Oh, Chang Suk

    2005-01-01

    Different detection characteristics of fluorescence immunochromatography method and high performance liquid chromatography (HPLC) method for the analysis of cyanobacterial toxins were studied. In particular, low and high limits of detection, detection time and reproducibility and detectable microcystin species were compared when fluorescence immunochromatography method and high performance liquid chromatography method were applied for the detection of microcystin (MC), a cyclic peptide toxin of the freshwater cyanobacterium Microcystis aeruginosa. A Fluorescence immunochromatography assay system has the unique advantages of short detection time and low detection limit, and high performance liquid chromatography detection method has the strong advantage of individual quantifications of several species of microcystins

  11. Development of Sensitive and Specific Analysis of Vildagliptin in Pharmaceutical Formulation by Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Ebru Uçaktürk

    2015-01-01

    Full Text Available A sensitive and selective gas chromatography-mass spectrometry (GC-MS method was developed and fully validated for the determination of vildagliptin (VIL in pharmaceutical formulation. Prior to GC-MS analysis, VIL was efficiently derivatized with MSTFA/NH4I/β-mercaptoethanol at 60°C for 30 min. The obtained O-TMS derivative of VIL was detected by selected ion monitoring mode using the diagnostic ions m/z 223 and 252. Nandrolone was chosen as internal standard. The GC-MS method was fully validated by the following validation parameters: limit of detection (LOD and quantitation (LOQ, linearity, precision, accuracy, specificity, stability, robustness, and ruggedness. LOD and LOQ were found to be 1.5 and 3.5 ng mL−1, respectively. The GC-MS method is linear in the range of 3.5–300 ng mL−1. The intra- and interday precision values were less than ≤3.62%. The intra- and interday accuracy values were found in the range of -0.26–2.06%. Finally, the GC-MS method was successfully applied to determine VIL in pharmaceutical formulation.

  12. Determination of ribavirin in human serum using liquid chromatography tandem mass spectrometry

    NARCIS (Netherlands)

    van der Lijke, H.; Alffenaar, J.-W. C.; Kok, W.Th.; Greijdanus, B.; Uges, D.R.A.

    2012-01-01

    A method has been developed for the determination of ribavirin in human serum for therapeutic drug monitoring purposes, using liquid chromatography electrospray ionization mass spectrometry. Separation was obtained with a mobile phase gradient starting and ending in 100% aqueous conditions using a

  13. Isolation of oxidative degradation products of atorvastatin with supercritical fluid chromatography.

    Science.gov (United States)

    Klobčar, Slavko; Prosen, Helena

    2015-12-01

    The isolation of four oxidative degradation products of atorvastatin using preparative high-performance liquid chromatography applying at least two chromatographic steps is known from the literature. In this paper it is shown that the same four impurities could be isolated from similarly prepared mixtures in only one step using supercritical fluid chromatography. The methods for separation were developed and optimized. The preparation of the mixtures was altered in such a way as to enhance the concentration of desired impurities. Appropriate solvents were applied for collection of separated impurities in order to prevent degradation. The structures of the isolated impurities were confirmed and their purity determined. The preparative supercritical fluid chromatography has proven to be superior to preparative HPLC regarding achieved purity of standards applying fewer chromatographic as well as isolation steps. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Optimized and validated high-performance liquid chromatography method for the determination of deoxynivalenol and aflatoxins in cereals.

    Science.gov (United States)

    Skendi, Adriana; Irakli, Maria N; Papageorgiou, Maria D

    2016-04-01

    A simple, sensitive and accurate analytical method was optimized and developed for the determination of deoxynivalenol and aflatoxins in cereals intended for human consumption using high-performance liquid chromatography with diode array and fluorescence detection and a photochemical reactor for enhanced detection. A response surface methodology, using a fractional central composite design, was carried out for optimization of the water percentage at the beginning of the run (X1, 80-90%), the level of acetonitrile at the end of gradient system (X2, 10-20%) with the water percentage fixed at 60%, and the flow rate (X3, 0.8-1.2 mL/min). The studied responses were the chromatographic peak area, the resolution factor and the time of analysis. Optimal chromatographic conditions were: X1 = 80%, X2 = 10%, and X3 = 1 mL/min. Following a double sample extraction with water and a mixture of methanol/water, mycotoxins were rapidly purified by an optimized solid-phase extraction protocol. The optimized method was further validated with respect to linearity (R(2) >0.9991), sensitivity, precision, and recovery (90-112%). The application to 23 commercial cereal samples from Greece showed contamination levels below the legally set limits, except for one maize sample. The main advantages of the developed method are the simplicity of operation and the low cost. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Liquid chromatography-tandem mass spectrometry method for the determination of thiosulfate in human blood and urine as an indicator of hydrogen sulfide poisoning.

    Science.gov (United States)

    Maseda, Chikatoshi; Hayakawa, Akira; Okuda, Katsuhiro; Asari, Masaru; Tanaka, Hiroki; Yamada, Hiromi; Jin, Shigeki; Horioka, Kie; Matoba, Kotaro; Shiono, Hiroshi; Matsubara, Kazuo; Shimizu, Keiko

    2017-01-01

    Being a stable metabolite of hydrogen sulfide, thiosulfate has been utilized as an index for hydrogen sulfide poisoning (HSP). Thiosulfate analysis is mainly performed using gas chromatography/mass spectrometry (GC-MS) due to its high sensitivity and specificity. The GC-MS analysis requires two-step derivatizations of thiosulfate, and the derivative is not stable in solution as it has a disulfide moiety. To resolve this stability issue, we developed a novel analytical method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for monitoring the pentafluorobenzyl derivative of thiosulfate (the first reaction product of the GC-MS method) in this study. The established method exhibited high reproducibility despite being a more simplified and rapid procedure compare to the GC-MS method. Phenyl 4-hydroxybenzoate was used as an internal standard because 1,3,5-tribromobenzene which had been used in the GC-MS method was not suitable compound for LC-MS/MS with Electrospray ionization (ESI) negative detection. The linear regression of the peak area ratios versus concentrations was fitted over the concentration ranges of 0.5-250μM and 0.25-250μM in blood and urine, respectively. The validation results satisfied the acceptance criteria for intra- and inter-day accuracy and precision. Blood and urine samples from 12 suspected HSP cases were tested using this method. The thiosulfate concentration detected in the sample coincided well with that determined at the scene of each HSP accident. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Ultra-performance liquid chromatography-tandem mass spectrometry method for the determination of febuxostat in dog plasma and its application to a pharmacokinetic study.

    Science.gov (United States)

    Zhang, Tianhong; Sun, Yuanpeng; Zhang, Peng; Gao, Jingmei; Wang, Shanshan; He, Zhonggui

    2013-02-01

    A rapid, sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the determination of febuxostat in dog plasma. Using paclitaxel as an internal standard (IS), a simple liquid-liquid extraction method with ethyl acetate was adopted for plasma sample pretreatment. Separation was carried out on an Acquity UPLC BEH C(18) column with a mobile phase consisting of acetonitrile and water (containing 0.2% formic acid). The assay was linear in the concentration ranged from 5 to 5000 ng/mL with a lower limit of quantification of 5 ng/mL for febuxostat. The single run analysis was as short as 2.0 min. Finally, the developed method was successfully applied to the pharmacokinetic study of febuxostat tablets following oral administration at a single dose of 40 mg in beagle dogs. Copyright © 2012 John Wiley & Sons, Ltd.

  17. Development and evaluation of a liquid chromatography tandem mass spectrometry method for simultaneous determination of salivary melatonin, cortisol and testosterone

    DEFF Research Database (Denmark)

    Jensen, Marie Aarrebo; Hansen, Åse Marie; Abrahamsson, Peter

    2011-01-01

    saliva. We used liquid-liquid extraction (LLE) followed by liquid chromatography coupled to electrospray tandem mass spectrometry (LC-ESI-MS/MS) recorded in positive ion mode. Saliva samples were collected by spitting directly into tubes and 250 µL were used for analysis. The limits of detection were 4...

  18. Mixed-mode chromatography/isotope ratio mass spectrometry.

    Science.gov (United States)

    McCullagh, James S O

    2010-03-15

    Liquid chromatography coupled to molecular mass spectrometry (LC/MS) has been a standard technique since the early 1970s but liquid chromatography coupled to high-precision isotope ratio mass spectrometry (LC/IRMS) has only been available commercially since 2004. This development has, for the first time, enabled natural abundance and low enrichment delta(13)C measurements to be applied to individual analytes in aqueous mixtures creating new opportunities for IRMS applications, particularly for the isotopic study of biological molecules. A growing number of applications have been published in a range of areas including amino acid metabolism, carbohydrates studies, quantification of cellular and plasma metabolites, dietary tracer and nucleic acid studies. There is strong potential to extend these to new compounds and complex matrices but several challenges face the development of LC/IRMS methods. To achieve accurate isotopic measurements, HPLC separations must provide baseline-resolution between analyte peaks; however, the design of current liquid interfaces places severe restrictions on compatible flow rates and in particular mobile phase compositions. These create a significant challenge on which reports associated with LC/IRMS have not previously focused. Accordingly, this paper will address aspects of chromatography in the context of LC/IRMS, in particular focusing on mixed-mode separations and their benefits in light of these restrictions. It aims to provide an overview of mixed-mode stationary phases and of ways to improve high aqueous separations through manipulation of parameters such as column length, temperature and mobile phase pH. The results of several practical experiments are given using proteogenic amino acids and nucleosides both of which are of noted importance in the LC/IRMS literature. This communication aims to demonstrate that mixed-mode stationary phases provide a flexible approach given the constraints of LC/IRMS interface design and acts as a

  19. Development and validation of an ultra high performance liquid chromatography tandem mass spectrometry method for simultaneous determination of sulfonamides, quinolones and benzimidazoles in bovine milk.

    Science.gov (United States)

    Hou, Xiao-Lin; Chen, Guo; Zhu, Li; Yang, Ting; Zhao, Jian; Wang, Lei; Wu, Yin-Liang

    2014-07-01

    A simple, sensitive and reliable analytical method was developed for the simultaneous determination of 38 veterinary drugs (18 sulfonamides, 11 quinolones and 9 benzimidazoles) and 8 metabolites of benzimidazoles in bovine milk by ultra high performance liquid chromatography-positive electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS). Samples were extracted with acidified acetonitrile, cleaned up with Oasis(®) MCX cartridges, and analyzed by LC-MS/MS on an Acquity UPLC(®) BEH C18 column with gradient elution. The method allows such multi-analyte measurements within a 13min runtime while the specificity is ensured through the MRM acquisition mode. The method was validated according to the European Commission Decision 2002/657/EC determining specificity, decision limit (CCα), detection capability (CCβ), recovery, precision, linearity and stability. For compounds which have MRLs in bovine milk, the CCα values fall into a range from 11 to 115μg/kg, and the CCβ values fall within a range of 12-125μg/kg. For compounds which have not MRLs in bovine milk, the CCα values fall into a range from 0.01 to 0.08μg/kg, and the CCβ values fall within a range of 0.02-0.11μg/kg. The mean recoveries of the 46 analytes were between 87 and 119%. The calculated RSD values of repeatability and within-laboratory reproducibility experiments were below 11% and 15% for the 46 compounds, respectively. The method was demonstrated to be suitable for the simultaneous determination of sulfonamides, quinolones and benzimidazoles in bovine milk. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Method development for speciation analysis of nanoparticle and ionic forms of gold in biological samples by high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Malejko, Julita; Świerżewska, Natalia; Bajguz, Andrzej; Godlewska-Żyłkiewicz, Beata

    2018-04-01

    A new method based on coupling high performance liquid chromatography (HPLC) to inductively coupled plasma mass spectrometry (ICP MS) has been developed for the speciation analysis of gold nanoparticles (AuNPs) and dissolved gold species (Au(III)) in biological samples. The column type, the composition and the flow rate of the mobile phase were carefully investigated in order to optimize the separation conditions. The usefulness of two polymeric reversed phase columns (PLRP-S with 100 nm and 400 nm pore size) to separate gold species were investigated for the first time. Under the optimal conditions (PLRP-S400 column, 10 mmol L-1 SDS and 5% methanol as the mobile phase, 0.5 mL min-1 flow rate), detection limits of 2.2 ng L-1 for Au(III), 2.8 ng L-1 for 10 nm AuNPs and 3.7 ng L-1 for 40 nm AuNPs were achieved. The accuracy of the method was proved by analysis of reference material RM 8011 (NIST) of gold nanoparticles of nominal diameter of 10 nm. The HPLC-ICP MS method has been successfully applied to the detection and size characterization of gold species in lysates of green algae Acutodesmus obliquus, typical representative of phytoplankton flora, incubated with 10 nm AuNPs or Au(III).

  1. A simplified but effective method for the quality control of medicinal plants by planar chromatography.

    Science.gov (United States)

    Eloff, J N; Ntloedibe, D T; van Brummelen, R

    2011-01-01

    Three of the factors limiting the rational use of herbal medicine are uncertainty on effectivity, uncertainty on safety and variation in quality of the product. Because many herbal medicines have been used over centuries by indigenous peoples, the safety and effectivity is frequently not such a big concern. With more people collecting and distributing herbal medicine, the offered product is however, frequently not what the label indicates either through a genuine mistake, but also through fraud especially where expensive herbal medicine is concerned. Some wrong identifications have already led to serious side effects and deaths. Planar chromatography or thin layer chromatography [TLC] is widely used to verify the identity of plant extracts by determining the chemical fingerprint of the extracts. In a leading publication 17 different extractants, 41 solvent systems and 44 spray reagents have been used to verify the identity of important herbal preparations. We investigated whether a simplified system could not be developed to aid small laboratories in identifying different herbal medicines. We compared the efficacy of different extractants, identified and developed three TLC solvent systems that would separate compounds with low, medium and high polarity and then also investigated the use of several spray reagents. With acetone as extractant and benzene:ethanol:ammonia [9:1:0.1], chloroform:ethylacetate:formic acid [5:4:1] and ethylacetate:methanol:water [10:1.35:1] as TLC solvent system and vanillin-sulphuric acid as spray reagent the identity of 81 samples of more than 50 herbal preparations could be verified on the basis of the chromatograms. The same product from different suppliers usually gave similar chromatograms. More importantly in several cases it was clear that products with the same label were so different that a mistake must have occurred in the labelling. This method has found application in the quality control of the most important African medicinal

  2. Advances in chromatography of the rare earth elements (review)

    International Nuclear Information System (INIS)

    Oguma, Koichi; Kuroda, Rokuro; Shimizu, Tsuneo.

    1995-01-01

    A review is presented which covers liquid chromatography, gas chromatography, and related techniques. This article intends to describe the chromatographic methods playing an important role in the separation of the rare earth elements. Special attention is paid to the usefulness of various types of liquid chromatography which enable the complete mutual separation of the rare earth elements. Applications are also discussed. (author) 161 refs

  3. Simultaneous determination of 13 carbohydrates using high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry.

    Science.gov (United States)

    Zhao, Dan; Feng, Feng; Yuan, Fei; Su, Jin; Cheng, Yan; Wu, Hanqiu; Song, Kun; Nie, Bo; Yu, Lian; Zhang, Feng

    2017-04-01

    A simple, accurate, and highly sensitive method was developed for the determination of 13 carbohydrates in polysaccharide of Spirulina platensis based on high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry. Samples were extracted with deionized water using ultrasonic-assisted extraction, and the ultrasound-assisted extraction conditions were optimized by Box-Behnken design. Then the extracted polysaccharide was hydrolyzed by adding 1 mol/L trifluoroacetic acid before determination by high-performance anion-exchange chromatography coupled with pulsed amperometric detection and confirmed by high-performance anion-exchange chromatography coupled with mass spectrometry. The high-performance anion-exchange chromatography coupled with pulsed amperometric detection method was performed on a CarboPac PA20 column by gradient elution using deionized water, 0.1 mol/L sodium hydroxide solution, and 0.4 mol/L sodium acetate solution. Excellent linearity was observed in the range of 0.05-10 mg/L. The average recoveries ranged from 80.7 to 121.7%. The limits of detection and limits of quantification for 13 carbohydrates were 0.02-0.10 and 0.2-1.2  μg/kg, respectively. The developed method has been successfully applied to ambient samples, and the results indicated that high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry could provide a rapid and accurate method for the simultaneous determination of carbohydrates. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Improved method for the determination of the cortisol production rate using high-performance liquid chromatography and liquid scintillation counting

    NARCIS (Netherlands)

    van Ingen, H. E.; Endert, E.

    1988-01-01

    Two new methods for the determination of the cortisol production rate using reversed-phase high-performance liquid chromatography are described. One uses ultraviolet detection at 205 nm, the other on-line post-column derivatization with benzamidine, followed by fluorimetric detection. The specific

  5. Cromatografia unificada Unified chromatography

    Directory of Open Access Journals (Sweden)

    Carin von Mühlen

    2004-10-01

    Full Text Available The scope of this study encompasses an overview of the principles of unified chromatography as well as the principles of chromatographic techniques as applied to unified systems, which include gas chromatography, liquid chromatography, supercritical fluid chromatography, high temperature and high pressure liquid chromatography, micro-liquid chromatography, enhanced fluidity chromatography, and solvating gas chromatography. Theoretical considerations and individual instrumental parameters such as mobile phase, sample introduction system, columns, and detection system are also discussed. Future applications of this separation approach are discussed.

  6. DETERMINATION OF CHLOROPHEONIS, NITROPHENOIS AND METHYLPHENOIS IN GROUND-WATER SAMPLES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Science.gov (United States)

    A high performance liquid chromatography (HPLC) method was developed to quantitatively determine phenolic compounds and their isomers in aqueous samples. The HPLC method can analyze a mixture of 15 contaminants in the same analytical run with an analysis time of 25 minutes. The...

  7. DETERMINATION OF CHLOROPHENOLS, NITROPHENOLS, AND METHYLPHENOLS IN GROUND-WATER SAMPLES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Science.gov (United States)

    A high performance liquid chromatography (HPLC) method was developed to quantitatively determine phenolic compounds and their isomers in aqueous samples. The HPLC method can analyze a mixture of 15 contaminants in the same analytical run with an analysis time of 25 minutes. The...

  8. Comparison of critical methods developed for fatty acid analysis: A review.

    Science.gov (United States)

    Wu, Zhuona; Zhang, Qi; Li, Ning; Pu, Yiqiong; Wang, Bing; Zhang, Tong

    2017-01-01

    Fatty acids are important nutritional substances and metabolites in living organisms. These acids are abundant in Chinese herbs, such as Brucea javanica, Notopterygium forbesii, Isatis tinctoria, Astragalus membranaceus, and Aconitum szechenyianum. This review illustrates the types of fatty acids and their significant roles in the human body. Many analytical methods are used for the qualitative and quantitative evaluation of fatty acids. Some of the methods used to analyze fatty acids in more than 30 kinds of plants, drugs, and other samples are presented in this paper. These analytical methods include gas chromatography, liquid chromatography, near-infrared spectroscopy, and NMR spectroscopy. The advantages and disadvantages of these techniques are described and compared. This review provides a valuable reference for establishing methods for fatty acid determination. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography.

    Science.gov (United States)

    Vu, Anh T; Wang, Xinying; Wickramasinghe, S Ranil; Yu, Bing; Yuan, Hua; Cong, Hailin; Luo, Yongli; Tang, Jianguo

    2015-08-01

    Hydrophobic interaction membrane chromatography has gained interest due to its excellent performance in the purification of humanized monoclonal antibodies. The membrane material used in hydrophobic interaction membrane chromatography has typically been commercially available polyvinylidene fluoride. In this contribution, newly developed inverse colloidal crystal membranes that have uniform pores, high porosity and, therefore, high surface area for protein binding are used as hydrophobic interaction membrane chromatography membranes for humanized monoclonal antibody immunoglobulin G purification. The capacity of the inverse colloidal crystal membranes developed here is up to ten times greater than commercially available polyvinylidene fluoride membranes with a similar pore size. This work highlights the importance of developing uniform pore size high porosity membranes in order to maximize the capacity of hydrophobic interaction membrane chromatography. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Peg Precipitation Coupled with Chromatography is a New and Sufficient Method for the Purification of Botulinum Neurotoxin Type B

    Science.gov (United States)

    Zhao, Yao; Kang, Lin; Gao, Shan; Gao, Xing; Xin, Wenwen; Wang, Jinglin

    2012-01-01

    Clostridium botulinum neurotoxins are used to treat a variety of neuro-muscular disorders, as well as in cosmetology. The increased demand requires efficient methods for the production and purification of these toxins. In this study, a new purification process was developed for purifying type B neurotoxin. The kinetics of C.botulinum strain growth and neurotoxin production were determined for maximum yield of toxin. The neurotoxin was purified by polyethylene glycol (PEG) precipitation and chromatography. Based on design of full factorial experiment, 20% (w/v) PEG-6000, 4°C, pH 5.0 and 0.3 M NaCl were optimal conditions to obtain a high recovery rate of 87% for the type B neurotoxin complex, as indicated by a purification factor of 61.5 fold. Furthermore, residual bacterial cells, impurity proteins and some nucleic acids were removed by PEG precipitation. The following purification of neurotoxin was accomplished by two chromatography techniques using Sephacryl™ S-100 and phenyl HP columns. The neurotoxin was recovered with an overall yield of 21.5% and the purification factor increased to 216.7 fold. In addition, a mouse bioassay determined the purified neurotoxin complex possessed a specific toxicity (LD50) of 4.095 ng/kg. PMID:22761863

  11. Quantification of the Pyrrolizidine Alkaloid Jacobine in Crassocephalum crepidioides by Cation Exchange High-Performance Liquid Chromatography.

    Science.gov (United States)

    Rozhon, Wilfried; Kammermeier, Lukas; Schramm, Sebastian; Towfique, Nayeem; Adebimpe Adedeji, N; Adesola Ajayi, S; Poppenberger, Brigitte

    2018-01-01

    Pyrrolizidine alkaloids (PAs) are secondary plant metabolites with considerable hepatoxic, tumorigenic and genotoxic potential. For separation, reversed phase chromatography is commonly used because of its excellent compatibility with detection by mass spectrometry. However, reversed phase chromatography has a low selectivity for PAs. The objective of this work was to investigate the suitability of cation exchange chromatography for separation of PAs and to develop a rapid method for quantification of jacobine in Crassocephalum crepidioides that is suitable for analysis of huge sample numbers as required for mutant screening procedures. We demonstrate that cation exchange chromatography offers excellent selectivity for PAs allowing their separation from most other plant metabolites. Due to the high selectivity, plant extracts can be directly analysed after simple sample preparation. Detection with UV at 200 nm instead of mass spectrometry can be applied, which makes the method very simple and cost-effective. The recovery rate of the method exceeded 95%, the intra-day and inter-day standard deviations were below 7% and the limit of detection and quantification were 1 mg/kg and 3 mg/kg, respectively. The developed method is sufficiently sensitive for reproducible detection of jacobine in C. crepidioides. Simple sample preparation and rapid separation allows for quantification of jacobine in plant material in a high-throughput manner. Thus, the method is suitable for genetic screenings and may be applicable for other plant species, for instance Jacobaea maritima. In addition, our results show that C. crepidioides cannot be considered safe for human consumption. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Adaptation to high throughput batch chromatography enhances multivariate screening.

    Science.gov (United States)

    Barker, Gregory A; Calzada, Joseph; Herzer, Sibylle; Rieble, Siegfried

    2015-09-01

    High throughput process development offers unique approaches to explore complex process design spaces with relatively low material consumption. Batch chromatography is one technique that can be used to screen chromatographic conditions in a 96-well plate. Typical batch chromatography workflows examine variations in buffer conditions or comparison of multiple resins in a given process, as opposed to the assessment of protein loading conditions in combination with other factors. A modification to the batch chromatography paradigm is described here where experimental planning, programming, and a staggered loading approach increase the multivariate space that can be explored with a liquid handling system. The iterative batch chromatography (IBC) approach is described, which treats every well in a 96-well plate as an individual experiment, wherein protein loading conditions can be varied alongside other factors such as wash and elution buffer conditions. As all of these factors are explored in the same experiment, the interactions between them are characterized and the number of follow-up confirmatory experiments is reduced. This in turn improves statistical power and throughput. Two examples of the IBC method are shown and the impact of the load conditions are assessed in combination with the other factors explored. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Confirmatory analysis method for zeranol, its metabolites and related mycotoxins in urine by liquid chromatography-negative ion electrospray tandem mass spectrometry

    International Nuclear Information System (INIS)

    Bennekom, E.O. van; Brouwer, L.; Laurant, E.H.M.; Hooijerink, H.; Nielen, M.W.F.

    2002-01-01

    The determination of the banned anabolic substance zeranol and the metabolites taleranol and zearalanone in bovine urine is complicated by the occurrence of the structurally-related mycotoxin zearalenone and the corresponding α- and β-zearalenol metabolites which possess similar estrogenic properties. A liquid chromatography-negative ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of all six resorcylic acid lactones ('zeranols') in urine samples using deuterium-labelled internal standards. The method was validated as a confirmatory method for bovine urine samples according to new draft EU guidelines and showed good precision and linearity, and CCα and CCβ values of 0.02-0.30 and -1 , respectively. The applicability was demonstrated by comparing the results of an incurred sample with previous results on the same sample obtained by gas chromatography high resolution mass spectrometry. Preliminary data show that following a simple matrix solid phase dispersion clean-up, liver samples from poultry will be amenable to this method as well

  14. Neutral monosaccharide composition analysis of plant-derived oligo- and polysaccharides by high performance liquid chromatography.

    Science.gov (United States)

    Yan, Jun; Shi, Songshan; Wang, Hongwei; Liu, Ruimin; Li, Ning; Chen, Yonglin; Wang, Shunchun

    2016-01-20

    A novel analytical method for neutral monosaccharide composition analysis of plant-derived oligo- and polysaccharides was developed using hydrophilic interaction liquid chromatography coupled to a charged aerosol detector. The effects of column type, additives, pH and column temperature on retention and separation were evaluated. Additionally, the method could distinguish potential impurities in samples, including chloride, sulfate and sodium, from sugars. The results of validation demonstrated that this method had good linearity (R(2) ≥ 0.9981), high precision (relative standard deviation ≤ 4.43%), and adequate accuracy (94.02-103.37% recovery) and sensitivity (detection limit: 15-40 ng). Finally, the monosaccharide compositions of the polysaccharide from Eclipta prostrasta L. and stachyose were successfully profiled through this method. This report represents the first time that all of these common monosaccharides could be well-separated and determined simultaneously by high performance liquid chromatography without additional derivatization. This newly developed method is convenient, efficient and reliable for monosaccharide analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Development and Validation of a Simple High Performance Liquid Chromatography/UV Method for Simultaneous Determination of Urinary Uric Acid, Hypoxanthine, and Creatinine in Human Urine

    Directory of Open Access Journals (Sweden)

    Nimanthi Wijemanne

    2018-01-01

    Full Text Available Uric acid and hypoxanthine are produced in the catabolism of purine. Abnormal urinary levels of these products are associated with many diseases and therefore it is necessary to have a simple and rapid method to detect them. Hence, we report a simple reverse phase high performance liquid chromatography (HPLC/UV technique, developed and validated for simultaneous analysis of uric acid, hypoxanthine, and creatinine in human urine. Urine was diluted appropriately and eluted with C-18 column 100 mm × 4.6 mm with a C-18 precolumn 25 mm × 4.6 mm in series. Potassium phosphate buffer (20 mM, pH 7.25 at a flow rate of 0.40 mL/min was employed as the solvent and peaks were detected at 235 nm. Tyrosine was used as the internal standard. The experimental conditions offered a good separation of analytes without interference of endogenous substances. The calibration curves were linear for all test compounds with a regression coefficient, r2>0.99. Uric acid, creatinine, tyrosine, and hypoxanthine were eluted at 5.2, 6.1, 7.2, and 8.3 min, respectively. Intraday and interday variability were less than 4.6% for all the analytes investigated and the recovery ranged from 98 to 102%. The proposed HPLC procedure is a simple, rapid, and low cost method with high accuracy with minimum use of organic solvents. This method was successfully applied for the determination of creatinine, hypoxanthine, and uric acid in human urine.

  16. A simple method for purification of lipopolysaccharides from E. coli 55:B5 using size exclusion chromatography

    International Nuclear Information System (INIS)

    Perdomo, Rolando; Montero, Vivian

    2006-01-01

    Several methods for the extraction of endotoxin or lipopolysaccharide from Gram negative bacteria have been described. However, the product is often contaminated with nucleic acids or proteins in a proportion depending on the extraction method used. Molecular and immunological studies require further purification of the raw LPS. We present here, a simple method for the purification of raw LPS obtained by the standard hot phenol-water procedure using size exclusion chromatography in Sepharose CL-6B. We demonstrated that the using of DNAse and RNAse treatment of the sample before the chromatographic step is necessary to abrogate the nucleic acid contamination in the LPS fraction. The spectrophotometric properties of the pure LPS were verified, supporting the immediate online detection of the LPS and oligonucleotides fractions spectrophotometrically at 206 nm. The mobile phase used (NaCl 0.2 M) do not absorb at 206 nm while maintains the LPS aggregates and therefore, allows the separation of the LPS fraction from the oligoribonucleotide and desoxioligoribonucleotide fractions. The yield of pure LPS was around 98%. Chemical and biological characterizations were conducted in order to assess the feasibility of the procedure developed. (Author)

  17. Specific capture of uranyl protein targets by metal affinity chromatography

    International Nuclear Information System (INIS)

    Basset, C.; Dedieu, A.; Guerin, P.; Quemeneur, E.; Meyer, D.; Vidaud, C.

    2008-01-01

    To improve general understanding of biochemical mechanisms in the field of uranium toxicology, the identification of protein targets needs to be intensified. Immobilized metal affinity chromatography (IMAC) has been widely developed as a powerful tool for capturing metal binding proteins from biological extracts. However uranyl cations (UO 2 2+ ) have particular physico-chemical characteristics which prevent them from being immobilized on classical metal chelating supports. We report here on the first development of an immobilized uranyl affinity chromatography method, based on the cation-exchange properties of amino-phosphonate groups for uranyl binding. The cation distribution coefficient and loading capacity on the support were determined. Then the stability of the uranyl-bonded phase under our chromatographic conditions was optimized to promote affinity mechanisms. The successful enrichment of uranyl binding proteins from human serum was then proven using proteomic and mass spectral analysis. (authors)

  18. Pressure drop effects on selectivity and resolution in packed-column supercritical fluid chromatography

    NARCIS (Netherlands)

    Lou, X.W.; Janssen, J.G.M.; Snijders, H.M.J.; Cramers, C.A.M.G.

    1996-01-01

    The influence of pressure drop on retention, selectivity, plate height and resolution was investigated systematically in packed supercritical fluid chromatography (SFC) using pure carbon dioxide as the mobile phase. Numerical methods developed previously which enabled the prediction of pressure

  19. Development and validation of a RP- HPLC method for the quantitation studies of bromadiolone in Ratitox F

    Directory of Open Access Journals (Sweden)

    Elena Gabriela Oltean

    2011-12-01

    Full Text Available An isocratic high-performance liquid chromatography (HPLC procedure was developed for the quantitative determination of bromadiolone (hydroxycoumarins in Ratitox F product – rodenticide. HPLC separation was carried out by reversed phase chromatography ODS 2 Hypersil C18 (250 mm x 4.6 mm i.e.; 5 ìm particle size, held in thermostat at 25°C. The mobile phase consisted of methanol/0.1% aqueous solution phosphoric acid (90/10v/v, with a flow rate of 1 ml/min and with UV detection at 265 nm. In order to validate the method, the following parameters have been investigated- linearity (r2 = 0.9999, range, precision, accuracy, specificity, limit of detection and limit of quantification. The described method can be successfully applied for the analysis of Ratitox F – rodenticide.

  20. 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

  1. A Simple Thin Layer Chromatography Method for Separation of Selected Natural Steroid Hormones

    International Nuclear Information System (INIS)

    Nowakowska, J.; Rudnicka-Litka, K.; Ciura, K.; Pikul, P.; Piotrowicz, J.

    2015-01-01

    Chromatographic properties of seven steroids: estrogens (β-estradiol and estrone), androgens (testosterone, methyltestosterone, trans-androsterone), progesterone and cholesterol have been studied by planar chromatography with usage of High Performance Thin Layer Chromatography (HPTLC) and Thin Layer Chromatography (TLC) plates. Normal, reversed and cyano-bonded silica stationary phases were tested with five binary mobile phases (acetonitrile-water, acetonitrile-DMSO, acetonitrile-methanol, acetone-petroleum ether, acetone-water) in which the concentration of organic modifier varied from 0 to 100 % (v/v). This study reports the optimization of steroid hormones separation. Principal Component Analysis (PCA) based on calculated molecular descriptors quantitatively differentiating solutes was performed in order to investigate the similarity and dissimilarity between tested compounds. The separation abilities of mobile and stationary phases were compared based on separation factor α. Chromatographic retention data and possible retention mechanisms also were discussed. (author)

  2. Method Development for Extraction and Quantification of Glycosides in Leaves of Stevia Rebaudiana

    International Nuclear Information System (INIS)

    Salmah Moosa; Hazlina Ahmad Hassali; Norazlina Noordin

    2015-01-01

    A solid-liquid extraction and an UHPLC method for determination of glycosides from the leave parts of Stevia rebaudiana were developed. Steviol glycosides found in the leaves of Stevia are natural sweetener and commercially sold as sugar substitutes. Extraction of the glycosides consisted of solvent extraction of leaf powder using various solvents followed by its concentration using rotary evaporator and analysis using Ultra High Performance Liquid Chromatography (UHPLC). Existing analytical methods are mainly focused on the quantification of either rebaudioside A or stevioside, whereas other glycosides, such as rebaudioside B and rebaudioside D present in the leaves also contribute to sweetness or its biological activity. Therefore, we developed an improved method by changing the UHPLC conditions to enable a rapid and reliable determination of four steviol glycosides rather than just two using an isocratic UHPLC method. (author)

  3. Nanoparticle Analysis by Online Comprehensive Two-Dimensional Liquid Chromatography combining Hydrodynamic Chromatography and Size-Exclusion Chromatography with Intermediate Sample Transformation

    Science.gov (United States)

    2017-01-01

    Polymeric nanoparticles have become indispensable in modern society with a wide array of applications ranging from waterborne coatings to drug-carrier-delivery systems. While a large range of techniques exist to determine a multitude of properties of these particles, relating physicochemical properties of the particle to the chemical structure of the intrinsic polymers is still challenging. A novel, highly orthogonal separation system based on comprehensive two-dimensional liquid chromatography (LC × LC) has been developed. The system combines hydrodynamic chromatography (HDC) in the first-dimension to separate the particles based on their size, with ultrahigh-performance size-exclusion chromatography (SEC) in the second dimension to separate the constituting polymer molecules according to their hydrodynamic radius for each of 80 to 100 separated fractions. A chip-based mixer is incorporated to transform the sample by dissolving the separated nanoparticles from the first-dimension online in tetrahydrofuran. The polymer bands are then focused using stationary-phase-assisted modulation to enhance sensitivity, and the water from the first-dimension eluent is largely eliminated to allow interaction-free SEC. Using the developed system, the combined two-dimensional distribution of the particle-size and the molecular-size of a mixture of various polystyrene (PS) and polyacrylate (PACR) nanoparticles has been obtained within 60 min. PMID:28745485

  4. Simultaneous determination of the styrene unit content and assessment of molecular weight of triblock copolymers in adhesives by a size exclusion chromatography method.

    Science.gov (United States)

    Wang, Mingfang; Wang, Yuerong; Luo, Pei; Zhang, Hongyang; Zhang, Min; Hu, Ping

    2017-10-01

    The content of styrene units in nonhydrogenated and hydrogenated styrene-butadiene-styrene and styrene-isoprene-styrene triblock copolymers significantly influences product performance. A size exclusion chromatography method was developed to determine the average styrene content of triblock copolymers blended with tackifier in adhesives. A complete separation of the triblock copolymer from the other additives was realized with size exclusion chromatography. The peak area ratio of the UV and refraction index signals of the copolymers at the same effective elution volume was correlated to the average styrene unit content using nuclear magnetic resonance spectroscopy with commercial copolymers as standards. The obtained calibration curves showed good linearity for both the hydrogenated and nonhydrogenated styrene-butadiene-styrene and styrene-isoprene-styrene triblock copolymers (r = 0.974 for styrene contents of 19.3-46.3% for nonhydrogenated ones and r = 0.970 for the styrene contents of 23-58.2% for hydrogenated ones). For copolymer blends, the developed method provided more accurate average styrene unit contents than nuclear magnetic resonance spectroscopy provided. These results were validated using two known copolymer blends consisting of either styrene-isoprene-styrene or hydrogenated styrene-butadiene-styrene and a hydrocarbon tackifying resin as well as an unknown adhesive with styrene-butadiene-styrene and an aromatic tackifying resin. The methodology can be readily applied to styrene-containing polymers in blends such as poly(acrylonitrile-butadiene styrene). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. [Multi-residue method for screening of pesticides in crops by liquid chromatography with tandem mass spectrometry].

    Science.gov (United States)

    Tanizawa, Haruna; Shima, Mikie; Ikehara, Chieko; Kobata, Masakazu; Sato, Motoaki

    2005-10-01

    A simple and rapid method was developed for the screening of 82 pesticides/metabolites in a wide variety of crops, using solid-phase extraction and liquid chromatography with tandem mass spectrometry (LC/MS/MS). After extraction with methanol, the filtered extracts were made up to 100 mL and a 2 mL aliquot was subjected to solid-phase extraction. Co-extractives were removed with a C18 mini-column, while pesticides were retained on 3 kinds of mini-columns (HLB, SAX, activated carbon), and then eluted with acetonitrile. Analysis was performed by LC/MS/MS, and MS acquisition parameters were established in positive and negative ESI modes. The utility of the method was demonstrated by the analysis of 6 crops (carrot, cabbage, onion, spinach, lemon, brown rice) and one mixed vegetable juice. Of 82 compounds tested, 75 in carrot and 62 in lemon were obtained with recoveries ranging from 70-120%. For all samples tested, 75 compounds could be obtained with recoveries of over 50%, and the detection limits of most compounds were lower than 0.01 microg/g. This method provides acceptable performance for analysis of these 75 compounds. Further, by using aliquots of the extracts with small-scale mini-columns, purified samples could be obtained. This proposed method with small matrix effects, is effective and suitable for screening of multiple residual pesticides by using LC/MS/MS.

  6. Gas Chromatography-Mass Spectroscopic (GC-MS) Analysis of n ...

    African Journals Online (AJOL)

    tuber-regium (synonym Pleurotus tuber regium) using gas chromatography-mass spectroscopic (GC-. MS) techniques. Methods: The n-hexane extract of the sclerotia ... Soxhlet extraction and analysed using gas chromatography-mass spectroscopic (MS) techniques. ..... Phytochemical composition of Pleurotus tuber regium.

  7. Development and validation of an analytical method for quality control and the stability of the eyedrops 10 % Phenylephrine and the 1 % Tropicamide

    International Nuclear Information System (INIS)

    Garcia Penna, Caridad Margarita; Botet Garcia, Martha; Troche Concepcion, Yenilen

    2011-01-01

    An analytical high-performance liquid chromatography method was developed and validated applicable to quality control and to stability study of 10 % phenylephrine plus eyedrops 1 % tropicamide. To quantify simultaneously both active principles in the finished product, separation was carried out through a Lichrosorb RP-18 (15 μm) (260 x 4 mm) column chromatography, with ultraviolet detection at 253 nm using the mobile phase composed of methanol: distilled water (1:1), with 1.1 g of sodium 1-octasulfanate by litre and pH fitted to 3.0 with phosphoric acid and the quantification of this front to a reference sample using the external standard method. The analytical method developed was linear, precise, specific and accurate in the rank of study concentrations, established for the quality control and stability study of the finished product since there were not analytical methods designed for these aims

  8. Determination of chloroacetanilide herbicide metabolites in water using high-performance liquid chromatography-diode array detection and high-performance liquid chromatography/mass spectrometry

    Science.gov (United States)

    Hostetler, K.A.; Thurman, E.M.

    2000-01-01

    Analytical methods using high-performance liquid chromatography-diode array detection (HPLC-DAD) and high-performance liquid chromatography/mass spectrometry (HPLC/MS) were developed for the analysis of the following chloroacetanilide herbicide metabolites in water: alachlor ethanesulfonic acid (ESA); alachlor oxanilic acid; acetochlor ESA; acetochlor oxanilic acid; metolachlor ESA; and metolachlor oxanilic acid. Good precision and accuracy were demonstrated for both the HPLC-DAD and HPLC/MS methods in reagent water, surface water, and ground water. The average HPLC-DAD recoveries of the chloroacetanilide herbicide metabolites from water samples spiked at 0.25, 0.5 and 2.0 ??g/l ranged from 84 to 112%, with relative standard deviations of 18% or less. The average HPLC/MS recoveries of the metabolites from water samples spiked at 0.05, 0.2 and 2.0 ??g/l ranged from 81 to 118%, with relative standard deviations of 20% or less. The limit of quantitation (LOQ) for all metabolites using the HPLC-DAD method was 0.20 ??g/l, whereas the LOQ using the HPLC/MS method was at 0.05 ??g/l. These metabolite-determination methods are valuable for acquiring information about water quality and the fate and transport of the parent chloroacetanilide herbicides in water. Copyright (C) 2000 Elsevier Science B.V.

  9. Gas chromatography

    International Nuclear Information System (INIS)

    Cram, S.P.; Risby, T.H.; Field, L.R.; Yu, W.L.

    1980-01-01

    In addition to the published literature for the years 1978 - 79, this review of developments in the field of gas chromatography includes earlier articles of particular significance appearing in foreign journals and the patent literature which was not available at the time of the previous review. The articles cited were selected as presenting the most fundamental developments in theory, methodology, and instrumentation. Some applications are cited if they reflect an advance in the state-of-the-art or have particular relevance to new developments. 1149 references are cited

  10. ANALYSIS AND IDENTIFICATION SPIKING CHEMICAL COMPOUNDS RELATED TO CHEMICAL WEAPON CONVENTION IN UNKNOWN WATER SAMPLES USING GAS CHROMATOGRAPHY AND GAS CHROMATOGRAPHY ELECTRON IONIZATION MASS SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Harry Budiman

    2010-06-01

    Full Text Available The identification and analysis of chemical warfare agents and their degradation products is one of important component for the implementation of the convention. Nowadays, the analytical method for determination chemical warfare agent and their degradation products has been developing and improving. In order to get the sufficient analytical data as recommended by OPCW especially in Proficiency Testing, the spiking chemical compounds related to Chemical Weapon Convention in unknown water sample were determined using two different techniques such as gas chromatography and gas chromatography electron-impact ionization mass spectrometry. Neutral organic extraction, pH 11 organic extraction, cation exchanged-methylation, triethylamine/methanol-silylation were performed to extract the chemical warfare agents from the sample, before analyzing with gas chromatography. The identification of chemical warfare agents was carried out by comparing the mass spectrum of chemicals with mass spectrum reference from the OPCW Central Analytical Database (OCAD library while the retention indices calculation obtained from gas chromatography analysis was used to get the confirmation and supported data of  the chemical warfare agents. Diisopropyl methylphosphonate, 2,2-diphenyl-2-hydroacetic acid and 3-quinuclidinol were found in unknown water sample. Those chemicals were classified in schedule 2 as precursor or reactant of chemical weapons compound in schedule list of Chemical Weapon Convention.   Keywords: gas chromatography, mass spectrometry, retention indices, OCAD library, chemical warfare agents

  11. Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

    Directory of Open Access Journals (Sweden)

    Gajda Anna

    2015-09-01

    Full Text Available A liquid chromatography – tandem mass spectrometry (LC-MS/MS method for the determination of oxytetracycline (OTC, 4-epi oxytetracycline (4-epi OTC, tetracycline (TC, 4-epi tetracycline (4-epi TC, chlortetracycline (CTC, 4-epi chlortetracycline (4-epi CTC, doxycycline (DC, minocycline (MINO, methacycline (META and rolitetracycline (ROLI residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

  12. Shuffling cross-validation-bee algorithm as a new descriptor selection method for retention studies of pesticides in biopartitioning micellar chromatography.

    Science.gov (United States)

    Zarei, Kobra; Atabati, Morteza; Ahmadi, Monire

    2017-05-04

    Bee algorithm (BA) is an optimization algorithm inspired by the natural foraging behaviour of honey bees to find the optimal solution which can be proposed to feature selection. In this paper, shuffling cross-validation-BA (CV-BA) was applied to select the best descriptors that could describe the retention factor (log k) in the biopartitioning micellar chromatography (BMC) of 79 heterogeneous pesticides. Six descriptors were obtained using BA and then the selected descriptors were applied for model development using multiple linear regression (MLR). The descriptor selection was also performed using stepwise, genetic algorithm and simulated annealing methods and MLR was applied to model development and then the results were compared with those obtained from shuffling CV-BA. The results showed that shuffling CV-BA can be applied as a powerful descriptor selection method. Support vector machine (SVM) was also applied for model development using six selected descriptors by BA. The obtained statistical results using SVM were better than those obtained using MLR, as the root mean square error (RMSE) and correlation coefficient (R) for whole data set (training and test), using shuffling CV-BA-MLR, were obtained as 0.1863 and 0.9426, respectively, while these amounts for the shuffling CV-BA-SVM method were obtained as 0.0704 and 0.9922, respectively.

  13. Development and validation of a liquid chromatography-MS/MS method for simultaneous quantification of tenofovir and efavirenz in biological tissues and fluids.

    Science.gov (United States)

    Barreiros, Luisa; Cunha-Reis, Cassilda; Silva, Eduarda M P; Carvalho, Joana R B; das Neves, José; Sarmento, Bruno; Segundo, Marcela A

    2017-03-20

    Millions of people worldwide live with human immunodeficiency virus (HIV) infection thus justifying the continuous search for new prevention and treatment strategies, including topical microbicide products combining antiretroviral drugs (ARVs) such as tenofovir (TFV) and efavirenz (EFV). Therefore, the aim of this work was to develop and validate a high performance liquid chromatography method coupled to triple quadrupole-tandem mass spectrometry (HPLC-MS/MS) for the quantification of TFV and EFV in biological matrices (mouse vaginal tissue, vaginal lavage and blood plasma). Chromatographic separation was achieved using a reversed phase C18 column (3μm, 100×2.1mm) at 45°C and elution in gradient mode using a combination of 0.1% (v/v) formic acid in water and 0.1% (v/v) formic acid in acetonitrile at 0.35mLmin -1 . Total run time was 9min, with retention time of 2.8 and 4.1min for TFV and EFV, respectively. The MS was operated in positive ionization mode (ESI+) for TFV and in negative ionization mode (ESI-) for EFV detection. Data were acquired in selected reaction monitoring (SRM) mode and deuterated ARVs were employed as internal standards. Calibration curves were linear for ARV concentrations ranging from 4 to 500ngmL -1 with LOD and LOQ for both analytes ≤0.4 and ≤0.7ngmL -1 in sample extracts, respectively. The method was found to be specific, accurate (96.0-106.0% of nominal values) and precise (RSDfluids were ≥88.4%. Matrix effects were observed for EFV determination in tissue and plasma extracts but compensated by the use of deuterated internal standards. The proposed methodology was successfully applied to a pharmacokinetic study following intravaginal administration of both ARVs. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Development of a thermal desorption modulator for gas chromatography

    NARCIS (Netherlands)

    Geus, H.J.; Boer, de J.; Brinkman, U.A.Th.

    1997-01-01

    The separation space in gas chromatography can be enhanced dramatically by the comprehensive coupling of two independent separation dimensions. An interface between the two columns must accumulate analytes eluting from the first dimension, focus them and at the appropriate moment transfer them to

  15. Development of a relatively cheap and simple automated separation system for a routine separation procedure based on extraction chromatography

    International Nuclear Information System (INIS)

    Petro Zoriy; Reinhold Flucht; Mechthild Burow; Peter Ostapczuk; Reinhard Lennartz; Myroslav Zoriy

    2010-01-01

    A robust analytical method has been developed in our laboratory for the separation of radionuclides by means of extraction chromatography using an automated separation system. The proposed method is both cheap and simple and provides the advantageous, rapid and accurate separation of the element of interest. The automated separation system enables a shorter separation time by maintaining a constant flow rate of solution and by avoiding clogging or bubbling in the chromatographic column. The present separation method was tested with two types of samples (water and urine) using UTEVA-, TRU- and Sr-specific resins for the separation of U, Th, Am, Pu and Sr. The total separation time for one radionuclide ranged from 60 to 100 min with the separation yield ranging from 68 to 98% depending on the elements separated. We used ICP-QMS, multi-low-level counter and alpha spectroscopy to measure the corresponding elements. (author)

  16. Ultra-high-pressure liquid chromatography tandem mass spectrometry method for the determination of 9 organophosphate flame retardants in water samples

    NARCIS (Netherlands)

    Lorenzo, M.; Campo, J.; Picó, Y.

    2016-01-01

    Few methods are available for comprehensive organophosphate flame retardants (PFRs) detection in water and wastewater. Gas chromatography has been employed previously, but this approach is less selective, not amenable for use with deuterated standards and can suffer unfavorable fragmentation.

  17. A validated liquid chromatography-tandem mass spectrometry method for the quantitative determination of 4 beta-hydroxycholesterol in human plasma

    NARCIS (Netherlands)

    van de Merbel, Nico C.; Bronsema, Kees J.; van Hout, Mischa W. J.; Nilsson, Ralf; Sillen, Henrik

    2011-01-01

    A novel liquid chromatography-tandem mass spectrometry method is described for the quantitative determination of the endogenous CYP 3A4/5 marker 4 beta-hydroxycholesterol in human K(2)-EDTA plasma. It is based on alkaline hydrolysis to convert esterified to free 4 beta-hydroxycholesterol, followed

  18. Liquid chromatography tandem mass spectrometry method for the estimation of lamotrigine in human plasma: Application to a pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Santosh Ghatol

    2013-04-01

    Full Text Available A reliable, selective and sensitive liquid chromatography tandem mass spectrometry method was developed and validated for the quantification of lamotrigine in human plasma using lamotrigine-13C3, d3 as an internal standard. Analyte and internal standard were extracted from human plasma by solid-phase extraction and detected in positive ion mode by tandem mass spectrometry with electrospray ionization (ESI interface. Chromatographic separation was performed on a Chromolith® SpeedROD; RP-18e column (50−4.6 mm i.d. using acetonitrile: 5±0.1 mM ammonium formate solution (90:10, v/v as the mobile phase at a flow rate of 0.500 mL/min. The calibration curves were linear over the range of 5.02–1226.47 ng/mL with the lower limit of quantitation validated at 5.02 ng/mL. The analytes were found stable in human plasma through three freeze (−20 °C-thaw (ice-cold water bath cycles and under storage on bench-top in ice-cold water bath for at least 6.8 h, and also in the mobile phase at 10 °C for at least 57 h. The method has shown good reproducibility, as the intra- and inter-day precisions were within 3.0%, while the accuracies were within ±6.0% of nominal values. The validated LC–MS/MS method was applied for the evaluation of pharmacokinetic and bioequivalence parameters of lamotrigine after an oral administration of 50 mg lamotrigine tablet to thirty-two healthy adult male volunteers. Keywords: Lamotrigine, Liquid chromatography/tandem mass spectrometry, Solid phase extraction, Pharmacokinetic study

  19. 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.

  20. Mathematical analysis of frontal affinity chromatography in particle and membrane configurations.

    Science.gov (United States)

    Tejeda-Mansir, A; Montesinos, R M; Guzmán, R

    2001-10-30

    The scaleup and optimization of large-scale affinity-chromatographic operations in the recovery, separation and purification of biochemical components is of major industrial importance. The development of mathematical models to describe affinity-chromatographic processes, and the use of these models in computer programs to predict column performance is an engineering approach that can help to attain these bioprocess engineering tasks successfully. Most affinity-chromatographic separations are operated in the frontal mode, using fixed-bed columns. Purely diffusive and perfusion particles and membrane-based affinity chromatography are among the main commercially available technologies for these separations. For a particular application, a basic understanding of the main similarities and differences between particle and membrane frontal affinity chromatography and how these characteristics are reflected in the transport models is of fundamental relevance. This review presents the basic theoretical considerations used in the development of particle and membrane affinity chromatography models that can be applied in the design and operation of large-scale affinity separations in fixed-bed columns. A transport model for column affinity chromatography that considers column dispersion, particle internal convection, external film resistance, finite kinetic rate, plus macropore and micropore resistances is analyzed as a framework for exploring further the mathematical analysis. Such models provide a general realistic description of almost all practical systems. Specific mathematical models that take into account geometric considerations and transport effects have been developed for both particle and membrane affinity chromatography systems. Some of the most common simplified models, based on linear driving-force (LDF) and equilibrium assumptions, are emphasized. Analytical solutions of the corresponding simplified dimensionless affinity models are presented. Particular

  1. Simultaneous monitoring of oxidation, deamidation, isomerization, and glycosylation of monoclonal antibodies by liquid chromatography-mass spectrometry method with ultrafast tryptic digestion.

    Science.gov (United States)

    Wang, Yi; Li, Xiaojuan; Liu, Yan-Hui; Richardson, Daisy; Li, Huijuan; Shameem, Mohammed; Yang, Xiaoyu

    Monoclonal antibodies are subjected to a wide variety of post-translational modifications (PTMs) that cause structural heterogeneity. Characterization and control of these modifications or quality attributes are critical to ensure antibody quality and to define any potential effects on the ultimate safety and potency of antibody therapeutics. The biopharmaceutical industry currently uses numerous tools to analyze these quality attributes individually, which requires substantial time and resources. Here, we report a simple and ultrafast bottom-up liquid chromatography-mass spectrometry (uLC-MS) method with 5 min tryptic digestion to simultaneously analyze multiple modifications, including oxidation, deamidation, isomerization, glycation, glycosylation, and N-terminal pyro-glutamate formation, which can occur during antibody production in mammalian cell culture, during purification and/or on storage. Compared to commonly used preparation procedures, this uLC-MS method eliminates assay artifacts of falsely-increased Met oxidation, Asp isomerization, and Asn deamidation, a problem associated with long digestion times in conventional LC-MS methods. This simple, low artifact multi-attribute uLC-MS method can be used to quickly and accurately analyze samples at any stage of antibody drug development, in particular for clone and media selection during cell culture development.

  2. Two-Dimensional Liquid Chromatography Analysis of Polystyrene/Polybutadiene Block Copolymers.

    Science.gov (United States)

    Lee, Sanghoon; Choi, Heejae; Chang, Taihyun; Staal, Bastiaan

    2018-05-15

    A detailed characterization of a commercial polystyrene/polybutadiene block copolymer material (Styrolux) was carried out using two-dimensional liquid chromatography (2D-LC). The Styrolux is prepared by statistical linking reaction of two different polystyrene- block-polybutadienyl anion precursors with a multivalent linking agent. Therefore, it is a mixture of a number of branched block copolymers different in molecular weight, composition, and chain architecture. While individual LC analysis, including size exclusion chromatography, interaction chromatography, or liquid chromatography at critical condition, is not good enough to resolve all the polymer species, 2D-LC separations coupling two chromatography methods were able to resolve all polymer species present in the sample; at least 13 block copolymer species and a homopolystyrene blended. Four different 2D-LC analyses combining a different pair of two LC methods provide their characteristic separation results. The separation characteristics of the 2D-LC separations are compared to elucidate the elution characteristics of the block copolymer species.

  3. New method for the discovery of adulterated cognacs and brandies based on solid-phase microextraction and gas chromatography - mass spectrometry

    Directory of Open Access Journals (Sweden)

    Darya Mozhayeva

    2014-10-01

    Full Text Available The article represents new method for discovery of adulterated cognacs and brandies based on solidphase microextraction (SPME in combination with gas chromatography – mass spectrometry (GC-MS. The work comprised optimization of SPME parameters (extraction temperature and time, concentration of added salt with subsequent analysis of authentic samples and comparison of the obtained chromatograms using principal component analysis (PCA. According to the obtained results, increase of extraction temperature resulted in an increase of response of the most volatile brandy constituents. To avoid chemical transformations and/or degradation of the samples, the extraction temperature must be limited to 30!C. Increase of the extraction time lead to higher total peak area, but longer extraction times (>10 min for 100 µm polydimethylsiloxane and >2 min for divinylbenzene/Carboxen/polydimethylsiloxane fibers caused displacement of analytes. Salt addition increased total response of analytes, but caused problems with reproducibility. The developed method was successfully applied for discovery of adulterated samples of brandy, cognac, whisky and whiskey sold in Kazakhstan. The obtained data was analyzed applying principal component analysis (PCA. Five adulterated brandy and whisky samples were discovered and confirmed. The developed method is recommended for application in forensic laboratories.

  4. Contribution to high-temperature chromatography and high-temperature-gas-chromatography-mass spectrometry of lipids

    International Nuclear Information System (INIS)

    Aichholz, R.

    1998-04-01

    This thesis describes the use of high temperature gas chromatography for the investigation of unusual triacylglycerols, cyanolipids and bees waxes. The used glass capillary columns were pretreated and coated with tailor made synthesized high temperature stable polysiloxane phases. The selective separation properties of the individual columns were tested with a synthetic lipid mixture. Suitable derivatization procedures for the gaschromatographic analyses of neutral lipids, containing multiple bonds as well as hydroxy-, epoxy-, and carboxyl groups, were developed and optimized. Therefore conjugated olefinic-, conjugated olefinic-acetylenic-, hydroxy-, epoxy-, and conjugated olefinic keto triacylglycerols in miscellaneous plant seed oils as well as hydroxy monoesters, diesters and hydroxy diesters in bees waxes could be analysed directly with high temperature gas chromatography for the first time. In order to elucidate the structures of separated lipid compounds, high temperature gas chromatography was coupled to mass spectrometry and tandem mass spectrometry, respectively. Comparable analytical systems are hitherto not commercial available. Therefore instrumental prerequisites for a comprehensive and detailed analysis of seed oils and bees waxes were established. In GC/MS commonly two ionization methods are used, electron impact ionization and chemical ionization. For the analysis of lipids the first is of limited use only. Due to intensive fragmentation only weak molecular ions are observed. In contrast, the chemical ionization yields in better results. Dominant quasi molecular ions enable an unambiguous determination of the molecular weight. Moreover, characteristic fragment ions provide important indications of certain structural features of the examined compounds. Nevertheless, in some cases the chromatographic resolution was insufficient in order to separate all compounds present in natural lipid mixtures. Owing to the selected detection with mass spectrometry

  5. On-line coupling of size exclusion chromatography with mixed-mode liquid chromatography for comprehensive profiling of biopharmaceutical drug product.

    Science.gov (United States)

    He, Yan; Friese, Olga V; Schlittler, Michele R; Wang, Qian; Yang, Xun; Bass, Laura A; Jones, Michael T

    2012-11-02

    A methodology based on on-line coupling of size exclusion chromatography (SEC) with mixed-mode liquid chromatography (LC) has been developed. The method allows for simultaneous measurement of a wide range of components in biopharmaceutical drug products. These components include the active pharmaceutical ingredient (protein) and various kinds of excipients such as cations, anions, nonionic hydrophobic surfactant and hydrophilic sugars. Dual short SEC columns are used to separate small molecule excipients from large protein molecules. The separated protein is quantified using a UV detector at 280 nm. The isolated excipients are switched, online, to the Trinity P1 mixed-mode column for separation, and detected by an evaporative light scattering detector (ELSD). Using a stationary phase with 1.7 μm particles in SEC allows for the use of volatile buffers for both SEC and mix-mode separation. This facilitates the detection of different excipients by ELSD and provides potential for online characterization of the protein with mass spectrometry (MS). The method has been applied to quantitate protein and excipients in different biopharmaceutical drug products including monoclonal antibodies (mAb), antibody drug conjugates (ADC) and vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Analysis of pollutants in air and water using gas chromatography and headspace gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, H.

    1980-01-01

    The combination 'personal sampling' with headspace gas chromatography to determine traces of formaldehyde, phenol and benzene in air is investigated in this work, with the aim of developing maximum workplace concentration values (MWL values). Further possible applications of gas chromatography in trace analysis in the environmentally protected area. The analysis of chromium in waste waters (Cr III as acetyl acetonate complex) is investigated as further possible application, whereby optimum conditions are obtained. A modified flame ionization detector was used to increase the detection sensitivity.

  7. Improved method for the determination of serotonin in plasma by high-performance liquid chromatography using on-line sample pre-treatment

    NARCIS (Netherlands)

    Takkenberg, B.; Endert, E.; van Ingen, H. E.; Ackermans, M.

    1991-01-01

    An improved method for the determination of serotonin in platelet-rich plasma (PRP) and platelet-poor plasma (PPP), by reversed-phase high-performance liquid chromatography with electrochemical detection and direct plasma injection, is described. The chromatographic system comprises a strong

  8. Determination of daminozide residues in apples using gas chromatography with nitrogen-phosphorus detection

    NARCIS (Netherlands)

    Brinkman, J.H.W.; Dijk, A.G. van; Wagenaar, R.; Quirijns, J.K.

    1996-01-01

    A method was developed for the determination of daminozide in apples using gas chromatography (GC) with nitrogen-phosphorus detection (NPD). Daminozide is hydrolysed to 1,1-dimethylhydrazine (UDMH) by alkaline digestion. The UDMH generated is distilled from the apple matrix, derivatized with

  9. 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.

  10. Development and validation of a liquid chromatography-tandem mass spectrometry method for topotecan determination in beagle dog plasma and its application in a bioequivalence study.

    Science.gov (United States)

    Ye, Ling; Shi, Jian; Wan, Shanhe; Yang, Xiaoshan; Wang, Ying; Zhang, Jiajie; Zheng, Dayong; Liu, Zhongqiu

    2013-11-01

    Topotecan (TPT) is an important anti-cancer drug that inhibits topoisomerase I. A sensitive and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method that potentially determines TPT in beagle dog plasma is needed for a bioequivalence study of TPT formulations. We developed and validated LC-MS/MS to evaluate TPT in beagle dog plasma in terms of specificity, linearity, precision, accuracy, stability, extraction recovery and matrix effect. Plasma samples were treated with an Ostro(TM) sorbent plate (a robust and effective tool) to eliminate phospholipids and proteins before analysis. TPT and camptothecin (internal standard) were separated on an Acquity UPLC BEH C18 column (1.7 µm, 2.1 × 50 mm) with 0.1% formic acid and methanol as the mobile phase at a flow rate of 0.25 mL/min. TPT was analyzed using positive ion electrospray ionization in multiple-reaction monitoring mode. The obtained lower limit of quantitation was 1 ng/mL (signal-to-noise ratio > 10). The standard calibration curve for TPT was linear (correlation coefficient > 0.99) at the concentration range of 1-400 ng/mL. The intra-day and inter-day precision, accuracy, stability, extraction recovery and matrix effect of TPT were within the acceptable limits. The validated method was successfully applied in a bioequivalence study of TPT in healthy beagle dogs. Copyright © 2013 John Wiley & Sons, Ltd.

  11. Development and validation of a stability-indicating HPLC-UV method for the determination of triamcinolone acetonide and its degradation products in an ointment formulation

    NARCIS (Netherlands)

    van Heugten, A J P; Boer, W.; de Vries, W S; Markesteijn, C M A; Vromans, H

    2018-01-01

    A stability indicating high performance liquid chromatography method has been developed for the determination of triamcinolone acetonide (TCA) and its main degradation products in ointment formulations. The method, based on extensive stress testing using metal salts, azobisisobutyronitrile, acid,

  12. HPTLC Method Development and Validation of Zolpidem Tartrate in Bulk and Marketed Formulation

    OpenAIRE

    Abhay R. Shirode; Bharti G. Jadhav; Vilasrao J. Kadam

    2015-01-01

    High performance thin layer chromatography (HPTLC) offers many advantages over HPLC. It reduces the cost of analysis as compare to HPLC. The mobile phase consumption per sample is extremely low in HPTLC, hence reducing the acquisition and disposal cost. Considering the cost and suitability of analysis for estimation of zolpidem tartrate in bulk and its marketed formulation, HPTLC method was developed and validated. The Camag HPTLC system, employed with software winCATS (ver.1.4.1.8) was used ...

  13. Quantification of the level of fat-soluble vitamins in feed based on the novel microemulsion electrokinetic chromatography (MEEKC) method.

    Science.gov (United States)

    Olędzka, Ilona; Kowalski, Piotr; Bałuch, Alicja; Bączek, Tomasz; Paradziej-Łukowicz, Jolanta; Taciak, Marcin; Pastuszewska, Barbara

    2014-02-01

    Simultaneous quantification of liposoluble vitamins is not a new area of interest, since these compounds co-determine the nutritional quality of food and feed, a field widely explored in the human and animal diet. However, the development of appropriate methods is still a matter of concern, especially when the vitamin composition is highly complex, as is the case with feed designated for laboratory animals, representing a higher health and microbiological status. A method combining microemulsion electrokinetic chromatography (MEEKC) with liquid-liquid extraction was developed for the determination of four fat-soluble vitamins in animal feed. A separation medium consisting of 25 mmol L⁻¹ phosphate buffer (pH 2.5), 2-propanol, 1-butanol, sodium dodecyl sulfate and octane allowed the simultaneous determination of vitamins A, D, E and K within a reasonable time of 25 min. The polarity of the separation voltage was reversed in view of the strongly suppressed electro-osmotic flow, and the applied voltage was set at 12 kV. The fat-soluble vitamins were separated in the order of decreasing hydrophobicity. It was proved that the proposed MEEKC method was sufficiently specific and sensitive for screening fat-soluble vitamins in animal feed samples after their sterilization. © 2013 Society of Chemical Industry.

  14. Determination of ketone bodies in blood by headspace gas chromatography-mass spectrometry

    DEFF Research Database (Denmark)

    Holm, Karen Marie Dollerup; Linnet, Kristian; Rasmussen, Brian Schou

    2010-01-01

    A gas chromatography-mass spectrometry (GC-MS) method for determination of ketone bodies (ß-hydroxybutyrate, acetone, and acetoacetate) in blood is presented. The method is based on enzymatic oxidation of D-ß-hydroxybutyrate to acetoacetate, followed by decarboxylation to acetone, which...... was quantified by the use of headspace GC-MS using acetone-(13)C(3) as an internal standard. The developed method was found to have intra- and total interday relative standard deviations

  15. [Application of off-line two dimensional reversed-phase liquid chromatography/supercritical fluid chromatography to the separation of the seeds of Trichosanthes kirilowii Maxim].

    Science.gov (United States)

    Yuan, Yun; Xin, Huaxia; Peng, Ziyue; Fu, Qing; Jin, Yu

    2017-07-08

    An off-line two dimensional reversed-phase liquid chromatography/supercritical fluid chromatography (2D RPLC/SFC) method was developed for the separation of the seeds of Trichosanthes kirilowii Maxim . ( T. kirilowii .). In the experiment, RPLC was used in the first dimension to analyze the samples. And 12 fractions (F 1 -F 12 ) were obtained according to the chromatographic peak collection mode, the fractions were re-analyzed in both RPLC and SFC modes. The results clearly showed that this 2D method had good orthogonality. The SFC was used as the second dimension. Ethanol- n -hexane (3:7, v/v) was used as a modifier in SFC. The modifier could provide appropriate elution power. When the sample load increased, it could also ensure the solubility of samples. The 2D RPLC/SFC method had obvious advantages for separating the compounds with similar properties, enriching and purifying the trace components. Finally, 150 peaks could be detected. The off-line 2D RPLC/SFC method will be further enlarged to a preparative level for preparation of compounds. The method can provide a practical reference for the purification of chemical constituents and material basis research of the seeds of T. kirilowii . in the future.

  16. Determination of low molecular weight thiols using monobromobimane fluorescent labeling and high-performance liquid chromatography

    Science.gov (United States)

    Fahey, Robert C.; Newton, Gerald L.

    1988-01-01

    Methods are described for the preparation and high-performance liquid chromatography (HPLC) analysis of monobromobimane derivatives of low molecular weight thiols in extracts of biological samples. Typical problems encountered in the development and application of these methods are discussed. Analysis of mung bean extract is used as an example.

  17. Doping control analysis of anabolic steroids in equine urine by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wong, April S Y; Leung, Gary N W; Leung, David K K; Wan, Terence S M

    2017-09-01

    Anabolic steroids are banned substances in equine sports. Gas chromatography-mass spectrometry (GC-MS) has been the traditional technique for doping control analysis of anabolic steroids in biological samples. Although liquid chromatography-mass spectrometry (LC/MS) has become an important technique in doping control, the detection of saturated hydroxysteroids by LC-MS remains a problem due to their low ionization efficiency under electrospray. The recent development in fast-scanning gas-chromatography-triple-quadrupole mass spectrometry (GC-MS/MS) has provided a better alternative with a significant reduction in chemical noise by means of selective reaction monitoring. Herein, we present a sensitive and selective method for the screening of over 50 anabolic steroids in equine urine using gas chromatography-tandem mass spectrometry (GC-MS/MS). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Development, validation and application of a micro-liquid chromatography-tandem mass spectrometry based method for simultaneous quantification of selected protein biomarkers of endothelial dysfunction in murine plasma.

    Science.gov (United States)

    Suraj, Joanna; Kurpińska, Anna; Olkowicz, Mariola; Niedzielska-Andres, Ewa; Smolik, Magdalena; Zakrzewska, Agnieszka; Jasztal, Agnieszka; Sitek, Barbara; Chlopicki, Stefan; Walczak, Maria

    2018-02-05

    The objective of this study was to develop and validate the method based on micro-liquid chromatography-tandem mass spectrometry (microLC/MS-MRM) for simultaneous determination of adiponectin (ADN), von Willebrand factor (vWF), soluble form of vascular cell adhesion molecule 1 (sVCAM-1), soluble form of intercellular adhesion molecule 1 (sICAM-1) and syndecan-1 (SDC-1) in mouse plasma. The calibration range was established from 2.5pmol/mL to 5000pmol/mL for ADN; 5pmol/mL to 5000pmol/mL for vWF; 0.375pmol/mL to 250pmol/mL for sVCAM-1 and sICAM-1; and 0.25pmol/mL to 250pmol/mL for SDC-1. The method was applied to measure the plasma concentration of selected proteins in mice fed high-fat diet (HFD), and revealed the pro-thrombotic status by increased concentration of vWF (1.31±0.17 nmol/mL (Control) vs 1.98±0.09 nmol/mL (HFD), p <0.05) and the dysregulation of adipose tissue metabolism by decreased concentration of ADN (0.62±0.08 nmol/mL (Control) vs 0.37±0.06 nmol/mL (HFD), p <0.05). In conclusion, the microLC/MS-MRM-based method allows for reliable measurements of selected protein biomarkers of endothelial dysfunction in mouse plasma. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Gas chromatography-mass spectrometry and high-performance liquid chromatography-diode array detection for dating of paper ink.

    Science.gov (United States)

    Díaz-Santana, Oscar; Vega-Moreno, Daura; Conde-Hardisson, Francisco

    2017-09-15

    An extraction and determination method is shown for the analysis of dyes and solvents present in two types of ballpoint pen inks that are deposited onto paper. Ink extracts are analysed using a combination of gas chromatography with mass spectrometry (GC-MS), and high-pressure liquid chromatography with photodiode array detection (HPLC-DAD), within a single sample extraction procedure. Seventeen solvents and thirteen dyes contained in two Montblanc ® inks (black and blue) were monitored for 45 months at monthly intervals, in order to determine variations in the concentrations of the compounds over time. We also studied the relative variations between different compounds and the generation of degradation products such as phenol. The concentration data obtained from these compounds during their exposure have been analysed and a multiple regression model is developed for each ink type that allows an estimate of the exposure time of the ink on paper with a maximum error of between 4 and 7 months. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. A novel method for analysing key corticosteroids in polar bear (Ursus maritimus) hair using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Weisser, Johan J; Hansen, Martin; Björklund, Erland; Sonne, Christian; Dietz, Rune; Styrishave, Bjarne

    2016-04-01

    This paper presents the development and evaluation of a methodology for extraction, clean-up and analysis of three key corticosteroids (aldosterone, cortisol and corticosterone) in polar bear hair. Such a methodology can be used to monitor stress biomarkers in polar bears and may provide as a useful tool for long-term and retrospective information. We developed a combined pressurized liquid extraction (PLE)-solid phase extraction (SPE) procedure for corticosteroid extraction and clean-up followed by high pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis. This procedure allows for the simultaneous determination of multiple steroids, which is in contrast to previous polar bear studies based on ELISA techniques. Absolute method recoveries were 81%, 75% and 60% for cortisol, corticosterone and aldosterone, respectively. We applied the developed method on a hair sample pooled from four East Greenland polar bears. Herein cortisol and corticosterone were successfully determined in levels of 0.32±0.02ng/g hair and 0.13±0.02ng/g hair, respectively. Aldosterone was below limit of detection (LODpolar bears was consistent with cortisol levels previously determined in the Southern Hudson Bay and James Bay in Canada using ELISA kits. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Bone protein extraction without demineralization using principles from hydroxyapatite chromatography.

    Science.gov (United States)

    Cleland, Timothy P; Vashishth, Deepak

    2015-03-01

    Historically, extraction of bone proteins has relied on the use of demineralization to better retrieve proteins from the extracellular matrix; however, demineralization can be a slow process that restricts subsequent analysis of the samples. Here, we developed a novel protein extraction method that does not use demineralization but instead uses a methodology from hydroxyapatite chromatography where high concentrations of ammonium phosphate and ammonium bicarbonate are used to extract bone proteins. We report that this method has a higher yield than those with previously published small-scale extant bone extractions, with and without demineralization. Furthermore, after digestion with trypsin and subsequent high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis, we were able to detect several extracellular matrix and vascular proteins in addition to collagen I and osteocalcin. Our new method has the potential to isolate proteins within a short period (4h) and provide information about bone proteins that may be lost during demineralization or with the use of denaturing agents. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Confirmatory analysis method for zeranol, its metabolites and related mycotoxins in urine by liquid chromatography-negative ion electrospray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bennekom, E.O. van; Brouwer, L.; Laurant, E.H.M.; Hooijerink, H.; Nielen, M.W.F

    2002-11-25

    The determination of the banned anabolic substance zeranol and the metabolites taleranol and zearalanone in bovine urine is complicated by the occurrence of the structurally-related mycotoxin zearalenone and the corresponding {alpha}- and {beta}-zearalenol metabolites which possess similar estrogenic properties. A liquid chromatography-negative ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of all six resorcylic acid lactones ('zeranols') in urine samples using deuterium-labelled internal standards. The method was validated as a confirmatory method for bovine urine samples according to new draft EU guidelines and showed good precision and linearity, and CC{alpha} and CC{beta} values of 0.02-0.30 and <1.0 ng ml{sup -1}, respectively. The applicability was demonstrated by comparing the results of an incurred sample with previous results on the same sample obtained by gas chromatography high resolution mass spectrometry. Preliminary data show that following a simple matrix solid phase dispersion clean-up, liver samples from poultry will be amenable to this method as well.

  3. Development and validation of an high-performance liquid chromatography-diode array detector method for the simultaneous determination of six phenolic compounds in abnormal savda munziq decoction

    Science.gov (United States)

    Tian, Shuge; Liu, Wenxian; Liu, Feng; Zhang, Xuejia; Upur, Halmuart

    2015-01-01

    Aims: Given the high-effectiveness and low-toxicity of abnormal savda munziq (ASMQ), its herbal formulation has long been used in traditional Uyghur medicine to treat complex diseases, such as cancer, diabetes, and cardiovascular diseases. Settings and Design: ASMQ decoction by reversed-phase high-performance liquid chromatography coupled with a diode array detector was successfully developed for the simultaneous quality assessment of gallic acid, protocatechuic acid, caffeic acid, rutin, rosmarinic acid, and luteolin. The six phenolic compounds were separated on an Agilent TC-C18 reversed-phase analytical column (4.6 × 250 mm, 5 μm) by gradient elution using 0.3% aqueous formic acid (v/v) and 0.3% methanol formic acid (v/v) at 1.0 mL/min. Materials and Methods: The plant material was separately ground and mixed at the following ratios (10): Cordia dichotoma (10.6), Anchusa italic (10.6), Euphorbia humifusa (4.9), Adiantum capillus-veneris (4.9), Ziziphus jujube (4.9), Glycyrrhiza uralensis (7.1), Foeniculum vulgare (4.9), Lavandula angustifolia (4.9), Dracocephalum moldavica L. (4.9), and Alhagi pseudoalhagi (42.3). Statistical Analysis Used: The precisions of all six compounds were Highly significant linear correlations were found between component concentrations and specific chromatographic peak areas (R2 > 0.999). Results: The proposed method was successfully applied to determine the levels of six active components in ASMQ. Conclusions: Given the simplicity, precision, specificity, and sensitivity of the method, it can be utilized as a quality control approach to simultaneously determining the six phenolic compounds in AMSQ. PMID:25709227

  4. Development of a new microextraction method based on elevated temperature dispersive liquid-liquid microextraction for determination of triazole pesticides residues in honey by gas chromatography-nitrogen phosphorus detection.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Mogaddam, Mohammad Reza Afshar; Ghorbanpour, Houshang

    2014-06-20

    In the present study, a rapid, highly efficient, and reliable sample preparation method named "elevated temperature dispersive liquid-liquid microextraction" followed by gas chromatography-nitrogen-phosphorus detection was developed for the extraction, preconcentration, and determination of five triazole pesticides (penconazole, hexaconazole, diniconazole, tebuconazole, and difenoconazole) in honey samples. In this method the temperature of high-volume aqueous phase was adjusted at an elevated temperature and then a disperser solvent containing an extraction solvent was rapidly injected into the aqueous phase. After cooling to room temperature, the phase separation was accelerated by centrifugation. Various parameters affecting the extraction efficiency such as type and volume of the extraction and disperser solvents, temperature, salt addition, and pH were evaluated. Under the optimum extraction conditions, the method resulted in low limits of detection and quantification within the range 0.05-0.21ngg(-1) in honey (15-70ngL(-1) in solution) and 0.15-1.1ngg(-1) in honey (45-210ngL(-1) in solution), respectively. Enrichment factors and extraction recoveries were in the ranges of 1943-1994 and 97-100%, respectively. The method precision was evaluated at 1.5ngg(-1) of each analyte, and the relative standard deviations were found to be less than 4% for intra-day (n=6) and less than 6% for inter-days. The method was successfully applied to the analysis of honey samples and difenoconazole was determined at ngg(-1) levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Recent development of ionic liquid stationary phases for liquid chromatography.

    Science.gov (United States)

    Shi, Xianzhe; Qiao, Lizhen; Xu, Guowang

    2015-11-13

    Based on their particular physicochemical characteristics, ionic liquids have been widely applied in many fields of analytical chemistry. Many types of ionic liquids were immobilized on a support like silica or monolith as stationary phases for liquid chromatography. Moreover, different approaches were developed to bond covalently ionic liquids onto the supporting materials. The obtained ionic liquid stationary phases show multi-mode mechanism including hydrophobic, hydrophilic, hydrogen bond, anion exchange, π-π, and dipole-dipole interactions. Therefore, they could be used in different chromatographic modes including ion-exchange, RPLC, NPLC and HILIC to separate various classes of compounds. This review mainly summarizes the immobilized patterns and types of ionic liquid stationary phases, their retention mechanisms and applications in the recent five years. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Thin-layer chromatography - liquid chromatography, an ideal supplement demonstrated by the separation of lanthanoids

    International Nuclear Information System (INIS)

    Specker, H.; Hufnagel, A.

    1984-01-01

    All lanthanoids have been separated by thin-layer chromatography (TLC) with short retention times by using a mixture of ether/tetrahydrofurane (THF)/bis-(2-ethylhexyl)-phosphate (HDEHP)/nitric acid. The eluent was empirically tested by synergistic effects. The results have been transferred to high-performance liquid chromatography /HPLC). It was possible to use the same eluent in TLC and HPLC both for the analytical separation of all lanthanoids and for the separation of fission products. The experimental experience gained in HPLC could be applied to the pre-concentration of isotopes in TLC. Both methods excellently supplemented each other in the separation of lanthanoids. (orig.) [de

  7. A rapid method for simultaneous determination of 52 marker compounds in Xiao-Qing-Long-Tang by ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Zhou, Lei; Qi, Wen; Xu, Cong; Makino, Toshiaki; Yuan, Dan

    2014-11-01

    Xiao-Qing-Long-Tang (XQLT) is a classical Chinese medicine formula. It is generally used for the treatment of common cold, bronchial asthma, and allergic rhinitis in Asia. In this study, a multicomponent quantification fingerprinting approach based on ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry has been developed for the analysis of compounds in XQLT in 14.5 min. A total of 52 compounds were identified by co-chromatography of sample extract with authentic standards and comparing the retention time, UV spectra, molecular ions and characteristic fragment ions with those of authentic standards, or tentatively identified by MS(E) determination along with Mass Fragment software. Moreover, the method was validated for the simultaneous quantification of 16 components in XQLT commercial products. The method is practical for comprehensive standardization of XQLT and holistic comparison of its commercial products from different manufacturers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. The analysis of aqueous mixtures using liquid chromatography-electrospray mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Steven [Iowa State Univ., Ames, IA (United States)

    1999-02-12

    The focus of this dissertation is the use of chromatographic methods coupled with electrospray mass spectrometry (ES-MS) for the determination of both organic and inorganic compounds in aqueous solutions. The combination of liquid chromatography (LC) methods and ES-MS offers one of the foremost methods for determining compounds in complex aqueous solutions. In this work, LC-ES-MS methods are devised using ion exclusion chromatography, reversed phase chromatography, and ion exchange chromatography, as well as capillary electrophoresis (CE). For an aqueous sample, these LC-ES-MS and CE-ES-MS techniques require no sample preparation or analyte derivatization, which makes it possible to observe a wide variety of analytes as they exist in solution. The majority of this work focuses on the use of LC-ES-MS for the determination of unknown products and intermediates formed during electrochemical incineration (ECI), an experimental waste remediation process. This report contains a general introduction to the project and the general conclusions. Four chapters have been removed for separate processing. Titles are: Chapter 2: Determination of small carboxylic acids by ion exclusion chromatography with electrospray mass spectrometry; Chapter 3: Electrochemical incineration of benzoquinone in aqueous media using a quaternary metal oxide electrode in the absence of a soluble supporting electrolyte; Chapter 4: The determination of electrochemical incineration products of 4-chlorophenol by liquid chromatography-electrospray mass spectrometry; and Chapter 5: Determination of small carboxylic acids by capillary electrophoresis with electrospray mass spectrometry.

  9. Simultaneous quantitative analysis of metabolites using ion-pair liquid chromatography-electrospray ionization mass spectrometry

    NARCIS (Netherlands)

    Coulier, L.; Bas, R.; Jespersen, S.; Verheij, E.; Werf, M.J. van der; Hankemeier, T.

    2006-01-01

    We have developed an analytical method, consisting of ion-pair liquid chromatography coupled to electrospray ionization mass spectrometry (IP-LC-ESI-MS), for the simultaneous quantitative analysis of several key classes of polar metabolites, like nucleotides, coenzyme A esters, sugar nucleotides,

  10. Method development for determination of herbicides and insecticides in surface waters using solid-phase extraction and high performance liquid chromatography

    International Nuclear Information System (INIS)

    Lebre, Daniel Temponi

    2000-01-01

    Determination of low concentrations of pesticides in surface and ground waters requires high sensitivity analytical techniques. Solid-Phase Extraction (SPE) has been successfully employed to pre concentrate and extract pesticides compounds from water samples. High Performance Liquid Chromatography (HPLC) coupled with UV/Vis detector was used to separate and quantify the extracted compounds. In this work, samples of surface waters with known concentrations of herbicides (atrazine, simazine and trifluralin) and insecticides (aldicarb, carbofuran and carbaryl) were extracted by using SPE off-line technique. The compounds were separated and quantified by reverse phase HPLC with UV detection at 220 ηm. The extraction efficiency was compared between two columns filled with different materials: C 18 -bonded silica phase (500 mg) and copolymer styrenedivynilbenzene resin (250 mg). The results were evaluated as the percent recovery of compounds obtained using different solvents at different concentrations. The results showed that recovery of the analytes greater than 80 % were obtained in SPE columns filled with C 18 bonded silica phase with 6 mL of acetonitrile. Once the optimum conditions were chosen for simulate water samples, the method was validated through analytical and statistical procedures and applied for surface waters. The suitability of the method was verified for the studied compounds showing good sensitivity, i. e., concentrations within the range of 0.4 to 4.0 μgL -1 of pesticides could be quantified attending the limits proposed by official regulations. (author)

  11. Validation of ascorbic acid tablets of national production by igh-performance liquid chromatography method

    International Nuclear Information System (INIS)

    Rodriguez Hernandez, Yaslenis; Suarez Perez, Yania; Izquierdo Castro, Idalberto

    2009-01-01

    We validate an analytical method by high-performance liquid chromatography to determine ascorbic acid proportion in vitamin C tablets, which was designed as an alternative method to quality control and to follow-up of active principle chemical stability, since official techniques to quality control of ascorbic acid in tablets are not selective with degradation products. Method was modified according to that reported in USP 28, 2005 for analysis of injectable product. We used a RP-18 column of 250 x 4.6 mm 5 μm with a UV detector to 245 nm. Its validation was necessary for both objectives, considering parameters required for methods of I and II categories. This method was enough linear, exact, and precise in the rank of 100-300 μg/mL. Also, it was selective with remaining components of matrix and with the possible degradation products achieved in stressing conditions. Detection and quantification limits were estimated. When method was validated it was applied to ascorbic acid quantification in two batches of expired tablets and we detected a marked influence of container in active degradation principle after 12 months at room temperature. (Author)

  12. A sensitive and selective liquid chromatography/tandem mass spectrometry method for quantitative analysis of efavirenz in human plasma.

    Directory of Open Access Journals (Sweden)

    Praveen Srivastava

    Full Text Available A selective and a highly sensitive method for the determination of the non-nucleoside reverse transcriptase inhibitor (NNRTI, efavirenz, in human plasma has been developed and fully validated based on high performance liquid chromatography tandem mass spectrometry (LC-MS/MS. Sample preparation involved protein precipitation followed by one to one dilution with water. The analyte, efavirenz was separated by high performance liquid chromatography and detected with tandem mass spectrometry in negative ionization mode with multiple reaction monitoring. Efavirenz and ¹³C₆-efavirenz (Internal Standard, respectively, were detected via the following MRM transitions: m/z 314.20243.90 and m/z 320.20249.90. A gradient program was used to elute the analytes using 0.1% formic acid in water and 0.1% formic acid in acetonitrile as mobile phase solvents, at a flow-rate of 0.3 mL/min. The total run time was 5 min and the retention times for the internal standard (¹³C₆-efavirenz and efavirenz was approximately 2.6 min. The calibration curves showed linearity (coefficient of regression, r>0.99 over the concentration range of 1.0-2,500 ng/mL. The intraday precision based on the standard deviation of replicates of lower limit of quantification (LLOQ was 9.24% and for quality control (QC samples ranged from 2.41% to 6.42% and with accuracy from 112% and 100-111% for LLOQ and QC samples. The inter day precision was 12.3% and 3.03-9.18% for LLOQ and quality controls samples, and the accuracy was 108% and 95.2-108% for LLOQ and QC samples. Stability studies showed that efavirenz was stable during the expected conditions for sample preparation and storage. The lower limit of quantification for efavirenz was 1 ng/mL. The analytical method showed excellent sensitivity, precision, and accuracy. This method is robust and is being successfully applied for therapeutic drug monitoring and pharmacokinetic studies in HIV-infected patients.

  13. Method transfer from high-pressure liquid chromatography to ultra-high-pressure liquid chromatography. II. Temperature and pressure effects.

    Science.gov (United States)

    Åsberg, Dennis; Samuelsson, Jörgen; Leśko, Marek; Cavazzini, Alberto; Kaczmarski, Krzysztof; Fornstedt, Torgny

    2015-07-03

    The importance of the generated temperature and pressure gradients in ultra-high-pressure liquid chromatography (UHPLC) are investigated and compared to high-pressure liquid chromatography (HPLC). The drug Omeprazole, together with three other model compounds (with different chemical characteristics, namely uncharged, positively and negatively charged) were used. Calculations of the complete temperature profile in the column at UHPLC conditions showed, in our experiments, a temperature difference between the inlet and outlet of 16 °C and a difference of 2 °C between the column center and the wall. Through van't Hoff plots, this information was used to single out the decrease in retention factor (k) solely due to the temperature gradient. The uncharged solute was least affected by temperature with a decrease in k of about 5% while for charged solutes the effect was more pronounced, with k decreases up to 14%. A pressure increase of 500 bar gave roughly 5% increase in k for the uncharged solute, while omeprazole and the other two charged solutes gave about 25, 20 and 15% increases in k, respectively. The stochastic model of chromatography was applied to estimate the dependence of the average number of adsorption/desorption events (n) and the average time spent by a molecule in the stationary phase (τs) on temperature and pressure on peak shape for the tailing, basic solute. Increasing the temperature yielded an increase in n and decrease in τs which resulted in less skew at high temperatures. With increasing pressure, the stochastic modeling gave interesting results for the basic solute showing that the skew of the peak increased with pressure. The conclusion is that pressure effects are more pronounced for both retention and peak shape than the temperature effects for the polar or charged compounds in our study. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Simultaneous determination of ascorbic acid and caffeine in commercial soft drinks using reversed-phase ultraperformance liquid chromatography.

    Science.gov (United States)

    Turak, Fatma; Güzel, Remziye; Dinç, Erdal

    2017-04-01

    A new reversed-phase ultraperformance liquid chromatography method with a photodiode array detector was developed for the quantification of ascorbic acid (AA) and caffeine (CAF) in 11 different commercial drinks consisting of one energy drink and 10 ice tea drinks. Separation of the analyzed AA and CAF with an internal standard, caffeic acid, was performed on a Waters BEH C 18 column (100 mm × 2.1 mm, 1.7 μm i.d.), using a mobile phase consisting of acetonitrile and 0.2M H 3 PO 4 (11:89, v/v) with a flow rate of 0.25 mL/min and an injection volume of 1.0 μL. Calibration graphs for AA and CAF were computed from the peak area ratio of AA/internal standard and CAF/internal standard detected at 244.0 nm and 273.6 nm, respectively. The developed reversed-phase ultraperformance liquid chromatography method was validated by analyzing standard addition samples. The proposed reversed-phase ultraperformance liquid chromatography method gave us successful results for the quantitative analysis of commercial drinks containing AA and CAF substances. Copyright © 2016. Published by Elsevier B.V.

  15. Simultaneous determination of ascorbic acid and caffeine in commercial soft drinks using reversed-phase ultraperformance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Fatma Turak

    2017-04-01

    Full Text Available A new reversed-phase ultraperformance liquid chromatography method with a photodiode array detector was developed for the quantification of ascorbic acid (AA and caffeine (CAF in 11 different commercial drinks consisting of one energy drink and 10 ice tea drinks. Separation of the analyzed AA and CAF with an internal standard, caffeic acid, was performed on a Waters BEH C18 column (100 mm × 2.1 mm, 1.7 μm i.d., using a mobile phase consisting of acetonitrile and 0.2M H3PO4 (11:89, v/v with a flow rate of 0.25 mL/min and an injection volume of 1.0 μL. Calibration graphs for AA and CAF were computed from the peak area ratio of AA/internal standard and CAF/internal standard detected at 244.0 nm and 273.6 nm, respectively. The developed reversed-phase ultraperformance liquid chromatography method was validated by analyzing standard addition samples. The proposed reversed-phase ultraperformance liquid chromatography method gave us successful results for the quantitative analysis of commercial drinks containing AA and CAF substances.

  16. Comparison of different cleanup procedures for oil crops based on the development of a trace analytical method for the determination of pyraclostrobin and epoxiconazole.

    Science.gov (United States)

    Pan, Xinglu; Dong, Fengshou; Xu, Jun; Liu, Xingang; Cheng, Youpu; Chen, Zenglong; Liu, Na; Chen, Xixi; Tao, Yan; Zheng, Yongquan

    2014-12-01

    The effects of different cleanup procedures in removing high-molecular-mass lipids and natural colorants from oil-crop extracts, including dispersive solid-phase extraction, low-temperature precipitation and gel permeation chromatography, were studied. The pigment removal, lipid quantity, and matrix effects of the three cleanup methods were evaluated. Results indicated that the gel permeation chromatography method is the most effective way to compare the dispersive solid-phase extraction and low-temperature precipitation. Pyraclostrobin and epoxiconazole applied extensively in oil-crop production were selected as typical pesticides to study and a trace analytical method was developed by gel permeation chromatography and ultra high performance liquid chromatography with tandem mass spectrometry. Average recoveries of the target pesticides at three levels (10, 50, and 100 μg/kg) were in the range of 74.7-96.8% with relative standard deviation values below 9.2%. The limits of detection did not exceed 0.46 μg/kg, whereas the limits of quantification were below 1.54 μg/kg and much lower than maximum residue limit in all matrices. This study may provide the essential data for optimizing the analytical method of pesticides in oil-crop samples. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Analysis of catecholamines in urine by unique LC/MS suitable ion-pairing chromatography.

    Science.gov (United States)

    Bergmann, Marianne L; Sadjadi, Seyed; Schmedes, Anne

    2017-07-01

    The catecholamines, epinephrine (E) and norepinephrine (NE) are small polar, hydrophilic molecules, posing significant challenges to liquid chromatography - tandem mass spectrometry (LC-MS/MS) method development. Specifically, these compounds show little retention on conventional reversed-phase liquid chromatography columns. This work presents development and validation of an LC-MS/MS method for determining catecholamines in urine, based on a new approach to ion-pairing chromatography (IPC), in which the ion-pairing reagent (IPR), 1-Heptane Sulfonic Acid (HSA), is added to the extracted samples instead of the mobile phases. A Hamilton STARlet workstation carried out the solid phase extraction of urine samples. The extracted samples were diluted with 60mmol/L HSA and injected on a Kinetex core-shell biphenyl column with conventional LC-MS/MS suitable mobile phases. Chromatographic separation of E and NE was achieved successfully with very stable retention times (RT). In 484 injections, the RTs were steady with a CV of less than ±4%. Furthermore, HSA was separated from E and NE, allowing HSA to be diverted to waste instead of entering the mass spectrometer ion chamber. The method was validated with good analytical performance, and even though the analysis for urinary catecholamines is increasingly being replaced by plasma free metanephrines in diagnosing pheochromocytomas, this work represents the application of a new analytical technique that can be transferred to other small polar molecules, that are difficult to chromatograph on traditional reversed phase columns. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Liquid-adsorption chromatography of metal 8-hydroxyquinolinates

    International Nuclear Information System (INIS)

    Basova, E.M.; Bol'shova, T.A.; Shirshova, T.S.

    1988-01-01

    Using the method of liquid-adsorption chromatography separation of 8-hydroxyquinolinates of Cu, Fe, Ga, In, Al, Ni is realized. Thin-layer chromatography (TLC) is used to define the optimum conditions of separation and highly efficient liquid column chromatography (HELC) - for chelate separation. Applicaton of the same sorbent is a very important condition of transition from TLC to HELC. Solica gel Partisil, mobile phase: benzene - isopropanol mixture, containing 1 x 10 -3 M of 8-hydroxyquinoline, are the optimal conditions for the studied chelates separation. But In and Ga in TLC move together, and in HELC they are partially separated, therefore, for their separation the column selectivity should be improved by selection of mobile phase

  19. Selective data reduction in gas chromatography/infrared spectrometry

    International Nuclear Information System (INIS)

    Pyo, Dong Jin; Shin, Hyun Du

    2001-01-01

    As gas chromatography/infrared spectrometry (GC/IR) becomes routinely available, methods must be developed to deal with the large amount of data produced. We demonstrate computer methods that quickly search through a large data file, locating those spectra that display a spectral feature of interest. Based on a modified library search routine, these selective data reduction methods retrieve all or nearly all of the compounds of interest, while rejection the vast majority of unrelated compounds. To overcome the shifting problem of IR spectra, a search method of moving the average pattern was designed. In this moving pattern search, the average pattern of a particular functional group was not held stationary, but was allowed to be moved a little bit right and left

  20. Activity ranking of synthetic analogs targeting vascular endothelial growth factor receptor 2 by an integrated cell membrane chromatography system.

    Science.gov (United States)

    Wang, Dongyao; Lv, Diya; Chen, Xiaofei; Liu, Yue; Ding, Xuan; Jia, Dan; Chen, Langdong; Zhu, Zhenyu; Cao, Yan; Chai, Yifeng

    2015-12-01

    Evaluating the biological activities of small molecules represents an important part of the drug discovery process. Cell membrane chromatography (CMC) is a well-developed biological chromatographic technique. In this study, we have developed combined SMMC-7721/CMC and HepG2/CMC with high-performance liquid chromatography and time-of-flight mass spectrometry to establish an integrated screening platform. These systems was subsequently validated and used for evaluating the activity of quinazoline compounds, which were designed and synthesized to target vascular endothelial growth factor receptor 2. The inhibitory activities of these compounds towards this receptor were also tested using a classical caliper mobility shift assay. The results revealed a significant correlation between these two methods (R(2) = 0.9565 or 0.9420) for evaluating the activities of these compounds. Compared with traditional methods of evaluating the activities analogous compounds, this integrated cell membrane chromatography screening system took less time and was more cost effective, indicating that it could be used as a practical method in drug discovery. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Liquid chromatography and liquid chromatography-mass spectrometry analysis of donepezil degradation products

    Directory of Open Access Journals (Sweden)

    Mladenović Aleksandar R.

    2015-01-01

    Full Text Available This study describes the investigation of degradation products of donepezil (DP using stability indicating RP-HPLC method for determination of donepezil, which is a centrally acting reversible acetylcholinesterase inhibitor. In order to investigate the stability of drug and formed degradation products, a forced degradation study of drug sample and finished product under different forced degradation conditions has been conducted. Donepezil hydrochloride and donepezil tablets were subjected to stress degradation conditions recommended by International Conference on Harmonization (ICH. Donepezil hydrochloride solutions were subjected to acid and alkali hydrolysis, chemical oxidation and thermal degradation. Significant degradation was observed under alkali hydrolysis and oxidative degradation conditions. Additional degradation products were observed under the conditions of oxidative degradation. The degradation products observed during forced degradation studies were monitored using the high performance liquid chromatography (HPLC method developed. The parent method was modified in order to obtain LC-MS compatible method which was used to identify the degradation products from forced degradation samples using high resolution mass spectrometry. The mass spectrum provided the precise mass from which derived molecular formula of drug substance and degradation products formed and proved the specificity of the method unambiguously. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  2. Compound-Specific Chlorine Isotope Analysis of Tetrachloromethane and Trichloromethane by Gas Chromatography-Isotope Ratio Mass Spectrometry vs Gas Chromatography-Quadrupole Mass Spectrometry: Method Development and Evaluation of Precision and Trueness.

    Science.gov (United States)

    Heckel, Benjamin; Rodríguez-Fernández, Diana; Torrentó, Clara; Meyer, Armin; Palau, Jordi; Domènech, Cristina; Rosell, Mònica; Soler, Albert; Hunkeler, Daniel; Elsner, Martin

    2017-03-21

    Compound-specific chlorine isotope analysis of tetrachloromethane (CCl 4 ) and trichloromethane (CHCl 3 ) was explored by both, gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and GC-quadrupole MS (GC-qMS), where GC-qMS was validated in an interlaboratory comparison between Munich and Neuchâtel with the same type of commercial GC-qMS instrument. GC-IRMS measurements analyzed CCl isotopologue ions, whereas GC-qMS analyzed the isotopologue ions CCl 3 , CCl 2 , CCl (of CCl 4 ) and CHCl 3 , CHCl 2 , CHCl (of CHCl 3 ), respectively. Lowest amount dependence (good linearity) was obtained (i) in H-containing fragment ions where interference of 35 Cl- to 37 Cl-containing ions was avoided; (ii) with tuning parameters favoring one predominant rather than multiple fragment ions in the mass spectra. Optimized GC-qMS parameters (dwell time 70 ms, 2 most abundant ions) resulted in standard deviations of 0.2‰ (CHCl 3 ) and 0.4‰ (CCl 4 ), which are only about twice as large as 0.1‰ and 0.2‰ for GC-IRMS. To compare also the trueness of both methods and laboratories, samples from CCl 4 and CHCl 3 degradation experiments were analyzed and calibrated against isotopically different reference standards for both CCl 4 and CHCl 3 (two of each). Excellent agreement confirms that true results can be obtained by both methods provided that a consistent set of isotopically characterized reference materials is used.

  3. Development of a new rapid HPLC method for the fractionation of histones

    International Nuclear Information System (INIS)

    Gurley, L.R.; Valdez, J.G.; Prentice, D.A.; Spall, W.D.

    1983-01-01

    To study histone functions, it is necessary to fractionate the histones into their five classes (H1, H2A, H2B, H3 and H4) and then to subfractionate these classes into variants having slightly different primary structures and into different phosphorylated and acetylated forms. With the advent of high-performance liquid chromatography (HPLC), it was hoped that laborious and time-consuming conventional methods could be replaced by a simple, rapid, high-resolving HPLC method for fractionating histones. However, problems of irreversible adsorption of the histones to HPLC column packings discouraged this development. Our laboratory has now determined that the strong adsorption of histones to HPLC columns results from two different forces: (1) polar interactions between the histones and the silanol groups of silica-based HPLC column packing, and (2) hydrophobic interactions between the histones and the bound organic phase of the column packings. By minimizing these forces, we have succeeded in developing an HPLC method suitable for histone studies

  4. Development and validation of a multiresidue method for pesticide analysis in honey by UFLC-MS

    Directory of Open Access Journals (Sweden)

    Adriana M. Zamudio S.

    2017-05-01

    Full Text Available A method for the determination of pesticide residues in honey by ultra fast liquid chromatography coupled with mass spectrometry was developed. For this purpose, different variations of the QuECHERS method were performed: (i amount of sample, (ii type of salt to control pH, (iii buffer pH, and (iv different mixtures for cleaning-up. In addition, to demonstrate that the method is reliable, different validation parameters were studied: accuracy, limits of detection and quantification, linearity and selectivity. The results showed that by means of the changes introduced it was possible to get a more selective method that improves the accuracy of about 19 pesticides selected from the original method. It was found that the method is suitable for the analysis of 50 pesticides, out of 56. Furthermore, with the developed method recoveries between 70 and 120% and relative standard deviation below 15% were found.

  5. A liquid chromatography – tandem mass spectrometry method to measure a selected panel of uremic retention solutes derived from endogenous and colonic microbial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Loor, Henriette de; Poesen, Ruben [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); De Leger, Wout; Dehaen, Wim [KU Leuven – University of Leuven, Department of Chemistry, Division of Molecular Design and Synthesis, B-3000 Leuven (Belgium); Augustijns, Patrick [KU Leuven – University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Drug Delivery and Disposition, B-3000 Leuven (Belgium); Evenepoel, Pieter [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium); Meijers, Björn, E-mail: bjorn.meijers@uzleuven.be [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium)

    2016-09-14

    Chronic kidney disease (CKD) is associated with an increased risk of mortality and cardiovascular disease, which is, at least partly, mediated by the accumulation of so-called uremic retention solutes. Although there has been an increasing interest in the behavior of these solutes, derived from both the endogenous and colonic microbial metabolism, methods to simultaneously and accurately measure a broad panel of relevant uremic retention solutes remain scarce. We developed a highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. A high throughput sample preparation was used with extraction of analytes from 50 μl serum using Ostro plate technology. For most solutes, stable isotopes labelled metabolites were used as internal standards. Chromatography was achieved using an Acquity UPLC CSH Fluoro Phenyl column. The total run time was 8 min, the mobile phase was a gradient of 0.1% formic acid in Milli-Q water and pure methanol at a flow rate of 0.5 ml min{sup −1}. Detection was performed using a tandem mass spectrometer with alternated positive and negative electrospray ionization. Calibration curves were linear for all solutes. Precision was assessed according to the NCCLS EP5-T guideline, being below 15% for all metabolites. Mean recoveries were between 83 and 104% for all metabolites. The validated method was successfully applied in a cohort of 488 patients with CKD. We developed and validated a sensitive and robust UPLC-MS/MS method for quantification of 15 uremic retention solutes derived from endogenous and colonic microbial metabolism. This method allows for studying the behavior and relevance of these solutes in patients with CKD. - Highlights: • Simultaneous quantification of fifteen relevant uremic retention solutes. • Comprehensive validation, highly sensitive and high through-put LC-MSMS method. • Comparison of different blood tubes. • Freeze-thaw stability. • Successful implementation in a

  6. CHARACTERIZATION OF DANSYLATED CYSTEINE, GLUTATHIONE DISULFIDE, CYSTEINE AND CYSTINE BY NARROW BORE LIQUID CHROMATOGRAPHY/ELECTROSPRAY IONIZATION MASS SPECTROMETRY

    Science.gov (United States)

    A method using reversed phase high performance liquid chromatography/electrospray ionization-mass spectrometric (RP-LC/ESI-MS) method has been developed to confirm the identity of dansylated derivatives of cysteine and glutathione, and their respective dimers. Cysteine, GSH, CSSC...

  7. Sensitive liquid chromatography-tandem mass spectrometry method for quantification of hydrochlorothiazide in human plasma.

    Science.gov (United States)

    Ramakrishna, N V S; Vishwottam, K N; Manoj, S; Koteshwara, M; Wishu, S; Varma, D P

    2005-12-01

    A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of hydrochlorothiazide (I), a common diuretic and anti-hypertensive agent. The analyte and internal standard, tamsulosin (II) were extracted by liquid-liquid extraction with diethyl ether-dichloromethane (70:30, v/v) using a Glas-Col Multi-Pulse Vortexer. The chromatographic separation was performed on a reversed-phase column (Waters symmetry C18) with a mobile phase of 10 mm ammonium acetate-methanol (15:85, v/v). The protonated analyte was quantitated in negative ionization by multiple reaction monitoring with a mass spectrometer. The mass transitions m/z 296.1 solidus in circle 205.0 and m/z 407.2 solidus in circle 184.9 were used to measure I and II, respectively. The assay exhibited a linear dynamic range of 0.5-200 ng/mL for hydrochlorothiazide in human plasma. The lower limit of quantitation was 500 pg/mL, with a relative standard deviation of less than 9%. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. A run time of 2.5 min for each sample made it possible to analyze a throughput of more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. (c) 2005 John Wiley & Sons, Ltd.

  8. Development of method for determination of Sodium monochloroacetate and sodium dichloroacetate in Cocoamido Propyl Betaine by gas chromatography: FID, ECD and MS

    International Nuclear Information System (INIS)

    Leao, Claudio; Redigolo, Marcelo Miyada; Amaral, Priscila Oliveira; Bustillos, Oscar Vega

    2015-01-01

    Cocoamide Propyl Betaine is a feedstock for consumer products of cosmetic and household segments. Sodium monochloroacetate and sodium dichloroacetate impurities are toxic, irritating and harmful to the environment and lower concentrations - parts per million level - are required in process control of producers and regulatory affairs. Regarding analytical test method, two conditions should be met: quantification limit, precision and accuracy should be appropriate; different techniques for gas chromatography - ECD, FID and MS - should be available, since for manufacturer is not so easy to keep electron capture detector by radioactive source Ni 63 due to government control and need of qualified radiological protection. The samples are obtained at manufacturers; for the analyte separation, treatment methodologies are employed by liquid-liquid extraction and solid phase extraction. Alternative detectors used in this study are: Flame Ionization and Mass Spectrometer with Electron Ionization. The validation process will be applied to methodology to ensure a selective, robust, accurate and reproducible analytical determination. (author)

  9. Development of method for determination of Sodium monochloroacetate and sodium dichloroacetate in Cocoamido Propyl Betaine by gas chromatography: FID, ECD and MS

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Claudio; Redigolo, Marcelo Miyada; Amaral, Priscila Oliveira; Bustillos, Oscar Vega, E-mail: claudio.leao@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Cocoamide Propyl Betaine is a feedstock for consumer products of cosmetic and household segments. Sodium monochloroacetate and sodium dichloroacetate impurities are toxic, irritating and harmful to the environment and lower concentrations - parts per million level - are required in process control of producers and regulatory affairs. Regarding analytical test method, two conditions should be met: quantification limit, precision and accuracy should be appropriate; different techniques for gas chromatography - ECD, FID and MS - should be available, since for manufacturer is not so easy to keep electron capture detector by radioactive source Ni 63 due to government control and need of qualified radiological protection. The samples are obtained at manufacturers; for the analyte separation, treatment methodologies are employed by liquid-liquid extraction and solid phase extraction. Alternative detectors used in this study are: Flame Ionization and Mass Spectrometer with Electron Ionization. The validation process will be applied to methodology to ensure a selective, robust, accurate and reproducible analytical determination. (author)

  10. Hydrophilic interaction liquid chromatography-tandem mass spectrometry quantitative method for the cellular analysis of varying structures of gemini surfactants designed as nanomaterial drug carriers.

    Science.gov (United States)

    Donkuru, McDonald; Michel, Deborah; Awad, Hanan; Katselis, George; El-Aneed, Anas

    2016-05-13

    Diquaternary gemini surfactants have successfully been used to form lipid-based nanoparticles that are able to compact, protect, and deliver genetic materials into cells. However, what happens to the gemini surfactants after they have released their therapeutic cargo is unknown. Such knowledge is critical to assess the quality, safety, and efficacy of gemini surfactant nanoparticles. We have developed a simple and rapid liquid chromatography electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the quantitative determination of various structures of gemini surfactants in cells. Hydrophilic interaction liquid chromatography (HILIC) was employed allowing for a short simple isocratic run of only 4min. The lower limit of detection (LLOD) was 3ng/mL. The method was valid to 18 structures of gemini surfactants belonging to two different structural families. A full method validation was performed for two lead compounds according to USFDA guidelines. The HILIC-MS/MS method was compatible with the physicochemical properties of gemini surfactants that bear a permanent positive charge with both hydrophilic and hydrophobic elements within their molecular structure. In addition, an effective liquid-liquid extraction method (98% recovery) was employed surpassing previously used extraction methods. The analysis of nanoparticle-treated cells showed an initial rise in the analyte intracellular concentration followed by a maximum and a somewhat more gradual decrease of the intracellular concentration. The observed intracellular depletion of the gemini surfactants may be attributable to their bio-transformation into metabolites and exocytosis from the host cells. Obtained cellular data showed a pattern that grants additional investigations, evaluating metabolite formation and assessing the subcellular distribution of tested compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Multiclass mycotoxin analysis in edible oils using a simple solvent extraction method and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Eom, Taeyong; Cho, Hyun-Deok; Kim, Junghyun; Park, Mihee; An, Jinyoung; Kim, Moosung; Kim, Sheen-Hee; Han, Sang Beom

    2017-11-01

    A simple and rapid method for the simultaneous determination of 11 mycotoxins - aflatoxins B 1 , B 2 , G 1 and G 2 ; fumonisins B 1 , B 2 and B 3 ; ochratoxin A; zearalenone; deoxynivalenol; and T-2 toxin - in edible oils was established using liquid chromatography tandem mass spectrometry (LC-MS/MS). In this study, QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe), QuEChERS with dispersive liquid-liquid microextraction, and solvent extraction were examined for sample preparation. Among these methods, solvent extraction with a mixture of formic acid/acetonitrile (5/95, v/v) successfully extracted all target mycotoxins. Subsequently, a defatting process using n-hexane was employed to remove the fats present in the edible oil samples. Mass spectrometry was carried out using electrospray ionisation in polarity switching mode with multiple reaction monitoring. The developed LC-MS/MS method was validated by assessing the specificity, linearity, recovery, limit of quantification (LOQ), accuracy and precision with reference to Commission Regulation (EC) 401/2006. Mycotoxin recoveries of 51.6-82.8% were achieved in addition to LOQs ranging from 0.025 ng/g to 1 ng/g. The edible oils proved to be relatively uncomplicated matrices and the developed method was applied to 9 edible oil samples, including soybean oil, corn oil and rice bran oil, to evaluate potential mycotoxin contamination. The levels of detection were significantly lower than the international regulatory standards. Therefore, we expect that our developed method, based on simple, two-step sample preparation process, will be suitable for the large-scale screening of mycotoxin contamination in edible oils.

  12. Chemometric approach for development, optimization, and validation of different chromatographic methods for separation of opium alkaloids.

    Science.gov (United States)

    Acevska, J; Stefkov, G; Petkovska, R; Kulevanova, S; Dimitrovska, A

    2012-05-01

    The excessive and continuously growing interest in the simultaneous determination of poppy alkaloids imposes the development and optimization of convenient high-throughput methods for the assessment of the qualitative and quantitative profile of alkaloids in poppy straw. Systematic optimization of two chromatographic methods (gas chromatography (GC)/flame ionization detector (FID)/mass spectrometry (MS) and reversed-phase (RP)-high-performance liquid chromatography (HPLC)/diode array detector (DAD)) for the separation of alkaloids from Papaver somniferum L. (Papaveraceae) was carried out. The effects of various conditions on the predefined chromatographic descriptors were investigated using chemometrics. A full factorial linear design of experiments for determining the relationship between chromatographic conditions and the retention behavior of the analytes was used. Central composite circumscribed design was utilized for the final method optimization. By conducting the optimization of the methods in very rational manner, a great deal of excessive and unproductive laboratory research work was avoided. The developed chromatographic methods were validated and compared in line with the resolving power, sensitivity, accuracy, speed, cost, ecological aspects, and compatibility with the poppy straw extraction procedure. The separation of the opium alkaloids using the GC/FID/MS method was achieved within 10 min, avoiding any derivatization step. This method has a stronger resolving power, shorter analysis time, better cost/effectiveness factor than the RP-HPLC/DAD method and is in line with the "green trend" of the analysis. The RP-HPLC/DAD method on the other hand displayed better sensitivity for all tested alkaloids. The proposed methods provide both fast screening and an accurate content assessment of the six alkaloids in the poppy samples obtained from the selection program of Papaver strains.

  13. Comparative investigation of the gel chromatography column scanning method for quality control of /sup 99/sup(m)Tc-methylenediphosphonate

    Energy Technology Data Exchange (ETDEWEB)

    Darte, L

    1981-04-01

    Gel chromatography column scanning (GCS) is the method of choice for quality control of sup(99m)Tc-MDP preparations. Using this method all the labelled components are obtained rapidly in one simple test procedure. The influence of various parameters such as gel type, column size, prehistory of column, equilibration, eluent, elution volume and flow rate upon the results have been investigated. Test results for sup(99 m)Tc-MDP have been compared for several different GCS systems, a few TLC systems and column chromatography with fraction collection. The GCS technique, optimized for testing sup(99m)Tc-MDP preparations has been applied in a few experiments in which very good reproducibility is required: Labelling kinetics and stability when stored at room temperature or in a refrigerator and influence of the sup(99m)Te/(sup(99m)Tc + /sup 99/Tc) atomic ratio and of the amount of radioactivity on the sup(99m)Tc-MDP labelling yield, covering parameter ranges of clinical interest, have been studied.

  14. A novel liquid chromatography/mass spectrometry method for determination of neurotransmitters in brain tissue: Application to human tauopathies.

    Science.gov (United States)

    Forgacsova, Andrea; Galba, Jaroslav; Garruto, Ralph M; Majerova, Petra; Katina, Stanislav; Kovac, Andrej

    2018-01-15

    Neurotransmitters, small molecules widely distributed in the central nervous system are essential in transmitting electrical signals across neurons via chemical communication. Dysregulation of these chemical signaling molecules is linked to numerous neurological diseases including tauopathies. In this study, a precise and reliable liquid chromatography method was established with tandem mass spectrometry detection for the simultaneous determination of aspartic acid, asparagine, glutamic acid, glutamine, γ-aminobutyric acid, N-acetyl-l-aspartic acid, pyroglutamic acid, acetylcholine and choline in human brain tissue. The method was successfully applied to the analysis of human brain tissues from three different tauopathies; corticobasal degeneration, progressive supranuclear palsy and parkinsonism-dementia complex of Guam. Neurotransmitters were analyzed on ultra-high performance chromatography (UHPLC) using an ethylene bridged hybrid amide column coupled with tandem mass spectrometry (MS/MS). Identification and quantification of neurotransmitters was carried out by ESI+ mass spectrometry detection. We optimized sample preparation to achieve simple and fast extraction of all nine analytes. Our method exhibited an excellent linearity for all analytes (all coefficients of determination >0.99), with inter-day and intra-day precision yielding relative standard deviations 3.2%-11.2% and an accuracy was in range of 92.6%-104.3%. The present study, using the above method, is the first to demonstrate significant alterations of brain neurotransmitters caused by pathological processes in the brain tissues of patient with three different tauopathies. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Atmospheric pressure photoionisation : An ionization method for liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Robb, DB; Covey, TR; Bruins, AP

    2000-01-01

    Atmospheric pressure photoionization (APPI) has been successfully demonstrated to provide high sensitivity to LC-MS analysis. A vacuum-ultraviolet lamp designed for photoionization detection in gas chromatography is used as a source of 10-eV photons. The mixture of samples and solvent eluting from

  16. METHOD 544. DETERMINATION OF MICROCYSTINS AND NODULARIN IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS)

    Science.gov (United States)

    Method 544 is an accurate and precise analytical method to determine six microcystins (including MC-LR) and nodularin in drinking water using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC/MS/MS). The advantage of this SPE-LC/MS/MS is its sensi...

  17. Enantioselective analysis of drugs: contributions of high-performance liquid chromatography and capillary electrophoresis

    OpenAIRE

    Bonato, Pierina Sueli; Jabor, Valquíria Aparecida Polisel; Gaitani, Cristiane Masetto de

    2005-01-01

    The demand for analytical methods suitable for accurate and reproducible determination of drug enantiomers has increased significantly in the last years. High-performance liquid chromatography (HPLC) using chiral stationary phases and capillary electrophoresis (CE) are the most important techniques used for this purpose. In this paper, the fundamental aspects of chiral separations using both techniques are presented. Some important aspects for the development of enantioselective methods, part...

  18. Schinus terebinthifolius countercurrent chromatography (Part II): Intra-apparatus scale-up and inter-apparatus method transfer.

    Science.gov (United States)

    Costa, Fernanda das Neves; Vieira, Mariana Neves; Garrard, Ian; Hewitson, Peter; Jerz, Gerold; Leitão, Gilda Guimarães; Ignatova, Svetlana

    2016-09-30

    Countercurrent chromatography (CCC) is being widely used across the world for purification of various materials, especially in natural product research. The predictability of CCC scale-up has been successfully demonstrated using specially designed instruments of the same manufacturer. The reality is that the most of CCC users do not have access to such instruments and do not have enough experience to transfer methods from one CCC column to another. This unique study of three international teams is based on innovative approach to simplify the scale-up between different CCC machines using fractionation of Schinus terebinthifolius berries dichloromethane extract as a case study. The optimized separation methodology, recently developed by the authors (Part I), was repeatedly performed on CCC columns of different design available at most research laboratories across the world. Hexane - ethyl acetate - methanol - water (6:1:6:1, v/v/v/v) was used as solvent system with masticadienonic and 3β-masticadienolic acids as target compounds to monitor stationary phase retention and calculate peak resolution. It has been demonstrated that volumetric, linear and length scale-up transfer factors based on column characteristics can be directly applied to different i.d., volume and length columns independently on instrument make in an intra-apparatus scale-up and inter-apparatus method transfer. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Online hyphenation of extraction, Sephadex LH-20 column chromatography, and high-speed countercurrent chromatography: A highly efficient strategy for the preparative separation of andrographolide from Andrographis paniculata in a single step.

    Science.gov (United States)

    Zhang, Ying-Qi; Wang, Shan-Shan; Han, Chao; Xu, Jin-Fang; Luo, Jian-Guang; Kong, Ling-Yi

    2017-12-01

    A novel isolation strategy, online hyphenation of ultrasonic extraction, Sephadex LH-20 column chromatography combined with high-speed countercurrent chromatography, was developed for pure compounds extraction and purification. Andrographolide from Andrographis paniculata was achieved only in a single step purification protocol via the present strategy. The crude powder was ultrasonic extracted and extraction was pumped into Sephadex LH-20 column directly to cut the nontarget fractions followed by the second-dimensional high-speed countercurrent chromatography, hyphenated by a six-port valve equipped at the post-end of Sephadex LH-20 column, for the final purification. The results yielded andrographolide with the amount of 1.02 mg and a purity of 98.5% in a single step, indicating that the present method is effective to harvest target compound from medicinal plant. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Stationary phases for superheated water chromatography

    International Nuclear Information System (INIS)

    Saha, Shikha

    2002-01-01

    This project focused on the comparison of conventional liquid chromatography and superheated water chromatography. It examined the differences in efficiency and retention of a range of different stationary phases. Alkyl aryl ketones and eight aromatic compounds were separated on PBD-zirconia, Xterra RP 18, Luna C 18 (2) and Oasis HLB columns using conventional LC and superheated water chromatography system. The retention indices were determined in the different eluents. On changing the organic component of the eluent from methanol to acetonitrile to superheated water considerable improvements were found in the peak shapes and column efficiencies on the PBD-zirconia and Oasis HLB columns. PS-DVB, PBD-zirconia and Xterra RP 18 columns have been used in efficiency studies. It was found that simply elevating the column temperature did not increase the efficiency of a separation in superheated water chromatography. The efficiency depended on flow rate, injection volume and also mobile phase preheating system. Although high efficiencies were not achieved with superheated water on PS-DVB and Xterra RP 18 columns, a higher efficiency was achieved on a PBD-zirconia column with superheated water than with 25-35% ACN at room temperature. The proposed theoretical increases in u opt were measured on three columns using superheated water as the mobile phase. The application of the superheated water chromatographic method to the separation of the pungent constituents of ginger by superheated water chromatography-NMR coupling system was studied. The coupling of superheated water chromatography using deuterium oxide to NMR spectroscopy for the separation of dry ginger extract was successful, although the NMR sensitivity in on-line mode coupling system was low. However, four compounds were identified in the ginger extract by stop-flow mode on superheated water chromatography-UV-NMR detection system. (author)

  1. Virtual Practice of Biochemistry: Ascendant Chromatography on Paper of Amino acids.

    Directory of Open Access Journals (Sweden)

    G. Zanatta

    2010-05-01

    Full Text Available Chromatography is a method used for analyses of mixture components based on different criteria: adsorbility, solubility, molecular mass, ionic charge and affinity. It is an important subject of Biochemistry. This work reports the development and the validation of a software that simulated a laboratory activity named Ascendant Chromatography on Paper of Aminoacids. The organization and the multimedia material collection were done during the 2008/2 semester. The most representative images were inserted into the learning object. The tool used for the software development was Adobe® Flash® CS3. The first application of this object was in Biochemistry I (Pharmacy-UFRGS in 2009/1. Using this experience, a new version was developed which was tested by the students of the same subject in 2009/2. After a 50-minute class (theoretical-practical, the students of both semesters were divided in two groups. Group I answered a questionnaire about chromatography basic concepts and after used the software. Group II was submitted to an inverse protocol. The groups also evaluated the technical aspects of the software animation/simulation and the activity carried out. Associating both applications results (2009/1 and 2009/2, the present learning object can be valid as a support for practical teaching of basic biochemistry.

  2. Alternatives to Chromatography in Plant Breeding

    Directory of Open Access Journals (Sweden)

    Keusgen, Michael

    2016-07-01

    Full Text Available Wild plants were taken into cultivation because of special features. Usually, medicinal plants or spices show distinct secondary metabolites combined with a specific pattern of these compounds. Typically, chromatographic methods like gas chromatography (GC or high performance liquid chromatography (HPLC were applied as standard methods for a meaningful analysis of secondary metabolites. However, these methods are labor and time intensive. In the breeding process, usually numerous single plants have to be analyzed and therefore, high throughput methods are required. In this article, some examples for alternative strategies are given. Besides spectroscopic methods like near infrared (NIR, also biosensoric approaches should be considered. For instance, several enzymes can oxidize or hydrolyze secondary metabolites in dependence of their functional groups. Polyphenols can be determined by laccases. Polyphenols like catechins and flavonoids contribute to the bioactivity of many medicinal plants. Also cysteine sulfoxides, which are typical for Allium species like garlic and onions, can be enzymatically determined with high specificity. Finally, toxic cyanogenic glycosides can be quantified by the enzyme cyanidase.

  3. Radioanalytical determination of plutonium and americium using ion exchange and extraction chromatography technique in urine

    International Nuclear Information System (INIS)

    Santhanakrishnan, V.; Sreedevi, K.R.; Rajaram, S.; Ravi, P.M.

    2011-01-01

    The use of anion exchange chromatography for the separation of Pu and extraction chromatography technique for the separation of Am from urine samples was studied. In the earlier method, Pu separation was carried out by anion exchange chromatography followed by Am separation by cation exchange chromatography. The chemical recovery of Am obtained by cation exchange separation method was inconsistent and low in the range 30-70%. In this study, the average Pu recovery obtained using anion exchange chromatography was 89.2 with standard deviation of 10.4 and the average Am recovery obtained using extraction chromatography with TRU resin was 77.4 with standard deviation of 14.8. Moreover, Am separation could be completed within three hours using the TRU column compared to two days that were required for the cation exchange chromatography. (author)

  4. Recent developments in comprehensive two-dimensional gas chromatography (GC X GC) I. Introduction and instrumental set-up

    NARCIS (Netherlands)

    Adahchour, M.; Beens, J.; Vreuls, R.J.J.; Brinkman, U.A.T.

    2006-01-01

    We review the literature on comprehensive two-dimensional gas chromatography (GC × GC), emphasizing developments in the period 2003-2005. The review opens with a general introduction, the principles of the technique and the set-up of GC × GC systems. It also discusses theoretical aspects, trends in

  5. Liquid chromatography-electrospray ionization tandem mass spectrometry and dynamic multiple reaction monitoring method for determining multiple pesticide residues in tomato.

    Science.gov (United States)

    Andrade, G C R M; Monteiro, S H; Francisco, J G; Figueiredo, L A; Botelho, R G; Tornisielo, V L

    2015-05-15

    A quick and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method, using dynamic multiple reaction monitoring and a 1.8-μm particle size analytical column, was developed to determine 57 pesticides in tomato in a 13-min run. QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for samples preparations and validations was carried out in compliance with EU SANCO guidelines. The method was applied to 58 tomato samples. More than 84% of the compounds investigated showed limits of detection equal to or lower than 5 mg kg(-1). A mild (50%) matrix effect was observed for 72%, 25%, and 3% of the pesticides studied, respectively. Eighty-one percent of the pesticides showed recoveries ranging between 70% and 120%. Twelve pesticides were detected in 35 samples, all below the maximum residue levels permitted in the Brazilian legislation; 15 samples exceeded the maximum residue levels established by the EU legislation for methamidophos; and 10 exceeded limits for acephate and four for bromuconazole. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Gas chromatography analysisof organic compounds labelled with 14C and T

    International Nuclear Information System (INIS)

    Matukha, M.; Zhilka, L.; Khejze, K.-Kh.; Gehrner, Kh.

    1982-01-01

    Various methods of radio gas chromatography (RGC) including non-destructiveones are analyzed and compared as well as systems for their realization. The selected methods were verified in interlaboratory studies. The developed RGC-system produce a linear output signal proportional to the measured sample activity within 10 to 200 kBg. The system includes a nondestructive mass and radioactivity detector in series with combustion chamber of the effluent after TCD passage and 14 CO 2 absorber with ethanolamine. The activity of obtained solution is measured by means of liquid scintillation method [ru

  7. 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)

  8. New radiochemical methods for determination of 237Np a 241Pu using extraction chromatography (Presentation)

    International Nuclear Information System (INIS)

    Strisovska, J.

    2013-01-01

    Thesis was focused on the development of a new methodology for the separation of anthropogenic transuranium radionuclides 237 Np a 241 Pu from different kinds of matrices. The analytical methods used in this study were based on extraction chromatography and were optimized according to the sample type. The proposed radiochemical procedure is a combination of two algorithms, which represent the separation of radionuclides by using extraction chromatographic sorbents TEVA resin and TRU resin supplied by Eichrom Technologies LLC. 239 Np a 237 Np were selectively captured on sorbent TEVA resin in oxidation state 4+. TRU resin was used for purification of plutonium fraction from interfering americium radionuclide. 242 Pu and 239 Np radionuclides as tracers have been used to monitor the radiochemical yields of separation. Before every radiochemical separation tracer radionuclide 239 Np was obtained by separation from the parent radionuclide 2 43 Am, which is in radioactive equilibrium to 239 Np. The average yield of chemical separation was 69,3% for 239 Np at 277 keV energy line and 65,9% at 228 keV energy line. The NPL AH-B08069 (2008) samples which consist of the mixture of alpha-radionuclides were used for the modification and optimization of separation method used for separation of Np and Pu in model samples. This method provided high radiochemical yields of 239,240 Pu (95,0 ± 3,5)% and 237 Np (87,9 ± 3,0)%.. Reliability of the method was verified by applying our modified separation procedures on reference materials IAEA-375 and IAEA-414 supplied by International Atomic Energy Agency. A good agreement between the results is obtained by this procedure and the certified values were found. Samples of contaminated soils from the area of Nuclear power plant A-1 Jaslovske Bohunice which is stored temporarily before disposal were analyzed using developed separation procedure. Specific activity of investigated radionuclides was determined in these samples. (author)

  9. Separating esterase targets of organophosphorus compounds in the brain by preparative chromatography.

    Science.gov (United States)

    Mangas, I; Vilanova, E; Benabent, M; Estévez, J

    2014-02-10

    Low level exposure to organophosphorus esters (OPs) may cause long-term neurological effects and affect specific cognition domains in experimental animals and humans. Action on known targets cannot explain most of these effects by. Soluble carboxylesterases (EC 3.1.1.1) of chicken brain have been kinetically discriminated using paraoxon, mipafox and phenylmethyl sulfonylfluoride as inhibitors and phenyl valerate as a substrate. Three different enzymatic components were discriminated and called Eα, Eβ and Eγ. In this work, a fractionation procedure with various steps was developed using protein native separation methods by preparative HPLC. Gel permeation chromatography followed by ion exchange chromatography allowed enriched fractions with different kinetic behaviors. The soluble chicken brain fraction was fractionated, while total esterase activity, proteins and enzymatic components Eα, Eβ and Eγ were monitored in each subfraction. After the analysis, 13 fractions were pooled and conserved. Preincubation of the soluble chicken brain fraction of with the organophosphorus mipafox gave rise to a major change in the ion exchange chromatography profile, but not in the molecular exchanged chromatography profile, which suggest that mipafox permanently modifies the ionic properties of numerous proteins. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. DETECTION AND QUANTIFICATION OF PHYTOCHEMICAL MARKERS OF Ilex paraguariensis BY LIQUID CHROMATOGRAPHY

    OpenAIRE

    Pinto,Rodrigo M. C.; Lemes,Bruna M.; Zielinski,Acácio A. F.; Klein,Traudi; Paula,Fernado de; Kist,Airton; Marques,Anna S. F.; Nogueira,Alessandro; Demiate,Ivo M.; Beltrame,Flávio L.

    2015-01-01

    Ilex paraguariensis (yerba-mate) is used as a beverage, and its extract requires adequate quality control methods in order to guarantee quality and safe use. Strategies to develop and optimize a chromatographic method to quantify theobromine, caffeine, and chlorogenic acid in I. paraguariensis extracts were evaluated by applying a quality by design (QbD) model and ultra high-performance liquid chromatography (UHPLC). The presence of these three phytochemical markers in the extracts was evalua...

  11. A multi-residue method for the analysis of pesticides and pesticide degradates in water using HLB solid-phase extraction and gas chromatography-ion trap mass spectrometry

    Science.gov (United States)

    Hladik, M.L.; Smalling, K.L.; Kuivila, K.M.

    2008-01-01

    A method was developed for the analysis of over 60 pesticides and degradates in water by HLB solid-phase extraction and gas-chromatography/mass spectrometry. Method recoveries and detection limits were determined using two surface waters with different dissolved organic carbon (DOC) concentrations. In the lower DOC water, recoveries and detection limits were 80%-108% and 1-12 ng/L, respectively. In the higher DOC water, the detection limits were slightly higher (1-15 ng/L). Additionally, surface water samples from four sites were analyzed and 14 pesticides were detected with concentrations ranging from 4 to 1,200 ng/L. ?? 2008 Springer Science+Business Media, LLC.

  12. Liquid chromatography tandem mass spectrometry determination of total budesonide levels in dog plasma after inhalation exposure.

    Science.gov (United States)

    Berg, Seija; Melamies, Marika; Rajamäki, Minna; Vainio, Outi; Peltonen, Kimmo

    2012-01-01

    A sensitive and selective method to quantify budesonide in dog plasma samples was developed and fully validated. Liquid-liquid extraction was followed by solid-phase extraction and liquid chromatography-tandem mass spectrometry with electrospray ionization. After reconstitution of the analytes in the mobile phase, samples were analysed by reversed-phase liquid chromatography with isocratic elution. d8-Budesonide was used as an internal standard, and characteristic transitions of d8-budesonide and budesonide were used for quantification. The method was validated with respect to selectivity, specificity, linearity, recovery, repeatability, reproducibility and limits of detection and quantification. The validated method was successfully applied to monitor the plasma levels of budesonide in dogs exposed to clinical doses of inhaled and intravenous drug.

  13. Investigation of the presence of β-hydroxy-β-methylbutyric acid and α-hydroxyisocaproic acid in bovine whole milk and fermented dairy products by a validated liquid chromatography-mass spectrometry method.

    Science.gov (United States)

    Ehling, Stefan; Reddy, Todime M

    2014-02-19

    A simple, rugged, quantitative, and confirmatory method based on liquid chromatography-mass spectrometry was developed and comprehensively validated for the analysis of the leucine metabolites β-hydroxy-β-methylbutyric acid (HMB) and α-hydroxyisocaproic acid (HICA) in bovine whole milk and yogurt. Mean accuracy (90-110% for HMB and 85-115% for HICA) and total precision (dairy products with HMB and/or HICA appears to be justified.

  14. On-line comprehensive two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography for preparative isolation of Peucedanum praeruptorum.

    Science.gov (United States)

    Wang, Xin-Yuan; Li, Jia-Fu; Jian, Ya-Mei; Wu, Zhen; Fang, Mei-Juan; Qiu, Ying-Kun

    2015-03-27

    A new on-line comprehensive preparative two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography (2D NPLC × RPLC) system was developed for the separation of complicated natural products. It was based on the use of a silica gel packed medium-pressure column as the first dimension and an ODS preparative HPLC column as the second dimension. The two dimensions were connected with normal-phase (NP) and reversed-phase (RP) enrichment units, involving a newly developed airflow assisted adsorption (AAA) technique. The instrument operation and the performance of this NPLC × RPLC separation method were illustrated by gram-scale isolation of ethanol extract from the roots of Peucedanum praeruptorum. In total, 19 compounds with high purity were obtained via automated multi-step preparative separation in a short period of time using this system, and their structures were comprehensively characterized by ESI-MS, (1)H NMR, and (13)C NMR. Including two new compounds, five isomers in two groups with identical HPLC and TLC retention values were also obtained and identified by 1D NMR and 2D NMR. This is the first report of an NPLC × RPLC system successfully applied in an on-line preparative process. This system not only solved the interfacing problem of mobile-phase immiscibility caused by NP and RP separation, it also exhibited apparent advantages in separation efficiency and sample treatment capacity compared with conventional methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Validation of Extraction Paper Chromatography as a Quality Control Technique for Analysis of Sr-90 in Y-90 Product

    International Nuclear Information System (INIS)

    Nipavan, Poramatikul; Jatupol, Sangsuriyan; Wiranee, Sriweing

    2009-07-01

    Full text: Yttrium-90 (Y-90) is a daughter product of strontium-90 (Sr-90). It is specified that there should be less than 2 micro-curie of Sr-90 in Y-90 radiopharmaceuticals. Since both nuclides are beta emitting and there is always a contamination of Y-90 in Sr-90 sample, validation of the analytical method is necessary. In this study, commercial Y-90 and Sr-85 (a gamma emitting isotope of strontium) were used as daughter and mother nuclides, respectively. Extraction paper chromatography technique and its efficient validation method were investigated. Bis-(2-ethylhexyl) diphosphonate was dropped at the origin of chromatography paper and air dried prior to sample drops. Validation of the separation was done by radio-chromatography scanning of the chromatography paper. Their energy spectra were identified in the spectra mode of Packard Cobra II automatic gamma counter, which can differentiate a pure gamma, a pure beta and a mixture of beta and gamma nuclides. Results showed that yttrium acetate remained fixed at the origin of the chromatography paper while strontium acetate moved to the solvent front when developed in saline. In conclusion, the extraction paper chromatography technique can effectively separate Sr-90 from Y-90

  16. Quantitative analysis of benzodiazepines in vitreous humor by high-performance liquid chromatography

    Science.gov (United States)

    Bazmi, Elham; Behnoush, Behnam; Akhgari, Maryam; Bahmanabadi, Leila

    2016-01-01

    Objective: Benzodiazepines are frequently screened drugs in emergency toxicology, drugs of abuse testing, and in forensic cases. As the variations of benzodiazepines concentrations in biological samples during bleeding, postmortem changes, and redistribution could be biasing forensic medicine examinations, hence selecting a suitable sample and a validated accurate method is essential for the quantitative analysis of these main drug categories. The aim of this study was to develop a valid method for the determination of four benzodiazepines (flurazepam, lorazepam, alprazolam, and diazepam) in vitreous humor using liquid–liquid extraction and high-performance liquid chromatography. Methods: Sample preparation was carried out using liquid–liquid extraction with n-hexane: ethyl acetate and subsequent detection by high-performance liquid chromatography method coupled to diode array detector. This method was applied to quantify benzodiazepines in 21 authentic vitreous humor samples. Linear curve for each drug was obtained within the range of 30–3000 ng/mL with coefficient of correlation higher than 0.99. Results: The limit of detection and quantitation were 30 and 100 ng/mL respectively for four drugs. The method showed an appropriate intra- and inter-day precision (coefficient of variation forensic toxicology laboratory. PMID:27635251

  17. Application of gas chromatography to the investigations on polypropylene radiolysis

    International Nuclear Information System (INIS)

    Zagorski, Z.P.; Gluszewski, W.

    2006-01-01

    Refinement of the gas chromatography (GC) instrumental approach permitted not only improvement of investigation in basic research, but also development of a new kind of polypropylene blends, more suitable for the production of medical devices and radiation sterilization. It has been shown, that using the GC method not only methane and carbon dioxide can be measured, but also the consumption of oxygen which reacts with free radicals on the polypropylene chain

  18. Ion-Exchange Membrane Chromatography as an Alternative Method of Separation of Potato y Virus

    Directory of Open Access Journals (Sweden)

    Treder Krzysztof

    2015-12-01

    Full Text Available Procedures of separation of virus particles from a plant material are multistage. Furthermore often they are difficult in terms of methodology and require use of expensive, highly specialist equipment and yield of separation is often low. The antigen obtained is often degraded and contains admixtures of other proteins. Therefore, generation of high quality and specificity antibodies based on such antigen is very difficult and quality of the antibodies has impact on reliability, sensitivity and unambiguity of results of immunodiagnostic tests (e.g. ELISA that are currently conventionally used to detect vegetable viruses. In this study three conventionally-performed methods of separation of potato virus Y (PVY were compared and a method of separation based on membrane chromatography, as an alternative separation technique, has been presented. It has been demonstrated that in proper process conditions good quality virus preparation can be obtained.

  19. Simplex-based optimization of numerical and categorical inputs in early bioprocess development: Case studies in HT chromatography.

    Science.gov (United States)

    Konstantinidis, Spyridon; Titchener-Hooker, Nigel; Velayudhan, Ajoy

    2017-08-01

    Bioprocess development studies often involve the investigation of numerical and categorical inputs via the adoption of Design of Experiments (DoE) techniques. An attractive alternative is the deployment of a grid compatible Simplex variant which has been shown to yield optima rapidly and consistently. In this work, the method is combined with dummy variables and it is deployed in three case studies wherein spaces are comprised of both categorical and numerical inputs, a situation intractable by traditional Simplex methods. The first study employs in silico data and lays out the dummy variable methodology. The latter two employ experimental data from chromatography based studies performed with the filter-plate and miniature column High Throughput (HT) techniques. The solute of interest in the former case study was a monoclonal antibody whereas the latter dealt with the separation of a binary system of model proteins. The implemented approach prevented the stranding of the Simplex method at local optima, due to the arbitrary handling of the categorical inputs, and allowed for the concurrent optimization of numerical and categorical, multilevel and/or dichotomous, inputs. The deployment of the Simplex method, combined with dummy variables, was therefore entirely successful in identifying and characterizing global optima in all three case studies. The Simplex-based method was further shown to be of equivalent efficiency to a DoE-based approach, represented here by D-Optimal designs. Such an approach failed, however, to both capture trends and identify optima, and led to poor operating conditions. It is suggested that the Simplex-variant is suited to development activities involving numerical and categorical inputs in early bioprocess development. © 2017 The Authors. Biotechnology Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Method Development and Validation for UHPLC-MS-MS Determination of Hop Prenylflavonoids in Human Serum

    OpenAIRE

    Yuan, Yang; Qiu, Xi; Nikolic, Dejan; Dahl, Jeffrey H.; van Breemen, Richard B.

    2012-01-01

    Hops (Humulus lupulus L.) are used in the brewing of beer, and hop extracts containing prenylated compounds such as xanthohumol and 8-prenylnaringenin are under investigation as dietary supplements for cancer chemoprevention and for the management of hot flashes in menopausal women. To facilitate clinical studies of hop safety and efficacy, a selective, sensitive, and fast ultra-high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS-MS) method was developed and validated for t...

  1. Determination of Grayanotoxins from Rhododendron brachycarpum in Dietary Supplements and Homemade Wine by Liquid Chromatography-Quadrupole Time-of-Flight-Mass Spectrometry and Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Hwang, Taeik; Noh, Eunyoung; Jeong, Ji Hye; Park, Sung-Kwan; Shin, Dongwoo; Kang, Hoil

    2018-02-28

    A sensitive and specific high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS) method combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of grayanotoxins I and III in dietary supplements and homemade wine. Grayanotoxins I and III were successfully extracted using solid-phase extraction cartridges, characterized by LC-QTOF-MS, and quantitated by LC-MS/MS. The LC-MS/MS calibration curves were linear over concentrations of 10-100 ng/mL (grayanotoxin I) and 20-400 ng/mL (grayanotoxin III). Grayanotoxins I and III were found in 51 foodstuffs, with quantitative determinations revealing total toxin concentrations of 18.4-101 000 ng/mL (grayanotoxin I) and 15.3-56 000 ng/mL (grayanotoxin III). The potential of the validated method was demonstrated by successful quantitative analysis of grayanotoxins I and III in dietary supplements and homemade wine; the method appears suitable for the routine detection of grayanotoxins I and III from Rhododendron brachycarpum.

  2. Simultaneous determination of aflatoxin B₁, B₂, G₁, and G₂ in corn powder, edible oil, peanut butter, and soy sauce by liquid chromatography with tandem mass spectrometry utilizing turbulent flow chromatography.

    Science.gov (United States)

    Fan, Sufang; Li, Qiang; Zhang, Xiaoguang; Cui, Xiaobin; Zhang, Dongsheng; Zhang, Yan

    2015-05-01

    A novel fully automated method based on dual column switching using turbulent flow chromatography followed by liquid chromatography with tandem mass spectrometry was developed for the determination of aflatoxin B1 , B2 , G1 , and G2 in corn powder, edible oil, peanut butter, and soy sauce samples. After ultrasound-assisted extraction, samples were directly injected to the chromatographic system and the analytes were concentrated into the clean-up loading column. Through purge switching, the analytes were transferred to the analytical column for subsequent detection by mass spectrometry. Different types of TurboFlow(TM) columns, transfer flow rate, transfer time were optimized. The limits of detection and quantification of this method ranged between 0.2-2.0 and 0.5-4.0 μg/kg for aflatoxins in different matrixes, respectively. Recoveries of aflatoxins were in range of 83-108.1% for all samples, matrix effects were in range of 34.1-104.7%. The developed method has been successfully applied in the analysis of aflatoxin B1 , B2 , G1 , and G2 in real samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Comprehensive two-dimensional liquid chromatography: Ion chromatography × reversed-phase liquid chromatography for separation of low-molar-mass organic acids

    NARCIS (Netherlands)

    Brudin, S.S.; Shellie, R.A.; Haddad, P.R.; Schoenmakers, P.J.

    2010-01-01

    In the work presented here a novel approach to comprehensive two-dimensional liquid chromatography is evaluated. Ion chromatography is chosen for the first-dimension separation and reversed-phase liquid chromatography is chosen for the second-dimension separation mode. The coupling of these modes is

  4. Liquid chromatography/tandem mass spectrometry method for quantitative estimation of solutol HS15 and its applications.

    Science.gov (United States)

    Bhaskar, V Vijaya; Middha, Anil; Srivastava, Pratima; Rajagopal, Sriram

    2015-04-01

    A rapid, sensitive and selective pseudoMRM (pMRM)-based method for the determination of solutol HS15 (SHS15) in rat plasma was developed using liquid chromatography/tandem mass spectrometry (LC-MS/MS). The most abundant ions corresponding to SHS15 free polyethyleneglycol (PEG) oligomers at m / z 481, 525, 569, 613, 657, 701, 745, 789, 833, 877, 921 and 965 were selected for pMRM in electrospray mode of ionization. Purity of the lipophilic and hydrophilic components of SHS15 was estimated using evaporative light scattering detector (ELSD). Plasma concentrations of SHS15 were measured after oral administration at 2.50 g/kg dose and intravenous administration at 1.00 g/kg dose in male Sprague Dawley rats. SHS15 has poor oral bioavailability of 13.74% in rats. Differences in pharmacokinetics of oligomers were studied. A novel proposal was conveyed to the scientific community, where formulation excipient could be analyzed as a qualifier in the analysis of new chemical entities (NCEs) to address the spiky plasma concentration profiles.

  5. Integration of electrochemistry with ultra-performance liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Cai, Yi; Zheng, Qiuling; Liu, Yong; Helmy, Roy; Loo, Joseph A; Chen, Hao

    2015-01-01

    This study presents the development of ultra-performance liquid chromatography (UPLC) mass spectrometry (MS) combined with electrochemistry (EC) for the first time and its application for the structural analysis of proteins/peptides that contain disulfide bonds. In our approach, a protein/peptide mixture sample undergoes a fast UPLC separation and subsequent electrochemical reduction in an electrochemical flow cell followed by online MS and tandem mass spectrometry (MS/MS) analyses. The electrochemical cell is coupled to the mass spectrometer using our recently developed desorption electrospray ionization (DESI) interface. Using this UPLC/EC/DESI-MS method, peptides that contain disulfide bonds can be differentiated from those without disulfide bonds, as the former are electroactive and reducible. MS/MS analysis of the disulfide-reduced peptide ions provides increased information on the sequence and disulfide-linkage pattern. In a reactive DESI- MS detection experiment in which a supercharging reagent was used to dope the DESI spray solvent, increased charging was obtained for the UPLC-separated proteins. Strikingly, upon online electrolytic reduction, supercharged proteins (e.g., α-lactalbumin) showed even higher charging, which will be useful in top- down protein structure MS analysis as increased charges are known to promote protein ion dissociation. Also, the separation speed and sensitivity are enhanced by approximately 1(~)2 orders of magnitude by using UPLC for the liquid chromatography (LC)/EC/MS platform, in comparison to the previously used high- performance liquid chromatography (HPLC). This UPLC/EC/DESI-MS method combines the power of fast UPLC separation, fast electrochemical conversion, and online MS structural analysis for a potentially valuable tool for proteomics research and bioanalysis.

  6. An on-line high performance liquid chromatography-crocin bleaching assay for detection of antioxidants

    NARCIS (Netherlands)

    Bountagkidou, O.; Klift, van der E.J.C.; Tsimidou, M.Z.; Ordoudi, S.A.; Beek, van T.A.

    2012-01-01

    An on-line HPLC (high performance liquid chromatography) method for the rapid screening of individual antioxidants in mixtures was developed using crocin as a substrate (i.e. oxidation probe) and 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH)) in phosphate buffer (pH 7.5) as a radical

  7. Identification of chemical components in Baidianling Capsule based on gas chromatography-mass spectrometry and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Wu, Wenying; Chen, Yu; Wang, Binjie; Sun, Xiaoyang; Guo, Ping; Chen, Xiaohui

    2017-08-01

    Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography-mass spectrometry in combination with retention indices and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkynes, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furans, pyrrole, acid amides, heterocycles, and oxides were detected from Baidianling Capsule by gas chromatography-mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index. Then, a total of 124 components were tentatively identified by high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Fifteen constituents from Baidianling Capsule were accurately identified by comparing the retention times with those of reference compounds, others were identified by comparing the retention times and mass spectrometry data, as well as retrieving the reference literature. This study provides a practical strategy for rapidly screening and identifying the multiple constituents of a complex traditional Chinese medicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Supercritical fluid chromatography for lipid analysis in foodstuffs.

    Science.gov (United States)

    Donato, Paola; Inferrera, Veronica; Sciarrone, Danilo; Mondello, Luigi

    2017-01-01

    The task of lipid analysis has always challenged separation scientists, and new techniques in chromatography were often developed for the separation of lipids; however, no single technique or methodology is yet capable of affording a comprehensive screening of all lipid species and classes. This review acquaints the role of supercritical fluid chromatography within the field of lipid analysis, from the early developed capillary separations based on pure CO 2 , to the most recent techniques employing packed columns under subcritical conditions, including the niche multidimensional techniques using supercritical fluids in at least one of the separation dimensions. A short history of supercritical fluid chromatography will be introduced first, from its early popularity in the late 1980s, to the sudden fall and oblivion until the last decade, experiencing a regain of interest within the chromatographic community. Afterwards, the subject of lipid nomenclature and classification will be briefly dealt with, before discussing the main applications of supercritical fluid chromatography for food analysis, according to the specific class of lipids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Simple micellar electrokinetic chromatography method for the determination of hydrogen sulfide in hen tissues.

    Science.gov (United States)

    Kubalczyk, Paweł; Borowczyk, Kamila; Chwatko, Grażyna; Głowacki, Rafał

    2015-04-01

    A new method for the determination of hydrogen sulfide in hen tissues has been developed and validated. For estimation of hydrogen sulfide content, a sample (0.1 g) of hen tissue was treated according to the procedure consisted of some essential steps: simultaneous homogenization of a tissue and derivatization of hydrogen sulfide to its S-quinolinium derivative with 2-chloro-1-methylquinolinium tetrafluoroborate, separation of so-formed derivative by micellar electrokinetic chromatography with sweeping, and detection and quantitation with the use of UV detector set to measure analytical signals at 375 nm. Effective electrophoretic separation was achieved using fused silica capillary (effective length 41.5 cm, 75 μm id) and 0.05 mol/L, pH 8 phosphate buffer with the addition of 0.04 mol/L SDS and 26% ACN. The lower limit of quantification was 0.12 μmol hydrogen sulfide in 1 g of tissue. The calibration curve prepared in tissue homogenate for hydrogen sulfide showed linearity in the range from 0.15 to 2.0 μmol/g, with the coefficient of correlation 0.9978. The relative standard deviation of the points of the calibration curve varied from 8.3 to 3.2% RSD. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Isotope ratio mass spectrometry coupled to liquid and gas chromatography for wine ethanol characterization.

    Science.gov (United States)

    Cabañero, Ana I; Recio, Jose L; Rupérez, Mercedes

    2008-10-01

    Two new procedures for wine ethanol 13C/12C isotope ratio determination, using high-performance liquid chromatography and gas chromatography isotope ratio mass spectrometry (HPLC/IRMS and GC/IRMS), have been developed to improve isotopic methods dedicated to the study of wine authenticity. Parameters influencing separation of ethanol from wine matrix such as column, temperature, mobile phase, flow rates and injection mode were investigated. Twenty-three wine samples from various origins were analyzed for validation of the procedures. The analytical precision was better than 0.15 per thousand, and no significant isotopic fractionation was observed employing both separative techniques coupled to IRMS. No significant differences and a very strong correlation (r = 0.99) were observed between the 13C/12C ratios obtained by the official method (elemental analyzer/isotope ratio mass spectrometry) and the proposed new methodology. The potential advantages of the developed methods over the traditional one are speed (reducing time required from hours to minutes) and simplicity. In addition, these are the first isotopic methods that allow 13C/12C determination directly from a liquid sample with no previous ethanol isolation, overcoming technical difficulties associated with sample treatment.

  11. Data on acetic acid–methanol–methyl acetate–water mixture analysised by dual packed column Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Mallaiah Mekala

    2018-06-01

    Full Text Available The composition of multicomponent determination by colorimetric titration is difficult. This complexity is easily overcome by using Gas Chromatography technique instead of wet method for multi-component mixture analysis. In Gas Chromatography, first the standard chart is prepared by using the known amount sample concentration as the reference. Once calibration chart is prepared the unknown sample concentration easily measured by using the standard chart. In the present study a standard calibration chart developed for the four component system of acetic acid–methanol–methyl acetate–water. The samples were taken at various concentrations of all components and different chromatograms obtained under various concentrations respectively. The method of optimization was first carried out to get the sharp peaks of individual components and binary pairs also. By using those conditions, the multi components concentrations were estimated. From the present results, the area under gas chromatogram is linearly varying with mole% of the components compared to mass%. Keywords: Gas Chromatography, Esterification, Calibration, Retention time, Optimization

  12. Determination of 2-alkylcyclobutanones by combining precolumn derivatization with 1-naphthalenyl hydrazine and ultra-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Meng, Xiangpeng; Tong, Tong; Wang, Lianrong; Liu, Hanxia; Chan, Wan

    2016-05-01

    2-Alkylcyclobutanones (2-ACBs) are uniquely formed when triglycerides-containing food products are exposed to ionizing radiation. Thus, 2-ACBs have been used as marker molecules to identify irradiated food. Most methods to determine 2-ACBs involve mass spectrometric detection after chromatographic separation. The spectrofluorometer is rarely used to determine 2-ACBs because these molecules do not fluoresce. In this study, we developed an ultra-performance liquid chromatography (UPLC) method to determine 2-ACBs. 2-ACBs were converted into fluorophores after reacting with 1-naphthalenyl hydrazine to facilitate their sensitive and selective detection using a fluorescence detector (FLD). Analysis of 2-ACBs using our developed UPLC-FLD method allows sensitive determination of 2-ACBs at a detection limit of 2 ng 2-ACBs per g of fat (30 pg/injection), which is significantly lower than that of existing analytical methods. After validation for trueness and precision, the method was applied to γ-irradiated chicken samples to determine their 2-ACB content. Comparative studies employing liquid chromatography-tandem mass spectrometric method revealed no systematic difference between the two methods, thereby demonstrating that the proposed UPLC-FLD method can be suitably used to determine 2-ACBs in irradiated foodstuffs. Graphical Abstract Determination of radiation-induced food-borne 2-dodecylcyclobutanone and 2-tetradecylcyclobutanone by combining 1-naphthalenyl hydrazine derivatization and ultra-performance liquid chromatography with fluorescence detection.

  13. Simultaneous determination of seven anticoagulant rodenticides in agricultural products by gel permeation chromatography and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Saito-Shida, Shizuka; Nemoto, Satoru; Matsuda, Rieko; Akiyama, Hiroshi

    2016-11-01

    A sensitive and reliable method for the simultaneous determination of hydroxycoumarin-type (brodifacoum, bromadiolone, coumatetralyl, and warfarin) and indandione-type (chlorophacinone, diphacinone, and pindone) rodenticides in agricultural products by gel permeation chromatography (GPC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The procedure involved extraction of the rodenticides from samples with acetone, followed by liquid-liquid partitioning with hexane/ethyl acetate (1:1, v/v) and 10% sodium chloride aqueous solution, then cleanup using GPC, and finally, analysis using LC-MS/MS. High recoveries from the GPC column were obtained for all rodenticides tested using a mobile phase of acetone/cyclohexane/triethylamine (400:1600:1, v/v/v). An ODS column, which contains low levels of metal impurities, gave satisfactory peak shapes for both hydroxycoumarin- and indandione-type rodenticides in the LC-MS/MS separation. The average recoveries of rodenticides from eight agricultural foods (apple, eggplant, cabbage, orange, potato, tomato, brown rice, and soybean) fortified at 0.0005-0.001 mg/kg ranged from 76 to 116%, except for bromadiolone in orange (53%) and diphacinone in soybean (54%), and the relative standard deviations ranged from 1 to 16%. The proposed method effectively removed interfering components, such as pigments and lipids, and showed high selectivity. In addition, the matrix effects were negligible for most of the rodenticide/food combinations. The results suggest that the proposed method is reliable and suitable for determining hydroxycoumarin- and indandione-type rodenticides in agricultural products.

  14. UHPLC: The Greening Face of Liquid Chromatography

    OpenAIRE

    Cielecka-Piontek, Judyta; Zalewski, Przemys?aw; Jeli?ska, Anna; Garbacki, Piotr

    2013-01-01

    Pharmaceutical analysis based on chromatographic separation is an important part of studies aimed at developing routine quality analysis of drugs. High-performance liquid chromatography (HPLC) is one of the main analytical techniques recommended for drug analysis. Although it meets many criteria vital for analysis, it is time-consuming and uses a relatively high amount of organic solvents compared to other analytical techniques. Recently, Ultra-high-performance liquid chromatography (UHPLC) h...

  15. Rapid determination of anti-estrogens by gas chromatography/mass spectrometry in urine: Method validation and application to real samples.

    Science.gov (United States)

    Gerace, E; Salomone, A; Abbadessa, G; Racca, S; Vincenti, M

    2012-02-01

    A fast screening protocol was developed for the simultaneous determination of nine anti-estrogenic agents (aminoglutethimide, anastrozole, clomiphene, drostanolone, formestane, letrozole, mesterolone, tamoxifen, testolactone) plus five of their metabolites in human urine. After an enzymatic hydrolysis, these compounds can be extracted simultaneously from urine with a simple liquid-liquid extraction at alkaline conditions. The analytes were subsequently analyzed by fast-gas chromatography/mass spectrometry (fast-GC/MS) after derivatization. The use of a short column, high-flow carrier gas velocity and fast temperature ramping produced an efficient separation of all analytes in about 4 min, allowing a processing rate of 10 samples/h. The present analytical method was validated according to UNI EN ISO/IEC 17025 guidelines for qualitative methods. The range of investigated parameters included the limit of detection, selectivity, linearity, repeatability, robustness and extraction efficiency. High MS-sampling rate, using a benchtop quadrupole mass analyzer, resulted in accurate peak shape definition under both scan and selected ion monitoring modes, and high sensitivity in the latter mode. Therefore, the performances of the method are comparable to the ones obtainable from traditional GC/MS analysis. The method was successfully tested on real samples arising from clinical treatments of hospitalized patients and could profitably be used for clinical studies on anti-estrogenic drug administration.

  16. 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.

  17. [Analysis of phthalates in plastic food-packaging bags by thin layer chromatography].

    Science.gov (United States)

    Chen, Hui; Wang, Yuan; Zhu, Ruohua

    2006-01-01

    The method for simultaneous determination of four phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) in plastic food-packaging bags by thin layer chromatography (TLC) was developed. The plastic food-packaging bags were extracted with ethanol by ultrasonication, then the mixture was filtrated through membrane (0.45 microm). The mixture of ethyl acetate-anhydrous ether-isooctane (1 : 4 : 15, v/v) was used as developing agent on the TLC silica gel plate for development. The filtered liquid was spotted on the TLC plate dealt by acetone, and detected with scanning wavelength of 275 nm and reference wavelength of 340 nm. The qualitative analysis of the phthalates was performed using the R(f) values of the chromatogram. The quantitative analysis was performed with external standard method. Good linearities were obtained for DMP, DEP, DBP and DEHP. The detection limits were 2.1 ng for DMP, 2.4 ng for DEP, 3.4 ng for DBP and 4.0 ng for DEHP. The relative standard deviations (RSDs) of the four phthalates were 2.8% - 3.5%. The recoveries of the four phthalate standards in real sample were 78.58% - 111.04%. The method presented has the advantages of high precision, high sensitivity, small sample size, and simple pretreatment . The method was used to detect the four phthalates in the food-packaging bags. The contents in real samples were close to the results by gas chromatography.

  18. Development of a sensitive method for the determination of acrylamide in coffee using high-performance liquid chromatography coupled to a hybrid quadrupole Orbitrap mass spectrometer.

    Science.gov (United States)

    Pugajeva, Iveta; Jaunbergs, Janis; Bartkevics, Vadims

    2015-01-01

    The emerging trend towards high-resolution mass spectrometry (MS) alternatives was evaluated by the application of Orbitrap MS for the determination of acrylamide in coffee samples. The high resolving power of the Orbitrap MS provided the high selectivity and sensitivity that enabled quantitative analysis of acrylamide in complex matrices, such as coffee. Several sample preparation methods and scanning modes of the MS (full MS, t-SIM, t-MS2) were assessed in order to optimise parameters of the analytical method. The final procedure involved the extraction of acrylamide with acetonitrile, solid-phase extraction with dispersive primary secondary amine (PSA) and amino columns, and the detection by ultra-performance liquid chromatography coupled to a hybrid quadrupole-Orbitrap MS (HPLC-Q-Orbitrap) operated in targeted MS2 scanning mode. The repeatability of the method at the lowest calibration level (10 μg kg(-1)), expressed as relative standard deviation, was 7.8% and the average recovery of acrylamide was 111%. The proposed method was applied to the determination of acrylamide in 22 samples of roasted coffee obtained from the Latvian retail market. Acrylamide concentration in coffee samples was in the range of 166-503 μg kg(-1).

  19. Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method Coupled with Dispersive Solid-Phase Extraction for Simultaneous Quantification of Eight Paralytic Shellfish Poisoning Toxins in Shellfish

    Science.gov (United States)

    Yang, Xianli; Zhou, Lei; Tan, Yanglan; Shi, Xizhi; Zhao, Zhiyong; Nie, Dongxia; Zhou, Changyan; Liu, Hong

    2017-01-01

    In this study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for simultaneous determination of eight paralytic shellfish poisoning (PSP) toxins, including saxitoxin (STX), neosaxitoxin (NEO), gonyautoxins (GTX1–4) and the N-sulfo carbamoyl toxins C1 and C2, in sea shellfish. The samples were extracted by acetonitrile/water (80:20, v/v) with 0.1% formic and purified by dispersive solid-phase extraction (dSPE) with C18 silica and acidic alumina. Qualitative and quantitative detection for the target toxins were conducted under the multiple reaction monitoring (MRM) mode by using the positive electrospray ionization (ESI) mode after chromatographic separation on a TSK-gel Amide-80 HILIC column with water and acetonitrile. Matrix-matched calibration was used to compensate for matrix effects. The established method was further validated by determining the linearity (R2 ≥ 0.9900), average recovery (81.52–116.50%), sensitivity (limits of detection (LODs): 0.33–5.52 μg·kg−1; limits of quantitation (LOQs): 1.32–11.29 μg·kg−1) and precision (relative standard deviation (RSD) ≤ 19.10%). The application of this proposed approach to thirty shellfish samples proved its desirable performance and sufficient capability for simultaneous determination of multiclass PSP toxins in sea foods. PMID:28661471

  20. RP-HPLC×HILIC chromatography for quantifying ertapenem sodium with a look at green chemistry.

    Science.gov (United States)

    Pedroso, Tahisa M; Medeiros, Ana C D; Salgado, Herida R N

    2016-11-01

    Ertapenem sodium is a polar and ionizable compound; therefore, it has little retention on traditional C18 columns in reverse-phase high-performance liquid chromatography, even using a highly-aqueous mobile phase that can result in dewetting in the stationary phase. Thus, the most coherent process for ERTM is to develop a method for Hydrophilic Interaction Chromatography. However, for the traditional methods in HILIC, the use of a highly organic mobile phase is necessary; usually an amount exceeding 80% acetonitrile is necessary. On the other hand, the RP-HPLC mode is considered for the analysis technique, which is more often used for quantification of substances, and new columns are often introduced to analyze different groups of compounds. Two new analytical methods have been developed for routine analysis. The proposed chromatographic method was adequate and advantageous by presenting simplicity, linearity, precision, accuracy, robustness, detection limits, and satisfactory quantification. Analytical methods are constantly undergoing changes and improvements. Researchers worldwide are rapidly adopting Green Chemistry. The development of new pharmaceutical methods based in Green chemistry has been encouraged by universities and the pharmaceutical industry. Issues related to green chemistry are in evidence and they have been featured in international journals of high impact. The methods described here have economic advantages and they feature an eco-friendly focus, which is discussed in this work. This work was developed with an environmental conscience, always looking to minimize the possible generated organic waste. Therefore, discussion on this aspect is included. Copyright © 2016 Elsevier B.V. All rights reserved.