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Sample records for extraction spe procedure

  1. Comparison of SPE/d-SPE and QuEChERS-Based Extraction Procedures in Terms of Fungicide Residue Analysis in Wine Samples by HPLC-DAD and LC-QqQ-MS.

    Science.gov (United States)

    Tuzimski, Tomasz; Rejczak, Tomasz; Pieniążek, Dominika; Buszewicz, Grzegorz; Teresiński, Grzegorz

    2016-11-01

    Two different extraction and clean-up protocols, based on either the SPE/dispersive SPE (d-SPE) or the quick, easy, cheap, effective, rugged, and safe approach, were optimized and compared for determination of six selected fungicides (benalaxyl, metalaxyl, triadimenol, tebuconazole, diniconazole, and epoxiconazole) in wine samples. The pilot study was performed by applying HPLC with diode-array detection, and optimized procedures were easily transferred to the LC triple-quadrupole MS system. Both extraction procedures presented good performance for all the analytes, with recoveries in the range of 70-132% and SDs ≤20%. The d-SPE clean-up step included in both procedures allows obtaining colorless extracts with the majority of coextracted matrix compounds removed. LC with electrospray ionization and tandem MS operating in the multiple reaction monitoring mode provide high sensitivity and selectivity for trace analysis. Both developed procedures were evaluated in terms of commercial wine sample analysis. In three wine samples, metalaxyl and tebuconazole residues were detected at concentrations from 0.14 to 30.7 ng/mL. Both approaches showed satisfactory feasibility for fungicide residue analysis in wine samples.

  2. Solid-Phase Extraction (SPE: Principles and Applications in Food Samples

    Directory of Open Access Journals (Sweden)

    Semih Ötles

    2016-03-01

    Full Text Available Solid-Phase Extraction (SPE is a sample preparation method that is practised on numerous application fields due to its many advantages compared to other traditional methods. SPE was invented as an alternative to liquid/liquid extraction and eliminated multiple disadvantages, such as usage of large amount of solvent, extended operation time/procedure steps, potential sources of error, and high cost. Moreover, SPE can be ap- plied to the samples combined with other analytical methods and sample preparation techniques optionally. SPE technique is a useful tool for many purposes through its versatility. Isolation, concentration, purification and clean-up are the main approaches in the practices of this method. Food structures represent a complicated matrix and can be formed into different physical stages, such as solid, viscous or liquid. Therefore, sample preparation step particularly has an important role for the determination of specific compounds in foods. SPE offers many opportunities not only for analysis of a large diversity of food samples but also for optimization and advances. This review aims to provide a comprehensive overview on basic principles of SPE and its applications for many analytes in food matrix.

  3. 检测葡萄酒中赭曲霉毒素A的SPE-HPLC方法优化%The optimized procedure of solid-phase extraction with HPLC for the determination of ochratoxin A in wine

    Institute of Scientific and Technical Information of China (English)

    宗楠; 李景明; 张柏林

    2011-01-01

    从固相萃取的上样体积、淋洗液体积以及高效液相色谱的洗脱程序等方面,优化并建立了检测葡萄酒中赭曲霉毒素A的(SPEHPLC)方法.采用10mL酒样与10mL水等体积混合上样,使用2mL水淋洗后再用2mL甲醇/水(60∶40,v/v)溶液的最佳淋洗条件,HPLC 检测首次采用梯度洗脱,优化后方法的加标回收率为94.6%~99.5%,相对标准偏差为0.36%~3.01%.6个市售葡萄酒样品检测表明,OTA阳性率为66.7%,平均含量为0.46μg/L,证明本方法能够排除杂质峰干扰,提高准确度,可以满足葡萄酒中赭曲霉毒素(OTA)的定量检测要求.%An assay procedure of solid-phase extraction(SPE) with high performance liquid chromatography( HPLC )for the detection of ochratoxin A (OTA) in wine was optimized and established. The optimized parameters included sample volume passed though the C18 cartridge and washing solution in SPE treatment, and HPLC elution. For sample volume, 10mL wine diluted with 10mL water were pre-concentrated on the C18 column. Then 2mL water was used for sample washing, followed by 2mL methanol-water solution (60/40, v/v) for further washing. For the first time, a gradient elution was used in detecting OTA in HPLC analysis. The optimized SPE-HPLC procedure improved that the recovery were between 94.6% and 99.5%, with relative standard deviations between 0.36% and 3.01%. This method was applied for the determination of OTA from 6 commercial wine samples. The percentage of OTA existing in all wine samples was 66.7%, and its content averaged to be 0.46μg/L. The SPE-HPLC procedure presented in this study should meet the needs of the quantitative measurement of OTA in wine due to the eliminated interference of impurity peak and improved accuracy of the method.

  4. Analysis of pharmaceutical creams: a useful approach based on solid-phase extraction (SPE) and UV spectrophotometry.

    Science.gov (United States)

    Bonazzi, D; Andrisano, V; Gatti, R; Cavrini, V

    1995-10-01

    Solid-phase extraction (SPE) using C-18, diol and ion-exchange sorbents followed by UV spectrophotometric (conventional and derivative mode) assay was applied to the analysis of basic, acidic and neutral drugs commercially available in creams. A representative set of drugs (promethazine, chlorhexidine, benzydamine, ketoprofen, ibuprofen, fentiazac, piroxicam, fluorouracil, crotamiton and hydrocortisone acetate) was selected, and for each drug the appropriate SPE conditions (adsorption, washing and elution) were investigated to obtain a practical and reliable sample clean-up. It was shown that the developed SPE procedures were capable of removing interfering cream components (excipients including preservatives) allowing accurate spectrophotometric analyses to be performed. In some applications, derivative spectrophotometry was advantageous over the conventional absorption mode with respect to higher selectivity and versatility.

  5. Optimization of a Pre-MEKC Separation SPE Procedure for Steroid Molecules in Human Urine Samples

    Directory of Open Access Journals (Sweden)

    Ilona Olędzka

    2013-11-01

    Full Text Available Many steroid hormones can be considered as potential biomarkers and their determination in body fluids can create opportunities for the rapid diagnosis of many diseases and disorders of the human body. Most existing methods for the determination of steroids are usually time- and labor-consuming and quite costly. Therefore, the aim of analytical laboratories is to develop a new, relatively low-cost and rapid implementation methodology for their determination in biological samples. Due to the fact that there is little literature data on concentrations of steroid hormones in urine samples, we have made attempts at the electrophoretic determination of these compounds. For this purpose, an extraction procedure for the optimized separation and simultaneous determination of seven steroid hormones in urine samples has been investigated. The isolation of analytes from biological samples was performed by liquid-liquid extraction (LLE with dichloromethane and compared to solid phase extraction (SPE with C18 and hydrophilic-lipophilic balance (HLB columns. To separate all the analytes a micellar electrokinetic capillary chromatography (MECK technique was employed. For full separation of all the analytes a running buffer (pH 9.2, composed of 10 mM sodium tetraborate decahydrate (borax, 50 mM sodium dodecyl sulfate (SDS, and 10% methanol was selected. The methodology developed in this work for the determination of steroid hormones meets all the requirements of analytical methods. The applicability of the method has been confirmed for the analysis of urine samples collected from volunteers—both men and women (students, amateur bodybuilders, using and not applying steroid doping. The data obtained during this work can be successfully used for further research on the determination of steroid hormones in urine samples.

  6. Analysis of halogenated and priority pesticides at different concentration levels. Automated SPE extraction followed by isotope dilution-GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Planas, C.; Saulo, J.; Rivera, J.; Caixach, J. [Institut Investigacions Quimiques i Ambientals (IIQAB-CSIC), Barcelona (Spain)

    2004-09-15

    In this work, automatic SPE extraction of 16 pesticides and metabolites with the automated Power-Prep trademark system is evaluated at different concentration levels using polymeric (ENV+) and C{sub 18} sorbent phases. The method was optimised by comparing recoveries obtained using different eluting solvents. The optimised procedure was then applied to spiked water samples at concentration levels of 0.1{mu}g/L (quality standard for individual pesticides in drinking water) and 0.02{mu}g/L (close to the detection limit of most pesticides).

  7. Micro-solid-phase extraction (µ-SPE) of organophosphorous pesticides from wheat followed by LC-MS/MS determination.

    Science.gov (United States)

    Della Pelle, Flavio; Di Crescenzo, Maria Chiara; Sergi, Manuel; Montesano, Camilla; Di Ottavio, Francesca; Scarpone, Rossana; Scortichini, Giampiero; Compagnone, Dario

    2016-01-01

    A rapid, selective and effective method of extraction, clean-up and concentration of organophosphorous pesticides from wheat followed by electrospray (ESI) LC-MS/MS analysis was developed. The μ-SPE (micro-solid-phase extraction) procedure resulted in good analytical performance and reduced at the same time matrix effects, analysis time and solvent consumption. Limits of detection (LODs) and quantification (LOQs) were in the range of 0.3-10 and 1-30 μg kg(-1), respectively, with good reproducibility (RSD ≤ 13.8) and recoveries between 75% and 109%. Coefficients of determination (r(2)) were greater than 0.996 for the studied pesticides. Despite the reduced sorbent bed mass of μ-SPE tips (4.2 mg), the analytical data showed that no saturation phenomena occurs in the tested range of concentration both for single compounds and mixtures. Several real samples were analysed and the concentrations of the selected pesticides were found to be below the respective maximum residue limit (MRLs).

  8. The Development and Optimization of Techniques for Monitoring Water Quality on-Board Spacecraft Using Colorimetric Solid-Phase Extraction (C-SPE)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, April Ann [Iowa State Univ., Ames, IA (United States)

    2007-12-01

    The main focus of this dissertation is the design, development, and ground and microgravity validation of methods for monitoring drinking water quality on-board NASA spacecraft using clorimetric-solid phase extraction (C-SPE). The Introduction will overview the need for in-flight water quality analysis and will detail some of the challenges associated with operations in the absence of gravity. The ability of C-SPE methods to meet these challenges will then be discussed, followed by a literature review on existing applications of C-SPE and similar techniques. Finally, a brief discussion of diffuse reflectance spectroscopy theory, which provides a means for analyte identification and quantification in C-SPE analyses, is presented. Following the Introduction, four research chapters are presented as separate manuscripts. Chapter 1 reports the results from microgravity testing of existing C-SPE methods and procedures aboard NASA's C-9 microgravity simulator. Chapter 2 discusses the development of a C-SPE method for determining the total concentration of biocidal silver (i.e., in both dissolved and colloidal forms) in water samples. Chapter 3 presents the first application of the C-SPE technique to the determination of an organic analyte (i.e., formaldehyde). Chapter 4, which is a departure from the main focus of the thesis, details the results of an investigation into the effect of substrate rotation on the kinetics involved in the antigen and labeling steps in sandwich immunoassays. These research chapters are followed by general conclusions and a prospectus section.

  9. Explorative Solid-Phase Extraction (E-SPE) for Accelerated Microbial Natural Product Discovery, Dereplication, and Purification

    DEFF Research Database (Denmark)

    Månsson, Maria; Phipps, Richard Kerry; Gram, Lone

    2010-01-01

    Microbial natural products (NP) cover a high chemical diversity, and in consequence extracts from microorganisms are often complex to analyze and purify. A distribution analysis of calculated pK(a) values from the 34390 records in Antibase2008 revealed that within pH 2-11, 44% of all included......-phase extraction" (E-SPE) protocol using SAX, Oasis MAX, SCX, and LH-20 columns for targeted exploitation of chemical functionalities. E-SPE provides a minimum of fractions (15) for chemical and biological analyses and implicates development into a preparative scale methodology. Overall, this allows fast extract...

  10. HPLC-F analysis of melatonin and resveratrol isomers in wine using an SPE procedure.

    Science.gov (United States)

    Mercolini, Laura; Addolorata Saracino, Maria; Bugamelli, Francesca; Ferranti, Anna; Malaguti, Marco; Hrelia, Silvana; Raggi, Maria Augusta

    2008-04-01

    An original analytical method has been developed for the determination of the antioxidants trans-resveratrol (t-RSV) and cis-resveratrol (c-RSV) and of melatonin (MLT) in red and white wine. The method is based on HPLC coupled to fluorescence detection. Separation was obtained by using a RP column (C8, 150 mm x 4.6 mm id, 5 mum) and a mobile phase composed of 79% aqueous phosphate buffer at pH 3.0 and 21% ACN. Fluorescence intensity was monitored at lambda = 386 nm while exciting at lambda = 298 nm, mirtazapine was used as the internal standard. A careful pretreatment of wine samples was developed, using SPE with C18 cartridges (100 mg, 1 mL). The calibration curves were linear over the following concentration ranges: 0.03-5.00 ng/mL for MLT, 3-500 ng/mL for t-RSV and 1-150 ng/mL for c-RSV. The LOD values were 0.01 ng/mL for MLT, 1 ng/mL for t-RSV and 0.3 ng/mL for c-RSV. Precision data, as well as extraction yield and sample purification results, were satisfactory. Thus, the method seems to be suitable for the analysis of MLT and resveratrol isomers in wine samples. Moreover, wine total polyphenol content and antioxidant activity were evaluated.

  11. Characterisation of antimicrobial extracts from dandelion root (Taraxacum officinale) using LC-SPE-NMR.

    Science.gov (United States)

    Kenny, O; Brunton, N P; Walsh, D; Hewage, C M; McLoughlin, P; Smyth, T J

    2015-04-01

    Plant extracts have traditionally been used as sources of natural antimicrobial compounds, although in many cases, the compounds responsible for their antimicrobial efficacy have not been identified. In this study, crude and dialysed extracts from dandelion root (Taraxacum officinale) were evaluated for their antimicrobial properties against Gram positive and Gram negative bacterial strains. The methanol hydrophobic crude extract (DRE3) demonstrated the strongest inhibition of microbial growth against Staphylococcus aureus, methicillin-resistant S. aureus and Bacillus cereus strains. Normal phase (NP) fractionation of DRE3 resulted in two fractions (NPF4 and NPF5) with enhanced antimicrobial activity. Further NP fractionation of NPF4 resulted in two fractions (NPF403 and NPF406) with increased antimicrobial activity. Further isolation and characterisation of compounds in NPF406 using liquid chromatography solid phase extraction nuclear magnetic resonance LC-SPE-NMR resulted in the identification of 9-hydroxyoctadecatrienoic acid and 9-hydroxyoctadecadienoic acid, while the phenolic compounds vanillin, coniferaldehyde and p-methoxyphenylglyoxylic acid were also identified respectively. The molecular mass of these compounds was confirmed by LC mass spectroscopy (MS)/MS. In summary, the antimicrobial efficacy of dandelion root extracts demonstrated in this study support the use of dandelion root as a source of natural antimicrobial compounds.

  12. Liquid-Liquid Extraction/Low-Temperature Purification (LLE/LTP Followed by Dispersive Solid-Phase Extraction (d-SPE Cleanup for Multiresidue Analysis in Palm Oil by LC-QTOF-MS

    Directory of Open Access Journals (Sweden)

    Elham Sobhanzadeh

    2013-01-01

    Full Text Available An evaluation of the extraction of multiresidue pesticides from palm oil by liquid-liquid extraction/low-temperature purification (LLE/LTP coupled with dispersive solid-phase extraction (d-SPE as the cleanup procedure with the determination by liquid chromatography mass spectrometry using electrospray as the ionization source (LC-ESI-MS was carried out. Optimization approaches were studied in terms of d-SPE to select efficiency of type and mass of adsorbents to obtain the highest recovery yield of pesticides and the lowest coextract fat residues in the final extract. The optimal conditions of d-SPE were obtained using 3 g of palm oil, 4 g anhydrous MgSO4, 150 mg of PSA, and 50 mg of GCB (PSA: GCB (3 : 1 w/w. Recovery study was performed at three concentration levels (25, 50, and 100 ng kg−1, yielding recovery rates between 71.8 and 112.4% except diuron with relative standard deviations of 3.2–15.1%. Detection and quantification limits were lower than 2.7 and 8.2 ng kg−1, respectively. The proposed method was successfully applied to the analysis of market-purchased palm oil samples from two different brands collected in Kuala Lumpur, showing its potential applicability and revealing the presence of some of the target species in the ng g−1 range.

  13. Determination of Phthalate Plasticisers in Palm Oil Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC

    Directory of Open Access Journals (Sweden)

    Nazarudin Ibrahim

    2014-01-01

    Full Text Available Contamination of phthalates plasticisers to food has raised concern as some of the phthalates are suspected to be endocrine disruptors. The phthalates have high affinity with oily environment and analysing these chemicals in such matrices is difficult because of the trace amount of the analyte and interference from matrix. An online solid phase extraction (SPE technique using a large volume (3.5 mL injection was developed for the analysis of 6 common plasticisers in palm oil. A simple sample preparation involving alumina as a fat retainer and methanol : acetonitrile (1 : 1 as the extraction solvent was performed prior to the usage of online SPE-LC system. This system consists of two columns, C16 for the solid phase extraction (SPE and C18 as the analytical column, and a photo diode array detector. The calibration curves were linear from 5 to 1000 μg L−1, with correlation coefficients above 0.99. The instrumental limit of detection was 3 μg L−1 and satisfactory recovery was obtained. A screening on a few samples in the retail market revealed the presence of dibutyl phthalate (DBP and butylbenzylphthalate (BBP in the palm oil, with concentration less than 1 mg L−1.

  14. Development and optimization of the SPE procedure for determination of pharmaceuticals in water samples by HPLC-diode array detection.

    Science.gov (United States)

    Mutavdzić Pavlović, Dragana; Babić, Sandra; Dolar, Davor; Asperger, Danijela; Kosutić, Kresimir; Horvat, Alka J M; Kastelan-Macan, Marija

    2010-02-01

    This paper focuses on the investigation of different types of SPE sorbents for the preconcentration of eight veterinary pharmaceuticals from water samples. The pharmaceuticals studied were sulfamethazine, sulfadiazine, sulfaguanidine, trimethoprim, oxytetracycline, enrofloxacin, norfloxacin and penicillin G/procaine. Five different SPE materials (Strata-X, Strata-X-C, Strata SDB-L, Strata C8 and Strata C18) from Phenomenex were compared with Oasis HLB with a view to obtaining the best cartridges for all pharmaceuticals investigated. Extraction efficiency was determined by HPLC with diode array detection (DAD). HPLC-DAD separation and quantification of the selected pharmaceuticals were carried out under gradient elution by a binary mixture of 0.01 M oxalic acid and ACN based on cyano modified column (LiChrosphere 100 CN) from Merck. Strata-X provided the best results in the preconcentration of 100 mL water samples, yielding average pharmaceutical recoveries of higher than 90%, except for sulfaguanidine (76.1%). The developed Strata-X-HLPC-DAD method was validated and applied, for the efficient investigation of reverse osmosis/nanofiltration membranes and for the removal of these eight pharmaceuticals from the production wastewater samples. NF90 and XLE membranes were shown to be the best for the rejection of all investigated pharmaceuticals.

  15. On-line SPE-UHPLC method using fused core columns for extraction and separation of nine illegal dyes in chilli-containing spices.

    Science.gov (United States)

    Khalikova, Maria A; Satínský, Dalibor; Smidrkalová, Tereza; Solich, Petr

    2014-12-01

    The presented work describes the development of a simple, fast and effective on-line SPE-UHPLC-UV/vis method using fused core particle columns for extraction, separation and quantitative analysis of the nine illegal dyes, most frequently found in chilli-containing spices. The red dyes Sudan I-IV, Sudan Red 7B, Sudan Red G, Sudan Orange G, Para Red, and Methyl Red were separated and analyzed in less than 9 min without labor-consuming pretreatment procedure. The chromatographic separation was performed on Ascentis Express RP-Amide column with gradient elution using mixture of acetonitrile and water, as a mobile phase at a flow rate of 1.0 mL min(-1) and 55°C of temperature. As SPE sorbent for cleanup and pre-concentration of illegal dyes short guard fused core column Ascentis Express F5 was used. The applicability of proposed method was proven for three different chilli-containing commercial samples. Recoveries for all compounds were between 90% and 108% and relative standard deviation ranged from 1% to 4% for within- and from 2% to 6% for between-day. Limits of detection showed lower values than required by European Union regulations and were in the range of 3.3-10.3 µg L(-1) for standard solutions, 5.6-235.6 µg kg(-1) for chilli-containing spices.

  16. Integrated Solid-Phase Extraction-Capillary Liquid Chromatography (speLC) Interfaced to ESI-MS/MS for Fast Characterization and Quantification of Protein and Proteomes

    DEFF Research Database (Denmark)

    Falkenby, Lasse Gaarde; Such-Sanmartín, Gerard; Larsen, Martin Røssel;

    2014-01-01

    in 30 h demonstrated the throughput, stability, and reproducibility of the system. The speLC-MS/MS system detected low-femtomole amounts of peptides and allowed sequencing of 1 μg of HeLa cells protein extracts at a rate of ∼90 peptides/min, identifying more than 1500 peptides (>500 proteins) in a 10...... min speLC-MS/MS experiment. Analysis by selected reaction monitoring by speLC-SRM-MS/MS of distinct peptides derived from the blood proteins IGF1, IGF2, IBP2, and IBP3 demonstrated protein quantification with CV values below 10% across 96 replicates. The speLC-MS/MS system is ideally suited for fast...

  17. Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Bryan Gazda

    2004-12-19

    Although having recently been extremely successful gathering data on the surface of Mars, robotic missions are not an effective substitute for the insight and knowledge about our solar system that can be gained though first-hand exploration. Earlier this year, President Bush presented a ''new course'' for the U.S. space program that shifts NASA's focus to the development of new manned space vehicles to the return of humans to the moon. Re-establishing the human presence on the moon will eventually lead to humans permanently living and working in space and also serve as a possible launch point for missions into deeper space. There are several obstacles to the realization of these goals, most notably the lack of life support and environmental regeneration and monitoring hardware capable of functioning on long duration spaceflight. In the case of the latter, past experience on the International Space Station (ISS), Mir, and the Space Shuttle has strongly underscored the need to develop broad spectrum in-flight chemical sensors that: (1) meet current environmental monitoring requirements on ISS as well as projected requirements for future missions, and (2) enable the in-situ acquisition and analysis of analytical data in order to further define on-orbit monitoring requirements. Additionally, systems must be designed to account for factors unique to on-orbit deployment such as crew time availability, payload restrictions, material consumption, and effective operation in microgravity. This dissertation focuses on the development, ground testing, and microgravity flight demonstration of Colorimetric Solid Phase Extraction (C-SPE) as a candidate technology to meet the near- and long-term water quality monitoring needs of NASA. The introduction will elaborate further on the operational and design requirements for on-orbit water quality monitoring systems by discussing some of the characteristics of an ''ideal'' system. A

  18. Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies

    Energy Technology Data Exchange (ETDEWEB)

    Gazda, Daniel Bryan [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Although having recently been extremely successful gathering data on the surface of Mars, robotic missions are not an effective substitute for the insight and knowledge about our solar system that can be gained though first-hand exploration. Earlier this year, President Bush presented a ''new course'' for the U.S. space program that shifts NASA's focus to the development of new manned space vehicles to the return of humans to the moon. Re-establishing the human presence on the moon will eventually lead to humans permanently living and working in space and also serve as a possible launch point for missions into deeper space. There are several obstacles to the realization of these goals, most notably the lack of life support and environmental regeneration and monitoring hardware capable of functioning on long duration spaceflight. In the case of the latter, past experience on the International Space Station (ISS), Mir, and the Space Shuttle has strongly underscored the need to develop broad spectrum in-flight chemical sensors that: (1) meet current environmental monitoring requirements on ISS as well as projected requirements for future missions, and (2) enable the in-situ acquisition and analysis of analytical data in order to further define on-orbit monitoring requirements. Additionally, systems must be designed to account for factors unique to on-orbit deployment such as crew time availability, payload restrictions, material consumption, and effective operation in microgravity. This dissertation focuses on the development, ground testing, and microgravity flight demonstration of Colorimetric Solid Phase Extraction (C-SPE) as a candidate technology to meet the near- and long-term water quality monitoring needs of NASA. The introduction will elaborate further on the operational and design requirements for on-orbit water quality monitoring systems by discussing some of the characteristics of an ''ideal'' system. A

  19. Increasing the large scale feasibility of a solid phase extraction procedure for the recovery of natural antioxidants from olive mill wastewaters

    OpenAIRE

    Scoma, Alberto; Pintucci, Cristina; Bertin, Lorenzo; Carlozzi, Pietro; Fava, Fabio

    2012-01-01

    The present investigation was focused on improving the feasibility of large scale applications of a solid phase extraction (SPE) procedure dedicated to the recovery of polyphenols from olive mill wastewaters (OMWs). To this aim, a previously developed SPE procedure was optimized in terms of contact time without negatively affecting the overall process productivity. The possibility of regenerating and recycling both the solid phase (Amberlite XAD16 non-polar resin) and the extraction solvent (...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    the isocratic solid phase extraction-liquid chromatography (SPE-LC) technology for rapid separation ( approximately 8 min) of simple peptide samples. We now extend these studies to demonstrate the potential of SPE-LC separation in combination with a hybrid linear ion trap-Orbitrap tandem mass spectrometer......Reversed-phase liquid chromatography interfaced to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) allows analysis of very complex peptide mixtures at great sensitivity, but it can be very time-consuming, typically using 60 min, or more, per sample analysis. We recently introduced...

  1. High Purity DNA Extraction with a SPE Microfluidic Chip Using KI as the Binding Salt

    Institute of Scientific and Technical Information of China (English)

    Xing CHEN; Da Fu CUI; Chang Chun LIU

    2006-01-01

    Based on solid phase extraction method, a novel silicon-PDMS-glass microchip for high purity DNA extraction has been developed by using KI as the binding salt. The microfluidic chip fabricated by MEMS technology was composed of a silicon substrate with a coiled channel and a compounded PDMS-glass cover. With this microfluidic chip, the wall of the coiled channel was used as solid phase matrix for binding DNA and DNA was extracted by the fluxion of the binding buffer, washing buffer and elution buffer. KI as a substitute for guanidine, was used successfully as binding salt for purification DNA, obtaining higher purity of genomic DNA and about 13.9 ng DNA from 1 μL rat whole blood in 35 minutes.

  2. Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

    Science.gov (United States)

    Gazda, Daniel B.; Schultz, John R.; Clarke, Mark S.

    2007-01-01

    Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

  3. Solid-phase extraction and purification of membrane proteins using a UV-modified PMMA microfluidic bioaffinity μSPE device.

    Science.gov (United States)

    Battle, Katrina N; Jackson, Joshua M; Witek, Małgorzata A; Hupert, Mateusz L; Hunsucker, Sally A; Armistead, Paul M; Soper, Steven A

    2014-03-21

    We present a novel microfluidic solid-phase extractionSPE) device for the affinity enrichment of biotinylated membrane proteins from whole cell lysates. The device offers features that address challenges currently associated with the extraction and purification of membrane proteins from whole cell lysates, including the ability to release the enriched membrane protein fraction from the extraction surface so that they are available for downstream processing. The extraction bed was fabricated in PMMA using hot embossing and was comprised of 3600 micropillars. Activation of the PMMA micropillars by UV/O3 treatment permitted generation of surface-confined carboxylic acid groups and the covalent attachment of NeutrAvidin onto the μSPE device surfaces, which was used to affinity select biotinylated MCF-7 membrane proteins directly from whole cell lysates. The inclusion of a disulfide linker within the biotin moiety permitted release of the isolated membrane proteins via DTT incubation. Very low levels (∼20 fmol) of membrane proteins could be isolated and recovered with ∼89% efficiency with a bed capacity of 1.7 pmol. Western blotting indicated no traces of cytosolic proteins in the membrane protein fraction as compared to significant contamination using a commercial detergent-based method. We highlight future avenues for enhanced extraction efficiency and increased dynamic range of the μSPE device using computational simulations of different micropillar geometries to guide future device designs.

  4. Determination of Rotenone Residues in Foodstuffs by Solid-Phase Extraction(SPE)and Liquid Chromatography/Tandem Mass Spectrometry(LC-MS/MS)

    Institute of Scientific and Technical Information of China (English)

    XU Dun-ming; ZHOU Yu; LIN Li-yi; ZHANG Zhi-gang; ZHANG Jin; LU Sheng-yu; YANG Fang; HUANG Peng-ying

    2010-01-01

    We developed a novel approach to determine rotenone residues in foodstuffs,by integrating solid-phase extraction(SPE)and liquid chromatography/tandem mass spectrometry(LC-MS/MS)technologies,to achieve high sensitivity and selectivity.In our method,the solvent extraction with n-hexane-dichloromethane(50:50,v/v)and cleanup with florisil SPE cartridges using ethyl acetate-ethyl ether(25:75,v/v)as eluents provided adequate recovery of rotenone.The detection of rotenone was then carried out by LC-MS/MS using acetonitrile-water with the 0.1% formic acid(w/v)as the mobile phase.The multiple reaction monitoring(MRM)scheme employed in the approach involved the transitions of the precursor ion to three selected product ions,in which one pair for quantification was m/z 395.3>213.2 and the other two pairs for identification were m/z 395.3>192.2 and 395.3>367.0.The limits of quantification(LOQs)of the method ranged from 0.001 to 0.005 mg kg-1 depending on the matrix,Intra-and inter-day precisions(relative standard deviations,RSDs)for rotenone were less than 7.1 and 14.8%,respectively.Results from repetitive analysis suggested good reproducibility of the method for rotenone residue detection.The recoveries at three concentrations(LOQ,10LOQ and 100LOQ)ranged from 79.3-118.3% in cabbage,potato,onion,carrot,apple,orange,banana,lichee,tea,and Shiitake mushroom.The proposed procedure was then applied to the analysis of 129 real samples collected from Xiamen,Fujian Province,China.The existence of rotenone was found in two tea products with concentrations of 0.012 and 0.016 mg kg-1,respectively.The method has great potential for routine analysis of monitoring rotenone residue in foodstuffs.

  5. Development of Chromatographic Fingerprints of Eurycoma longifolia (Tongkat Ali) Roots Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC).

    Science.gov (United States)

    Zaini, Nor Nasriah; Osman, Rozita; Juahir, Hafizan; Saim, Norashikin

    2016-04-30

    E. longifolia is attracting interest due to its pharmacological properties and pro-vitality effects. In this study, an online SPE-LC approach using polystyrene divinyl benzene (PSDVB) and C18 columns was developed in obtaining chromatographic fingerprints of E. longifolia. E. longifolia root samples were extracted using pressurized liquid extraction (PLE) technique prior to online SPE-LC. The effects of mobile phase compositions and column switching time on the chromatographic fingerprint were optimized. Validation of the developed method was studied based on eurycomanone. Linearity was in the range of 5 to 50 µg∙mL(-1) (r² = 0.997) with 3.2% relative standard deviation of peak area. The developed method was used to analyze 14 E. longifolia root samples and 10 products (capsules). Selected chemometric techniques: cluster analysis (CA), discriminant analysis (DA), and principal component analysis (PCA) were applied to the fingerprint datasets of 37 selected peaks to evaluate the ability of the chromatographic fingerprint in classifying quality of E. longifolia. Three groups were obtained using CA. DA yielded 100% correlation coefficient with 19 discriminant compounds. Using PCA, E. longifolia root samples were clearly discriminated from the products. This study showed that the developed online SPE-LC method was able to provide comprehensive evaluation of E. longifolia samples for quality control purposes.

  6. Development of Chromatographic Fingerprints of Eurycoma longifolia (Tongkat Ali Roots Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC

    Directory of Open Access Journals (Sweden)

    Nor Nasriah Zaini

    2016-04-01

    Full Text Available E. longifolia is attracting interest due to its pharmacological properties and pro-vitality effects. In this study, an online SPE-LC approach using polystyrene divinyl benzene (PSDVB and C18 columns was developed in obtaining chromatographic fingerprints of E. longifolia. E. longifolia root samples were extracted using pressurized liquid extraction (PLE technique prior to online SPE-LC. The effects of mobile phase compositions and column switching time on the chromatographic fingerprint were optimized. Validation of the developed method was studied based on eurycomanone. Linearity was in the range of 5 to 50 µg∙mL−1 (r2 = 0.997 with 3.2% relative standard deviation of peak area. The developed method was used to analyze 14 E. longifolia root samples and 10 products (capsules. Selected chemometric techniques: cluster analysis (CA, discriminant analysis (DA, and principal component analysis (PCA were applied to the fingerprint datasets of 37 selected peaks to evaluate the ability of the chromatographic fingerprint in classifying quality of E. longifolia. Three groups were obtained using CA. DA yielded 100% correlation coefficient with 19 discriminant compounds. Using PCA, E. longifolia root samples were clearly discriminated from the products. This study showed that the developed online SPE-LC method was able to provide comprehensive evaluation of E. longifolia samples for quality control purposes.

  7. A rapid, solid phase extraction (SPE technique for the extraction and gas chromatographic determination lindane pesticide residue in tissue and milk

    Directory of Open Access Journals (Sweden)

    Yuningsih

    2006-03-01

    Full Text Available Organochlorine pesticide contamination in feed can cause residue in animal product (tissue and milk, so its become a problem in food safety. Solid phase extraction (SPE has been carried out for determination organochlorine pesticide residues in food animal production. The technique was rapid, not costly and produce limited amount of hazardous-waste. Samples were homogenized with acetonitrile trough cartridge C18, eluted in fluorocyl column with 2% ether-petroleum or acetonitrile fortissue and milk samples respectively. The recoveries of tissue sample by addition lindane standard solution: 0.50 and 1.00 μg are 85.10 and 103.10% respectively, while that of milk with the addition of 0.50, 1.00 and 1.50 μg are 83.80, 88.69 and 91.24% respectively. Three replicates were carried out for every sample. According of validation criteria of FAO/IAEA the recovery for analysis of pesticide residues was 70-110%. Therefore, the method is applicable.

  8. Chelating agent free solid phase extraction (CAF-SPE) method for separation and/or preconcentration of iron(III) ions

    OpenAIRE

    for, Chelating agent free solid phase extract

    2014-01-01

    This paper presents a chelating agent free solid phase extraction (CAF-SPE) method for the separation and/or preconcentration of trace iron(III) ions. This method is based on the sorption of Fe(III) ions without using any chelating agent onto Amberlyst 36 resin. A good relative standard deviation (3%), high recovery (>95%), high enrichment factor (100), and low detection limit (0.32 m g L-1) were obtained. The adsorption capacity of resin was 117 mg g-1 for iron(III). The me...

  9. Extração em fase sólida (SPE e micro extração em fase sólida (SPME de piretróides em água Solid-phase extraction (SPE and solid-phase microextraction of pyrethroids in water

    Directory of Open Access Journals (Sweden)

    Wilma Regina Barrionuevo

    2001-04-01

    Full Text Available The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE and solid phase microextraction (SPME. The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD. Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.

  10. High-throughput assay for quantification of the plasma concentrations of thiopental using automated solid phase extraction (SPE) directly coupled to LC-MS/MS instrumentation.

    Science.gov (United States)

    Moosavi, Seyed Mojtaba; Shekar, Kiran; Fraser, John; Smith, Maree T; Ghassabian, Sussan

    2016-12-01

    Most previous assays for thiopental are time-consuming due to laborious sample extraction steps prior to analysis using gas chromatography or high pressure liquid chromatography. Here, we describe the first high-throughput liquid chromatography - tandem mass spectrometry (LC-MS/MS) method for quantification of thiopental concentrations in samples of human plasma. Robotic on-line solid phase extraction (SPE) was used to elute the analytes of interest from samples of human plasma (50μL) loaded onto C18 SPE cartridges to which were added aliquots (50μL) of internal standard solution (thiopental-d5 100ng/mL) and 0.5% formic acid in water (100μL). Cartridges were washed using 10% methanol in ammonium acetate buffer (50mM, pH 7) before elution with mobile phase comprising 0.1% formic acid in water and acetonitrile with a flow rate of 0.55mL/min using a 7.2min run time. The analytes were separated on a C18 XTerra(®) analytical column. Mass spectrometry detection was performed using a QTrap 5500 mass spectrometer (AB Sciex) with negative ionisation. The multiple reaction monitoring (MRM) transitions for thiopental and the internal standard were 241→58, and 246→58, respectively. The calibration curve was linear over a range of 6-600ng/mL. Thiopental was stable in human plasma samples for at least 36h in the autosampler, as well as after three cycles of freeze and thaw, and after 3h storage at room temperature. The absolute recovery and matrix effect were 102% and 6.9%, respectively, and the within-run and between-run precision and accuracy were ≤15%. Our method is fully-validated and satisfies the requirements of the 2012 European Medicines Agency (EMEA) guideline for Bioanalytical Method Validation. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Perfluorinated compounds (PFCs) in groundwater and aqueous soil extracts: using inline SPE-LC-MS/MS for screening and sorption characterisation of perfluorooctane sulphonate and related compounds

    Energy Technology Data Exchange (ETDEWEB)

    Enevoldsen, Rasmus [Geological Survey of Denmark and Greenland (GEUS), Department of Geochemistry, Copenhagen (Denmark); Novo Nordisk A/S, Kalundborg (Denmark); Juhler, Rene K. [Geological Survey of Denmark and Greenland (GEUS), Department of Geochemistry, Copenhagen (Denmark)

    2010-10-15

    Perfluorinated compounds (PFCs) have been recognised as emerging pollutants of global relevance. A fully automated method with inline solid-phase extraction coupled to electrospray ionisation liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) is presented and used for characterisation of soil adsorption and desorption for six PFCs: perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorobutane sulphonate (PFBS), and perfluorooctane sulphonate (PFOS). The method reduces sample turnaround time and solvent consumption and is suitable for low volume sampling. The only sample preparation necessary for water samples was sedimentation by centrifugation. The method has a total runtime of 21 min including inline sample cleanup (2 min for injection and SPE, 14 min for the chromatographic separation, 5 min for reconditioning). Negative AP-ESI with selective reaction monitoring (SRM) was used and the method was documented for quantification of the six environmentally important PFCs in subsoil matrix and related aqueous matrixes (groundwater and drainage water). Linearity was demonstrated in the range 5 to 2,500 ng/l and the LOD was between 2 and 8 ng/l in groundwater. Adsorption was characterised by linear Freundlich isotherms for all six compounds in two agricultural top soils (A horizon, sandy and clayey soil).Variability in sorption characteristics for soil types as well as compound properties were found, and correlation between the organic carbon normalised sorption coefficient (K{sub OC}) and PFC molecular weight was demonstrated. The K{sub d} values were in the range 0.1 to 33 (l/kg), and 0.3 to 65 (l/kg) for sorption and desorption respectively. (orig.)

  12. Design of online solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) hyphenated systems for quantitative analysis of small organic compounds in biological matrices.

    Science.gov (United States)

    Kuklenyik, Zsuzsanna; Calafat, Antonia M; Barr, John R; Pirkle, James L

    2011-12-01

    Three online solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method examples are presented where two different types of chromatographic columns or solvent systems were coupled to meet specific analytical objectives: (i) SPE of target analytes by restricted access media from high ionic strength urine matrix was coupled with reversed phase LC-MS/MS conditions accommodating high ionization potentials of the analytes (urinary bisphenol A and other phenolic derivatives); (ii) strong cation exchange SPE of analytes of diverse polarity and pK(a) was coupled with reversed phase LC-MS/MS analysis (urinary atrazine metabolites); (iii) pre-concentration of low pg per sample analytes by weak anion exchange SPE was hyphenated with ion pair LC-MS analysis (intracellular nucleotide triphosphate analogs). With these examples we suggest a conductive generic work flow for the development of online SPE-LC-MS methods and show how advanced commercial LC devices and software allow for the design of complex yet highly versatile analytical separation systems suited to the unique physicochemical properties of the target analytes.

  13. Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum (LLE-GCMS)and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

    Institute of Scientific and Technical Information of China (English)

    MA Xiaoyan; GAO Naiyun; CHEN Beibei; LI Qingsong; ZHANG Qiaoli; GU Guofen

    2007-01-01

    Two sample preparation methods were introduced and compared in this paper to establish a simple,quick and exact analysis of geosmin and 2-methylisoborneol.LC-18 column was employed in solid phase extraction (SPE),1.0 mL of hexane was adopted in liquid-liquid extraction(LLE),and the extracts were analyzed by gas chromatograph mass spectrum (GCMS) in selected ion mode.Mean recoveries of SPE were low for 2-methylisoborneol (2-MIB)and geosmin (GSM) with values below 50%.For LLE,the recoveries were satisfyingly above 50% for 2-MIB and 80% for GSM.Detection limits of the LLE method were as low as 1.0 ng/L for GSM and 5.0 ng/L for 2-MIB.A year-long investigation on odor chemicals of drinking water in Shanghai demonstrated that in the summer,there was a serious odor problem induced by a high concentration of 2-MIB.The highest concentration of 152.82 ng/L appeared in July in raw water,while GSM flocculation was minimal with concentrations below odor threshold.

  14. Dual High-Resolution α-Glucosidase and Radical Scavenging Profiling Combined with HPLC-HRMS-SPE-NMR for Identification of Minor and Major Constituents Directly from the Crude Extract of Pueraria lobata

    DEFF Research Database (Denmark)

    Liu, Bingrui; Kongstad, Kenneth Thermann; Qinglei, Sun

    2015-01-01

    The crude methanol extract of Pueraria lobata was investigated by dual high-resolution α-glucosidase inhibition and radical scavenging profiling combined with hyphenated HPLC-HRMS-SPE-NMR. Direct analysis of the crude extract without preceding purification was facilitated by combining chromatograms...... from two analytical-scale HPLC separations of 120 and 600 μg on-column, respectively. High-resolution α-glucosidase and radical scavenging profiles were obtained after microfractionation of the eluate in 96-well microplates. This allowed full bioactivity profiling of individual peaks in the HPLC...... chromatogram of the crude methanol extract. Subsequent HPLC-HRMS-SPE-NMR analysis allowed identification of 21 known compounds in addition to two new compounds, i.e., 3′-methoxydaidzein 8-C-[α-d-apiofuranosyl-(1→6)]-β-d-glucopyranoside and 6″-O-malonyl-3′-methoxydaidzin, as well as an unstable compound...

  15. Analysis of xanthines in beverages using a fully automated SPE-SPC-DAD hyphenated system

    Energy Technology Data Exchange (ETDEWEB)

    Medvedovici, A. [Bucarest Univ., Bucarest (Romania). Faculty of Chemistry, Dept. of Analytical Chemistry; David, F.; David, V.; Sandra, P. [Research Institute of Chromatography, Kortrijk (Belgium)

    2000-08-01

    Analysis of some xanthines (caffeine, theophylline and theobromine) in beverages has been achieved by a fully automated on-line Solid Phase Extraction - Supercritical Fluid Chromatography - Diode Array Detection (Spe - Sofc - Dad). Three adsorbents have been tested for the Spe procedure: octadecyl modified silicagel (ODS) and two types of styrene-divinylbenzen copolymer based materials, from which Porapack proved to be the most suitable adsorbent. Optimisation and correlation of both Spe and Sofc operational parameters are also discussed. By this technique, caffeine was determined in ice tea and Coca-Cola in a concentration of 0.15 ppm, theobromine - 1.5 ppb, and theophylline - 0.15 ppb. [Italian] Si e' realizzata l'analis di alcune xantine (caffeina, teofillina e teobromina) mediante un sistema, in linea, completamente automatizzato basato su Estrazione in Fase Solida - Cromatografia in Fase Supercritica - Rivelazione con Diode Array (Spe - Sfc - Dad). Per la procedura Spe sono stati valutati tre substrati: silice ottadecilica (ODS) e due tipi di materiali polimerici a base stirene-divinilbenzene, di cui, quello denominato PRP-1, e' risultato essere il piu' efficiente. Sono discusse sia l'ottimizzazione che la correlazione dei parametri operazionali per la Spe e la Sfc. Con questa tecnica sono state determinate, in te' ghiacciato e Coca-Cola, la caffeina, la teobromina e la teofillina alle concentrazini di 0.15, 1.5 e 0.15 ppm.

  16. Relationship between magnesium extracted by 0.01 M calcium chloride extraction procedure and conventional procedures

    NARCIS (Netherlands)

    Erp, van P.J.; Houba, V.J.G.; Reijneveld, J.A.; Beusichem, van M.L.

    2001-01-01

    A multinutrient soil extraction procedure in routine soil testing is attractive. Therefore, it has been suggested to convert conventional soil testing programs into a 0.01 M calcium chloride (CaCl2) multinutrient soil testing program using the relationship between test values of the 0.01 M CaCl2 ext

  17. Relationship between magnesium extracted by 0.01 M calcium chloride extraction procedure and conventional procedures

    NARCIS (Netherlands)

    Erp, van P.J.; Houba, V.J.G.; Reijneveld, J.A.; Beusichem, van M.L.

    2001-01-01

    A multinutrient soil extraction procedure in routine soil testing is attractive. Therefore, it has been suggested to convert conventional soil testing programs into a 0.01 M calcium chloride (CaCl2) multinutrient soil testing program using the relationship between test values of the 0.01 M CaCl2 ext

  18. Improved methods for urinary atrazine mercapturate analysis-Assessment of an enzyme-linked immunosorbent assay (ELISA) and a novel liquid chromatography-mass spectrometry (LC-MS) method utilizing online solid phase extraction (SPE)

    Energy Technology Data Exchange (ETDEWEB)

    Koivunen, Marja E. [Department of Entomology and the UC Davis Cancer Center, University of California, Davis (United States); Dettmer, Katja [Department of Entomology and the UC Davis Cancer Center, University of California, Davis (United States); Vermeulen, Roel [Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Rockville, MD (United States); Bakke, Berit [Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Rockville, MD (United States); National Institute of Occupational Health, Oslo (Norway); Gee, Shirley J. [Department of Entomology and the UC Davis Cancer Center, University of California, Davis (United States); Hammock, Bruce D. [Department of Entomology and the UC Davis Cancer Center, University of California, Davis (United States)]. E-mail: bdhammock@ucdavis.edu

    2006-07-21

    Elimination of interfering substances in urine by solid phase extraction (SPE) prior to analysis resulted in 10-fold improvement in the sensitivity of atrazine mercapturate (AM) enzyme-linked immunosorbent assay (ELISA) compared to previous reports. Of the two tested SPE systems, Oasis[reg] HLB and MCX, the mixed-mode MCX gave good recoveries (82%) of AM in spiked samples measured by ELISA, whereas the reverse-phase HLB phase was not compatible with the immunochemical method. At relatively high concentrations of urinary AM (>20 ng mL{sup -1}), sample dilution was effective enough for the elimination of interfering substances. The new liquid chromatography-mass spectrometry (LC-MS) method developed for AM utilizes online-SPE with Oasis[reg] HLB, column switching and a stable-isotope internal standard. The limit of quantification (0.05 ng mL{sup -1}) indicates improved sensitivity compared with most previously published LC-MS methods for AM. Validation of all three methods, LC-MS, ELISA + SPE and ELISA + dilution with spiked urine samples showed good correlation between the known and measured concentrations with R {sup 2} values of 0.996, 0.957 and 0.961, respectively. When a set (n = 70 plus 12 blind duplicates) of urine samples from farmers exposed to atrazine was analyzed, there was a good agreement (R {sup 2} = 0.917) between the log normalized data obtained by ELISA + SPE and LC-MS. High correlation among the data obtained by the two tested methods and the LC-MS method by the Center of Disease Control and Prevention (CDC), together with low variability among the blind duplicates, suggests that both methods reported here would be suitable for the analysis of urinary AM as a biomarker for human exposure of atrazine.

  19. Schistosoma mansoni antigenic extracts obtained by different extraction procedures

    Directory of Open Access Journals (Sweden)

    Miriam Tendler

    1981-06-01

    Full Text Available Solubilization of Schistosoma mansoni antigens was obtained by agitation of adult worms in a 3M KCl solution. The protein contents of the KCl extrats varied from 0.35 to 0.96 mg/ml. Sera from 97 patients with hepatointestinal shistosomiasis and viable eggs in stools from a Brazilian endemic area were studied by immunoelectroomophoresis and Ouchterlony immunodiffusion methods with the KCl extract and with another antigen, obtained by homogenization of adult schistosomes in saline. The rate of positiveness of immunoprecipitation deterctions by immunoelectroomophoresis with the KCl extract was 53.5%. A correlation was verified between methods of detection and extration procedures, resulting in a better association of the extract obtained by agitation in 3M KCl and immunoelectroomophoresis.Foi obtida a solubilização de antígenos do Schistosoma mansoni por agitação de vermes adultos em solução de KCl 3M. O teor protéico dos extratos de KCl variou de 0,35 a 0,96mg/ ml. Foram testados pelos métodos de imunoeletroosmoforese (IEOP e dupla imunodifusão (Ouchterlony, 97 soros de doentes de area endêmica brasileira de esquistossomose, forma clínica hepatointestinal e com exames coprológicos positivos para S. mansoni, com o extrato de KCl e outro antígeno obtido pela homogenização de vermes adultos em salina. A taxa de positividade das reações de imunoprecipitação por IEOP com o antígeno extraído pela ação do KCl 3M foi 53,5%. Foi verificada a correlação entre os métodos de detecção e de extração resultando numa melhor associação entre o extrato obtido por agitação no KCl 3M e a IEOP.

  20. Chelating agent free-solid phase extraction (CAF-SPE) of Co(II), Cu(II) and Cd(II) by new nano hybrid material (ZrO{sub 2}/B{sub 2}O{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Yalcinkaya, Ozcan [Gazi University, Science Faculty, Department of Chemistry, 06500, Ankara (Turkey); Kalfa, Orhan Murat [Dumlupinar University, Science and Art Faculty, Department of Chemistry, 43100, Kuetahya (Turkey); Tuerker, Ali Rehber, E-mail: aturker@gazi.edu.tr [Gazi University, Science Faculty, Department of Chemistry, 06500, Ankara (Turkey)

    2011-11-15

    Highlights: {yields} A novel sorbent for solid phase extraction for the preconcentration of metal ions. {yields} Hybrid nano-scale ZrO{sub 2}/B{sub 2}O{sub 3} as a new SPE material. {yields} There is a no need for using any chelating agents before the preconcentration procedure. - Abstract: New nano hybrid material (ZrO{sub 2}/B{sub 2}O{sub 3}) was synthesized and applied as a sorbent for the separation and/or preconcentration of Co(II), Cu(II) and Cd(II) in water and tea leaves prior to their determination by flame atomic absorption spectrometry. Synthesized nano material was characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction. The optimum conditions for the quantitative recovery of the analytes, including pH, eluent type and volume, flow rate of sample solution were examined. The effect of interfering ions was also investigated. Under the optimum conditions, adsorption isotherms and adsorption capacities have been examined. The recoveries of Co(II), Cu(II) and Cd(II) were 96 {+-} 3%, 95 {+-} 3%, 98 {+-} 4% at 95% confidence level, respectively. The analytical detection limits for Co(II), Cu(II), and Cd(II) were 3.8, 3.3, and 3.1 {mu}g L{sup -1}, respectively. The reusability and adsorption capacities (32.2 mg g{sup -1} for Co, 46.5 mg g{sup -1} for Cu and 109.9 mg g{sup -1} for Cd) of the sorbent were found as satisfactory. The accuracy of the method was confirmed by analyzing certified reference material (GBW-07605 Tea leaves) and spiked real samples. The method was applied for the determination of analytes in tap water and tea leaves.

  1. Determination of ampicillin in human plasma by solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) and its use in bioequivalence studies.

    Science.gov (United States)

    Gonçalves, Talita Mota; Bedor, Danilo César Galindo; de Abreu, Luís Renato Pires; de Sousa, Carlos Eduardo Miranda; Rolim, Clarice M Bueno; de Santana, Davi Pereira

    2008-01-01

    A simple, fast, sensitive and selective solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method for the quantitative analysis of ampicillin (CAS 69-53-4) in human plasma was developed using amoxicillin as internal standard, and sample extraction by solid-phase extraction (SPE). Extracts were separated by reversed-phase C18 with aqueous mobile phase (acetonitrile, 80:20, v/v) with 0.1% formic acid. The method was validated and successfully applied in a bioequivalence study of capsules 500 mg of ampicillin. Using a short running time of 2.5 min, the lower limit of quantification (LLOQ) for obtained ampicillin was 0.1 microg/ml for a plasma sample of 250 microl and a recovery of 94.38% +/- 4.05. Bioequivalence between the products was determined by calculating 90% confidence intervals (CI) for the ratio of Cmax, AUC0-t and AUC0-inf values for the test and reference products, which were within the 0.80-1.25 interval proposed by FDA and EMEA. It is concluded that the two formulations are bioequivalent in their rate and extent of absorption, and thus, may be used interchangeably.

  2. Improved Bligh and Dyer extraction procedure

    DEFF Research Database (Denmark)

    Jensen, Søren K

    2008-01-01

    Fatty acids are specific compounds with well known chemical composition, but they exist in a great variety of molecules which differ in chemical and physical characteristics. Quantitative extraction of fatty acids is therefore a challenge. An acidic Bligh and Dyer method has been developed...... and compared with the traditional Stoldt fat extraction method. It is shown that depending on the matrix, the HCl-Bligh and Dyer extraction leads to 10-15% more total fatty acids and a 30-50% increase in polyunsaturated fatty acids compared with the official EU method. Besides being much more efficient...... for extraction of fatty acids, the HCl-Bligh and Dyer method is faster, and allows the inclusion of internal standard at the beginning of the sample treatment....

  3. Ultra preconcentration of polycyclic aromatic hydrocarbons in smoked bacon by a combination of SPE and DLLME.

    Science.gov (United States)

    Liu, Xiaofang; Zhou, Shu; Zhu, Quanfei; Ye, Yong; Chen, Huaixia

    2014-09-01

    A sample pretreatment method, solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME), was established for the sensitive determination of polycyclic aromatic hydrocarbons (PAHs) in smoked bacon samples. In the SPE-DLLME process, three PAHs including naphthalene (Naph), phenanthrene (Phen) and pyrene (Pyr) were extracted from samples and transferred into C18 SPE cartridge. The target analytes were subsequently eluted with 1.2 ml of acetonitrile-dichloromethane (5:1, v/v) mixture solution. The eluent was injected directly into the 5.0 ml ultrapure water in the subsequent DLLME procedure. The sedimented phase was concentrated under a gentle nitrogen flow to 120.0 µl. Finally, the analytes in the extraction solvent were determined by high-performance liquid chromatography with a ultra-violet detector. Some important extraction parameters affecting the performance, such as the sample solution flow rate, breakthrough volume, salt addition as well as the type and volume of the elution solvent were optimized. The developed method provided an ultra enrichment factors for PAHs ranged from 3478 to 3824. The method was applied for the selective extraction and sensitive determination of PAHs in smoked bacon samples. The limits of detection (S/N = 3) were 0.05, 0.01, 0.02 μg kg(-1) for Naph, Phen, Pyr, respectively.

  4. Solid-phase extraction procedures in systematic toxicological analysis

    NARCIS (Netherlands)

    Franke, J.P.; de Zeeuw, R.A

    1998-01-01

    In systematic toxicological analysis (STA) the substance(s) present is (are) not known at the start of the analysis. in such an undirected search the extraction procedure cannot be directed to a given substance but must be a general procedure where a compromise must be reached in that the substances

  5. High-Throughput Quantitation of Busulfan in Plasma Using Ultrafast Solid-Phase Extraction Tandem Mass Spectrometry (SPE-MS/MS).

    Science.gov (United States)

    Langman, Loralie J; Danso, Darlington; Robert, Enger; Jannetto, Paul J

    2016-01-01

    Busulfan is a commonly used antineoplastic agent to condition/ablate bone marrow cells before hematopoietic stem cell transplant. While intravenous (IV) formulations of busulfan are now available and have lower incidences of toxicity and treatment related mortality compared to oral dosing, it still displays large pharmacokinetic variability. As a result, studies have shown that therapeutic drug monitoring is clinically useful to minimize graft failure, disease reoccurrence, and toxicities like veno-occlusive disease and neurologic toxicity. Current methods for assaying busulfan include the use of GC/MS, HPLC, and LC-MS/MS. The clinical need for faster turnaround times and increased testing volumes has required laboratories to develop faster methods of analysis for higher throughput of samples. Therefore, we present a method for the quantification of busulfan in plasma using an ultrafast SPE-MS/MS which has much faster sample cycle times (<20 s per sample) and comparable analytical results to GC/MS.

  6. Analysis of trace contamination of phthalate esters in ultrapure water using a modified solid-phase extraction procedure and automated thermal desorption-gas chromatography/mass spectrometry.

    Science.gov (United States)

    Liu, Hsu-Chuan; Den, Walter; Chan, Shu-Fei; Kin, Kuan Tzu

    2008-04-25

    The present study was aimed to develop a procedure modified from the conventional solid-phase extraction (SPE) method for the analysis of trace concentration of phthalate esters in industrial ultrapure water (UPW). The proposed procedure allows UPW sample to be drawn through a sampling tube containing hydrophobic sorbent (Tenax TA) to concentrate the aqueous phthalate esters. The solid trap was then demoisturized by two-stage gas drying before subjecting to thermal desorption and analysis by gas chromatography-mass spectrometry. This process removes the solvent extraction procedure necessary for the conventional SPE method, and permits automation of the analytical procedure for high-volume analyses. Several important parameters, including desorption temperature and duration, packing quantity and demoisturizing procedure, were optimized in this study based on the analytical sensitivity for a standard mixture containing five different phthalate esters. The method detection limits for the five phthalate esters were between 36 ng l(-1) and 95 ng l(-1) and recovery rates between 15% and 101%. Dioctyl phthalate (DOP) was not recovered adequately because the compound was both poorly adsorbed and desorbed on and off Tenax TA sorbents. Furthermore, analyses of material leaching from poly(vinyl chloride) (PVC) tubes as well as the actual water samples showed that di-n-butyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) were the common contaminants detected from PVC contaminated UPW and the actual UPW, as well as in tap water. The reduction of DEHP in the production processes of actual UPW was clearly observed, however a DEHP concentration of 0.20 microg l(-1) at the point of use was still being quantified, suggesting that the contamination of phthalate esters could present a barrier to the future cleanliness requirement of UPW. The work demonstrated that the proposed modified SPE procedure provided an effective method for rapid analysis and contamination

  7. Aftershock Analysis for SPE1

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, Jerry J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Harben, Phil E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-11-08

    The current seismic data collection plan for the SPE calls for installation of seismometers and accelerometers along several profiles, radiating from ground zero, out to distances of kilometers, with instrument spacing of hundreds to thousands of meters. For the propagation studies of the SPE, only data collected at the time of detonation is needed, but by merely extending the data collection time out to several days, we are able to also use these data for aftershock studies. This report describes the aftershock data collection that took place during and after the first SPE explosion that took place on May 3, 2011.

  8. HybridSPE: A novel technique to reduce phospholipid-based matrix effect in LC-ESI-MS Bioanalysis.

    Science.gov (United States)

    Ahmad, Shafeeque; Kalra, Harsh; Gupta, Amit; Raut, Bharat; Hussain, Arshad; Rahman, Md Akhlaquer

    2012-10-01

    When complex biological materials are analyzed without an adequate sample preparation technique, MS signal and response undergo significant alteration and result in poor quantification and assay. This problem generally takes place due to the presence of several endogenous materials component in samples. One of the major causes of ion suppression in bioanalysis is the presence of phospholipids during LC-MS analysis. The phospholipid-based matrix effect was investigated with a commercially available electro spray ionization (ESI) source coupled with a triple quadrupole mass spectrometer. HybridSPE dramatically reduced the levels of residual phospholipids in biological samples, leading to significant reduction in matrix effects. This new procedure that combines the simplicity of precipitation with the selectivity of SPE allows obtaining much cleaner extracts than with conventional procedures. HybridSPE-precipitation procedure provides significant improvement in bioanalysis and a practical and fast way to ensure the avoidance of phospholipids-based matrix effects. The present review outlines the HybridSPE technique to minimize phospholipids-based matrix effects on LC-ESI-MS bioanalysis.

  9. HybridSPE: A novel technique to reduce phospholipid-based matrix effect in LC-ESI-MS Bioanalysis

    Directory of Open Access Journals (Sweden)

    Shafeeque Ahmad

    2012-01-01

    Full Text Available When complex biological materials are analyzed without an adequate sample preparation technique, MS signal and response undergo significant alteration and result in poor quantification and assay. This problem generally takes place due to the presence of several endogenous materials component in samples. One of the major causes of ion suppression in bioanalysis is the presence of phospholipids during LC-MS analysis. The phospholipid-based matrix effect was investigated with a commercially available electro spray ionization (ESI source coupled with a triple quadrupole mass spectrometer. HybridSPE dramatically reduced the levels of residual phospholipids in biological samples, leading to significant reduction in matrix effects. This new procedure that combines the simplicity of precipitation with the selectivity of SPE allows obtaining much cleaner extracts than with conventional procedures. HybridSPE-precipitation procedure provides significant improvement in bioanalysis and a practical and fast way to ensure the avoidance of phospholipids-based matrix effects. The present review outlines the HybridSPE technique to minimize phospholipids-based matrix effects on LC-ESI-MS bioanalysis.

  10. Development of a triple hyphenated HPLC-radical scavenging detection-DAD-SPE-NMR system for the rapid identification of antioxidants in complex plant extracts

    NARCIS (Netherlands)

    Pukalskas, A.; Beek, van T.A.; Waard, de P.

    2005-01-01

    A rapid method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining an HPLC with on-line radical scavenging using DPPH as a model radical and an HPLC¿DAD¿SPE¿NMR system. Using this method a commercial rosemary extract was inve

  11. Combined use of high-resolution α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for investigation of antidiabetic principles in crude plant extracts

    DEFF Research Database (Denmark)

    Kongstad, Kenneth Thermann; Özdemir, Ceylan; Barzak, Asmah

    2015-01-01

    Type 2 diabetes is a metabolic disorder affecting millions of people worldwide, and new drug leads or functional foods containing selective α-glucosidase inhibitors are needed. Crude extract of 24 plants were assessed for α-glucosidase inhibitory activity. Methanol extracts of Cinnamomum zeylanicum...

  12. Comprehensive automation of the solid phase extraction gas chromatographic mass spectrometric analysis (SPE-GC/MS) of opioids, cocaine, and metabolites from serum and other matrices.

    Science.gov (United States)

    Lerch, Oliver; Temme, Oliver; Daldrup, Thomas

    2014-07-01

    The analysis of opioids, cocaine, and metabolites from blood serum is a routine task in forensic laboratories. Commonly, the employed methods include many manual or partly automated steps like protein precipitation, dilution, solid phase extraction, evaporation, and derivatization preceding a gas chromatography (GC)/mass spectrometry (MS) or liquid chromatography (LC)/MS analysis. In this study, a comprehensively automated method was developed from a validated, partly automated routine method. This was possible by replicating method parameters on the automated system. Only marginal optimization of parameters was necessary. The automation relying on an x-y-z robot after manual protein precipitation includes the solid phase extraction, evaporation of the eluate, derivatization (silylation with N-methyl-N-trimethylsilyltrifluoroacetamide, MSTFA), and injection into a GC/MS. A quantitative analysis of almost 170 authentic serum samples and more than 50 authentic samples of other matrices like urine, different tissues, and heart blood on cocaine, benzoylecgonine, methadone, morphine, codeine, 6-monoacetylmorphine, dihydrocodeine, and 7-aminoflunitrazepam was conducted with both methods proving that the analytical results are equivalent even near the limits of quantification (low ng/ml range). To our best knowledge, this application is the first one reported in the literature employing this sample preparation system.

  13. Determination of pharmaceutical residues in drinking water in Poland using a new SPE-GC-MS(SIM) method based on Speedisk extraction disks and DIMETRIS derivatization.

    Science.gov (United States)

    Caban, Magda; Lis, Ewa; Kumirska, Jolanta; Stepnowski, Piotr

    2015-12-15

    The presence of pharmaceuticals in drinking water, even at very low concentrations, has raised concerns among stakeholders such as drinking-water regulators, governments, water suppliers and the public, with regard to the potential risks to humans. Despite this, the occurrence and the fate of pharmaceuticals in drinking waters of many countries (e.g. in Poland) remains unknown. There is a lack of sufficiently sensitive and reliable analytical methods for such analyses and a need for more in-depth hydrogeological analysis of the possible sources of drug residues in drinking water. In this paper, a multi-residual method for the simultaneous determination of seventeen human pharmaceuticals in drinking waters has been developed. Large-volume extractions using Speedisk extraction disks, and derivatization prior to GC-MS-SIM analysis using a new silylating agent DIMETRIS were applied. The method detection limits (MDLs) ranged from 0.9 to 5.7ng/L and the absolute recoveries of the target compounds were above 80% for most analytes. The developed method was successfully applied in the analysis of the target compounds in drinking water collected in Gdansk (Poland), and of the 17 pharmaceuticals, 6 compounds were detected at least once. During the investigation, the geomorphology of the site region was taken into account, possible sources of pharmaceuticals in the analysed drinking water samples were investigated, and the presence of the drugs in ground and surface waters, raw and treated drinking waters was determined. Concentrations were also compared with those observed in other countries. As a result, this study has not only developed a new analytical method for determining pharmaceuticals in drinking waters as well as rendering missing information for Poland (a country with one of the highest consumptions of pharmaceuticals in Europe), but it also presents a modelled in-depth hydrogeological analysis of the real sources of drugs in drinking waters.

  14. UHPLC-MS/MS Determination of Ochratoxin A and Fumonisins in Coffee Using QuEChERS Extraction Combined with Mixed-Mode SPE Purification

    DEFF Research Database (Denmark)

    Nielsen, Kristian Fog; Ngemela, Archard Ferdinand; Jensen, Lene Bai

    2015-01-01

    A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed...... system increased the signal intensity by 50% and decreased the ion-suppression with 50−75% in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg....../kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However...

  15. A Procedure for the supercritical fluid extraction of coal samples, with subsequent analysis of extracted hydrocarbons

    Science.gov (United States)

    Kolak, Jonathan J.

    2006-01-01

    Introduction: This report provides a detailed, step-by-step procedure for conducting extractions with supercritical carbon dioxide (CO2) using the ISCO SFX220 supercritical fluid extraction system. Protocols for the subsequent separation and analysis of extracted hydrocarbons are also included in this report. These procedures were developed under the auspices of the project 'Assessment of Geologic Reservoirs for Carbon Dioxide Sequestration' (see http://pubs.usgs.gov/fs/fs026-03/fs026-03.pdf) to investigate possible environmental ramifications associated with CO2 storage (sequestration) in geologic reservoirs, such as deep (~1 km below land surface) coal beds. Supercritical CO2 has been used previously to extract contaminants from geologic matrices. Pressure-temperature conditions within deep coal beds may render CO2 supercritical. In this context, the ability of supercritical CO2 to extract contaminants from geologic materials may serve to mobilize noxious compounds from coal, possibly complicating storage efforts. There currently exists little information on the physicochemical interactions between supercritical CO2 and coal in this setting. The procedures described herein were developed to improve the understanding of these interactions and provide insight into the fate of CO2 and contaminants during simulated CO2 injections.

  16. Volume overload cleanup: An approach for on-line SPE-GC, GPC-GC, and GPC-SPE-GC

    NARCIS (Netherlands)

    Kerkdijk, H.; Mol, H.G.J.; Nagel, B. van der

    2007-01-01

    A new concept for cleanup, based on volume overloading of the cleanup column, has been developed for on-line coupling of gel permeation chromatography (GPC), solid-phase extraction (SPE), or both, to gas chromatography (GC). The principle is outlined and the applicability demonstrated by the determi

  17. Preconcentration and determination of cadmium in water and food samples by in situ surfactant-based solid-phase extraction and flame atomic absorption spectrometry

    National Research Council Canada - National Science Library

    Jamali, Mohammad Reza; Boromandi, Afsaneh

    2014-01-01

    In situ surfactant-based solid-phase extraction (ISS-SPE) is proposed as a preconcentration procedure for the determination of cadmium in water and food samples by flame atomic absorption spectrometry...

  18. A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

    Science.gov (United States)

    Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

    2013-11-15

    A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Identification of some Bioactive Metabolites in a Fractionated Methanol Extract from Ipomoea aquatica (Aerial Parts) through TLC, HPLC, UPLC-ESI-QTOF-MS and LC-SPE-NMR Fingerprints Analyses.

    Science.gov (United States)

    Hefny Gad, Mahmoud; Tuenter, Emmy; El-Sawi, Nagwa; Younes, Sabry; El-Ghadban, El-Mewafy; Demeyer, Kristiaan; Pieters, Luc; Vander Heyden, Yvan; Mangelings, Debby

    2017-08-04

    The plant species Ipomoea aquatica contains various bioactive constituents, e.g. phenols and flavonoids, which have several medical uses. All previous studies were executed in Asia; however, no reports are available from Africa, and the secondary metabolites of this plant species from Africa are still unknown. The present study aims finding suitable conditions to identify the bioactive compounds from different fractions. Chromatographic fingerprint profiles of different fractions were developed using high-performance liquid chromatography (HPLC) and then these conditions were transferred to thin-layer chromatography (TLC). Subsequently, the chemical structure of some bioactive compounds was elucidated using ultra-performance liquid chromatography-quadrupole time of flight-tandem mass spectrometry (UPLC-QTOF-MS) and liquid chromatography-solid phase extraction-nuclear magnetic resonance (LC-SPE-NMR) spectroscopy. The HPLC fingerprints, developed on two coupled Chromolith RP-18e columns, using a gradient mobile phase (methanol/water/trifluoroacetic acid, 5:95:0.05, v/v/v), showed more peaks than the TLC profile. The TLC fingerprint allows the identification of the types of chemical constituents, e.g. flavonoids. Two flavonoids (nicotiflorin and ramnazin-3-O-rutinoside) and two phenolic compounds (dihydroxybenzoic acid pentoside and di-pentoside) were tentatively identified by QTOF-MS, while NMR confirmed the structure of rutin and nicotiflorin. The HPLC and TLC results showed that HPLC fingerprints give more and better separated peaks, but TLC helped in determining the class of the active compounds in some fractions. Bioactive constituents were identified as well using MS and NMR analyses. Two flavonoids and two phenolic compounds were tentatively identified in this species for the first time, to the best of our knowledge. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  20. On-line solid-phase extraction coupled with high-performance liquid chromatography and tandem mass spectrometry (SPE-HPLC-MS-MS) for quantification of bromazepam in human plasma: an automated method for bioequivalence studies.

    Science.gov (United States)

    Gonçalves, José Carlos Saraiva; Monteiro, Tânia Maria; Neves, Claúdia Silvana de Miranda; Gram, Karla Regina da Silva; Volpato, Nádia Maria; Silva, Vivian A; Caminha, Ricardo; Gonçalves, Maria do Rocio Bencke; Santos, Fábio Monteiro Dos; Silveira, Gabriel Estolano da; Noël, François

    2005-10-01

    A validated method for on-line solid-phase extraction coupled with high-performance liquid chromatography tandem mass spectrometry (SPE-HPLC-MS-MS) is described for the quantification of bromazepam in human plasma. The method involves a dilution of 300 muL of plasma with 100 muL of carbamazepine (2.5 ng/mL), used as internal standard, vortex-mixing, centrifugation, and injection of 100 muL of the supernate. The analytes were ionized using positive electrospray mass spectrometry then detected by multiple reaction monitoring (MRM). The m/z transitions 316-->182 (bromazepam) and 237-->194 (carbamazepine) were used for quantification. The calibration curve was linear from 1 ng/mL (limit of quantification) to 200 ng/mL. The retention times of bromazepam and carbamazepine were 2.6 and 3.2 minutes, respectively. The intraday and interday precisions were 3.43%-15.45% and 5.2%-17%, respectively. The intraday and interday accuracy was 94.00%-103.94%. This new automated method has been successfully applied in a bioequivalence study of 2 tablet formulations of 6 mg bromazepam: Lexotan(R) from Produtos Roche Químicos e Farmacêuticos SA, Rio de Janeiro, Brazil (reference) and test formulation from Laboratórios Biosintética Ltda, São Paulo, Brazil. Because the 90% CI of geometric mean ratios between reference and test were completely included in the 80%-125% interval, the 2 formulations were considered bioequivalent. The comparison of different experimental conditions for establishing a dissolution profile in vitro along with our bioavailability data further allowed us to propose rationally based experimental conditions for a dissolution test of bromazepam tablets, actually lacking a pharmacopeial monograph.

  1. Comparison of the Usefulness of SPE Cartridges for the Determination of β-Blockers and β-Agonists (Basic Drugs in Environmental Aqueous Samples

    Directory of Open Access Journals (Sweden)

    Magda Caban

    2015-01-01

    Full Text Available Even though the methodology used for the determination of β-blockers and β-agonists in environmental samples is based mainly on solid-phase extraction (SPE and gas chromatography or liquid chromatography with mass spectrometric detection, the available literature data on the applied SPE procedures is rather sparse. In this paper such comparison is presented. Moreover, the usefulness of the eight SPE cartridges for the determination of five β-blockers (acebutolol, atenolol, metoprolol, nadolol, and propranolol and two β-agonists (salbutamol and terbutaline in environmental aqueous samples using GC techniques is tested. Among them, three (the trifunction sorbent Strata Screen C, the copolymers LiChrolut EN, and the functionalized copolymer Isolute ENV+ were used for the first time for this purpose. It was confirmed that polystyrene-divinylbenzene-N-vinylpyrrolidone copolymers (PS-DVB-VP, Strata-X, and Oasis HLB cartridges have a better potential than a cation-exchange sorbent for the extraction of the target drugs from environmental water samples. However, it should be stressed out that the direct application of the tested SPE conditions for the analysis of real environmental water samples is not possible, and such parameters, like volume of loading sample, appropriate solvents for washing and elution steps, and so forth, must be optimized again in order to achieve satisfactory recovery values for the target compounds.

  2. Analysis of terpenes in white wines using SPE-SPME-GC/MS approach.

    Science.gov (United States)

    Dziadas, Mariusz; Jeleń, Henryk H

    2010-09-10

    Terpenes contribute to some white wines aroma, especially these produced from Muscat grapes and others aromatic ones of high terpene contents (Gewürtztramminer, Traminer, Huxel, Sylvaner). Terpenes are present in wine in free and bound (in a form of glycosides) forms. Analyses of bound terpenes are usually performed using solid phase extraction after hydrolysis of glycosides. A new method for determination of terpenes from wine, focused on determination of terpenes released after acidic hydrolysis, based on solid phase extraction (SPE) followed by solid phase microextraction (SPME) was developed. Non-polar (free) and polar (bound terpenes) fractions were separated on 500 mg C18 cartridges. Bound terpenes were sampled using SPME immediately after acidic hydrolysis in non-equilibrium conditions. Application of combined SPE-SPME approach allowed quantification of selected terpenes in lower concentrations than in SPE approach and added a selectivity to the method, which enabled detection of compounds non-detectable in SPE extracts. Results obtained by SPE and SPE-SPME approach were correlated for free terpenes and those released after acid hydrolysis 20 white wines obtained from different grape varieties (R(2)=0.923). Although developed for wine terpenes analysis, SPE followed by SPME approach has a great potential in analysis of other bound wine flavor compounds, especially those potent odorants present in trace amounts.

  3. Determination of amphetamines in human urine by liquid chromatography with fluorimetric detection using a solid-phase extraction procedure.

    Science.gov (United States)

    Bugamelli, Francesca; Mandrioli, Roberto; Cavallini, Annalisa; Baccini, Cesare; Conti, Matteo; Raggi, Maria Augusta

    2006-10-01

    A precise and feasible HPLC method has been developed for the analysis of amphetamine (AMPH), methamphetamine (MAMPH) and methylenedioxymethamphetamine (MDMA, ecstasy) in human urine. A chromatographic run on a C8 Genesis (150 mm x 4.6 mm, 5 microm) column maintained at 30 degrees C lasts about 17 min, using a mobile phase composed of ACN (12%) and a pH 2.5 phosphate buffer (88%) containing 0.3% triethylamine. Mirtazapine was used as the internal standard. Good linearity was found in the 100-2000 ng/mL concentration range for AMPH and MAMPH and in the 12-2000 ng/mL concentration range for MDMA. The pretreatment of urine samples was carried out by means of a careful SPE procedure on C2 cartridges. The extraction yields were very satisfactory for all analytes, with average values greater than 97%. The leading conditions allowed the determination of AMPH, MAMPH and MDMA with satisfactory precision and accuracy. The method has been successfully applied to the determination of the analytes in urine of AMPH users.

  4. Simultaneous determination of PPCPs, EDCs, and artificial sweeteners in environmental water samples using a single-step SPE coupled with HPLC-MS/MS and isotope dilution.

    Science.gov (United States)

    Tran, Ngoc Han; Hu, Jiangyong; Ong, Say Leong

    2013-09-15

    A high-throughput method for the simultaneous determination of 24 pharmaceuticals and personal care products (PPCPs), endocrine disrupting chemicals (EDCs) and artificial sweeteners (ASs) was developed. The method was based on a single-step solid phase extraction (SPE) coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and isotope dilution. In this study, a single-step SPE procedure was optimized for simultaneous extraction of all target analytes. Good recoveries (≥ 70%) were observed for all target analytes when extraction was performed using Chromabond(®) HR-X (500 mg, 6 mL) cartridges under acidic condition (pH 2). HPLC-MS/MS parameters were optimized for the simultaneous analysis of 24 PPCPs, EDCs and ASs in a single injection. Quantification was performed by using 13 isotopically labeled internal standards (ILIS), which allows correcting efficiently the loss of the analytes during SPE procedure, matrix effects during HPLC-MS/MS and fluctuation in MS/MS signal intensity due to instrument. Method quantification limit (MQL) for most of the target analytes was below 10 ng/L in all water samples. The method was successfully applied for the simultaneous determination of PPCPs, EDCs and ASs in raw wastewater, surface water and groundwater samples collected in a local catchment area in Singapore. In conclusion, the developed method provided a valuable tool for investigating the occurrence, behavior, transport, and the fate of PPCPs, EDCs and ASs in the aquatic environment.

  5. Microwave-Assisted Extraction Followed by Solid-Phase Extraction for the Chromatographic Analysis of Alkaloids in Stephania cepharantha.

    Science.gov (United States)

    Liu, Ying; Xie, Daotao; Kang, Yun; Wang, Yaqin; Yang, Ping; Guo, Jixian; Huang, Jianming

    2016-04-01

    A procedure involving microwave-assisted extraction (MAE) followed by solid-phase extraction (SPE) was established for the extraction and purification of three bisbenzylisoquinoline alkaloids from Stephania cepharantha, and a reversed-phase high-performance liquid chromatography (HPLC) method was developed for the quantification of the target alkaloids. Chromatographic separation was achieved on a Phenomenex Luna Phenyl-Hexyl column. Prior to the HPLC analysis, the alkaloids were rapidly extracted by an optimized MAE process using 0.01 mol/L hydrochloric acid as the solvent. The MAE extract was subsequently purified by SPE using a cation-exchange polymeric cartridge. The MAE-SPE procedure extracted the three alkaloids with satisfactory recoveries ranging from 100.44 to 102.12%. In comparison with the MAE, Soxhlet and ultrasonic-assisted extractions, the proposed MAE-SPE method showed satisfactory cleanup efficiency. Thus, the validated MAE-SPE-HPLC method is specific, accurate and applicable to the determination of alkaloids in S. cepharantha.

  6. Biodiesel from mixed culture algae via a wet lipid extraction procedure.

    Science.gov (United States)

    Sathish, Ashik; Sims, Ronald C

    2012-08-01

    Microalgae are a source of renewable oil for liquid fuels. However, costs for dewatering/drying, extraction, and processing have limited commercial scale production of biodiesel from algal biomass. A wet lipid extraction procedure was developed that was capable of extracting 79% of transesterifiable lipids from wet algal biomass (84% moisture) via acid and base hydrolysis (90 °C and ambient pressures), and 76% of those extracted lipids were isolated, by further processing, and converted to FAMEs. Furthermore, the procedure was capable of removing chlorophyll contamination of the algal lipid extract through precipitation. In addition, the procedure generated side streams that serve as feedstocks for microbial conversion to additional bioproducts. The capability of the procedure to extract lipids from wet algal biomass, to reduce/remove chlorophyll contamination, to potentially reduce organic solvent demand, and to generate feedstocks for high-value bioproducts presents opportunities to reduce costs of scaling up algal lipid extraction for biodiesel production.

  7. Analytical performance of three commonly used extraction methods for the gas chromatography-mass spectrometry analysis of wine volatile compounds.

    Science.gov (United States)

    Andujar-Ortiz, I; Moreno-Arribas, M V; Martín-Alvarez, P J; Pozo-Bayón, M A

    2009-10-23

    The analytical performance of three extraction procedures based on cold liquid-liquid extraction using dicloromethane (LLE), solid phase extraction (SPE) using a styrene-divinylbenzene copolymer and headspace solid phase microextraction (SPME) using a carboxen-polydimethylsiloxane coated fibre has been evaluated based on the analysis of 30 representative wine volatile compounds. From the comparison of the three procedures, LLE and SPE showed very good linearity covering a wide range of concentrations of wine volatile compounds, low detection limits, high recovery for most of the volatile compounds under study and higher sensitivity compared to the headspace-SPME procedure. The latter showed in general, poor recovery for polar volatile compounds. Despite some drawbacks associated with the LLE and SPE procedures such as the more tedious sampling treatment and the use of organic solvents, the analytical performance of both procedures showed that they are more adequate for the analysis of wine volatiles.

  8. Modelling dental implant extraction by pullout and torque procedures.

    Science.gov (United States)

    Rittel, D; Dorogoy, A; Shemtov-Yona, K

    2017-07-01

    Dental implants extraction, achieved either by applying torque or pullout force, is used to estimate the bone-implant interfacial strength. A detailed description of the mechanical and physical aspects of the extraction process in the literature is still missing. This paper presents 3D nonlinear dynamic finite element simulations of a commercial implant extraction process from the mandible bone. Emphasis is put on the typical load-displacement and torque-angle relationships for various types of cortical and trabecular bone strengths. The simulations also study of the influence of the osseointegration level on those relationships. This is done by simulating implant extraction right after insertion when interfacial frictional contact exists between the implant and bone, and long after insertion, assuming that the implant is fully bonded to the bone. The model does not include a separate representation and model of the interfacial layer for which available data is limited. The obtained relationships show that the higher the strength of the trabecular bone the higher the peak extraction force, while for application of torque, it is the cortical bone which might dictate the peak torque value. Information on the relative strength contrast of the cortical and trabecular components, as well as the progressive nature of the damage evolution, can be revealed from the obtained relations. It is shown that full osseointegration might multiply the peak and average load values by a factor 3-12 although the calculated work of extraction varies only by a factor of 1.5. From a quantitative point of view, it is suggested that, as an alternative to reporting peak load or torque values, an average value derived from the extraction work be used to better characterize the bone-implant interfacial strength. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Comparison between sequential and single extraction procedures for metal speciation in fresh and dried Sedum Plumbizincicola

    Institute of Scientific and Technical Information of China (English)

    宋祖威; 仲兆平; 钟道旭; 吴龙华; 骆永明

    2015-01-01

    Sequential and single extraction procedures were applied to both fresh and driedSedum Plumbizincicola leaves and stems. The extractants, different from those of soil, sediment or sewage sludge metal fractions, were water, 80% (v/v) ethanol, 1 mol/L NaCl, 2% HAc and 0.6 mol/L HCl. Zn, Cd and Cu in the extracts and samples were measured by flame atomic adsorption spectrometry. In sequential extraction procedures, water soluble form and ethanol soluble form are the main fractions for Zn, while water soluble form and NaCl soluble form for Cd, and comparatively uniform distribution for Cu with the residue form most and HCl soluble form second. Single extraction procedures are used to compare the extraction efficiencies of the five reagents to screen appropriate extractants and operating conditions for liquid extraction to deal with large amount of harvested metal-contained biomass, which will pose a threat to the environment if treated improperly. The sequences of extraction efficiencies are HCl>NaCl≈HAc>Water≈Ethanol for Zn and HCl≈NaCl≈HAc>Water>Ethanol for Cd. As for Cu, all the five extractants cannot effectively extract Cu, but HCl achieves a higher efficiency (>70% in fresh samples, and 45%−60% in dried samples). Besides, extraction efficiencies for most extractants in fresh samples are higher than those in dried samples, and extraction efficiencies of stems and leaves for the five extractants are close. The two extraction procedures can obtain high degree of accuracy with the relative standard deviation (RSD) lower than 10%, and metal recoveries are controlled between 80%−120% with most of 90%−110%.

  10. Determination of polar aromatic amines using newly synthesized sol-gel titanium (IV) butoxide cyanopropyltriethoxysilane as solid phase extraction sorbent.

    Science.gov (United States)

    Miskam, Mazidatulakmam; Abu Bakar, Nor Kartini; Mohamad, Sharifah

    2014-03-01

    A solid phase extraction (SPE) method has been developed using a newly synthesized titanium (IV) butoxide-cyanopropyltriethoxysilane (Ti-CNPrTEOS) sorbent for polar selective extraction of aromatic amines in river water sample. The effect of different parameters on the extraction recovery was studied using the SPE method. The applicability of the sorbents for the extraction of polar aromatic amines by the SPE was extensively studied and evaluated as a function of pH, conditioning solvent, sample loading volume, elution solvent and elution solvent volume. The optimum experimental conditions were sample at pH 7, dichloromethane as conditioning solvent, 10 mL sample loading volume and 5 mL of acetonitrile as the eluting solvent. Under the optimum conditions, the limit of detection (LOD) and limit of quantification (LOQ) for solid phase extraction using Ti-CNPrTEOS SPE sorbent (0.01-0.2; 0.03-0.61 µg L(-1)) were lower compared with those achieved using Si-CN SPE sorbent (0.25-1.50; 1.96-3.59 µg L(-1)) and C18 SPE sorbent (0.37-0.98; 1.87-2.87 µg L(-1)) with higher selectivity towards the extraction of polar aromatic amines. The optimized procedure was successfully applied for the solid phase extraction method of selected aromatic amines in river water, waste water and tap water samples prior to the gas chromatography-flame ionization detector separation.

  11. Isolation of Components with Anti-angiogenesis Activity from Albizia julibrissin by Solid Phase Extraction Coupled with Preparative HPLC%SPE-HPLC法分离合欢皮中抗血管新生的活性组分

    Institute of Scientific and Technical Information of China (English)

    蔡维维; 施建军; 冯磊; 杜斌; 邱丽颖

    2014-01-01

    应用固相萃取-高效液相色谱法(SPE-HPLC),从合欢皮乙醇提取物-正丁醇相中分离得到若干个组分,再用HMEC-1细胞活性检测以及HPLC分析鉴定,筛选得到具有较高抑制新生血管活性的组分Ⅱ-4(IC50=1.45+0.11 μg/mL),且组成较简单.本法简单快速,可以为中药材有效组分的快速分离提供新的方法,也为后续进一步分离得到细胞活性有效单体化合物提供组成比较简单的合欢皮活性组分提取物.

  12. A Procedure for Measuring Microplastics using Pressurized Fluid Extraction.

    Science.gov (United States)

    Fuller, Stephen; Gautam, Anil

    2016-06-07

    A method based on pressurized fluid extraction (PFE) was developed for measuring microplastics in environmental samples. This method can address some limitations of the current microplastic methods and provide laboratories with a simple analytical method for quantifying common microplastics in a range of environmental samples. The method was initially developed by recovering 101% to 111% of spiked plastics on glass beads and was then applied to a composted municipal waste sample with spike recoveries ranging from 85% to 94%. The results from municipal waste samples and soil samples collected from an industrial area demonstrated that the method is a promising alternative for determining the concentration and identity of microplastics in environmental samples.

  13. Selective extraction of berberine from Cortex Phellodendri using polydopamine-coated magnetic nanoparticles.

    Science.gov (United States)

    Shi, Hai-Li; Peng, Shu-Lin; Sun, Jun; Liu, Yi-Ming; Zhu, Yuan-Ting; Qing, Lin-Sen; Liao, Xun

    2014-03-01

    A new extraction agent featuring dopamine self-polymerized on magnetic Fe3 O4 nanoparticles has been successfully synthesized and evaluated for the SPE of berberine from the extract of the traditional Chinese medicinal plant, Cortex Phellodendri. The nanoparticles prepared possessed a core-shell structure and showed super-paramagnetism. It was found that these polydopamine-coated nanoparticles exhibited strong and selective adsorption for berberine. Among the chemical components present in C. Phellodendri, only berberine was adsorbed by the nanoparticles and extracted by a following SPE procedure. Various conditions such as the amount of polydopamine-coated nanoparticles, desorption solvent, desorption time and equilibrium time were optimized for the SPE of berberine. The purity of berberine extracted from C. Phellodendri was determined to be as high as 91.3% compared with that of 9.5% in the extract. The established SPE protocol combined advantages of highly selective enrichment with easy magnetic separation, and proved to be a facile efficient procedure for the isolation of berberine. Further, the prepared polydopamine-coated magnetic nanoparticles could be reused for multiple times, reducing operational cost. The applicability and reliability of the developed SPE method were demonstrated by isolating berberine from three different C. Phellodendri extracts. Recoveries of 85.4-111.2% were obtained with relative standard deviations ranging from 0.27-2.05%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Comparison of three sequential extraction procedures to describe metal fractionation in anaerobic granular sludges

    NARCIS (Netherlands)

    Hullebusch, van E.D.; Sudarno, S.; Zandvoort, M.H.; Lens, P.N.L.

    2005-01-01

    In the last few decades. several sequential extraction procedures have been developed to quantify the chemical status of metals in the solid phase. In this study. three extraction techniques (modified [A. Tessier, P.G.C. Campbell, M. Bisson, Anal. Chem. 51 (1979) 844]: [R.C. Stover. L.E. Sommers, D.

  15. Optimization of an effective extraction procedure for the analysis of microcystins in soils and lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Chen Wei [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Li Lin [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Gan Nanqin [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Song Lirong [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)]. E-mail: lrsong@ihb.ac.cn

    2006-09-15

    Microcystin analysis in sediments and soils is considered very difficult due to low recovery for extraction. This is the primary limiting factor for understanding the fate of toxins in the interface between water and sediment in both the aquatic ecosystem as well as in soils. In the present study, a wide range of extraction solvents were evaluated over a wide range of pH, extraction approaches and equilibration time to optimize an effective extraction procedure for the analysis of microcystins in soils and lake sediments. The number of extractions required and acids in extraction solutions were also studied. In this procedure, EDTA-sodium pyrophosphate solution was selected as an extraction solvent based on the adsorption mechanism study. The optimized procedure proved to be highly efficient and achieved over 90% recovery. Finally, the developed procedure was applied to field soil and sediment sample collected from Chinese lakes during bloom seasons and microcystins were determined in six of ten samples. - Efficiency of extraction of microcystins from soil and sediment was greatly increased.

  16. Comparison of three sequential extraction procedures to describe metal fractionation in anaerobic granular sludges

    NARCIS (Netherlands)

    Hullebusch, van E.D.; Sudarno, S.; Zandvoort, M.H.; Lens, P.N.L.

    2005-01-01

    In the last few decades. several sequential extraction procedures have been developed to quantify the chemical status of metals in the solid phase. In this study. three extraction techniques (modified [A. Tessier, P.G.C. Campbell, M. Bisson, Anal. Chem. 51 (1979) 844]: [R.C. Stover. L.E. Sommers, D.

  17. Bryophytes: liverworts, mosses, and hornworts: extraction and isolation procedures.

    Science.gov (United States)

    Asakawa, Yoshinori; Ludwiczuk, Agnieszka

    2013-01-01

    There are more than 20,000 species of bryophytes in the world. Among them, almost of liverworts (Marchantiophyta) possess beautiful blue, yellow colored or colorless cellular oil bodies from which over several hundred new terpenoids, acetogenins, and aromatic compounds including flavonoids with more than 40 new carbon skeletons have been isolated. Some of the isolated compounds from liverworts show antimicrobial, antifungal, antiviral, allergenic contact dermatitis, cytotoxicity, insect antifeedant and mortality, antioxidant, nitric oxide (NO) production and plant growth inhibitory, neurotrophic and piscicidal activity, tublin polymerization inhibitory, muscle relaxing, and liver X-receptor (LXR)α agonist and (LXR)β antagonist activities, among others. The bio- and chemical diversity, chemical analysis of bryophytes including extraction, distillation, purification, TLC, GC and GC-MS, and HPLC analysis of oil bodies of liverworts are surveyed.

  18. A salting out and resin procedure for extracting Schistosoma mansoni DNA from human urine samples

    Directory of Open Access Journals (Sweden)

    Rodrigues Nilton B

    2010-04-01

    Full Text Available Abstract Background In this paper a simple and cheap salting out and resin (InstaGene matrix® resin - BioRad DNA extraction method from urine for PCR assays is introduced. The DNA of the fluke Schistosoma mansoni was chosen as the target since schistosomiasis lacks a suitable diagnostic tool which is sensitive enough to detect low worm burden. It is well known that the PCR technique provides high sensitivity and specificity in detecting parasite DNA. Therefore it is of paramount importance to take advantage of its excellent performance by providing a simple to handle and reliable DNA extraction procedure, which permits the diagnosis of the disease in easily obtainable urine samples. Findings The description of the extraction procedure is given. This extraction procedure was tested for reproducibility and efficiency in artificially contaminated human urine samples. The reproducibility reached 100%, showing positive results in 5 assay repetitions of 5 tested samples each containing 20 ng DNA/5 ml. The efficiency of the extraction procedure was also evaluated in a serial dilution of the original 20 ng DNA/5 ml sample. Detectable DNA was extracted when it was at a concentration of 1.28 pg DNA/mL, revealing the high efficiency of this procedure. Conclusions This methodology represents a promising tool for schistosomiasis diagnosis utilizing a bio-molecular technique in urine samples which is now ready to be tested under field conditions and may be applicable to the diagnosis of other parasitic diseases.

  19. Plant location and extraction procedure strongly alter the antimicrobial activity of murta extracts

    DEFF Research Database (Denmark)

    Shene, Carolina; Reyes, Agnes K.; Villarroel, Mario

    2009-01-01

    Leaves and fruits of Murta (Ugni Molinae Turcz.) growing in three locations of Chile with diverse climatic conditions were extracted by using ethanol/water mixtures at different ratios and the antimicrobial activity was assessed. Extracts containing the highest polyphenolic content were from murta...

  20. Development and validation of an extraction method for the analysis of perfluoroalkyl substances in human hair.

    Science.gov (United States)

    Kim, Da-Hye; Oh, Jeong-Eun

    2017-02-16

    Human hair has many advantages as a non-invasive sample; however, analytical methods for detecting perfluoroalkyl substances (PFASs) in human hair are still in the development stage. Therefore, the aim of this study was to develop and validate a method for monitoring 11 PFASs in human hair. Solid-phase extraction (SPE), ion-pairing extraction (IPE), a combined method (SPE+IPE) and solvent extraction with ENVI-carb clean-up were compared to develop an optimal extraction method using two types of hair sample (powder and piece forms). Analysis of PFASs was performed using liquid chromatography and tandem mass spectrometry. Among the four different extraction procedures, the SPE method using powdered hair showed the best extraction efficiency and recoveries ranged from 85.8 to 102%. The method detection limits for the SPE method were 0.114-0.796 ng/g and good precision (below 10%) and accuracy (66.4-110%) were obtained. In light of these results, SPE is considered the optimal method for PFAS extraction from hair. It was also successfully used to detect PFASs in human hair samples.

  1. A (-)-norephedrine-based molecularly imprinted polymer for the solid-phase extraction of psychoactive phenylpropylamino alkaloids from Khat (Catha edulis Vahl. Endl.) chewing leaves.

    Science.gov (United States)

    Atlabachew, Minaleshewa; Torto, Nelson; Chandravanshi, Bhagwan Singh; Redi-Abshiro, Mesfin; Chigome, Samuel; Mothibedi, Kediemetse; Combrinck, Sandra

    2016-07-01

    A molecularly imprinted polymer (MIP) was prepared using (-)-norephedrine as the template, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and chloroform as the porogen. The MIP was used as a selective sorbent in the molecularly imprinted solid-phase extraction (MIP-SPE) of the psychoactive phenylpropylamino alkaloids, norephedrine and its analogs, cathinone and cathine, from Khat (Catha edulis Vahl. Endl.) leaf extracts prior to HPLC-DAD analysis. The MIP was able to selectively extract the alkaloids from the aqueous extracts of Khat. Loading, washing and elution of the alkaloids bound to the MIP were evaluated under different conditions. The clean baseline of the Khat extract obtained after MIP-SPE confirmed that a selective and efficient sample clean-up was achieved. Good recoveries (90.0-107%) and precision (RSDs 2.3-3.2%) were obtained in the validation of the MIP-SPE-HPLC procedure. The content of the three alkaloids in Khat samples determined after treatment with MIP-SPE and a commercial Isolute C18 (EC) SPE cartridge were in good agreement. These findings indicate that MIP-SPE is a reliable method that can be used for sample pre-treatment for the determination of Khat alkaloids in plant extracts or similar matrices and could be applicable in pharmaceutical, forensic and biomedical laboratories. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Improved data extraction procedures for IUE Low Resolution Spectra The INES System

    CERN Document Server

    Rodríguez-Pascual, P M; Schartel, N; Wamsteker, W

    1999-01-01

    We present the extraction and processing of the IUE Low Dispersion spectra within the framework of the ESA ``IUE Newly Extracted Spectra'' (INES) System. Weak points of SWET, the optimal extraction implementation to produce the NEWSIPS output products (extracted spectra) are discussed, and the procedures implemented in INES to solve these problems are outlined. The more relevant modifications are: 1) the use of a new noise model, 2) a more accurate representation of the spatial profile of the spectrum and 3) a more reliable determination of the background. The INES extraction also includes a correction for the contamination by solar light in long wavelength spectra. Examples showing the improvements obtained in INES with respect to SWET are described. Finally, the linearity and repeatability characteristics of INES data are evaluated and the validity of the errors provided in the extraction is discussed.

  3. Optimization and application of an extraction procedure to determine drugs of abuse in solid environmental matrices of Turia River Basin

    Science.gov (United States)

    Andres, Maria Jesus; Alvarez, Rodrigo; Andreu, Vicente; Pico, Yolanda

    2015-04-01

    After their consumption, drug of abuse are excreted through urine or faeces, as parent compound or as secondary metabolites that arrive to wastewater treatment plants. Accordingly, the incomplete removal of these compounds in the treatment plants could release them into environmental compartments [1]. This scenario needs attention from an ecotoxicological perspective because their possible negative effects [2]. The aim of this study is to optimize and apply a solvent extraction and solid phase clean-up methodology to obtain a valid procedure for the extraction of these compounds in different solid matrices. Amphetamine, methamphetamine, ethylamphetamine, ecstasy, ethylone, bk-MMBDB and MBDB belong to phenylethylamine group; codeine and ketamine belong to opioid and phencyclidine group, respectively, and benzoylecgonine is the major excreted metabolite of the alkaloid cocaine. To optimize the method to determinate drugs of abuse in environmental solid matrices, two replicates and one blank were prepared for each sample of sediment. They were prepared by adding 1 g of sediment sample, 5 mL of buffer (methanol-Mc Ilvaine 50:50) and internal standard to obtain a final concentration in the extract of 25 ng/g. Also standards of drugs of abuse were added to the replicates to obtain a final concentration of 100 ng/g. Then all samples were shaken, sonicated and centrifuged and the supernatant was separated and placed in a 250 mL volumetric flask, which was filled the rest with distilled water. SPE was carried out with Strata-X cartridges and 250 mL of sample were passed through them. The extracts were eluted with 6 mL of methanol, evaporated to dryness and reconstituted in 1 mL of methanol-water 1:9. One of the replicates was filtrated through 0.22 μm pore size and the others were not. The samples were determined by liquid chromatography triple quadrupole mass spectrometry (LC-QqQ-MS/MS) using an electrospray ionization source (ESI) in positive ionization mode. The results

  4. Identification of Radical Scavenging Compounds in Rhaponticum carthamoides by Means of LC-DAD-SPE-NMR

    NARCIS (Netherlands)

    Miliauskas, G.; Beek, van T.A.; Waard, de P.; Venskutonis, R.P.; Sudhölter, E.J.R.

    2005-01-01

    A hyphenated LC-DAD-SPE-NMR setup in combination with on-line radical scavenging detection has been applied for the identification of radical scavenging compounds in extracts of Rhaponticum carthamoides. After NMR measurements, the pure compounds were infused into a mass spectrometer. The technique

  5. Soil DNA Extraction Procedure Influences Protist 18S rRNA Gene Community Profiling Outcome

    DEFF Research Database (Denmark)

    Santos, Susana S; Nunes, Inês; Nielsen, Tue Kjærgaard

    2017-01-01

    Advances in sequencing technologies allow deeper studies of the soil protist diversity and function. However, little attention has been given to the impact of the chosen soil DNA extraction procedure to the overall results. We examined the effect of three acknowledged DNA recovery methods, two ma...... high replication reproducibility. A comprehensive understanding of the DNA extraction techniques impact on soil protist diversity can enable more accurate diversity assays....

  6. Effects of extraction procedures on metal binding properties of extracellular polymeric substances (EPS) from anaerobic granular sludges

    NARCIS (Netherlands)

    Abzac, D' P.; Bordas, F.; Hullebusch, E.; Lens, P.N.L.; Guibaud, G.

    2010-01-01

    The effects of the extraction procedure of extracellular polymeric substances (EPS) on their proton/metal binding properties were studied. Nine extraction procedures (one control, four physical and four chemical procedures) were applied to four types of anaerobic granular sludges. The binding capaci

  7. Determination of the two major endocannabinoids in human plasma by μ-SPE followed by HPLC-MS/MS.

    Science.gov (United States)

    Sergi, Manuel; Battista, Natalia; Montesano, Camilla; Curini, Roberta; Maccarrone, Mauro; Compagnone, Dario

    2013-01-01

    Endocannabinoids (ECs) are endogenous compounds that interact with type-1 and type-2 cannabinoid receptors (CB(1) and CB(2)), as well as non-cannabinoid receptors. The multitude of roles attributed to ECs makes them an emerging target of pharmacotherapy for a number of disparate diseases. Here a high-throughput bioanalytical method based on micro SPE (μ-SPE) followed by LC-MS/MS analysis for the simultaneous determination of the two major endocannabinoids 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (anandamide, AEA) in human plasma is presented. The chromatographic conditions obtained with the fused-core column allowed a good separation in 10 min also of the AG isomers. A very simple and reliable extraction has been optimised by means of C18-modified tips: it requires only 100 μL of plasma and allows the use of minimal volumes of organic solvent. The present method allows a rapid and effective clean-up, which also minimises the isomerisation of 2-AG. The whole procedure has been validated following the FDA guidelines for bioanalytical methods validation: the satisfactory recovery values, the negligible matrix effect and the good values of accuracy and reproducibility make it a simple and high-throughput analytical tool for clinical and biochemical studies on endocannabinoid signaling in humans.

  8. Fiber-in-Tube Solid Phase Extraction (FIT-SPE) for Miniaturized Sample Preparation Process%管中纤维固相萃取法用于微型化的样品处理过程

    Institute of Scientific and Technical Information of China (English)

    JINNO Kiyokatsu; SAITO Yoshihiro

    2004-01-01

    A typical analytical separation procedure has several important steps: sample preparation, isolation, identification, quantitation, statistical evaluation and final decision. Each step is alwayscritical to obtain correct results to fulfill the analytical purpose. In these various steps sample

  9. Toxicological validation of a procedure for extracting organic micropollutants form water samples

    NARCIS (Netherlands)

    Vaal MA; Folkerts AJ; Kamp RE van de; Struijs J; ECO

    1999-01-01

    A procedure, developed to extract micropollutants from water samples into a concentrate that is suitable for the performance of aquatic toxicity tests, was toxicologically validated. Toxicity of known cocktail of toxicants concentrated to a level measurable in short-term toxicity tests was measured

  10. Toxicological validation of a procedure for extracting organic micropollutants form water samples

    NARCIS (Netherlands)

    Vaal MA; Folkerts AJ; Kamp RE van de; Struijs J; ECO

    1999-01-01

    A procedure, developed to extract micropollutants from water samples into a concentrate that is suitable for the performance of aquatic toxicity tests, was toxicologically validated. Toxicity of known cocktail of toxicants concentrated to a level measurable in short-term toxicity tests was measured

  11. Solid Phase Extraction Disk Procedure to Determine 239Pu in Soils

    Directory of Open Access Journals (Sweden)

    ZHANG Ji-qiao;ZHAO Ya-ping;DING You-qian;ZHANG Sheng-dong;YANG Jin-ling

    2016-11-01

    Full Text Available 239Pu in many soil samples should be analyzed to survey radioactive pollution level in nuclear facilities and its affinity environment efficiently. In order to input the opt conditions for column experiment, the experiments of the static adsorption coefficient of 239Pu to solid phase extraction disk with different contact time, concentration of HNO3 and different temperature were carried out. The chemical procedure for the rapid separation and determination of 239Pu in soils had been formulated, which using solid phase extraction disk (EmporeTM Anion Exchange-SR as extraction material and liquid scintillation spectrometry counting as measurement. In the procedure, soil sample usage was 10 g, and were leached by 8 mol/L HNO3, the chemical recovery of the procedure was about 78.9%, and the minimum detectable concentration was 3.7 Bq/kg. It took less than 3 hours once and the presence of 137Cs, 90Sr-90Y and natural uranium, 241Am, 99Tc did not interfere with the procedure, owning high DF of them. The procedure can be used extensively in determination of 239Pu in soils.

  12. Application of SPE-HPLC-DAD and SPE-TLC-DAD to the determination of pesticides in real water samples.

    Science.gov (United States)

    Tuzimski, Tomasz

    2008-10-01

    Planar chromatography with diode array scanning (TLC-DAD) and high-performance chromatography with diode array detection (HPLC-DAD) were used to screen water samples for pesticides. Pesticides were enriched from lake water samples by SPE on C18/SDB-1, C18, C18 Polar Plus and cyanopropyl (CN) cartridges. The recovery rates were high for all extraction materials except for all pesticides on CN cartridges, for which the values were lower. SPE was used not only for preconcentration of analytes but also for their fractionation. The analytes were eluted first with methanol and then with dichloromethane. Methanol eluates were analysed by HPLC-DAD, the dichloromethane eluates with TLC-DAD. The method was validated for precision, repeatability and accuracy. The calibration plots were linear between 0.1 and 50.0 microg/mL for all pesticides, the correlation coefficients, r, were between 0.9992 and 1.000 as determined by HPLC-DAD. In the TLC experiments, the best fit for the calibration lines was found when the calibration data were analysed using a second-degree polynomial regression. Calibration plots lay between 0.1 and 17 microg/spot for all pesticides, the correlation coefficients, r, were between 0.9974 and 0.9997 determined by TLC-DAD. The LOD was between 0.04 and 0.65 microg/spot (TLC-DAD) and between 0.02 and 3.68 microg/mL (HPLC-DAD).

  13. Zeolite imidazolate frameworks 8 as sorbent and its application to sonication-assisted emulsification microextraction combined with vortex-assisted porous membrane-protected micro-solid-phase extraction for fast analysis of acidic drugs in environmental water samples.

    Science.gov (United States)

    Ge, Dandan; Lee, Hian Kee

    2012-09-28

    A novel and fast procedure, sonication-assisted emulsification microextraction combined with vortex-assisted porous membrane protected micro-solid-phase extraction (SAEME-VA-μ-SPE), was developed for the gas chromatography-mass spectrometric determination of acidic drugs from environmental water samples. One advantage of the new procedure is that any solvent immiscible with water can be used as extractant solvent of SAEME and any solid sorbent can be used for μ-SPE in the SAEME-VA-μ-SPE process. In the present work, zeolite imidazolate framework 8 (ZIF-8) was employed as extraction sorbent for μ-SPE and 1-octanol as extractant solvent for SAEME. ZIF-8 has very good thermal, chemical and water stability, which make it a suitable material for the extraction of trace analytes from aqueous samples. Under the optimized extraction conditions, the developed method exhibited low limits of detection (0.01-0.04 ng/ml), good linearity (with r² between 0.9965 and 0.9993) from 0.5 to 50 ng/ml and satisfactory repeatability (between 4.1% and 7.6%). In essence SAEME-VA-μ-SPE is a combination of two different and efficient miniaturized techniques. It was demonstrated to be a fast, accurate, and convenient pretreatment procedure for trace analysis of environmental water samples.

  14. DNA extraction procedure affects organic-aggregate-attached bacterial community profiles from a shallow eutrophic lake.

    Science.gov (United States)

    Tang, Xiangming; Gao, Guang; Zhu, Liping; Chao, Jianying; Qin, Boqiang

    2009-06-01

    Organic aggregates (OA) in aquatic ecosystems harbour diverse microbial communities. The colonization and growth of OA-attached bacteria are important processes in the degradation and transformation of the particles. The development of efficient and comparative DNA extraction methods is one of the most critical steps in the study of the composition and diversity of OA-attached bacterial communities. To evaluate whether different DNA extraction procedures affect the measurement of bacterial community composition, we compared four in situ lysis procedures using OA from three locations in a shallow eutrophic lake (Lake Taihu, China). The extracted DNA was analyzed using denaturing gradient gel electrophoresis profiles. We found that the choice of DNA extraction protocol had a significant influence on the fingerprints of the OA-attached bacterial community. This was shown not only in the number of bands but also in their relative representation of certain DNA bands. Using the bead-beating DNA extraction method in the presence of hexadecyltrimethylammonium bromide, we found that crude microbial DNA could be extracted efficiently from different OA types. This protocol is reproducible and gives very pure DNA of relatively high molecular mass. More importantly, the protocol provided more representative and informative data on the diversity of OA-attached bacterial communities.

  15. Rapid determination of memantine in human plasma by using nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer d-μ-SPE and UFLC-MS/MS.

    Science.gov (United States)

    Qiu, Hai-Wen; Xia, Lei; Gong, Li-Min; Ruan, Lie-Min; Zhao, Yong-Gang

    2015-06-01

    A novel, simple, and sensitive method based on the use of dispersive micro-solid-phase extraction (d-μ-SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the determination of memantine (ME) was developed and validated over the linearity range 0.05-10.0 µg/L with 100 μL of human plasma using memantine-D6 (ME-D6) as the internal standard. The novel nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer (NR-CF-Mag-MIP) was synthesized by ultrasound-assisted suspension polymerization, using ME as a template molecule, methacrylic acid as a functional monomer, and divinylbenzene as a cross-linking agent. The NR-CF-Mag-MIP was used as the d-μ-SPE sorbent to extract ME from human plasma samples. The obtained results demonstrated the higher extraction capacity of NR-CF-Mag-MIP with recoveries between 97.6 and 101%. The limits of quantification (LOQs) for ME was 0.015 µg/L. Validation results on linearity, specificity, accuracy, precision, and stability, as well as on application to the analysis of samples taken up to 480 h after oral administration of 20 mg (two 10 mg capsules) of ME in healthy volunteers demonstrated the applicability to bioequivalence studies.

  16. Selenium speciation in phosphate mine soils and evaluation of a sequential extraction procedure using XAFS.

    Science.gov (United States)

    Favorito, Jessica E; Luxton, Todd P; Eick, Matthew J; Grossl, Paul R

    2017-10-01

    Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO4-extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analyses indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A comparison between heavy metals released from soil and its efficient speciation extracted by sequential extraction procedure

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui

    2008-01-01

    A simulating experiment was carried out on the interaction between natural precipitation and soil. The results demonstrated that the contents of heavy metals (V, Co, Cr, and Ni) released from soil into the solution under Earth's surface conditions are higher than the contents of those metals bonded to exchangeable species, which were extracted by sequential extraction procedure recommended by Tessier and others in 1979. It is demonstrated that the metals bonded to other 3 species (carbonate, Fe-Mn oxide, and organic matter) except those bonded to the exchangeable species in efficient speciation can be released under the Earth's surface conditions, when pH=4 in the reaction system, and the higher correlation coefficient indicated that the concentrations of heavy metals released from soil into the solution vary approximately with reaction time in terms of index regulations.

  18. A solid-phase extraction procedure coupled to {sup 1}H NMR, with chemometric analysis, to seek reliable markers of the botanical origin of honey

    Energy Technology Data Exchange (ETDEWEB)

    Beretta, Giangiacomo [Istituto di Chimica Farmaceutica e Tossicologica ' Pietro Pratesi' , Faculty of Pharmacy, University of Milan, via Mangiagalli 25, 20133 Milan (Italy)], E-mail: giangiacomo.beretta@unimi.it; Caneva, Enrico [Ciga - Centro Interdipartimentale Grandi Apparecchiature, University of Milan, via Golgi 19, 20133 Milan (Italy); Regazzoni, Luca; Bakhtyari, Nazanin Golbamaki; Maffei Facino, Roberto [Istituto di Chimica Farmaceutica e Tossicologica ' Pietro Pratesi' , Faculty of Pharmacy, University of Milan, via Mangiagalli 25, 20133 Milan (Italy)

    2008-07-14

    The aim of this work was to establish an analytical method for identifying the botanical origin of honey, as an alternative to conventional melissopalynological, organoleptic and instrumental methods (gas-chromatography coupled to mass spectrometry (GC-MS), high-performance liquid chromatography HPLC). The procedure is based on the {sup 1}H nuclear magnetic resonance (NMR) profile coupled, when necessary, with electrospray ionisation-mass spectrometry (ESI-MS) and two-dimensional NMR analyses of solid-phase extraction (SPE)-purified honey samples, followed by chemometric analyses. Extracts of 44 commercial Italian honeys from 20 different botanical sources were analyzed. Honeydew, chestnut and linden honeys showed constant, specific, well-resolved resonances, suitable for use as markers of origin. Honeydew honey contained the typical resonances of an aliphatic component, very likely deriving from the plant phloem sap or excreted into it by sap-sucking aphids. Chestnut honey contained the typical signals of kynurenic acid and some structurally related metabolite. In linden honey the {sup 1}H NMR profile gave strong signals attributable to the mono-terpene derivative cyclohexa-1,3-diene-1-carboxylic acid (CDCA) and to its 1-O-{beta}-gentiobiosyl ester (CDCA-GBE). These markers were not detectable in the other honeys, except for the less common nectar honey from rosa mosqueta. We compared and analyzed the data by multivariate techniques. Principal component analysis found different clusters of honeys based on the presence of these specific markers. The results, although obviously only preliminary, suggest that the {sup 1}H NMR profile (with HPLC-MS analysis when necessary) can be used as a reference framework for identifying the botanical origin of honey.

  19. On-line MSPD-SPE-HPLC/FLD analysis of polycyclic aromatic hydrocarbons in bovine tissues.

    Science.gov (United States)

    Gutiérrez-Valencia, Tania M; García de Llasera, Martha P

    2017-05-15

    A fast method was optimized and validated for simultaneous trace determination of four polycyclic aromatic hydrocarbons: benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene in bovine tissues. The determination was performed by matrix solid-phase dispersion (MSPD) coupled on-line to solid phase extraction (SPE) and high performance liquid chromatography (HPLC) with fluorescence detection (FLD). The sample was dispersed on C18 silica sorbent and then the on-line MSPD-SPE-HPLC/FLD method was applied. Several parameters were optimized: cleaning and elution sequences applied to the MSPD cartridge, the flow rate and dilution of extract used for SPE loading. The on-line method was validated over a concentration range of 0.1-0.6ngg(-1) obtaining good linearity (r⩾0.998) and precision (RSD)⩽10%. Recovery ranged from 96 to 99% and the limits of detection were 0.012ngg(-1). This methodology was applied to liver samples from unhealthy animals. The results demonstrate that MSDP-SPE-HPLC/FLD method provides reliable, sensitive, accurate and fast data to the food control.

  20. Comparison of Column Solid-Phase Extraction Procedures for Spectrophotometric Determination of E129 (Allura Red) in Foodstuff, Pharmaceutical, and Energy Drink Samples.

    Science.gov (United States)

    Bişgin, Abdullah Taner; Uçan, Mustafa; Narin, İbrahim

    2015-01-01

    Two novel spectrophotometric determination procedures based on retention of Allura Red onto Amberlite XAD-1180 and XAD-16 resins for its preconcentration, purification, and separation were developed. Analytical parameters of the methods including pH, eluent type, sample volume, and sample and eluent flow rates, were investigated and optimized. Interference effects of some cations, anions, and widely used food dyes were also investigated. Detection limits of the two methods were found to be 1.2 and 1.5 μg/L for XAD-1180 and XAD-16 columns, respectively, under optimum conditions. Linear calibration curve ranges of the methods were 0.4-8.0 and 0.5-6.0 μg/mL of Allura Red for XAD-1180 and XAD-16 resins, respectively. Preconcentration factors were found as 80 for both the XAD-1180 and XAD-16 columns using maximum sample volume and minimum eluent volume. RSDs of the methods were below 6% throughout all experiments. All absorbance measurements were performed at 506 nm. Validations of the methods were performed comparatively with determination of the Allura Red contents of some foodstuff, pharmaceutical, and energy drink samples. Allura Red concentrations in investigated solid and liquid samples ranged from 298 to 501 μg/g and 53.8 to 508 μg/mL, respectively. Satisfactory results were obtained from the real samples analysis. Allura Red contents of samples were determined to be highly similar using the two extraction methods. Comparisons of the methods were performed by analysis of Allura Red contents of the real samples. In addition to analytical parameters, adsorption isotherm studies were performed for the two kinds of Amberlite resins. It was observed that developed methods fit the linear form of the Freundlich adsorption isotherm model. All of the experimental results suggested that the developed SPE procedures are suitable for separation, preconcentration, and determination of Allura Red in solid and liquid matrixes.

  1. Procedure for extraction of disparate data from maps into computerized data bases

    Science.gov (United States)

    Junkin, B. G.

    1979-01-01

    A procedure is presented for extracting disparate sources of data from geographic maps and for the conversion of these data into a suitable format for processing on a computer-oriented information system. Several graphic digitizing considerations are included and related to the NASA Earth Resources Laboratory's Digitizer System. Current operating procedures for the Digitizer System are given in a simplified and logical manner. The report serves as a guide to those organizations interested in converting map-based data by using a comparable map digitizing system.

  2. Procedure for obtaining an extract rich in triterpenic acids from solutions from the process of preparation of table olives

    OpenAIRE

    2008-01-01

    [EN] Procedure for obtaining an extract having a high proportion of triterpenic acids, preferably of oleanolic and maslinic acids, from the solutions obtained in the process of preparation of table olives. Furthermore the invention refers to the extract obtained through said procedure and to application thereof in the food, cosmetic or pharmaceutical industries.

  3. Comparison of two sequential extraction procedures for uranium fractionation in contaminated soils.

    Science.gov (United States)

    Vandenhove, Hildegarde; Vanhoudt, Nathalie; Duquène, Lise; Antunes, Kenny; Wannijn, Jean

    2014-11-01

    Two sequential extraction procedures were carried out on six soils with different chemical properties and contamination history to estimate the partitioning of uranium (U) between different soil fractions. The first standard method (method of Schultz) was specifically developed for actinides, while the second one (method of Rauret) was initially created for heavy metals. Reproducibility of both methods was compared by means of the coefficient of variation (CV). A soil-to-plant transfer experiment was also carried out with ryegrass to verify if one of the extracted fractions efficiently predicted plant uptake. In artificially contaminated soils, most of the U was retrieved from the exchangeable and the carbonates fractions. In soils with high natural levels of U or contaminated by industrial activity, most of the U was found in the less available fractions. Different U concentrations were found in the fractions which were supposed to be comparable in the two methods. Extracted fractions following Schultz differentiated more strongly between the tested soils but no relationships with soil parameters could be established. As expected, the highest U transfer factors (TF) were observed for ryegrass grown on artificially contaminated soils and the lowest on soils with high natural concentrations or industrial contamination, in agreement with the extraction procedures. No good relation was found between the soil-to-shoot TF and the extracted U concentrations. On the other hand, the U concentration in the roots, the U concentration in the shoots and the soil-to-root TF are well correlated to the U concentration determined in the first extracted fractions (so called exchangeable fractions) from the method of Schultz. We conclude that the extraction method according to Schultz should be preferably used for U, and that the exchangeable fraction can be proposed as a potential indicator to evaluate plant uptake in soils.

  4. An optimized and validated SPE-LC-MS/MS method for the determination of caffeine and paraxanthine in hair.

    Science.gov (United States)

    De Kesel, Pieter M M; Lambert, Willy E; Stove, Christophe P

    2015-11-01

    Caffeine is the probe drug of choice to assess the phenotype of the drug metabolizing enzyme CYP1A2. Typically, molar concentration ratios of paraxanthine, caffeine's major metabolite, to its precursor are determined in plasma following administration of a caffeine test dose. The aim of this study was to develop and validate an LC-MS/MS method for the determination of caffeine and paraxanthine in hair. The different steps of a hair extraction procedure were thoroughly optimized. Following a three-step decontamination procedure, caffeine and paraxanthine were extracted from 20 mg of ground hair using a solution of protease type VIII in Tris buffer (pH 7.5). Resulting hair extracts were cleaned up on Strata-X™ SPE cartridges. All samples were analyzed on a Waters Acquity UPLC® system coupled to an AB SCIEX API 4000™ triple quadrupole mass spectrometer. The final method was fully validated based on international guidelines. Linear calibration lines for caffeine and paraxanthine ranged from 20 to 500 pg/mg. Precision (%RSD) and accuracy (%bias) were below 12% and 7%, respectively. The isotopically labeled internal standards compensated for the ion suppression observed for both compounds. Relative matrix effects were below 15%RSD. The recovery of the sample preparation procedure was high (>85%) and reproducible. Caffeine and paraxanthine were stable in hair for at least 644 days. The effect of the hair decontamination procedure was evaluated as well. Finally, the applicability of the developed procedure was demonstrated by determining caffeine and paraxanthine concentrations in hair samples of ten healthy volunteers. The optimized and validated method for determination of caffeine and paraxanthine in hair proved to be reliable and may serve to evaluate the potential of hair analysis for CYP1A2 phenotyping.

  5. Giardia lamblia allergenic extract as diagnosis procedures for determining sensitization to this protozoa.

    Science.gov (United States)

    Crespo Guerrero, V; Alfonso Fernández, L A; Gómez Echevarría, A H

    1991-12-01

    We studied 200 patients assisting at the Allergy Department and the Gastroenterology Department in "Hermanos Ameijeiras" Clinical-Surgical Hospital. They were clinically and immunologically tested for giardiasis through duodenal fortis or gall bladder drainage and total IgE serum levels. All patients underwent intradermal and skin prick tests with Giardine allergenic extract. These skin tests showed high sensitivity and increased specificity. Thus, our procedure in diagnosis is accurate, accessible and economical.

  6. Development of a nested PCR detection procedure for Nectria fuckeliana direct from Norway spruce bark extracts.

    Science.gov (United States)

    Langrell, Stephen R H

    2005-01-01

    A pair of primers specific for Nectria fuckeliana, a bark infecting pathogen predominantly of Norway spruce (Picea abies), were designed from comparisons of nucleotide sequences of the nuclear ribosomal internal transcribed spacer (ITS) regions of nine isolates from Norway, Lithuania, Switzerland, Austria, Slovakia, Scotland (Larix sp.) and New Zealand (Pinus radiata), and other closely related nectriaceous species, including Neo. Neomacrospora, and 'N'. mammoidea, to which it exhibits taxonomic similarities. Complete ITS sequence homology was observed between each of the nine N. fuckeliana isolates, regardless of geographic provenance, including a previously published Danish strain. Primers Cct1 and Cct2 consistently amplified a single product of 360 bp from DNA prepared from 20 isolates covering the principle range of the disease from Central and Northern Europe, but not from other Neonectria, 'Nectria' or a range of species commonly encountered in forest ecosystems, as well as P. abies or P. radiata DNA. A quick, simple and efficient mechanical lysis procedure for the extraction of high quality total DNA from bark, coupled with post-extraction polyvinylpolypyrrolidone (PVPP) chromatography purification, is described to facilitate successful PCR detection of N. fuckeliana direct from bark extracts. Detection of N. fuckeliana from bark preparations was only possible following nested PCR of PVPP purified extracts using universal primers ITS5 and 4 in first round amplification. The identity of products from bark tissues was confirmed by Southern hybridisation and sequencing. Using the above procedure, positive diagnosis of N. fuckeliana was achievable within 5 h and has the potential for full exploitation as both a forest management and ecological research tool. As the DNA extraction procedure described here has been successful in application against other tree species, it has potential for incorporation into other molecular diagnostic systems for other

  7. Distributions and concentrations of thallium in Korean soils determined by single and sequential extraction procedures.

    Science.gov (United States)

    Lee, Jin-Ho; Kim, Dong-Jin; Ahn, Byung-Koo

    2015-06-01

    The objectives of this study were to investigate the distribution of thallium in soils collected near suspected areas such as cement plants, active and closed mines, and smelters and to examine the extraction of thallium in the soils using 19 single chemical and sequential chemical extraction procedures. Thallium concentrations in soils near cement plants were distributed between 1.20 and 12.91 mg kg(-1). However, soils near mines and smelters contained relatively low thallium concentrations ranging from 0.18 to 1.09 mg kg(-1). Thallium extractability with 19 single chemical extractants from selected soils near cement plants ranged from 0.10% to 8.20% of the total thallium concentration. In particular, 1.0 M NH4Cl, 1.0 M (NH4)2SO4, and 1.0 M CH3COONH4 extracted more thallium than other extractants. Sequential fractionation results of thallium from different soils such as industrially and artificially contaminated soils varied with the soil properties, especially soil pH and the duration of thallium contamination.

  8. The influence of extraction procedure on ion concentrations in sediment pore water

    Science.gov (United States)

    Winger, P.V.; Lasier, P.J.; Jackson, B.P.

    1998-01-01

    Sediment pore water has the potential to yield important information on sediment quality, but the influence of isolation procedures on the chemistry and toxicity are not completely known and consensus on methods used for the isolation from sediment has not been reached. To provide additional insight into the influence of collection procedures on pore water chemistry, anion (filtered only) and cation concentrations were measured in filtered and unfiltered pore water isolated from four sediments using three different procedures: dialysis, centrifugation and vacuum. Peepers were constructed using 24-cell culture plates and cellulose membranes, and vacuum extractors consisted of fused-glass air stones attached with airline tubing to 60cc syringes. Centrifugation was accomplished at two speeds (2,500 and 10,000 x g) for 30 min in a refrigerated centrifuge maintained at 4?C. Only minor differences in chemical characteristics and cation and anion concentrations were found among the different collecting methods with differences being sediment specific. Filtering of the pore water did not appreciably reduce major cation concentrations, but trace metals (Cu and Pb) were markedly reduced. Although the extraction methods evaluated produced pore waters of similar chemistries, the vacuum extractor provided the following advantages over the other methods: (1) ease of extraction, (2) volumes of pore water isolated, (3) minimal preparation time and (4) least time required for extraction of pore water from multiple samples at one time.

  9. Mercury and trace element fractionation in Almaden soils by application of different sequential extraction procedures

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, D.M.; Quejido, A.J.; Fernandez, M.; Hernandez, C.; Schmid, T.; Millan, R.; Gonzalez, M.; Aldea, M.; Martin, R.; Morante, R. [CIEMAT, Madrid (Spain)

    2005-04-01

    A comparative evaluation of the mercury distribution in a soil sample from Almaden (Spain) has been performed by applying three different sequential extraction procedures, namely, modified BCR (three steps in sequence), Di Giulio-Ryan (four steps in sequence), and a specific SEP developed at CIEMAT (six steps in sequence). There were important differences in the mercury extraction results obtained by the three procedures according to the reagents applied and the sequence of their application. These findings highlight the difficulty of setting a universal SEP to obtain information on metal fractions of different mobility for any soil sample, as well as the requirement for knowledge about the mineralogical and chemical characteristics of the samples. The specific six-step CIEMAT sequential extraction procedure was applied to a soil profile (Ap, Ah, Bt1, and Bt2 horizons). The distribution of mercury and major, minor, and trace elements in the different fractions were determined. The results indicate that mercury is mainly released with 6 M HCl. The strong association of mercury with crystalline iron oxyhydroxides, present in all the horizons of the profile, and/or the solubility of some mercury compounds in such acid can explain this fact. Minor mercury is found in the fraction assigned to oxidizable matter and in the final insoluble residue (cinnabar). (orig.)

  10. Supercritical fluid extraction for some carbamate insecticides in potatoes samples, with HPLC/fluorescence determination and HPLC/mass spectrometry confirmation

    OpenAIRE

    Gilvanda Silva Nunes; Teresa Cristina R. Santos; Damiá Barceló; Alexandre Santos Pimenta; Maria Lúcia Ribeiro

    2002-01-01

    Six supercritical fluid extraction (SFE) methods were tested, by varying the following operational parameters: CO2 pressure, time and temperature of extraction, type and proportion of static modifier, and Hydromatrix®/sample rate into cell. Firstly, insecticide carbamates were extracted from spiked potatoes samples (fortification level of 0,5 mg.Kg-1) by using SPE procedures, and then final extracts were analyzed HPLC/fluorescence. Good performance was observed with SFE methods that operated ...

  11. Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application.

    Science.gov (United States)

    Rousset, Davy; Durand, Thibaut

    2016-01-01

    Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks.

  12. Improved extraction of saturated fatty acids but not omega-3 fatty acids from sheep red blood cells using a one-step extraction procedure.

    Science.gov (United States)

    Clayton, Edward H; Gulliver, Catherine E; Piltz, John W; Taylor, Robert D; Blake, Robert J; Meyer, Richard G

    2012-07-01

    Several methods are available to extract total lipid and methylate fatty acids from a range of samples including red blood cells (RBC). Fatty acid analysis of human RBC can be undertaken using a two-step extraction and methylation or a combined one-step extraction and methylation procedure. The lipid composition of sheep RBC differs significantly from that of humans and may affect their extraction. The purpose of the current study was to examine the efficiency of extraction of lipid and detection of fatty acids from sheep RBC using a one-step procedure. Fatty acids were analysed using a one-step extraction and methylation procedure using methanol:toluene and acetyl chloride in comparison with a two-step procedure involving extraction of lipid using chloroform:methanol and separate methylation. Concentrations of saturated fatty acids including C16:0 and C18:0 were significantly higher (42.6 and 33.9 % respectively) following extraction using the one-step procedure compared with the two-step procedure. However, concentrations of some polyunsaturated fatty acids, including C20:5n-3 and C22:6n-3 were not significantly different between either procedure. The improved detection of fatty acids may be related to the ability of different solvents to extract different lipid fractions. The differential extraction of lipids and detection of fatty acids from sheep RBC may have important implications in studies examining the effect of dietary treatment on the possible health benefits of fatty acids.

  13. Experimental design for TBT quantification by isotope dilution SPE-GC-ICP-MS under the European water framework directive.

    Science.gov (United States)

    Alasonati, Enrica; Fabbri, Barbara; Fettig, Ina; Yardin, Catherine; Del Castillo Busto, Maria Estela; Richter, Janine; Philipp, Rosemarie; Fisicaro, Paola

    2015-03-01

    In Europe the maximum allowable concentration for tributyltin (TBT) compounds in surface water has been regulated by the water framework directive (WFD) and daughter directive that impose a limit of 0.2 ng L(-1) in whole water (as tributyltin cation). Despite the large number of different methodologies for the quantification of organotin species developed in the last two decades, standardised analytical methods at required concentration level do not exist. TBT quantification at picogram level requires efficient and accurate sample preparation and preconcentration, and maximum care to avoid blank contamination. To meet the WFD requirement, a method for the quantification of TBT in mineral water at environmental quality standard (EQS) level, based on solid phase extraction (SPE), was developed and optimised. The quantification was done using species-specific isotope dilution (SSID) followed by gas chromatography (GC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The analytical process was optimised using a design of experiment (DOE) based on a factorial fractionary plan. The DOE allowed to evaluate 3 qualitative factors (type of stationary phase and eluent, phase mass and eluent volume, pH and analyte ethylation procedure) for a total of 13 levels studied, and a sample volume in the range of 250-1000 mL. Four different models fitting the results were defined and evaluated with statistic tools: one of them was selected and optimised to find the best procedural conditions. C18 phase was found to be the best stationary phase for SPE experiments. The 4 solvents tested with C18, the pH and ethylation conditions, the mass of the phases, the volume of the eluents and the sample volume can all be optimal, but depending on their respective combination. For that reason, the equation of the model conceived in this work is a useful decisional tool for the planning of experiments, because it can be applied to predict the TBT mass fraction recovery when the

  14. Electrochemical hydrogenation of thiophene on SPE electrodes

    Science.gov (United States)

    Huang, Haiyan; Yuan, Penghui; Yu, Ying; Chung, Keng H.

    2017-01-01

    Electrochemical reduction desulfurization is a promising technology for petroleum refining which is environmental friendly, low cost and able to achieve a high degree of automation. Electrochemical hydrogenation of thiophene was performed in a three-electrode system which SPE electrode was the working electrode. The electrochemical desulfurization was studied by cyclic voltammetry and bulk electrolysis with coulometry (BEC) techniques. The results of cyclic voltammetry showed that the electrochemical hydrogenation reduction reaction occurred at -0.4V. The BEC results showed that the currents generated from thiophene hydrogenation reactions increased with temperature. According to Arrhenius equation, activation energy of thiophene electrolysis was calculated and lower activation energy value indicated it was diffusion controlled reaction. From the products of electrolytic reactions, the mechanisms of electrochemical hydrogenation of thiophene were proposed, consisting of two pathways: openingring followed by hydrogenation, and hydrogenation followed by ring opening.

  15. 西番莲果中嘧霉胺残留的SPE-RP-HPLC降解分析%Degradation analysis of pyrimethanil residue in passion fruit by RP-HPLC with solid-phase extraction

    Institute of Scientific and Technical Information of China (English)

    高智席; 敖克厚; 曾启华; 李新发; 刘焱; 牟青松; 邓传跃

    2012-01-01

    建立固相萃取-反相高效液相色谱法测定西番莲果中嘧霉胺的残留降解分析的方法.色谱柱为Shim-pack VP-ODS 150 mm×4.6 mm,流动相为甲醇:1%冰乙酸=90:10(V/V),流速为0.4 mL/min,进样量20μL.嘧霉胺在0.0760~21.20 mg/L(r=0.9964)范围内与峰面积呈良好线性关系,检出限为0.05 mg/L,嘧霉胺的回收率为85.6%~102.3%,相对标准偏差0.89%~2.7%.方法可作为西番莲果中嘧霉胺含量监测的控制方法.同时,还对嘧霉胺由西番莲果皮向西番莲果肉的迁移,在西番莲果体上的降解动态进行了测定.%A reversed-phase high performance liquid chromatograghic method with solid-phase extraction was used for the degradation analysis of pyrimethanil residue in passion fruit. The HPLC conditions were as follows: the column was Shim-pack VP-ODS 150 mm ×4. 6 mm. CH3OH: 1% CH3COOH = 90:10 ( V/V)as mobile phase, flow rate 0. 4 mL /min, injection volume 20 μL and detection wavelength at 270 nm. Good linearity of pyrimeth-anil was obtained over the range of 0.0760 ~21.20 mg/L(r =0.9964). The detection limit was 0. 0500 mg/L for pyrimedianil. The average recoveries ranged from 85. 6% to 102. 3% with relative standard deviation of 0. 89% ~2. 7% . The method is fast and simple for the residue detection and analysis of pyrimethanil in passion fruit, and it is suitable for the determination of fungicide residue of pyrimethanil in passion fruit.

  16. Combination of dispersive solid-phase extraction and salting-out homogeneous liquid-liquid extraction for the determination of organophosphorus pesticides in cereal grains.

    Science.gov (United States)

    Jia, Chunhong; Zhu, Xiaodan; Wang, Jihua; Zhao, Ercheng; He, Min; Chen, Li; Yu, Pingzhong

    2014-07-01

    A new analytical method for the determination of organophosphorus pesticides in cereal samples was developed by combining dispersive SPE (d-SPE) and salting-out homogeneous liquid-liquid extraction (SHLLE). The pesticides were first extracted from cereal grains with acetonitrile, followed by d-SPE cleanup. A 2 mL aliquot of the extract was then added to a centrifuge tube containing 9.2 mL water and 3.3 g NaCl for SHLLE. Analysis of the extract was carried out by gas chromatography coupled with flame photometric detection. The d-SPE procedure effectively provides the necessary cleanup of the extract while SHLLE is used as an efficient concentration technique. Experimental parameters influencing the extraction efficiency including amounts of added water and salt were investigated. Recovery studies were carried out at three fortification levels, yielding recoveries in the range of 57.7-98.1% with the RSD from 3.7 to 10.9%. The reported limits of determination obtained from this study were 1 μg/kg, which is better than the conventional methods. In the analysis of 40 wheat and corn samples taken from Beijing suburbs, only two wheat samples have chlorpyrifos residue over the limits of determination.

  17. Targeted natural product isolation guided by HPLC-SPE-NMR: Constituents of Hubertia species

    DEFF Research Database (Denmark)

    Sprogoe, K.; Staek, D.; Jager, A.K.;

    2007-01-01

    full or partial identification of all major extract constituents and demonstrated the presence of unusual quinic acid derivatives containing the (1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl residue that exhibit strongly coupled ABXY patterns, the parameters of which were obtained by spin simulations......The hyphenated technique, high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-SPE-NMR), has been applied for rapid identification of novel natural products in crude extracts of Hubertia ambavilla and Hubertia tomentosa. The technique allowed...

  18. Procedures for extraction and purification of leaf wax biomarkers from peats

    Directory of Open Access Journals (Sweden)

    J.E. Nichols

    2011-12-01

    Full Text Available Palaeoecological and palaeoclimate reconstruction, using leaf wax biomarkers, is a relatively new sub-discipline of peatland science. The ability to process large numbers of samples rapidly for biomarkers makes this type of analysis particularly appealing. This review is a guide to the preparation of leaf waxes for analysis by gas chromatography. The main phases of preparation are extraction of soluble organic compounds from sediment, separation of the total extract into fractions of differing polarity, and the derivatisation of polar functional groups. The procedures described here are not meant be exhaustive of all organic geochemical possibilities in peatlands, but a distillation of methods for the preparation of leaf waxes that are commonly and increasingly being used in palaeoecological and palaeoclimatological studies.

  19. Improved extraction procedures for polychlorinated biphenyls in solid samples with aqueous sodium hydroxide under autoclave conditions.

    Science.gov (United States)

    Akimoto, Y; Inouye, Y

    2000-03-01

    The efficacy of the extraction of polychlorinated biphenyls (PCBs) from varnish-infiltrated insulating papers as a model of solid materials with an aqueous sodium hydroxide (NaOH) by autoclaving at 121 degrees C for 30 min was compared with those for the conventional procedures, i.e., saponification with 1 N ethanolic NaOH in a boiling water bath for 60 min and extraction with benzene in a Soxhlet apparatus. The newly invented autoclaving method was found to be superior to the conventional ones, yielding approximately 5- to 6-fold cumulative PCB congeners without being accompanied by extended decomposition. Therefore, the autoclave-based sample treatment is recommended for more accurate determination of PCBs in the case of PCB-impregnated solid materials such as hardened oils and resin-coated or -infiltrated papers instead of being treated conventionally.

  20. Development of a modified cortisol extraction procedure for intermediately sized fish not amenable to whole-body or plasma extraction methods.

    Science.gov (United States)

    Guest, Taylor W; Blaylock, Reginald B; Evans, Andrew N

    2016-02-01

    The corticosteroid hormone cortisol is the central mediator of the teleost stress response. Therefore, the accurate quantification of cortisol in teleost fishes is a vital tool for addressing fundamental questions about an animal's physiological response to environmental stressors. Conventional steroid extraction methods using plasma or whole-body homogenates, however, are inefficient within an intermediate size range of fish that are too small for phlebotomy and too large for whole-body steroid extractions. To assess the potential effects of hatchery-induced stress on survival of fingerling hatchery-reared Spotted Seatrout (Cynoscion nebulosus), we developed a novel extraction procedure for measuring cortisol in intermediately sized fish (50-100 mm in length) that are not amenable to standard cortisol extraction methods. By excising a standardized portion of the caudal peduncle, this tissue extraction procedure allows for a small portion of a larger fish to be sampled for cortisol, while minimizing the potential interference from lipids that may be extracted using whole-body homogenization procedures. Assay precision was comparable to published plasma and whole-body extraction procedures, and cortisol quantification over a wide range of sample dilutions displayed parallelism versus assay standards. Intra-assay %CV was 8.54%, and average recovery of spiked samples was 102%. Also, tissue cortisol levels quantified using this method increase 30 min after handling stress and are significantly correlated with blood values. We conclude that this modified cortisol extraction procedure provides an excellent alternative to plasma and whole-body extraction procedures for intermediately sized fish, and will facilitate the efficient assessment of cortisol in a variety of situations ranging from basic laboratory research to industrial and field-based environmental health applications.

  1. Comparison of Two Procedures for Extraction and Clean-up of Organophosphorus and Pyrethroid Pesticides in Sediment

    Institute of Scientific and Technical Information of China (English)

    WANG Li-Gang; JIANG Xin; YAN Dong-Yun; S.FORSTER; D.MARTENS

    2004-01-01

    Two procedures were compared for extraction and clean-up of 20 organophosphorus and 19 pyrethroid pesticides in sediment to identify the more effective procedure for groups of pesticides or individual compounds. In Procedure Ⅰ,methanol/water and n-hexane were used for extraction,and 1:10 (v/v) dichloromethane in n-hexane and acetone were used as eluents for eluting the analyte through the cartridge,with one evaporating steps on a rotary evaporator and two eluting steps on the cartridge. n-hexane/acetone (2:1,v/v) was used for extraction and elution in Procedure Ⅱ with one evaporating step on a rotary evaporator and one eluting step on the cartridge. All extractions were performed under an ultrasonic bath and gas chromatography and mass spectrometry were utilized for measurements. Procedure Ⅱ was developed as a rapid,timesaving,less costly and safer substitute for Procedure Ⅰ which was an old method. Procedure Ⅱ was more effective for ahnost all the organophosphorus pesticides tested and 11 of the 19 pyrethroid pesticides,while Procedure Ⅰ was more appropriate for analysis of 5 pyrethroid pesticides. However,recoveries of most pyrethroid pesticides were fairly low. Thus,further studies should focus on adjustment and formulation of solvents for more efficient extraction and clean-up of pyrethroid pesticides from sediment samples.

  2. Determination of zinc in edible oils by flow injection FAAS after extraction induced by emulsion breaking procedure.

    Science.gov (United States)

    Bakircioglu, Dilek; Topraksever, Nukte; Kurtulus, Yasemin Bakircioglu

    2014-05-15

    A new procedure using extraction induced by emulsion breaking (EIEB) procedure has been developed for extraction/preconcentration of zinc in various edible oils (canola oil, corn oil, hazelnut oil, olive oil, and sunflower oil) prior to its determination by the single line flow injection (FI) flame atomic absorption spectrometry (FAAS). Several parameters affecting the extraction efficiency of the procedure were investigated including the type and concentrations of surfactant, the concentration of HNO3, and the other operational conditions (emulsion breaking time and temperature). The limits of detection of 1.1 and 1.0 μg L(-1) were observed for zinc when aqueous standard and oil-based standards were added to the emulsions for calibration, respectively. The proposed procedure of combining EIEB and single line FI-FAAS can be regarded as a new procedure for the determination of zinc in edible oil samples.

  3. Development and optimization of SPE-HPLC-UV/ELSD for simultaneous determination of nine bioactive components in Shenqi Fuzheng Injection based on Quality by Design principles.

    Science.gov (United States)

    Wang, Lu; Qu, Haibin

    2016-03-01

    A method combining solid phase extraction, high performance liquid chromatography, and ultraviolet/evaporative light scattering detection (SPE-HPLC-UV/ELSD) was developed according to Quality by Design (QbD) principles and used to assay nine bioactive compounds within a botanical drug, Shenqi Fuzheng Injection. Risk assessment and a Plackett-Burman design were utilized to evaluate the impact of 11 factors on the resolutions and signal-to-noise of chromatographic peaks. Multiple regression and Pareto ranking analysis indicated that the sorbent mass, sample volume, flow rate, column temperature, evaporator temperature, and gas flow rate were statistically significant (p design combined with response surface analysis was employed to study the relationships between the quality of SPE-HPLC-UV/ELSD analysis and four significant factors, i.e., flow rate, column temperature, evaporator temperature, and gas flow rate. An analytical design space of SPE-HPLC-UV/ELSD was then constructed by calculated Monte Carlo probability. In the presented approach, the operating parameters of sample preparation, chromatographic separation, and compound detection were investigated simultaneously. Eight terms of method validation, i.e., system-suitability tests, method robustness/ruggedness, sensitivity, precision, repeatability, linearity, accuracy, and stability, were accomplished at a selected working point. These results revealed that the QbD principles were suitable in the development of analytical procedures for samples in complex matrices. Meanwhile, the analytical quality and method robustness were validated by the analytical design space. The presented strategy provides a tutorial on the development of a robust QbD-compliant quantitative method for samples in complex matrices.

  4. Optimization of extraction procedures for ecotoxicity analyses: Use of TNT contaminated soil as a model

    Energy Technology Data Exchange (ETDEWEB)

    Sunahara, G.I.; Renoux, A.Y.; Dodard, S.; Paquet, L.; Hawari, J. [BRI, Montreal, Quebec (Canada); Ampleman, G.; Lavigne, J.; Thiboutot, S. [DREV, Courcelette, Quebec (Canada)

    1995-12-31

    The environmental impact of energetic substances (TNT, RDX, GAP, NC) in soil is being examined using ecotoxicity bioassays. An extraction method was characterized to optimize bioassay assessment of TNT toxicity in different soil types. Using the Microtox{trademark} (Photobacterium phosphoreum) assay and non-extracted samples, TNT was most acutely toxic (IC{sub 50} = 1--9 PPM) followed by RDX and GAP; NC did not show obvious toxicity (probably due to solubility limitations). TNT (in 0.25% DMSO) yielded an IC{sub 50} 0.98 + 0.10 (SD) ppm. The 96h-EC{sub 50} (Selenastrum capricornutum growth inhibition) of TNT (1. 1 ppm) was higher than GAP and RDX; NC was not apparently toxic (probably due to solubility limitations). Soil samples (sand or a silt-sand mix) were spiked with either 2,000 or 20,000 mg TNT/kg soil, and were adjusted to 20% moisture. Samples were later mixed with acetonitrile, sonicated, and then treated with CaCl{sub 2} before filtration, HPLC and ecotoxicity analyses. Results indicated that: the recovery of TNT from soil (97.51% {+-} 2.78) was independent of the type of soil or moisture content; CaCl{sub 2} interfered with TNT toxicity and acetonitrile extracts could not be used directly for algal testing. When TNT extracts were diluted to fixed concentrations, similar TNT-induced ecotoxicities were generally observed and suggested that, apart from the expected effects of TNT concentrations in the soil, the soil texture and the moisture effects were minimal. The extraction procedure permits HPLC analyses as well as ecotoxicity testing and minimizes secondary soil matrix effects. Studies will be conducted to study the toxic effects of other energetic substances present in soil using this approach.

  5. Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

    NARCIS (Netherlands)

    Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

    1998-01-01

    A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC system

  6. Kriging analysis of geochemical data obtained by sequential extraction procedure (BCR)

    Science.gov (United States)

    Fajkovic, Hana; Pitarević Svedružić, Lovorka; Prohić, Esad; Rončević, Sanda; Nemet, Ivan

    2015-04-01

    Field examination and laboratory analysis were performed to establish whether nonsanitary landfill Bastijunski brig has a negative influence on Vransko Lake, situated only 1500 m away. Vransko Lake is Croatia's largest natural lake, and it is a part of the Nature Park and ornithological reserve, which indicates its high biodiversity. Therefore it is necessary to understand the environmental processes and complex sediment/water interface. Lake sediments are considered to be a good "sinkhole'and are often the final recipients of anthropogenic and natural pollutants through adsorption onto the organic or clay fraction in sediments. Geochemical investigation were obtained throughout more than 50 lake sediments cores situated in different parts of the lake Speciation of heavy metals by modified BCR sequential extraction procedure with the addition of a first step of sequential extraction procedure by Tessier and analysis of residual by aqua regia were used to determine the amounts of selected elements (Al, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb, Zn) in different fractions. With such approach it is possible to determine which element will be extracted from sediment/soil in a different environmental conditions and can be valuable tool for interpretation of the mobile fraction of the elements, considered bioavailability, that present threat to biota in a case of a contaminant concentration magnification. All sediment and soil samples were analyzed by inductively coupled plasma atomic emission spectrometry. More accurate interpretation of data is an advantage of BCR sequential extraction procedure while high number of the data together with point data type could be considered as a drawback. Due to high amount of data, graphical presentation is advisable while interpolation tool is a first choice for point type of data, as it makes predictions for defined area based on the measurements. Distribution maps of analysed elements were obtained by kriging as a geostatistical method and

  7. Identification of the major constituents of Hypericum perforatum by LC/SPE/NMR and/or LC/MS.

    NARCIS (Netherlands)

    Tatsis, E.C.; Boeren, J.A.; Exarchou, V.; Troganis, A.N.; Vervoort, J.J.M.; Gerothanassis, I.P.

    2007-01-01

    The newly established hyphenated instrumentation of LC/DAD/SPE/NMR and LC/UV/(ESI)MS techniques have been applied for separation and structure verification of the major known constituents present in Greek Hypericum perforatum extracts. The chromatographic separation was performed on a C18 column. Ac

  8. Liquid-Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting.

    Science.gov (United States)

    Kumari, Chandrawati; Varughese, Bijo; Ramji, Siddarth; Kapoor, Seema

    2016-10-01

    Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid-liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis.

  9. Highly specific purification of N-glycans using phosphate-based derivatization as an affinity tag in combination with Ti(4+)-SPE enrichment for mass spectrometric analysis.

    Science.gov (United States)

    Zhang, Ying; Peng, Ye; Bin, Zhichao; Wang, Huijie; Lu, Haojie

    2016-08-31

    N-linked protein glycosylation is involved in regulation of a wide variety of cellular processes and associated with numerous diseases. Highly specific identification of N-glycome remains a challenge while its biological significance is acknowledged. The relatively low abundance of glycan in complex biological mixtures, lack of basic sites for protonation, and suppression by other highly abundant proteins/peptides lead to the particularly poor detection sensitivity of N-glycans in the MS analysis. Therefore, the highly specific purification procedure becomes a crucial step prior to MS analysis of the N-glycome. Herein, a novel N-glycans enrichment approach based on phosphate derivatization combined with Ti(4+)-SPE (solid phase extraction) was developed. Briefly, in this strategy, N-glycans were chemically labeled with a phospho-group at their reducing ends, such that the Ti(4+)-SPE microspheres were able to capture the phospho-containing glycans. The enrichment method was developed and optimized using model oligosaccharides (maltoheptaose DP7 and sialylated glycan A1) and also glycans from a standard glycoprotein (asialofetuin, ASF). This method experimentally showed high derivatization efficiency (almost 100%), excellent selectivity (analyzing DP7 in the digests of bovine serum albumin at a mass ratio of 1:100), high enriching recovery (90%), good reproducibility (CVN-glycome in human serum, in which a total of 31 N-glycan masses were identified.

  10. Simultaneous determination of five anthraquinones in a Chinese traditional preparation by RP-HPLC using an improved extraction procedure

    Institute of Scientific and Technical Information of China (English)

    Yan-bin Shi; Hui-li Li; Hai-qin Wang; Yan-biao Yang; Xiao-yun Zhang; Hui Wang; Zong-jie Zhu; Zhi-ye Zhang; Cheng-an Zhang

    2014-01-01

    OBJECTIVE:The stable quality of Chinese herbal medicines is a critical factor for their reliable clinical efficiency. An improved liquid-liquid extraction procedure and a liquid chromatographic method were developed to simultaneously analyze five anthraquinones (aloe-emodin, rhein, emodin, chrysophanol and physcion) in a Chinese traditional hospital preparation, Fuyankang mixture, in order to quantitatively control its quality in a more effective way. METHODS: A more economical and repeatable extraction procedure based on conventional liquid-liquid extraction technique was developed and used to extract ifve marker components in Fuyankang mixture. These anthraquinones were separated in less than 20 min on a C18 column with methanol and 0.1%phosphoric acid (88:12, v/v) as mobile phase. The method was validated for speciifcity, precision, spiked recovery and stability. RESULTS: Compared to conventional liquid-liquid extraction, the improved liquid-liquid extraction was found to be more effective for simultaneous extraction of anthraquinones from an aqueous Chinese herbal preparation, especially for hydrophobic compounds. The improved extraction method was successful y applied to determine the content of ifve marker components in Fuyankang mixture by the means of reverse phase high-performance liquid chromatography. CONCLUSION:The improved extraction procedure may be suitable for routine quality control of Fuyankang mixture and other traditional preparations at city-level hospitals in China.

  11. An Alternative and Rapid Method for the Extraction of Nucleic Acids from Ixodid Ticks by Potassium Acetate Procedure

    Directory of Open Access Journals (Sweden)

    Islay Rodríguez

    2014-08-01

    Full Text Available Four variants of the potassium acetate procedure for DNA extraction from ixodid ticks at different stage of their life cycles were evaluated and compared with phenol-chloroform and ammonium hydroxide methods. The most rapid and most efficient variant was validated in the DNA extraction procedure from the engorged ticks collected from bovine, canine as well as from house ticks for the screening of Borrelia burgdorferi sensu lato, Anaplasma spp. and Babesia spp. The ammonium hydroxide procedure was used for non-engorged ticks. All the variants were efficient and allowed obtaining PCR-quality material according to the specific amplification of 16S rRNA gene fragment of the original tick. DNA extracted from the ticks under the study was tested by multiplex PCR for the screening of tick-borne pathogens. Anaplasma spp. and Babesia spp. amplification products were obtained from 29/48 extracts. Ammonium hydroxide protocol was not efficient for two extracts. Detection of amplification products from the PCR indicated that DNA had been successfully extracted. The potassium acetate procedure could be an alternative, rapid, and reliable method for DNA extraction from the ixodid ticks, mainly for poorly-resourced laboratories.

  12. Evaluation of the ISO standard 11063 DNA extraction procedure for assessing soil microbial abundance and community structure.

    Directory of Open Access Journals (Sweden)

    Pierre Plassart

    Full Text Available Soil DNA extraction has become a critical step in describing microbial biodiversity. Historically, ascertaining overarching microbial ecological theories has been hindered as independent studies have used numerous custom and commercial DNA extraction procedures. For that reason, a standardized soil DNA extraction method (ISO-11063 was previously published. However, although this ISO method is suited for molecular tools such as quantitative PCR and community fingerprinting techniques, it has only been optimized for examining soil bacteria. Therefore, the aim of this study was to assess an appropriate soil DNA extraction procedure for examining bacterial, archaeal and fungal diversity in soils of contrasting land-use and physico-chemical properties. Three different procedures were tested: the ISO-11063 standard; a custom procedure (GnS-GII; and a modified ISO procedure (ISOm which includes a different mechanical lysis step (a FastPrep ®-24 lysis step instead of the recommended bead-beating. The efficacy of each method was first assessed by estimating microbial biomass through total DNA quantification. Then, the abundances and community structure of bacteria, archaea and fungi were determined using real-time PCR and terminal restriction fragment length polymorphism approaches. Results showed that DNA yield was improved with the GnS-GII and ISOm procedures, and fungal community patterns were found to be strongly dependent on the extraction method. The main methodological factor responsible for differences between extraction procedure efficiencies was found to be the soil homogenization step. For integrative studies which aim to examine bacteria, archaea and fungi simultaneously, the ISOm procedure results in higher DNA recovery and better represents microbial communities.

  13. Evaluation of the ISO Standard 11063 DNA Extraction Procedure for Assessing Soil Microbial Abundance and Community Structure

    Science.gov (United States)

    Griffiths, Robert; Dequiedt, Samuel; Lelievre, Mélanie; Regnier, Tiffanie; Nowak, Virginie; Bailey, Mark; Lemanceau, Philippe; Bispo, Antonio; Chabbi, Abad; Maron, Pierre-Alain; Mougel, Christophe; Ranjard, Lionel

    2012-01-01

    Soil DNA extraction has become a critical step in describing microbial biodiversity. Historically, ascertaining overarching microbial ecological theories has been hindered as independent studies have used numerous custom and commercial DNA extraction procedures. For that reason, a standardized soil DNA extraction method (ISO-11063) was previously published. However, although this ISO method is suited for molecular tools such as quantitative PCR and community fingerprinting techniques, it has only been optimized for examining soil bacteria. Therefore, the aim of this study was to assess an appropriate soil DNA extraction procedure for examining bacterial, archaeal and fungal diversity in soils of contrasting land-use and physico-chemical properties. Three different procedures were tested: the ISO-11063 standard; a custom procedure (GnS-GII); and a modified ISO procedure (ISOm) which includes a different mechanical lysis step (a FastPrep ®-24 lysis step instead of the recommended bead-beating). The efficacy of each method was first assessed by estimating microbial biomass through total DNA quantification. Then, the abundances and community structure of bacteria, archaea and fungi were determined using real-time PCR and terminal restriction fragment length polymorphism approaches. Results showed that DNA yield was improved with the GnS-GII and ISOm procedures, and fungal community patterns were found to be strongly dependent on the extraction method. The main methodological factor responsible for differences between extraction procedure efficiencies was found to be the soil homogenization step. For integrative studies which aim to examine bacteria, archaea and fungi simultaneously, the ISOm procedure results in higher DNA recovery and better represents microbial communities. PMID:22984486

  14. Evaluation of the ISO standard 11063 DNA extraction procedure for assessing soil microbial abundance and community structure.

    Science.gov (United States)

    Plassart, Pierre; Terrat, Sébastien; Thomson, Bruce; Griffiths, Robert; Dequiedt, Samuel; Lelievre, Mélanie; Regnier, Tiffanie; Nowak, Virginie; Bailey, Mark; Lemanceau, Philippe; Bispo, Antonio; Chabbi, Abad; Maron, Pierre-Alain; Mougel, Christophe; Ranjard, Lionel

    2012-01-01

    Soil DNA extraction has become a critical step in describing microbial biodiversity. Historically, ascertaining overarching microbial ecological theories has been hindered as independent studies have used numerous custom and commercial DNA extraction procedures. For that reason, a standardized soil DNA extraction method (ISO-11063) was previously published. However, although this ISO method is suited for molecular tools such as quantitative PCR and community fingerprinting techniques, it has only been optimized for examining soil bacteria. Therefore, the aim of this study was to assess an appropriate soil DNA extraction procedure for examining bacterial, archaeal and fungal diversity in soils of contrasting land-use and physico-chemical properties. Three different procedures were tested: the ISO-11063 standard; a custom procedure (GnS-GII); and a modified ISO procedure (ISOm) which includes a different mechanical lysis step (a FastPrep ®-24 lysis step instead of the recommended bead-beating). The efficacy of each method was first assessed by estimating microbial biomass through total DNA quantification. Then, the abundances and community structure of bacteria, archaea and fungi were determined using real-time PCR and terminal restriction fragment length polymorphism approaches. Results showed that DNA yield was improved with the GnS-GII and ISOm procedures, and fungal community patterns were found to be strongly dependent on the extraction method. The main methodological factor responsible for differences between extraction procedure efficiencies was found to be the soil homogenization step. For integrative studies which aim to examine bacteria, archaea and fungi simultaneously, the ISOm procedure results in higher DNA recovery and better represents microbial communities.

  15. Comparison of Reduced Displacement Potentials from Spe Free Field Measurements: SPE-4PRIME Versus Previous Events

    Science.gov (United States)

    Patton, H. J.; Rougier, E.

    2015-12-01

    Since 2010, the U. S. Department of Energy has funded a series of chemical tests at the National Nuclear Security Site (NNSS) in Climax Stock granite as part of the Source Physics Experiment (SPE) with the aim of gaining a better understanding of the generation and propagation of seismic energy from underground explosions in hard rock media. To date, four tests have been conducted in the same borehole with yields of 100, 1000, 900 and 100 kg at different depths of burials. The nominal scaled depths of burial are 938, 363, 376 and 1556 m/kt1/3 compared to standard containment practices of ~120 m/kt1/3. A quite dense array of free field accelerometers were installed around the borehole, both on and off shot depth. Acceleration data were corrected for shock-generated baseline-shifts, and free field ground velocity waveforms were obtained. This work concentrates on the qualitative analysis of the reduced displacement potentials and the explosion source spectra for the last shot of the series (SPE-4Prime) and the comparison of the obtained results against the previous events. Finally, the results obtained from the experimental data are compared to the Mueller-Murphy empirical explosion model both using the Heard and Ackerman and Denny and Johnson cavity radius scaling laws.

  16. SPE Membrane Electrode and Its Application to Chemical Sensor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The structure and proton conducting mechanism of solid polymer electrolyte (SPE) are described. Since the conductivity of electrolyte is important in SPE electrochemical cell research and development, we investigate quantitatively the conductivity of Nafion membrane and its dependence on temperature and relative humidity. Ex perimental results show that the conductivity of Nafion membrane increases with temperature and relative humidity. We also reports on the preparation and development of SPE membrane electrode with the emphasis on the mix ture pressing method and impregnation-reduction process to prepare SPE composite electrode assemblies and their application to electrochemical sensors. We also investigate and fabricate a potentiometric electrochemical sensor of hydrogen and ethylene to measure the hydrogen and ethylene partial pressure.

  17. Optimized extraction procedure for quantifying norisoprenoids in honey and honey food products.

    Science.gov (United States)

    Guyot-Declerck, C; Chevance, F; Lermusieau, G; Collin, S

    2000-12-01

    Norisoprenoids appear as promising compounds for authenticating unifloral honeys. So far, however, no method has been optimized for their isolation from a matrix so rich in sugars. In this framework, an original extraction procedure based on the use of Amberlite XAD-16 was developed. Recovery factors were determined and compared with those obtained with another resin (XAD-2). This was done for different model media and various norisoprenoids. In aqueous or alcoholic solutions, the efficiency of both resins proved very high. As expected, addition of honey decreased the adsorption of nonpolar compounds. This effect was much more pronounced with the lower-porosity XAD-2 support. Sugar addition markedly improved the recovery factors obtained with the XAD-16 resin in the case of more polar norisoprenoids.

  18. Minimally invasive surgical technique integrating multiple procedures with large specimen extraction via inguinal hernia orifice

    Science.gov (United States)

    Mani, Vishnu R.; Ahmed, Leaque

    2015-01-01

    While laparoscopic surgery can be performed using small skin incisions, any resected specimen must still be able to fit through these opening. For procedures, such as cholecystectomies and appendectomies, this is not usually a problem; however, for large specimens such as bowel or large tumors, this becomes problematic. Currently, the standard technique is to attempt piecemeal removal of the specimen or enlarge one of the laparoscopic incisions, effectively creating a mini laparotomy. Creating a larger incision adds many of the drawbacks of open laparotomy and should be avoided whenever possible. In this article, we present a new technique of combining the repair of an inguinal hernia, umbilical hernia with a duodenal tumor resection in order to extract the specimen through the inguinal hernia orifice. PMID:26703927

  19. Extraction procedure testing of solid wastes generated at selected metal ore mines and mills

    Science.gov (United States)

    Harty, David M.; Terlecky, P. Michael

    1986-09-01

    Solid waste samples from a reconnaissance study conducted at ore mining and milling sites were subjected to the U.S. Environmental Protection Agency extraction procedure (EP) leaching test Sites visited included mines and mills extracting ores of antimony (Sb), mercury (Hg), vanadium (V), tungsten (W), and nickel (Ni). Samples analyzed included mine wastes, treatment pond solids, tailings, low grade ore, and other solid wastes generated at these facilities Analysis of the leachate from these tests indicates that none of the samples generated leachate in which the concentration of any toxic metal parameter exceeded EPA criteria levels for those metals. By volume, tailings generally constitute the largest amount of solid wastes generated, but these data indicate that with proper management and monitoring, current EPA criteria can be met for tailings and for most solid wastes associated with mining and milling of these metal ores. Long-term studies are needed to determine if leachate characteristics change with time and to assist in development of closure plans and post closure monitoring programs.

  20. A comparison of three DNA extractive procedures with Leptospira for polymerase chain reaction analysis

    Directory of Open Access Journals (Sweden)

    Veloso IF

    2000-01-01

    Full Text Available Three DNA extraction methods were evaluated in this study: proteinase K followed by phenol-chloroform; a plant proteinase (E6870 followed by phenol-chloroform; and boiling of leptospires in 0.1 mM Tris, pH 7.0 for 10 min at 100°C, with no phenol treatment. Every strain treated with proteinase K or E6870 afforded positive polymerase chain reaction (PCR reaction. On the other hand, from five strains extracted by the boiling method, three did not feature the 849 bp band characteristic in Leptospira. We also evaluated by RAPD-PCR, DNAs from serovars isolated with proteinase K and proteinase 6870 with primers B11/B12. Each of the DNA samples provided PCR profiles in agreement with previous data. Moreover, the results with E6870 showed less background non-specific amplification, suggesting that removal of nucleases was more efficient with E6870. The limit for detection by PCR using Lep13/Lep14 was determined to be 10(2 leptospira, using the silver stain procedure.

  1. Multiresidue Analysis of Pesticides in Soil by Liquid-Solid Extraction Procedure

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2012-01-01

    Full Text Available A multiresidue method for simultaneous determination of four pesticides (diazinon,acetochlor, aldrine and carbofuran belonging to different pesticide groups, extractedfrom soil samples, is described. The method presented is based on liquid-solid extraction(LSE and determination of pesticides, i.e. the pesticides were extracted by methanol-acetone mixture, purified on florisil column and eluted by ethyl acetate-acetone mixture.Optimization of the main parameters affecting the LSE procedure, such as the choiceof purification sorbent, as well as the elution solvent and its volume, were investigated indetails and optimized. Also, validation of the proposed method was done.Gas chromatography-mass spectrometry (GC-MS was used for detection and quantificationof the pesticides studied. Relative standard deviation (RSD and recovery values formultiple analysis of soil samples fortified with 30 μg/kg of each pesticide were below 8%and higher than 89%, respectively. Limits of detection (LOD for all the compounds studiedwere less than 4 μg/kg.

  2. Evaluating bioavailability of organic pollutants in soils by sequential ultrasonic extraction procedure.

    Science.gov (United States)

    Wu, Xiang; Zhu, Lizhong

    2016-08-01

    Under current retrospective risk assessment framework, the total concentrations of organic pollutants in soils have been employed as the standard for over 30 years. The total concentrations reflect the overall accumulation in soils but tend to be overly conservative for assessing the ecological risks, where the bioavailability plays an important role. In this study, the bioavailability of organic pollutants in soils was evaluated using a stepwise and tiered classification method, namely the sequential ultrasonic extraction procedure (SEUP). The water-soluble and acid-soluble fractions extracted by the SEUP were the bioavailable fractions. The reliability and environmental relevance of the speciation method were examined with representative organic pollutants using the root uptake methods and the semipermeable membrane devices (SPMDs). The plant uptake amounts corrected with weight were highly correlated with the bioavailable fractions (R(2) > 0.75). The amounts of the bioavailable fractions were negatively correlated with the logKow values (R(2) ranging from 0.71 to 0.77) of the organic pollutants and the contents of soil organic matter (R(2) ranging from 0.68 to 0.96). As a refinement of the current risk assessment framework, the SUEP that has proved to be a reliable and convenient is thus highly recommended for evaluating the bioavailability of organic pollutants in soils.

  3. A single extraction and HPLC procedure for simultaneous analysis of phytosterols, tocopherols and lutein in soybeans.

    Science.gov (United States)

    Slavin, Margaret; Yu, Liangli Lucy

    2012-12-15

    A saponification/extraction procedure and high performance liquid chromatography (HPLC) analysis method were developed and validated for simultaneous analysis of phytosterols, tocopherols and lutein (a carotenoid) in soybeans. Separation was achieved on a phenyl column with a ternary, isocratic solvent system of acetonitrile, methanol and water (48:22.5:29.5, v/v/v). Evaporative light scattering detection (ELSD) was used to quantify β-sitosterol, stigmasterol, campesterol, and α-, δ- and γ-tocopherols, while lutein was quantified with visible light absorption at 450 nm. Peak identification was verified by retention times and spikes with external standards. Standard curves were constructed (R(2)>0.99) to allow for sample quantification. Recovery of the saponification and extraction was demonstrated via analysis of spiked samples. Also, the accuracy of results of four soybeans using the described saponification and HPLC analytical method was validated against existing methods. This method offers a more efficient alternative to individual methods for quantifying lutein, tocopherols and sterols in soybeans.

  4. Convenient solid phase extraction of cephalosporins in milk using a molecularly imprinted polymer.

    Science.gov (United States)

    Quesada-Molina, Carolina; Claude, Bérengère; García-Campaña, Ana M; del Olmo-Iruela, Monsalud; Morin, Philippe

    2012-11-15

    In this paper, a molecularly imprinted polymer (MIP) for cephalosporin molecules (cephalexin (CFL) and cephapirin (CFP)), was prepared by non covalent molecular imprinting approach and applied to solid phase extraction (SPE). For MIP synthesis, a tributylammonium cefadroxil salt (TBA-CFD) was used as template with methacrylic acid and ethylene glycol dimethacrylate as monomer and cross-linker, respectively, in acetone-methanol 92/8 (v/v) mixture. The selectivity of MIP versus non imprinted polymer (NIP) was confirmed for CFL, CFD and CFP in standard solutions as well as in milk samples. The efficiency of the synthesized MIP was evaluated by means of the application of the proposed MIP-SPE procedure to spiked milk samples previous to the HPLC method for the detection of cephalosporins. The MIP-SPE recoveries were higher than 60% for the three target analytes in spiked milk. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. In-line coupling SPE and CE for DNA preconcentration and separation.

    Science.gov (United States)

    Feng, Airong; Tran, Nguyet Thuy; Chen, Chen; Hu, Jiming; Taverna, Myriam; Zhou, Ping

    2011-06-01

    An in-line SPE method coupled to CE was developed for the analysis of DNA. The amino silica monolith was prepared in situ by polymerization of tetraethoxysilane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane in ethanol aqueous solution at the inlet end of a 100 μm id fused-silica capillary, and the remaining part of the capillary was used as separation channel. The procedure for this in-line SPE-CE method was constructed on the basis of investigation on operational conditions such as the introduction mode of sieving matrix, the composition of elution solvent and the elution time. Twenty millimolar ammonium hydroxide was demonstrated to be effective for DNA desorption from the monolith, and linear poly(N-isopropylacrylamide) was used as the separation matrix. The proposed method could achieve limits of detection of 0.065-0.123 ng/mL for six DNA fragments ranging 100-2000 bp. Compared with conventional CE, preconcentration factors of over 100 times were obtained. The applicability of the in-line SPE-CE method was further demonstrated by analyzing plasmid DNA from Escherichia coli crude lysate. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

    Science.gov (United States)

    Mcelroy, J. F.

    1990-01-01

    Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

  7. Effective application of freezing lipid precipitation and SCX-SPE for determination of pyrrolizidine alkaloids in high lipid foodstuffs by LC-ESI-MS/MS.

    Science.gov (United States)

    Yoon, Soo Hwan; Kim, Min-Sun; Kim, Sang Hoon; Park, Hyun Mee; Pyo, Heesoo; Lee, Yong Moon; Lee, Kyung-Tae; Hong, Jongki

    2015-06-15

    Pyrrolizidine alkaloids (PAs) are naturally occurring plant toxins associated with serious hepatic disease in humans and animals. In this study, rapid and sensitive analytical method was developed for the determination of 9 toxic PAs in popularly high lipid foodstuffs by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). PAs in lipid foodstuff were effectively purified by freezing lipid precipitation (FLP) and strong cation exchange (SCX)-solid-phase extraction (SPE). Especially, FLP could easily remove the large amounts of triacylglycerols in the lipid sample extract and effectively combine with SPE cleanup. During the FLP procedure, over 77% of the lipids in the foodstuff extracts were rapidly eliminated without any significant loss of the PAs with over 81% recovery. The elimination efficiency of lipids by FLP was tested with LC-atmospheric chemical ionization (APCI)-MS. For further purification, SCX-SPE cartridge could successfully purify PAs from the remaining interfering substances by the variation pH with 5% NH4OH in methanol. For precise quantification and confirmation of PAs in complicate sample matrices, appropriate transition ions in LC-MS/MS-multiple-ion reaction monitoring (MRM) mode were selected on the basis of MS/MS fragmentation pathways of PAs. The established analytical method was validated in terms of the linearity, limits of detection (LOD), and quantification (LOQ), precision, and accuracy. The method was deemed satisfactory by inter- and intra-day validation and exhibited both high accuracy and precision (relative standard deviation<11.06%). Overall limits of detection and quantitation of PAs were approximately 0.06-0.60ng/mL at a signal-to-noise ratio (S/N) of 3 and were about 0.20-1.99ng/mL at a S/N of 10 for all foodstuffs. The established method was successfully applied for the monitoring of toxic PAs in several types of high lipid foodstuffs such as soybeans, seed oil, milk, and margarine.

  8. Comparison of different extraction methods for the determination of statin drugs in wastewater and river water by HPLC/Q-TOF-MS.

    Science.gov (United States)

    Martín, Julia; Buchberger, Wolfgang; Alonso, Esteban; Himmelsbach, Markus; Aparicio, Irene

    2011-07-15

    Three preconcentration techniques including solid phase extraction (SPE), dispersive liquid-liquid microextraction (DLLME) and stir-bar sorptive extraction (SBSE) have been optimized and compared for the analysis of six hypolipidaemic statin drugs (atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin and simvastatin) in wastewater and river water samples by high performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (HPLC/Q-TOF-MS). Parameters that affect the efficiency of the different extraction methods such as solid phase material, sample pH and elution solvent in the case of SPE; the type and volume of the extracting and dispersive solvent, pH of sample, salt addition and number of extraction steps in the case of DLLME; and the stirring time, pH of sample, sample volume and salt addition for SBSE were evaluated. SPE allowed the best recoveries for most of the analytes. Pravastatin was poorly extracted by DLLME and could not be determined. SBSE was only applicable for lovastatin and simvastatin. However, despite the limitations of having poorer recovery than SPE, DLLME and SBSE offered some advantages because they are simple, require low organic solvent volumes and present low matrix effects. DLLME required less time of analysis, and for SBSE the stir-bar was re-usable. SPE, DLLME and SBSE provided method detection limits in the range of 0.04-11.2 ng L(-1), 0.10-17.0 ng L(-1) for 0.52-2.00 ng L(-1), respectively, in real samples. To investigate and compare their applicability, SPE, DLLME and SBSE procedures were applied to the detection of statin drugs in effluent wastewater and river samples.

  9. Preparation and characterization of foxtail millet bran oil using subcritical propane and supercritical carbon dioxide extraction

    National Research Council Canada - National Science Library

    Shi, Yuzhong; Ma, Yuxiang; Zhang, Ruitin; Ma, Hanjun; Liu, Benguo

    2015-01-01

    ...), supercritical carbon dioxide extraction (SCE) and subcritical propane extraction (SPE) and analyzed the yield, physicochemical property, fatty acid profile, tocopherol composition, oil oxidative stability in this study...

  10. Application of Hplc-Pda Method Using Two Different Extraction Procedures for the Determination of Alkylresorcinols in Cereals

    Directory of Open Access Journals (Sweden)

    Gailāne Natālija

    2015-09-01

    Full Text Available Cereals, especially barley, are an important source of vitamins, minerals, dietary fibre and various phytochemicals, such as alkylresorcinols (ARs. Cereal ARs are a group of phenolic lipids located in the outer parts of grain, particularly in rye and wheat, but not found in refined flour or in refined products from cereals. This study focuses on the comparison of different extraction procedures applied for the determination of the content of ARs (C15:0 - C23:0 in grain of Latvian barley genotypes. The content of ARs in 1 rye and 16 barley samples grown with different amounts of fertilier was determined by High Performance Liquid Chromatography method with Photodiode Array detection (HPLC-PDA developed by us. Two different extraction methods were compared: accelerated Soxhlet extraction and 24-hour extraction. Aside from validation of the extraction procedures, validation parameters for the HPLC-PDA based quantitation method were provided. The coefficients of variation for repeatability and intermediate precision were < 9% and < 3%, respectively. The content of ARs determined with the HPLC-PDA method in conjunction with accelerated Soxhlet extraction was up to 1.5 times higher than using 24-hour extraction. AR content varied from 2.11 ± 0.04 to 3.80 ± 0.10 mg·100 g-1 for 24-hour extraction and from 2.66 ± 0.06 to 5.70 ± 0.20 mg·100 g-1 for accelerated Soxhlet extraction, indicating the increased efficiency of this procedure in analysis of ARs.

  11. A comparison of an optimised sequential extraction procedure and dilute acid leaching of elements in anoxic sediments, including the effects of oxidation on sediment metal partitioning.

    Science.gov (United States)

    Larner, Bronwyn L; Palmer, Anne S; Seen, Andrew J; Townsend, Ashley T

    2008-02-11

    The effect of oxidation of anoxic sediment upon the extraction of 13 elements (Cd, Sn, Sb, Pb, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As) using the optimised Community Bureau of Reference of the European Commission (BCR) sequential extraction procedure and a dilute acid partial extraction procedure (4h, 1 molL(-1) HCl) was investigated. Elements commonly associated with the sulfidic phase, Cd, Cu, Pb, Zn and Fe exhibited the most significant changes under the BCR sequential extraction procedure. Cd, Cu, Zn, and to a lesser extent Pb, were redistributed into the weak acid extractable fraction upon oxidation of the anoxic sediment and Fe was redistributed into the reducible fraction as expected, but an increase was also observed in the residual Fe. For the HCl partial extraction, sediments with moderate acid volatile sulfide (AVS) levels (1-100 micromolg(-1)) showed no significant difference in element partitioning following oxidation, whilst sediments containing high AVS levels (>100 micromolg(-1)) were significantly different with elevated concentrations of Cu and Sn noted in the partial extract following oxidation of the sediment. Comparison of the labile metals released using the BCR sequential extraction procedure (SigmaSteps 1-3) to labile metals extracted using the dilute HCl partial extraction showed that no method was consistently more aggressive than the other, with the HCl partial extraction extracting more Sn and Sb from the anoxic sediment than the BCR procedure, whilst the BCR procedure extracted more Cr, Co, Cu and As than the HCl extraction.

  12. SPE-5 Ground-Motion Prediction at Far-Field Geophone and Accelerometer Array Sites and SPE-5 Moment and Corner-Frequency Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoning [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Patton, Howard John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Ting [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-25

    This report offers predictions for the SPE-5 ground-motion and accelerometer array sites. These predictions pertain to the waveform and spectral amplitude at certain geophone sites using Denny&Johnson source model and a source model derived from SPE data; waveform, peak velocity and peak acceleration at accelerometer sites using the SPE source model and the finite-difference simulation with LLNL 3D velocity model; and the SPE-5 moment and corner frequency.

  13. SPE-5 Ground-Motion Prediction at Far-Field Geophone and Accelerometer Array Sites and SPE-5 Moment and Corner-Frequency Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoning [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Patton, Howard John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Ting [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-25

    This report offers predictions for the SPE-5 ground-motion and accelerometer array sites. These predictions pertain to the waveform and spectral amplitude at certain geophone sites using Denny&Johnson source model and a source model derived from SPE data; waveform, peak velocity and peak acceleration at accelerometer sites using the SPE source model and the finite-difference simulation with LLNL 3D velocity model; and the SPE-5 moment and corner frequency.

  14. Comparison of single and sequential extraction procedures for the study of rare earth elements remobilisation in different types of soils

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Chebrolu Rama Mohan [Geological Survey of India, Hyderabad 500068 (India); Sahuquillo, Angels [Universitat de Barcelona, Department de Quimica Analitica, Marti i Franques, 1-11, E-08028 Barcelona (Spain); Lopez-Sanchez, Jose Fermin, E-mail: fermin.lopez@ub.edu [Universitat de Barcelona, Department de Quimica Analitica, Marti i Franques, 1-11, E-08028 Barcelona (Spain)

    2010-03-10

    With the continual increase in the utilisation of rare earth elements (REE) for industrial and agricultural purposes, research into the environmental and biogeochemical behaviour of REE had attracted much interest in recent times. This study principally describes the distribution of REE in four different types of soils like lateritic soil (S-1), in situ natural soil (S-2), soil contaminated by mining activity (S-3) and accidentally polluted soil (S-4) utilizing the optimised BCR sequential extraction procedure and partial extractions with various types of single extractants such as unbuffered salt solutions 0.1 M NaNO{sub 3}, 0.01 M CaCl{sub 2}, 1 M NH{sub 4}NO{sub 3}; complexing agents 0.005 M DTPA and 0.05 M EDTA; acid solutions 0.43 M CH{sub 3}COOH and 1 M HCl. Comparison of the sum of the four BCR fractions, which included an aqua regia attack on the residue, with the pseudo-total aqua regia digest values to assess the accuracy of the BCR partioning approach has been undertaken. Partial extraction results with several single extractants have also been reported for all the REE elements including yttrium which have been analysed by the optimised BCR procedure. Results obtained after 24 h extraction with each of the single extractant have also been discussed. The extraction with 1 M HCl during 24 h yielded similar quantities of REE as those released under the combined steps of 1, 2 and 3 of the BCR sequential extraction for all the four different type of soil samples indicating that this reagent can be used successfully to estimate the total extractable contents of REE in various types of soil samples.

  15. Description of the ECMWF/WMO Global Observational Data Set, and associated data extraction and interpolation procedures

    NARCIS (Netherlands)

    Potma CJM

    1993-01-01

    This report presents a description of data-extraction and interpolation procedures using the ECMWF/WMO Global Observational Data Set (ODS), an archive of unvalidated observational meteorological surface data measured at 00, 06, 12 and 18 UT. The archive covers the period 1 January 1980 to 31

  16. Automated extraction of 11-nor-delta9-tetrahydrocannabinol carboxylic acid from urine samples using the ASPEC XL solid-phase extraction system.

    Science.gov (United States)

    Langen, M C; de Bijl, G A; Egberts, A C

    2000-09-01

    The analysis of 11-nor-delta9-tetrahydrocannabinol-carboxylic acid (THCCOOH, the major metabolite of cannabis) in urine with gas chromatography and mass spectrometry (GC-MS) and solid-phase extraction (SPE) sample preparation is well documented. Automated SPE sample preparation of THCCOOH in urine, although potentially advantageous, is to our knowledge poorly investigated. The objective of the present study was to develop and validate an automated SPE sample-preparation step using ASPEC XL suited for GC-MS confirmation analysis of THCCOOH in urine drug control. The recoveries showed that it was not possible to transfer the protocol for the manual SPE procedure with the vacuum manifold to the ASPEC XL without loss of recovery. Making the sample more lipophilic by adding 1 mL 2-propanol after hydrolysis to the urine sample in order to overcome the problem of surface adsorption of THCCOOH led to an extraction efficiency (77%) comparable to that reached with the vacuum manifold (84%). The reproducibility of the automated SPE procedure was better (coefficient of variation 5%) than that of the manual procedure (coefficient of variation 12%). The limit of detection was 1 ng/mL, and the limit of quantitation was 4 ng/mL. Precision at the 12.5-ng/mL level was as follows: mean, 12.4 and coefficient of variation, 3.0%. Potential carryover was evaluated, but a carryover effect could not be detected. It was concluded that the proposed method is suited for GC-MS confirmation urinalysis of THCCOOH for prisons and detoxification centers.

  17. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell

    Science.gov (United States)

    Savinell, Robert F.; Fritts, S. D.

    1987-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  18. SPE-HPLC purification of endocrine disrupting compounds from human serum for assessment of xenoestrogenic activity

    DEFF Research Database (Denmark)

    Hjelmborg, P.S.; Ghisari, Mandana; Bonefeld-Jørgensen, Eva

    2006-01-01

    Assessment of xenoestrogenic activity in human serum samples requires the removal of endogenous sex hormones to assure that the activity measured originates from xenobiotic compounds only. Serum samples representing high, medium and lower accumulation of persistent organic pollutants (POPs) were...... extracted using solid-phase extraction (SPE) followed by normal-phase high-performance liquid chromatography (NP-HPLC) for separation of POPs from endogenous hormones. The recovery of polychlorinated biphenyl (PCB) congeners in spiked serum samples was up to 86 %, making the extraction method suitable...... measured by ERE-CALUX was validated and considered to be a valuable tool to assess the combined ER effect of lipophilic serum POPs where additive/synergistic and agonistic/antagonistic effects are integrated giving an overall estimate of exposure and bioactivity....

  19. Anion exchange SPE and liquid chromatography-tandem mass spectrometry in GHB analysis.

    Science.gov (United States)

    Elian, Albert A; Hackett, Jeffery

    2011-12-01

    In this study, the extraction of γ-hydroxybutyrate (GHB) from urine using solid-phase extraction (SPE) is described. SPE was performed on anion exchange columns after samples of urine had been diluted with de-ionized water. After application of the diluted samples containing GHB-d(6) as an internal standard, the sorbent was washed with deionized water and methanol and dried. The GHB was eluted from the SPE column with a solvent consisting of methanol containing 6% glacial acetic acid. The eluent was collected, evaporated to dryness, and dissolved in mobile phase (100 μL) for analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in negative multiple reaction monitoring (MRM) mode. Liquid chromatography was performed in gradient mode employing a biphenyl column and a mobile phase consisting of acetontitrile (containing 0.1% formic acid) and 0.1% aqueous formic acid. The total run time for each analysis was less than 5 min. The limits of detection/quantification for this method were determined to be 50 and 100 ng/mL, respectively. The method was found to be linear from 500 ng/mL to 10,000 ng/mL (r(2)>0.995). The recovery of GHB was found to be greater than 75%. In this report, results of authentic urine samples analyzed for GHB by this method are presented. GHB concentrations in these samples were found to be range from less than 500 ng/mL to 5110 ng/mL.

  20. Leach and EP (extraction procedure) toxicity tests on grouted waste from Tank 106-AN

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R.J.; Martin, W.J.; Lokken, R.O.; LeGore, V.L.; Lindenmeier, C.W.; Martin, P.F.C.

    1989-09-01

    Pacific Northwest Laboratory is conducting laboratory experiments to produce leach rate data for various waste species that will be contained in grout at Hanford. In the work reported here, grout made from Tank 106-AN liquid waste was used to produce empirical leach rate data for several radionuclides ({sup 60}Co, {sup 90}Sr, {99}Tc, {129}I, {137}Cs, and {sup 241}Am), stable major components (NO{sub 3}{sup {minus}}, NO{sub 2}{sup {minus}}, F, Cl, and Na), and trace metals (Cr, Mo, and Ni). Two types of tests were used to produce leach rate data: an intermittent replacement leach test (ANS 16.1 leach test) and a static leach test. Measured effective diffusivities of key species are as follows: 4 to 6 {times} 10{sup {minus}8} cm{sup 2}/sec for {sup 99}Tc, 3 to 7 {times} 10{sup {minus}8} cm{sup 2}/sec for {sup 129}I, 4 to 6 {times} 10{sup {minus}9} cm{sup 2}/sec for nitrate, and 6 to 7 {times} 10{sup {minus}9} cm{sup 2}/sec for nitrite. The leach indices of all species studied are above (more favorable than) the waste form criteria. The leach indices for {sup 99}Tc and {sup 129}I are 7.4 {plus minus} 1.2 and 7.6 {plus minus} 0.4, respectively, and are being further investigated in continuing studies of double-shell slurry feed grouts. An Extraction Procedure (EP) toxicity test was also conducted and the grouted water is considered nontoxic per this test protocol. 19 refs., 9 figs., 8 tabs.

  1. Comparison of three protein extraction procedures from toxic and non-toxic dinoflagellates for proteomics analysis.

    Science.gov (United States)

    Jiang, Xi-Wen; Wang, Jing; Chan, Leo Lai; Lam, Paul Kwan Sing; Gu, Ji-Dong

    2015-08-01

    Three methods for extraction and preparation of high-quality proteins from both toxic and non-toxic dinoflagellates for proteomics analysis, including Trizol method, Lysis method and Tris method, were compared with the subsequent protein separation profiles using 2-D differential gel electrophoresis (2-D DIGE), Coomassie Blue and silver staining. These methods showed suitability for proteins with different pIs and molecular weights. Tris method was better for low molecular weight and low pI protein isolation; whereas both Lysis and Trizol method were better for high-molecular weight and high pI protein purification. Trizol method showed good results with Alexandrium species and Gynodinium species, and the background in gel was much clearer than the other two methods. At the same time, only Lysis method caused breaking down of the target proteins. On the other hand, Trizol method obtained higher concentration of ribulose-1,5-bisphosphate carboxylase/oxygenase proteins by Western-blotting, while Tris method was the best for peridinin-chlorophyll-protein complexes protein and T1 protein preparation. DIGE was better than Coomassie Blue and silver staining, except for some limitations, such as the high cost of the dyes, relatively short shelf life and the requirements for extensive and special image capturing equipment. Some proteins related to PSTs synthesis in dinoflagellates are hydrophobic with high molecular weight or binding on membranes and Trizol method performed better than Tris method for these proteins. The Trizol method and 2-D DIGE were effective combination for proteomics investigations of dinoflagellates. This procedure allows reliable and high recovery efficiency of proteins from dinoflagellates for better understanding on their occurrence and toxin-production for physiological and biochemical information.

  2. Comparison of solvent extraction and solid-phase extraction for the determination of polychlorinated biphenyls in transformer oil.

    Science.gov (United States)

    Mahindrakar, A N; Chandra, S; Shinde, L P

    2014-01-01

    Solid-phase extraction (SPE) of nine polychlorinated biphenyls (PCBs) from transformer oil samples was evaluated using octadecyl (CI8)-bonded porous silica. The efficiency of SPE of these PCBs was compared with those obtained by solvent extraction with DMSO and hexane. Average recoveries exceeding 95% for these PCBs were obtained via the SPE method using small cartridges containing 100mg of 40 pm CI8-bonded porous silica. The average recovery by solvent extraction with DMSO and hexane exceeded 83%. It was concluded that the recoveries and precision for the solvent extraction of PCBs were poorer than those for the SPE.

  3. High performance solid-phase extraction cleanup method coupled with gas chromatography-triple quadrupole mass spectrometry for analysis of polychlorinated naphthalenes and dioxin-like polychlorinated biphenyls in complex samples.

    Science.gov (United States)

    Li, Fang; Jin, Jing; Tan, Dongqin; Xu, Jiazhi; Dhanjai; Ni, Yuwen; Zhang, Haijun; Chen, Jiping

    2016-05-27

    A solid-phase extraction (SPE) cleanup method was developed to purify the sample extracts for the analysis of polychlorinated naphthalenes (PCNs) and dioxin-like polychlorinated biphenyls (dl-PCBs). Monodisperse magnesium oxide (MgO) microspheres and basic alumina were used as SPE adsorbents. Important parameters of the SPE procedure were optimized, including the amount of basic alumina and the type and volume of the washing and elution solvents. The optimized SPE cleanup method exhibited excellent purification performance for the removal of organochlorinated compounds, lipid compounds, sulfur, and pigments. Additionally, it was found that the retention activities of congeners differed with the number and position of the chlorine substituents in PCNs. In this study, an analytical method based on a combination of accelerated solvent extraction (ASE) coupled with SPE cleanup and gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) is proposed for the analysis of PCNs and dl-PCBs in complex samples (sediment, pine needle, and scallop samples). The analytical method demonstrates good linearity, acceptable recovery (63-148%) and precision (relative standard deviations less than 26%). The limits of detection (LODs) of PCN and dl-PCB congeners were in the range of 0.6-19.1pgg(-1) and 0.4-8.6pgg(-1), respectively. The PCNs and dl-PCBs levels in these samples ranged from 0.16 to 3.07ngg(-1) dry weight (dw) and from undetectable to 0.07ngg(-1) dw, respectively.

  4. Development of a Nucleic Acid Extraction Procedure for Simultaneous Recovery of DNA and RNA from Diverse Microbes in Water

    Directory of Open Access Journals (Sweden)

    Vincent R. Hill

    2015-05-01

    Full Text Available Drinking and environmental water samples contain a diverse array of constituents that can interfere with molecular testing techniques, especially when large volumes of water are concentrated to the small volumes needed for effective molecular analysis. In this study, a suite of enteric viruses, bacteria, and protozoan parasites were seeded into concentrated source water and finished drinking water samples, in order to investigate the relative performance of nucleic acid extraction techniques for molecular testing. Real-time PCR and reverse transcription-PCR crossing threshold (CT values were used as the metrics for evaluating relative performance. Experimental results were used to develop a guanidinium isothiocyanate-based lysis buffer (UNEX buffer that enabled effective simultaneous extraction and recovery of DNA and RNA from the suite of study microbes. Procedures for bead beating, nucleic acid purification, and PCR facilitation were also developed and integrated in the protocol. The final lysis buffer and sample preparation procedure was found to be effective for a panel of drinking water and source water concentrates when compared to commercial nucleic acid extraction kits. The UNEX buffer-based extraction protocol enabled PCR detection of six study microbes, in 100 L finished water samples from four drinking water treatment facilities, within three CT values (i.e., within 90% difference of the reagent-grade water control. The results from this study indicate that this newly formulated lysis buffer and sample preparation procedure can be useful for standardized molecular testing of drinking and environmental waters.

  5. Macrocyclic polyamine-functionalized silica as a solid-phase extraction material coupled with ionic liquid dispersive liquid-liquid extraction for the enrichment of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Liu, Longhui; He, Lijun; Jiang, Xiuming; Zhao, Wenjie; Xiang, Guoqiang; Anderson, Jared L

    2014-04-01

    In this study, silica modified with a 30-membered macrocyclic polyamine was synthesized and first used as an adsorbent material in SPE. The SPE was further combined with ionic liquid (IL) dispersive liquid-liquid microextraction (DLLME). Five polycyclic aromatic hydrocarbons were employed as model analytes to evaluate the extraction procedure and were determined by HPLC combined with UV/Vis detection. Acetone was used as the elution solvent in SPE as well as the dispersive solvent in DLLME. The enrichment of analytes was achieved using the 1,3-dibutylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL/acetone/water system. Experimental conditions for the overall macrocycle-SPE-IL-DLLME method, such as the amount of adsorbent, sample solution volume, sample solution pH, type of elution solvent as well as addition of salt, were studied and optimized. The developed method could be successfully applied to the analysis of four real water samples. The macrocyclic polyamine offered higher extraction efficiency for analytes compared with commercially available C18 cartridge, and the developed method provided higher enrichment factors (2768-5409) for model analytes compared with the single DLLME. Good linearity with the correlation coefficients ranging from 0.9983 to 0.9999 and LODs as low as 0.002 μg/L were obtained in the proposed method.

  6. In Spe algkoosseis tuleb üheks kontserdiks kokku

    Index Scriptorium Estoniae

    2009-01-01

    1.-2. mail tähistatakse 30 aasta möödumist Tartu muusikapäevadest kontsertidega, kus esineb ka proge-rock'i ansambel In Spe. Ansambli esimesest kontserdist TPI aulas ja 1981 aastal salvestatud heliplaadist

  7. In Spe algkoosseis tuleb üheks kontserdiks kokku

    Index Scriptorium Estoniae

    2009-01-01

    1.-2. mail tähistatakse 30 aasta möödumist Tartu muusikapäevadest kontsertidega, kus esineb ka proge-rock'i ansambel In Spe. Ansambli esimesest kontserdist TPI aulas ja 1981 aastal salvestatud heliplaadist

  8. Study on Response Time of SPE Carbon Monoxide Sensor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of structural design and the parameters of the working electrode on the response time of a solid polymer electrolyte (SPE) carbon monoxide sensor has been studied. Results show that the response time is mainly determined by the RC time constant of the catalyst layer and also related with the working electrode potential.

  9. Relationship between heavy metals and minerals extracted from soil clay by standard and novel acid extraction procedures.

    Science.gov (United States)

    Melo, Vander Freitas; Batista, Araína Hulmann; Gilkes, Robert J; Rate, Andrew W

    2016-12-01

    Strong acid digestions are commonly used to determine heavy metal (HM) contents in soils. In order to understand more fully the acid digestion processes, a logical step is to determine the extent of dissolution of mineral phases. The aims of this study were to compare the efficiency of extraction of HM by different acid digestions and to monitor the associated dissolution of the clay fraction. The context of the study was to develop a milder chemical extraction method (microwave-assisted 1 mol L(-1) HNO3 closed system (NACS)), which recovers more reactive HM and with little dissolution of minerals. The different acid digestion methods dissolved different amounts of minerals from the clay fraction. Both aqua regia (AR) and EPA 3051 dissolved all of the Fe and Al oxides, and the dissolution of kaolin was limited to thinner particles (c dimension), smaller particles in a and b dimensions and grains with lower crystallinity. The lower recovery of HM for AR compared with EPA 3051 was related to the large amount of short-range order phases formed during the AR extraction as these phases have the capacity to re-adsorb HM. The new method (NACS) has the potential to replace other methods of determining bioavailable forms of HM, such as AR and EPA 3051. The contents of Pb, As, Co, Zn, and Cu determined by EPA 3051 and EPA 3052 were quite close.

  10. An On-Line Solid Phase Extraction-Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Perfluoroalkyl Acids in Drinking and Surface Waters

    Directory of Open Access Journals (Sweden)

    Michela Mazzoni

    2015-01-01

    Full Text Available An UHPLC-MS/MS multiresidue method based on an on-line solid phase extraction (SPE procedure was developed for the simultaneous determination of 9 perfluorinated carboxylates (from 4 to 12 carbon atoms and 3 perfluorinated sulphonates (from 4 to 8 carbon atoms. This work proposes using an on-line solid phase extraction before chromatographic separation and analysis to replace traditional methods of off-line SPE before direct injection to LC-MS/MS. Manual sample preparation was reduced to sample centrifugation and acidification, thus eliminating several procedural errors and significantly reducing time-consuming and costs. Ionization suppression between target perfluorinated analytes and their coeluting SIL-IS were detected for homologues with a number of carbon atoms less than 9, but the quantitation was not affected. Total matrix effect corrected by SIL-IS, inclusive of extraction efficacy, and of ionization efficiency, ranged between −34 and +39%. The percentage of recoveries, between 76 and 134%, calculated in different matrices (tap water and rivers impacted by different pollutions was generally satisfactory. LODs and LOQs of this on-line SPE method, which also incorporate recovery losses, ranged from 0.2 to 5.0 ng/L and from 1 to 20 ng/L, respectively. Validated on-line SPE-LC/MS/MS method has been applied in a wide survey for the determination of perfluoroalkyl acids in Italian surface and ground waters.

  11. Detection of noroviruses in foods: a study on virus extraction procedures in foods implicated in outbreaks of human gastroenteritis.

    Science.gov (United States)

    Rutjes, Saskia A; Lodder-Verschoor, Froukje; van der Poel, Wim H M; van Duijnhoven, Yvonne T H P; de Roda Husman, Ana Maria

    2006-08-01

    Disease outbreaks in which foods are epidemiologically implicated as the common source are frequently reported. Noroviruses and enteric hepatitis A viruses are among the most prevalent causative agents of foodborne diseases. However, the detection of these viruses in foods other than shellfish is often time-consuming and unsuccessful. In this study, three virus concentration methods were compared: polyethylene glycol (PEG) plus NaCl, ultracentrifugation, and ultrafiltration. Two RNA extraction methods, TRIzol and RNeasy Mini Kit (Qiagen), were compared for detection of viruses in whipped cream and lettuce (as representatives of the dairy and vegetable-fruit food groups, respectively). A seeding experiment with canine calicivirus was conducted to determine the efficiency of each virus extraction procedure. The PEG-NaCl-TRIzol method was most efficient for the detection of viruses in whipped cream and the ultracentrifugation-RNeasy-Mini Kit procedure was best for detection on lettuce. Based on the seeding experiments, food items implicated in norovirus-associated gastroenteritis outbreaks were subjected to the optimal procedure for a specific composition and matrix. No noroviruses were detected in the implicated food items, possibly because the concentration of virus on the food item was too low or because of the presence of inhibitory factors. For each food group, a specific procedure is optimal. Inhibitory factors should be controlled in these procedures because they influence virus detection in food.

  12. Determination of abamectin in citrus fruits using SPE combined with dispersive liquid-liquid microextraction and HPLC-UV detection.

    Science.gov (United States)

    Rezaee, Mohammad; Mashayekhi, Hossein Ali; Saleh, Abolfazl; Abdollahzadeh, Yaser; Naeeni, Mohammad Hosein; Fattahi, Nazir

    2013-08-01

    A new pretreatment method, SPE combined with dispersive liquid-liquid microextraction, was proposed for the determination of abamectin in citrus fruit samples for the first time. In this method, fruit samples were extracted by ultrasound-assisted extraction followed by SPE. Then, the SPE was used as a disperser solvent in the next dispersive liquid-liquid microextraction step for further purification and enrichment of abamectin. The effects of various parameters on the extraction efficiency of the proposed method were investigated and optimized. Good linearity of abamectin was obtained from 0.005 to 10.0 mg/kg for B1a and from 0.05 to 10.0 mg/kg for B1b with correlation coefficient (r(2)) of 0.998 for B1a and 0.991 for B1b, respectively. The LODs were 0.001 and 0.008 mg/kg (S/N = 3) for B1a and B1b, respectively. The relative recoveries at three spiked levels were ranged from 87 to 96% with the RSD less than 11% (n = 3). The method has been successfully applied to the determination of abamectin in citrus fruit samples.

  13. Evaluation of extraction procedures for the ion chromatographic determination of arsenic species in plant materials.

    Science.gov (United States)

    Schmidt, A C; Reisser, W; Mattusch, J; Popp, P; Wennrich, R

    2000-08-11

    The determination of arsenic species in plants grown on contaminated sediments and soils is important in order to understand the uptake, transfer and accumulation processes of arsenic. For the separation and detection of arsenic species, hyphenated techniques can be applied successfully in many cases. A lack of investigations exists in the handling (e.g., sampling, pre-treatment and extraction) of redox- and chemically labile arsenic species prior to analysis. This paper presents an application of pressurized liquid extraction (PLE) using water as the solvent for the effective extraction of arsenic species from freshly harvested plants. The method was optimized with respect to extraction time, number of extraction steps and temperature. The thermal stability of the inorganic and organic arsenic species under PLE conditions (60-180 degrees C) was tested. The adaptation of the proposed extraction method to freeze-dried, fine-grained material was limited because of the insufficient reproducibility in some cases.

  14. Simple and accurate measurement of carbamazepine in surface water by use of porous membrane-protected micro-solid-phase extraction coupled with isotope dilution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Teo, Hui Ling [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Wong, Lingkai [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Liu, Qinde, E-mail: liu_qinde@hsa.gov.sg [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Teo, Tang Lin; Lee, Tong Kooi [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Lee, Hian Kee, E-mail: chmleehk@nus.edu.sg [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore)

    2016-03-17

    To achieve fast and accurate analysis of carbamazepine in surface water, we developed a novel porous membrane-protected micro-solid-phase extraction (μ-SPE) method, followed by liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) analysis. The μ-SPE device (∼0.8 × 1 cm) was fabricated by heat-sealing edges of a polypropylene membrane sheet to devise a bag enclosing the sorbent. The analytes (both carbamazepine and isotope-labelled carbamazepine) were first extracted by μ-SPE device in the sample (10 mL) via agitation, then desorbed in an organic solvent (1 mL) via ultrasonication. Several parameters such as organic solvent for pre-conditioning of μ-SPE device, amount of sorbent, adsorption time, and desorption solvent and time were investigated to optimize the μ-SPE efficiency. The optimized method has limits of detection and quantitation estimated to be 0.5 ng L{sup −1} and 1.6 ng L{sup −1}, respectively. Surface water samples spiked with different amounts of carbamazepine (close to 20, 500, and 1600 ng L{sup −1}, respectively) were analysed for the validation of method precision and accuracy. Good precision was obtained as demonstrated by relative standard deviations of 0.7% for the samples with concentrations of 500 and 1600 ng kg{sup −1}, and 5.8% for the sample with concentration of 20 ng kg{sup −1}. Good accuracy was also demonstrated by the relative recoveries in the range of 96.7%–103.5% for all samples with uncertainties of 1.1%–5.4%. Owing to the same chemical properties of carbamazepine and isotope-labelled carbamazepine, the isotope ratio in the μ-SPE procedure was accurately controlled. The use of μ-SPE coupled with IDMS analysis significantly facilitated the fast and accurate measurement of carbamazepine in surface water. - Highlights: • μ-SPE coupled with IDMS for the measurement of carbamazepine. • The method is the first report of coupling μ-SPE with IDMS. • μ-SPE is fast, time

  15. Phytochemical analysis of Myrtus communis plant: Conventional versus microwave assisted-extraction procedures.

    Science.gov (United States)

    Bouaoudia-Madi, Nadia; Boulekbache-Makhlouf, Lila; Kadri, Nabil; Dahmoune, Farid; Remini, Hocine; Dairi, Sofiane; Oukhmanou-Bensidhoum, Sonia; Madani, Khodir

    2017-06-10

    Background Myrtle (Myrtus communis L) may constitute an interesting dietary source of health protective compounds. Microwave-assisted extraction (MAE) of total phenolic compounds (TPC) from myrtle leaf, stems, pericarp, and seeds was studied and the results were compared with those of the conventional method extraction (CME) in terms of extraction time. Methods Extraction yield/efficiency and antioxidant activity were measured using radical scavenging assay (DPPH•) and reducing power. Results The results show that the MAE was higher in terms of saving energy, extraction time (62 s) and extraction efficiency of bioactive compound compared to CME (2 h). Leaf presented the optimum content of total phenols (250 mg GAE.g-1 DW) and flavonoids (13.65 mg GAE.g-1 DW). However, the anthocyanin content was most important in pericarp extract (176.50±2.17 mg Cyd-3-glu g-1 DW). The antioxidant activity was important in all parts, mainly in leaves. The results indicated that appropriate microwave treatment could be an efficient process to phenolic compounds recovery and thus, better the antioxidant activity of myrtle extract. Conclusions Principal component analysis (PCA) applied to the experimental data shows that the distribution of the myrtle phenolic compounds depended on their plant part localization as well as the extraction method.

  16. Application of dissolvable layered double hydroxides as sorbent in dispersive solid-phase extraction and extraction by co-precipitation for the determination of aromatic acid anions.

    Science.gov (United States)

    Tang, Sheng; Lee, Hian Kee

    2013-08-06

    Three types of magnesium-aluminum layered double hydroxides were synthesized and employed as solid-phase extraction (SPE) sorbents to extract several aromatic acids (protocatechuic acid, mandelic acid, phthalic acid, benzoic acid, and salicylic acid) from aqueous samples. An interesting feature of these sorbents is that they dissolve when the pH of the solution is lower than 4. Thus, the analyte elution step, as needed in conventional sorbent-based extraction, was obviated by dissolving the sorbent in acid after extraction and separation from the sample solution. The extract was then directly injected into a high-performance liquid chromatography-ultraviolet detection system for analysis. In the key adsorption process, both dispersive SPE and co-precipitation extraction with the sorbents were conducted and experimental parameters such as pH, temperature, and extraction time were optimized. The results showed that both extraction methods provided low limits of detection (0.03-1.47 μg/L) and good linearity (r(2) > 0.9903). The optimized extraction conditions were applied to human urine and sports drink samples. This new and interesting extraction approach was demonstrated to be a fast and efficient procedure for the extraction of organic anions from aqueous samples.

  17. Polar Lipid Profile of Nannochloropsis oculata Determined Using a Variety of Lipid Extraction Procedures.

    Science.gov (United States)

    Servaes, K; Maesen, M; Prandi, B; Sforza, S; Elst, K

    2015-04-22

    Lipid compositions obtained from microalgae species are affected by both the cultivation conditions and the extraction method used. In this study, the extraction of lipids from Nannochloropsis oculata using traditional and modern extraction technologies with several solvents has been compared. Because important polyunsaturated fatty acids are bound to polar lipids, these polar lipids were the main focus of this study. The dominant compounds in the glycolipid fractions were monogalactosyldiglycerides and digalactosyldiglycerides bearing fatty acid chains containing at least one site of unsaturation. Phosphatidylcholine and trimethylhomoserines were detected in the phospholipid fractions. The fatty acid profile comprised large fractions of C16:0, C16:1, C20:5, and C18:3. Extraction of specific compounds was determined by extraction efficiency as well as differences in the selectivity of the method used. The composition derived from a glycolipid fraction was observed to be affected by the method used to a greater extent than the phospholipid fraction.

  18. Flavonoids extraction from Alpinia zerumbet (Pers.) Burtt et Smith leaves using different procedures

    Energy Technology Data Exchange (ETDEWEB)

    Victorio, Cristiane P.; Lage, Celso Luiz S., E-mail: cris.pvictor@gmail.co [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho. Lab. de Fisiologia Vegetal; Kuster, Ricardo M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Nucleo de Pesquisas de Produtos Naturais (NPPN). Lab. de Fitoquimica

    2010-07-01

    The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversed-phase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). Relative concentration of rutin and kaempferol-3-O-glucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g{sup -1} dried leaves) and by microwave (1.0 and 6.64 mg g{sup -1} dried leaves) methods using 70% ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites. (author)

  19. Development and validation of an SPE HG-AAS method for determination of inorganic arsenic in samples of marine origin

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Rie R.; Larsen, Erik H.; Sloth, Jens J. [Technical University of Denmark, National Food Institute, Division of Food Chemistry, Soeborg (Denmark); Hedegaard, Rikke V. [Technical University of Denmark, National Food Institute, Division of Food Chemistry, Soeborg (Denmark); University of Copenhagen, Faculty of Life Sciences, Department of Food Science, Frederiksberg (Denmark)

    2012-07-15

    The present paper describes a novel method for the quantitative determination of inorganic arsenic (iAs) in food and feed of marine origin. The samples were subjected to microwave-assisted extraction using diluted hydrochloric acid and hydrogen peroxide, which solubilised the analytes and oxidised arsenite (As{sup III}) to arsenate (As{sup V}). Subsequently, a pH buffering of the sample extract at pH 6 enabled selective elution of As{sup V} from a strong anion exchange solid-phase extraction (SPE) cartridge. Hydride generation atomic absorption spectrometry (HG-AAS) was applied to quantify the concentration of iAs (sum of As{sup III} and As{sup V}) as the total arsenic (As) in the SPE eluate. The results of the in-house validation showed that mean recoveries of 101-104% were achieved for samples spiked with iAs at 0.5, 1.0 and 1.5 mg.kg{sup -1}, respectively. The limit of detection was 0.08 mg kg{sup -1}, and the repeatability (RSD{sub r}) and intra-laboratory reproducibility (RSD{sub IR}) were less than 8% and 13%, respectively, for samples containing 0.2 to 1.5 mg kg{sup -1} iAs. The trueness of the SPE HG-AAS method was verified by confirming results obtained by parallel analysis using high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry. It was demonstrated that the two sets of results were not significantly different (P < 0.05). The SPE HG-AAS method was applied to 20 marine food and feed samples, and concentrations of up to 0.14 mg kg{sup -1} of iAs were detected. (orig.)

  20. Assessment of a sequential phase extraction procedure for uranium-series isotope analysis of soils and sediments.

    Science.gov (United States)

    Suresh, P O; Dosseto, A; Handley, H K; Hesse, P P

    2014-01-01

    The study of uranium-series (U-series) isotopes in soil and sediment materials has been proposed to quantify rates and timescales of soil production and sediment transport. Previous works have studied bulk soil or sediment material, which is a complex assemblage of primary and secondary minerals and organic compounds. However, the approach relies on the fractionation between U-series isotopes in primary minerals since they were liberated from the parent rock via weathering. In addition, secondary minerals and organic compounds have their own isotopic compositions such that the composition of the bulk material may not reflect that of primary minerals. Hence, there is a need for a sample preparation procedure that allows the isolation of primary minerals in soil or fluvial sediment samples. In this study, a sequential extraction procedure to separate primary minerals from soils and sediments was assessed. The procedure was applied to standard rock sample powders (TML-3 and BCR-2) to test whether it introduced any artefactual radioactive disequilibrium. A new step was introduced to remove the clay-sized fraction (extraction process to test how each step modifies the uranium-series activity ratios and mineralogy. Although no secondary minerals were detected in the unleached soil aliquots, the sequential leaching process removed up to 17% of U and Th and modified their activity ratios by up to 3%. The modification of the activity ratios poses a demand for careful means to avoid redistribution of isotopes back to the residual phase during phase extraction.

  1. The use of copper(II) isonicotinate-based micro-solid-phase extraction for the analysis of polybrominated diphenyl ethers in soils

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Youya, E-mail: zhouyy@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Zhang Chaoyan; Yan Zengguang; Li Keji [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wang, Lin [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China); Xie Yabo [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China); Li Fasheng [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Liu Zhou [Shijiazhuang Municiple Environmental Protection Bureau, Shijiangzhuang 050011 (China); Yang Jin [SGS-CSTC Standards Technical Services Co. Ltd., Shanghai Branch, Shanghai 200233 (China)

    2012-10-17

    Highlights: Black-Right-Pointing-Pointer A Cu(4-C{sub 5}H{sub 4}N-COO){sub 2}(H{sub 2}O){sub 4}-based {mu}-SPE device was developed for determining PBDEs. Black-Right-Pointing-Pointer Extraction parameters for determination of PBDEs using {mu}-SPE in soils were optimized. Black-Right-Pointing-Pointer The {mu}-SPE showed a high selectivity to PBDEs, especially lower brominated PBDEs. Black-Right-Pointing-Pointer The {mu}-SPE is a promising microextraction technique for monitoring PBDEs in soils. - Abstract: A micro-solid-phase extraction ({mu}-SPE) device was developed by filling copper(II) isonicotinate coordination polymer (Cu(4-C{sub 5}H{sub 4}N-COO){sub 2}(H{sub 2}O){sub 4}) into a porous polypropylene envelope, and the {mu}-SPE, coupling with gas chromatography (GC) with a micro-cell electron capture detector ({mu}-ECD), was used for extraction and determination of PBDEs in soils. Variables affecting extraction procedures, including temperature, water volume, extraction time, and desorption time, were investigated in a spiked soil, and the parameters were optimized. Under the optimal experimental conditions, the method detection limits for seven PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) were in the range of 0.026-0.066 ng g{sup -1}, and the reproducibility was satisfactory with the relative standard deviation in range of 1.3-10.1%. Good linear relationship between PBDEs concentrations and GC signals (defined as peak area) was obtained in the range between 0.1 and 200 ng g{sup -1}. The recovery of the seven PBDEs by {mu}-SPE varied from 70 to 90%, which was comparable to that determined by accelerated solvent extraction method. Finally, the proposed method was used to determine PBDEs in several field-contaminated soils, and it was suggested that the {mu}-SPE is a promising alternative microextraction technique for the detection of PBDEs in soils.

  2. Procedures for DNA extraction and amplification from quills of crested porcupine (Hystrix cristata

    Directory of Open Access Journals (Sweden)

    Domenico Fulgione

    2000-09-01

    Full Text Available Abstract Genetic analysis in mammalian populations are useful for any conservation management. This kind of analysis utilised tissue of specimens studied involving a damages to the populations, only recently many study are indicated alternative procedure based on scales, hairs or feathers. The porcupine (Histrix cristata is an elusive species with localised populations. In this work I propose one procedure of genetic analysis starting by DNA quill in order to help studies about this species, without damage the population examined. The quills are easy to find because the porcupine loss them constantly. Nucleic acids extraction was done utilising synthetic resin (chelex and then ipervariable region of mitochondrial DNA was amplified through PCR with specific primers. The advantages of this selective amplification is the selective increase of interest DNA in spite of possible organic contamination. At this point two different procedure could be utilised to characterise of population: restriction fragment analysis or sequence analysis.

  3. Magnetic ligand fishing as a targeting tool for HPLC-HRMS-SPE-NMR: α-glucosidase inhibitory ligands and alkylresorcinol glycosides from Eugenia catharinae

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Brighente, Inês M. C.; Moaddel, Ruin

    2015-01-01

    A bioanalytical platform combining magnetic ligand fishing for α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for structural identification of α-glucosidase inhibitory ligands, both directly from crude plant extracts, is presented. Magnetic beads with N-terminus-coupled α-glucosidase we...

  4. Optimization of SPE for Analysis of Mandelic Acid as a Biomarker of Exposure to Ethyl Benzene

    Directory of Open Access Journals (Sweden)

    SJ Shahtaheri, M Abdollahi, F Golbabaei, A Rahimi-Froushani, F Ghamari

    2004-10-01

    Full Text Available Ethyl benzene is an important constituent of widely used solvents in industries and laboratories, causing widespread environmental and industrial pollutions. For evaluation of occupational exposure to such pollutants, biological monitoring is an essential process, in which, preparation of environmental and biological samples is one of the most time-consuming and error-prone aspects prior to chromatographic techniques. The use of solid-phase extraction (SPE has been grown and is a fertile technique of sample preparation as it provides better results than those of liquid-liquid extraction (LLE. In this study, SPE using bonded silica has been optimized with regard to sample pH, sample concentration, elution solvent, elution volume, sorbent type, and sorbent mass. Through experimental evaluation, a strong anion exchange silica cartridge (SAX has been found successful in simplifying sample preparation. The present approach proved that, mandelic acid could be retained on SAX sorbent based on specific interaction. Further study was employed using 10% acetic acid to extract the analyte from spiked urine and gave a clean sample for HPLC-UV system. In this study, a high performance liquid chromatography, using reverse-phase column was used. The isocratic run was done at a constant flow rate of 0.85 ml/min, the mobile phase was water/methanol/acetic acid and a UV detector was used, setting at 225 nm. At the developed conditions the extraction recovery was exceeded 98%. The factors were evaluated statically and also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments.

  5. Impact of metagenomic DNA extraction procedures on the identifiable endophytic bacterial diversity in Sorghum bicolor (L. Moench).

    Science.gov (United States)

    Maropola, Mapula Kgomotso Annah; Ramond, Jean-Baptiste; Trindade, Marla

    2015-05-01

    Culture-independent studies rely on the quantity and quality of the extracted environmental metagenomic DNA (mDNA). To fully access the plant tissue microbiome, the extracted plant mDNA should allow optimal PCR applications and the genetic content must be representative of the total microbial diversity. In this study, we evaluated the endophytic bacterial diversity retrieved using different mDNA extraction procedures. Metagenomic DNA from sorghum (Sorghum bicolor L. Moench) stem and root tissues were extracted using two classical DNA extraction protocols (CTAB- and SDS-based) and five commercial kits. The mDNA yields and quality as well as the reproducibility were compared. 16S rRNA gene terminal restriction fragment length polymorphism (t-RFLP) was used to assess the impact on endophytic bacterial community structures observed. Generally, the classical protocols obtained high mDNA yields from sorghum tissues; however, they were less reproducible than the commercial kits. Commercial kits retrieved higher quality mDNA, but with lower endophytic bacterial diversities compared to classical protocols. The SDS-based protocol enabled access to the highest sorghum endophytic diversities. Therefore, "SDS-extracted" sorghum root and stem microbiome diversities were analysed via 454 pyrosequencing, and this revealed that the two tissues harbour significantly different endophytic communities. Nevertheless, both communities are dominated by agriculturally important genera such as Microbacterium, Agrobacterium, Sphingobacterium, Herbaspirillum, Erwinia, Pseudomonas and Stenotrophomonas; which have previously been shown to play a role in plant growth promotion. This study shows that DNA extraction protocols introduce biases in culture-independent studies of environmental microbial communities by influencing the mDNA quality, which impacts the microbial diversity analyses and evaluation. Using the broad-spectrum SDS-based DNA extraction protocol allows the recovery of the most

  6. Validation of a whole-body cortisol extraction procedure for channel catfish (Ictalurus punctatus) fry

    Science.gov (United States)

    We developed and validated a whole-body cortisol extraction technique for catfish fry. Their small size (cortisol, a common indicator of a stress response, using conventional assay methods. Three volume enhancement methods were tested: CAL method (zero calibrator...

  7. Separation and preconcentration by a cloud point extraction procedure for determination of metals: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, C.B.; Rojas, F.S. [University of Malaga, Department of Analytical Chemistry, Faculty of Sciences, Malaga (Spain)

    2009-06-15

    Recently, cloud point extraction (CPE) has been an attractive subject as an alternative to liquid-liquid extraction. The technique is based on the property of most non-ionic surfactants in aqueous solutions to form micelles and become turbid when heated to the cloud point temperature. This review covers a selection of the literature published on applications of CPE in determination of metal ions over the period between 2004 and 2008. (orig.)

  8. Toxicological validation of a procedure for extracting organic micropollutants form water samples

    NARCIS (Netherlands)

    Vaal MA; Folkerts AJ; Kamp RE van de; Struijs J; ECO

    1999-01-01

    Een procedure, ontwikkeld met het doel om microverontreinigingen uit watermonsters te concentreren, zodanig dat het uitvoeren van aquatische toxiciteitstesten mogelijk is, werd aan een toxicologisch validatieonderzoek onderworpen. Een bekende cocktail aan toxische stoffen werd geconcentreerd tot

  9. Toxicological validation of a procedure for extracting organic micropollutants form water samples

    NARCIS (Netherlands)

    Vaal MA; Folkerts AJ; Kamp RE van de; Struijs J; ECO

    1999-01-01

    Een procedure, ontwikkeld met het doel om microverontreinigingen uit watermonsters te concentreren, zodanig dat het uitvoeren van aquatische toxiciteitstesten mogelijk is, werd aan een toxicologisch validatieonderzoek onderworpen. Een bekende cocktail aan toxische stoffen werd geconcentreerd tot

  10. Single surgical procedure combining epicardial pacemaker implantation and subsequent extraction of the infected pacing system for pacemaker-dependent patients.

    Science.gov (United States)

    Amraoui, Sana; Barandon, Laurent; Whinnett, Zachary; Ploux, Sylvain; Labrousse, Louis; Denis, Arnaud; Oses, Pierre; Ritter, Philippe; Haissaguerre, Michel; Bordachar, Pierre

    2013-08-01

    Management of pacemaker infection in pacing-dependent patients is often challenging. Typically, temporary pacing is used while antibiotic therapy is given for a number of days before reimplantation of a new endocardial system. This results in a prolonged hospital stay and complications associated with temporary pacing. In this study, we examine the feasibility of performing a single combined procedure of epicardial pacemaker implantation followed by system extraction. One hundred consecutive infected pacemaker-dependent patients underwent implantation of 2 epicardial ventricular leads and were converted to a ventricular demand pacing system. The infected pacing system was then extracted during the same procedure. Patients were followed up for 12 months. Significant pericardial bleeding developed during the procedure in 3 patients. The presence of the pericardial drain positioned during the implantation of the epicardial pacing system meant that cardiac tamponade did not occur, allowing surgical repair with sternotomy to be carried out under stable hemodynamic conditions. Two of these 100 patients died in the 30-day postoperative period; 1 death was due to septic shock and 1 to pulmonary distress. Median 1-year epicardial pacing thresholds were stable and excellent (1.4 ± 0.9 volts). However, 1 of the 2 leads developed increased thresholds in 6 patients, which led to the exclusive use of other ventricular lead. A single combined procedure of surgical epicardial pacemaker implantation and pacemaker system extraction appears to be a safe and effective method for managing pacemaker-dependent patients with infected pacemakers. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  11. SPE5 Sub-Scale Test Series Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, Kevin S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reeves, Robert V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); DeHaven, Martin R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Strickland, Shawn L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-14

    A series of 2 SPE5 sub-scale tests were performed to experimentally confirm that a booster system designed and evaluated in prior tests would properly initiate the PBXN-110 case charge fill. To conduct the experiments, a canister was designed to contain the nominally 50 mm diameter booster tube with an outer fill of approximately 150 mm diameter by 150 mm in length. The canisters were filled with PBXN-110 at NAWS-China Lake and shipped back to LLNL for testing in the High Explosives Applications Facility (HEAF). Piezoelectric crystal pins were placed on the outside of the booster tube before filling, and a series of piezoelectric crystal pins along with Photonic Doppler Velocimetry (PDV) probes were placed on the outer surface of the canister to measure the relative timing and magnitude of the detonation. The 2 piezoelectric crystal pins integral to the booster design were also utilized along with a series of either piezoelectric crystal pins or piezoelectric polymer pads on the top of the canister or outside case that utilized direct contact, gaps, or different thicknesses of RTV cushions to obtain time of arrival data to evaluate the response in preparation for the large-scale SPE5 test. To further quantify the margin of the booster operation, the 1st test (SPE5SS1) was functioned with both detonators and the 2nd test (SPE5SS2) was functioned with only 1 detonator. A full detonation of the material was observed in both experiments as observed by the pin timing and PDV signals. The piezoelectric pads were found to provide a greater measured signal magnitude during the testing with an RTV layer present, and the improved response is due to the larger measurement surface area of the pad. This report will detail the experiment design, canister assembly for filling, final assembly, experiment firing, presentation of the diagnostic results, and a discussion of the results.

  12. SPE and HPLC/UV of resin acids in colophonium-containing products.

    Science.gov (United States)

    Nilsson, Ulrika; Berglund, Naghmeh; Lindahl, Fredrik; Axelsson, Sara; Redeby, Theres; Lassen, Pia; Karlberg, Ann-Therese

    2008-08-01

    A new method, involving SPE and HPLC/UV diode-array detection (DAD), was developed for the quantification of colophonium components in different consumer products, such as cosmetics. Colophonium is a common cause of contact dermatitis since its components can oxidize into allergens on exposure to air. Three different resin acids were used as markers for native and oxidized colophonium, abietic acid (AbA), dehydroabietic acid (DeA), and 7-oxodehydroabietic acid (7-O-DeA). The SPE method, utilizing a mixed-mode hydrophobic and anion exchange retention mechanism, was shown to yield very clean extracts. The use of a urea-embedded C(12) HPLC stationary phase improved the separation of the resin acids compared to common C(18). Concentrations higher than 2 mg/g of both AbA and DeA were detected in wax strips. In this product also 7-O-DeA, a marker for oxidized colophonium, was detected at a level of 28 microg/g. The LODs were in the range of 7-19 microg/g and the LOQs 22-56 microg/g. The method is simple to use and can be applied on many types of technical products, not only cosmetics. For the first time, a method for technical products was developed, which separates AbA from pimaric acid.

  13. Systematic optimization of an SPE with HPLC-FLD method for fluoroquinolone detection in wastewater.

    Science.gov (United States)

    He, Ke; Blaney, Lee

    2015-01-23

    This paper describes a selective and ultra-sensitive analytical method for simultaneous determination of 11 fluoroquinolone (FQ) antibiotics in environmental and wastewater samples. The method employs offline solid-phase extraction (SPE) and reversed-phase high performance liquid chromatography with fluorescence detection (HPLC-FLD). A weak cation exchange SPE protocol was developed with a novel loading volume optimization algorithm and a methanol cleanup step to remove background organic matter. Various parameters were optimized to recover FQs from water/wastewater and analyte recovery was generally greater than 80%. Chromatographic separation of the 11 FQs was achieved on a 150 mm pentafluorophenyl column using a gradient elution scheme with methanol, acetonitrile, and 20mM phosphate buffer (pH=2.4). Excitation and emission wavelengths were individually optimized for each FQ using fluorescence spectroscopy; the excitation and emission wavelengths were 276-296 nm and 444-506 nm, respectively. Instrumental quantitation limits were 20-100 pg of mass injected. Of the 11 FQs investigated, seven (i.e., ciprofloxacin, difloxacin, enrofloxacin, fleroxacin, norfloxacin, moxifloxacin, and ofloxacin) were detected during a four-month sampling campaign of wastewater and wastewater-impacted surface water. Concentrations of FQs in raw wastewater, wastewater effluent, and wastewater-impacted surface water were 5-1292, 2-504, and 4-187ng/L, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. An efficient procedure for protein extraction from formalin-fixed, paraffin-embedded tissues for reverse phase protein arrays

    Directory of Open Access Journals (Sweden)

    Guo Huifang

    2012-09-01

    Full Text Available Abstract Introduction Protein extraction from formalin-fixed paraffin-embedded (FFPE tissues is challenging due to extensive molecular crosslinking that occurs upon formalin fixation. Reverse-phase protein array (RPPA is a high-throughput technology, which can detect changes in protein levels and protein functionality in numerous tissue and cell sources. It has been used to evaluate protein expression mainly in frozen preparations or FFPE-based studies of limited scope. Reproducibility and reliability of the technique in FFPE samples has not yet been demonstrated extensively. We developed and optimized an efficient and reproducible procedure for extraction of proteins from FFPE cells and xenografts, and then applied the method to FFPE patient tissues and evaluated its performance on RPPA. Results Fresh frozen and FFPE preparations from cell lines, xenografts and breast cancer and renal tissues were included in the study. Serial FFPE cell or xenograft sections were deparaffinized and extracted by six different protein extraction protocols. The yield and level of protein degradation were evaluated by SDS-PAGE and Western Blots. The most efficient protocol was used to prepare protein lysates from breast cancer and renal tissues, which were subsequently subjected to RPPA. Reproducibility was evaluated and Spearman correlation was calculated between matching fresh frozen and FFPE samples. The most effective approach from six protein extraction protocols tested enabled efficient extraction of immunoreactive protein from cell line, breast cancer and renal tissue sample sets. 85% of the total of 169 markers tested on RPPA demonstrated significant correlation between FFPE and frozen preparations (p Conclusions With optimized protein extraction methods, FFPE tissues can be a valuable source in generating reproducible and biologically relevant proteomic profiles using RPPA, with specific marker performance varying according to tissue type.

  15. Influence of extraction procedures on phenolic content and antioxidant activity of Cretan barberry herb.

    Science.gov (United States)

    Kukula-Koch, Wirginia; Aligiannis, Nektarios; Halabalaki, Maria; Skaltsounis, Alexios-Leandros; Glowniak, Kazimierz; Kalpoutzakis, Eleftherios

    2013-05-01

    The main goal of present study was the development, optimization and application of different extraction protocols, especially those employing green technologies, in order to obtain from Berberis cretica extracts with high antioxidant capacity. For this purpose, the applied methods: maceration, ASE and SFE coupled with ASE were incorporated. The antioxidant assessment was carried out using DPPH and total phenolic content (Folin-Ciocalteu) assays. Major constituents were elucidated using HPLC-DAD and UHPLC-HRMS/MS (hybrid IT-Orbital trap spectrometer) equipped with an ESI probe. The chromatographic and spectral data revealed the presence of several simple phenolic acids, derivatives of both caffeic and benzoic acids, and flavonoids in the produced extracts. It was clearly evidenced that the extraction method and solvents used affected both the activity and the chemical content of the results, significantly. The most beneficial conditions were calculated for methanol and water:ethanol (50:50) extracts derived from the combination of SFE and ASE methodologies. Obtained results classify Cretan barberry as a strong antioxidant agent.

  16. Development, optimization, and validation of a novel extraction procedure for the removal of opiates from human hair's surface.

    Science.gov (United States)

    Restolho, José; Barroso, Mário; Saramago, Benilde; Dias, Mário; Afonso, Carlos A M

    2015-05-01

    Room temperature ionic liquids (ILs) have proved to be efficient extraction media for several systems, and their ability to capture volatile compounds from the atmosphere is well established. We report herein a contactless extraction procedure for the removal of opiate drugs from the surface of human hair. The compounds were chosen as a model drug, particularly due to their low volatility. Equal amounts of IL and hair (about 100 mg) were introduced in a customized Y-shaped vial, and the process occurred simply by heating. After testing several ILs, some of them (e.g. 1-methyl-3-ethanol-imidazolium tetrafluoroborate, phenyl-trimethyl-ammonium triflate or bis(dimethyl) diheptylguanidinium iodide) showed extraction efficiencies higher than 80% for the two studied compounds, morphine and 6-monoacetylmorphine. Using the design of experiments (DOE) approach as an optimization tool, and bearing in mind the hygroscopic properties of the ILs (in particular, 1-methyl-3-ethanol-imidazolium tetrafluoroborate), the process was optimized concerning the following variables: temperature (50-120 ºC), extraction time (8-24 h), IL amount (50-200 mg) and water content of the IL (0.01-60%). This study not only provided the optimum conditions for the process (120 ºC, 16 h, 100 mg of IL containing 40% of water), but has also showed that the water content of the IL represents the variable with the most significant effect on the extraction efficiency. Finally, we validated our method through the comparison of the results obtained by treating hair samples with the described procedure to those obtained using a standard washing method and criteria for positivity.

  17. CATHARE2 calculation of SPE-3 test small break loca on PMK facility

    Energy Technology Data Exchange (ETDEWEB)

    Laugier, E.; Radet, J. [Institut de Protection et de Surete Nucleaire, Cadarache (France)

    1995-09-01

    Bind and post test calculations with CATHARE2 have been performed concerning the SPE-4 exercise organized under the auspices of IAEA on the hungarian PMK-2 facility, a one loop scaled model of VVER 440/213 Nuclear Power Plant. The SPE-4 test is a cold leg SBLOCA associated to a {open_quotes}bleed and feed{close_quotes} procedure applied in the secondary circuit. The present paper is devoted to the analysis of the post test calculation. For the first part of the transient (until the end of the SIT activations), the primary and secondary pressures are rather well predicted, leading to a good agreement with the experimental trips, as scram, flow coast down, SIT beginning and end of activation. Nevertheless, some discrepancy with the experiment may be due to an over prediction of the thermal exchanges from the primary to the secondary circuits. For the second part of the transient, the predicted primary circuit repressurization is shifted after the SITs are off, while in the experiment this event immediately follows the end of SIT activation. The delay in the calculation leads to underpredict primary and secondary pressures, thus anticipating the timing of events, such as LPIS and emergency feedwater activation.

  18. Recent improvements in SPE3D: a VR-based surgery planning environment

    Science.gov (United States)

    Witkowski, Marcin; Sitnik, Robert; Verdonschot, Nico

    2014-02-01

    SPE3D is a surgery planning environment developed within TLEMsafe project [1] (funded by the European Commission FP7). It enables the operator to plan a surgical procedure on the customized musculoskeletal (MS) model of the patient's lower limbs, send the modified model to the biomechanical analysis module, and export the scenario's parameters to the surgical navigation system. The personalized patient-specific three-dimensional (3-D) MS model is registered with 3-D MRI dataset of lower limbs and the two modalities may be visualized simultaneously. Apart from main planes, any arbitrary MRI cross-section can be rendered on the 3-D MS model in real time. The interface provides tools for: bone cutting, manipulating and removal, repositioning muscle insertion points, modifying muscle force, removing muscles and placing implants stored in the implant library. SPE3D supports stereoscopic viewing as well as natural inspection/manipulation with use of haptic devices. Alternatively, it may be controlled with use of a standard computer keyboard, mouse and 2D display or a touch screen (e.g. in an operating room). The interface may be utilized in two main fields. Experienced surgeons may use it to simulate their operative plans and prepare input data for a surgical navigation system while student or novice surgeons can use it for training.

  19. Control of the extraction procedures on the response of DOC concentration and composition to soil temperature increase

    Science.gov (United States)

    Lambert, Thibault; Pierson-Wickmann, Anne-Catherine; Gruau, Gérard; Jaffrézic, Anne; Jeanneau, Laurent; Racape, Armelle

    2014-05-01

    Dissolved organic carbon (DOC) leached from soils is a crucial component of the terrestrial C cycling and a major source for DOC export at the landscape scale by stream and river waters. In the context of global warming, it is necessary to understand how changes in soil temperature will impact the DOC dynamic in soils, but this remains a matter of debate. We conducted a series of experiments in order to study both biological and physical processes involved in soil DOC production and mobilisation at different temperatures. Two experiments of DOC extraction were conducted at different temperatures: (i) soil solution percolation through a soil column and (ii) soil solution agitation in jars, which are both commonly used in the literature. The organo-mineral horizon of a wetland soil was incubated during 14 days at temperature ranging from 4 to 30 ° C. Along with DOC concentrations, changes in DOC composition were assessed by monitoring the natural stable carbon isotopic composition of (δ13C) and the specific ultra violet absorbance (SUVA) of DOC. The results showed strong differences between the two extraction procedures in term of DOC response to temperature rise, both in concentration and composition. DOC released by percolation through soil column displayed a strong concentration increase with increasing temperature. Whatever the temperature, a low SUVA and relatively high δ13C values indicated a release of molecules with lower aromaticity and lower molecular weight the two first days than after. On the contrary, DOC extracted by agitation in jars showed minor changes in both concentrations and composition along the incubation. The difference observed between soil leaching and batch incubation can mainly be explained by the extraction procedures. Indeed, the percolation procedure favors transfer from the micro-porosity to the macro-porosity pool between two successive leaching, whereas agitation procedure releases DOC produced and accumulated in the whole soil

  20. Fractionation of Heavy Metals in Fly Ash from Wood Biomass Using the BCR Sequential Extraction Procedure.

    Science.gov (United States)

    Jukić, Mirela; Ćurković, Lidija; Šabarić, Jasenka; Kerolli-Mustafa, Mihone

    2017-08-20

    The aim of this study was to extract the wood biomass fly ash fractions by a three-stage sequential extraction method for acetic acid and ion exchangeable (BCR 1), hydroxylamine hydrochloride reduction (BCR 2), and hydrogen peroxide oxidation (BCR 3) fractions in order to access the leaching behavior of this residue. The fly ash was collected as a by-product from the processing of mixed wood biomass in Udbina combustion facility, Croatia. Concentrations of several elements (As, Cd, Cr, Cu, Ni, Pb and Zn) in all extracts were determined by inductively coupled plasma atomic emission spectrometry. The acidic exchangeable form of the metals was used to evaluate the potential ecological risk of biomass fly ash. According to calculated potential ecological risk index, it is confirmed that mobility of Ni and As has major environmental impact. However the results of potential ecological risk show that biomass fly ash had a low risk.

  1. Fractionation of metals by sequential extraction procedures (BCR and Tessier) in soil exposed to fire of wide temperature range

    Science.gov (United States)

    Fajkovic, Hana; Rončević, Sanda; Nemet, Ivan; Prohić, Esad; Leontić-Vazdar, Dana

    2017-04-01

    Forest fire presents serious problem, especially in Mediterranean Region. Effects of fire are numerous, from climate change and deforestation to loss of soil organic matter and changes in soil properties. One of the effects, not well documented, is possible redistribution and/or remobilisation of pollutants previously deposited in the soil, due to the new physical and chemical soil properties and changes in equilibrium conditions. For understanding and predicting possible redistribution and/or remobilisation of potential pollutants from soil, affected by fire different in temperature, several laboratory investigations were carried out. To evaluate the influence of organic matter on soil under fire, three soil samples were analysed and compared: (a) the one with added coniferous organic matter; (b) deciduous organic matter (b) and (c) soil without additional organic matter. Type of organic matter is closely related to pH of soil, as pH is influencing the mobility of some pollutants, e.g. metals. For that reason pH was also measured through all experimental steps. Each of mentioned soil samples (a, b and c) were heated at 1+3 different temperatures (25°C, 200°C, 500°C and 850°C). After heating, whereby fire effect on soil was simulated, samples were analysed by BCR protocol with the addition of a first step of sequential extraction procedure by Tessier and analysis of residual by aqua regia. Element fractionation of heavy metals by this procedure was used to determine the amounts of selected elements (Al, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb and Zn). Selected metal concentrations were determined using inductively coupled plasma atomic emission spectrometer. Further on, loss of organic matter was calculated after each heating procedure as well as the mineral composition. The mineral composition was determined using an X-ray diffraction. From obtained results, it can be concluded that temperature has an influence on concentration of elements in specific step of

  2. Optimization of a wet microalgal lipid extraction procedure for improved lipid recovery for biofuel and bioproduct production.

    Science.gov (United States)

    Sathish, Ashik; Marlar, Tyler; Sims, Ronald C

    2015-10-01

    Methods to convert microalgal biomass to bio based fuels and chemicals are limited by several processing and economic hurdles. Research conducted in this study modified/optimized a previously published procedure capable of extracting transesterifiable lipids from wet algal biomass. This optimization resulted in the extraction of 77% of the total transesterifiable lipids, while reducing the amount of materials and temperature required in the procedure. In addition, characterization of side streams generated demonstrated that: (1) the C/N ratio of the residual biomass or lipid extracted (LE) biomass increased to 54.6 versus 10.1 for the original biomass, (2) the aqueous phase generated contains nitrogen, phosphorous, and carbon, and (3) the solid precipitate phase was composed of up to 11.2 wt% nitrogen (70% protein). The ability to isolate algal lipids and the possibility of utilizing generated side streams as products and/or feedstock material for downstream processes helps promote the algal biorefinery concept. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. HS3D, A Dataset of Homo Sapiens Splice Regions, and its Extraction Procedure from a Major Public Database

    Science.gov (United States)

    Pollastro, Pasquale; Rampone, Salvatore

    The aim of this work is to describe a cleaning procedure of GenBank data, producing material to train and to assess the prediction accuracy of computational approaches for gene characterization. A procedure (GenBank2HS3D) has been defined, producing a dataset (HS3D - Homo Sapiens Splice Sites Dataset) of Homo Sapiens Splice regions extracted from GenBank (Rel.123 at this time). It selects, from the complete GenBank Primate Division, entries of Human Nuclear DNA according with several assessed criteria; then it extracts exons and introns from these entries (actually 4523 + 3802). Donor and acceptor sites are then extracted as windows of 140 nucleotides around each splice site (3799 + 3799). After discarding windows not including canonical GT-AG junctions (65 + 74), including insufficient data (not enough material for a 140 nucleotide window) (686 + 589), including not AGCT bases (29 + 30), and redundant (218 + 226), the remaining windows (2796 + 2880) are reported in the dataset. Finally, windows of false splice sites are selected by searching canonical GT-AG pairs in not splicing positions (271 937 + 332 296). The false sites in a range +/- 60 from a true splice site are marked as proximal. HS3D, release 1.2 at this time, is available at the Web server of the University of Sannio: http://www.sci.unisannio.it/docenti/rampone/.

  4. A new procedure for extraction of collagen from modern and archaeological bones for {sup 14}C dating

    Energy Technology Data Exchange (ETDEWEB)

    Maspero, F. [CUDaM, University of Milano Bicocca, Milano (Italy); Sala, S.; Papagni, A. [University of Milano Bicocca, Materials Science Department, Milano (Italy); Fedi, M.E. [INFN sezione di Firenze, Sesto Fiorentino (Firenze) (Italy); Martini, M. [CUDaM, University of Milano Bicocca, Milano (Italy); University of Milano Bicocca, Materials Science Department, Milano (Italy); INFN sezione di Milano Bicocca, Milano (Italy)

    2011-10-15

    Bones are potentially the best age indicators in a stratigraphic study, because they are closely related to the layer in which they are found. Collagen is the most suitable fraction and is the material normally used in radiocarbon dating. Bone contaminants can strongly alter the carbon isotopic fraction values of the samples, so chemical pretreatment for {sup 14} C dating by accelerator mass spectrometry (AMS) is essential. The most widespread method for collagen extraction is based on the Longin procedure, which consists in HCl demineralization to dissolve the inorganic phase of the samples, followed by dissolution of collagen in a weak acid solution. In this work the possible side effects of this procedure on a modern bone are presented; the extracted collagen was analyzed by ATR-IR spectroscopy. An alternative procedure, based on use of HF instead of HCl, to minimize unwanted degradation of the organic fraction, is also given. A study by ATR-IR spectroscopic analysis of collagen collected after different demineralization times and with different acid volumes, and a study of an archaeological sample, are also presented. (orig.)

  5. Loop-mediated isothermal amplification with the Procedure for Ultra Rapid Extraction kit for the diagnosis of pneumocystis pneumonia.

    Science.gov (United States)

    Kawano, Shuichi; Maeda, Takuya; Suzuki, Takefumi; Abe, Tatsuhiro; Mikita, Kei; Hamakawa, Yusuke; Ono, Takeshi; Sonehara, Wataru; Miyahira, Yasushi; Kawana, Akihiko

    2015-03-01

    Loop-mediated isothermal amplification (LAMP) is an innovative molecular technique requiring only a heating device and isothermal conditions to amplify a specific target gene. The results of current microscopic diagnostic tools for pneumocystis pneumonia are not sufficiently consistent for detecting infection with a low-density of Pneumocystis jirovecii. Although polymerase chain reaction (PCR) is highly sensitive, it is not suitable for resource-limited facilities. LAMP is a potential diagnostic replacement for PCR in such settings but a critical disadvantage of DNA extraction was still remained. Therefore, we employed the Procedure for Ultra Rapid Extraction (PURE) kit, which uses a porous material, to isolate the DNA from clinical samples in a simple way in combination with previously reported LAMP procedure for diagnosing PCP. The detection limit of the PURE-LAMP method applied to artificial bronchoalveolar lavage fluid samples was 100 copies/tube, even with the use of massive blood-contaminated solutions. In addition, we concluded the diagnostic procedure within 1 h without the need for additional equipment. PURE-LAMP coupled with suitable primers for specific pathogens has good potential for diagnosing various infectious diseases.

  6. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Margaret [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States); Obi, Curtis [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States)

    2015-04-30

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and farfield data that are available.This revised document includes reports on baseline shift corrections for the SPE-2 and SPE-3 shots that were missing from the original January 2015 version.

  7. Evaluation of extraction procedures for 2-DE analysis of aphid proteins.

    Science.gov (United States)

    Yiou, Pan; Shaoli, An; Kebin, Li; Tao, Wang; Kui, Fang; Hua, Zhang; Yu, Sun; Xun, Yang; Jinghui, Xi

    2013-02-01

    Protein sample preparation is a crucial step in a 2-DE proteomics approach. In order to establish a routine protocol for the application of proteomics analysis to aphids, this study focuses on the specific protein extraction problems in insect tissues and evaluates four methods to bypass them. The approaches of phenol extraction methanol/ammonium acetate precipitation (PA), TCA/acetone precipitation, PEG precipitation, and no precipitation were evaluated for proteins isolation and purification from apterous adult aphids, Sitobion avenae. For 2-DE, the PA protocol was optimal, resulting in good IEF and clear spots. PA method yielded the greatest amount of protein and displayed most protein spots in 2-DE gels, as compared with the TCA/acetone precipitation, PEG precipitation and no precipitation protocols. Analysis of protein yield, image quality and spot numbers demonstrate that the TCA/acetone precipitation protocol is a reproducible and reliable method for extracting proteins from aphids. The PEG precipitation approach is a newly developed protein extraction protocol for aphids, from which more unique protein spots can be detected, especially for detection of acid proteins. These protocols are expected to be applicable to other insects or could be of interest to laboratories involved in insect proteomics, despite the amounts and types of interfering compounds vary considerably in different insects.

  8. Effect of different extraction procedures on antimicrobial activity of marine bivalves: A comparison

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, S.; Chatterji, A.; Das, P.

    was assessed on the antimicrobial activity. Antimicrobial assay was carried out against 8 bacterial strains (3 Gram positive and 5 negative bacteria) and 1 species of fungi. The AEH extracts showed higher activity against the tested organisms as compared to Me...

  9. Analytical method for the determination of trace levels of steroid hormones and corticosteroids in soil, based on PLE/SPE/LC-MS/MS.

    Science.gov (United States)

    Gineys, N; Giroud, B; Vulliet, E

    2010-07-01

    The aim of this study was to develop an efficient, sensitive and reliable analytical method for the determination of traces of steroid hormones (including oestrogen, androgens and progestagens) and corticosteroids in soil. A method of sample preparation involving pressurized liquid extraction (PLE) and solid-phase extraction (SPE) was developed for the determination of six steroids and five corticosteroids in soils, followed by analysis by liquid chromatography-tandem mass spectrometry. The conditions employed for PLE involved acetone/methanol (50:50) as the extracting solvent, a temperature of 80 degrees C, two cycles and a static time of 5 min. The extraction was followed by a SPE clean-up based on a polymeric phase. With use of protocol, a residual matrix effect was, however, highlighted. The limit of detection in soil was 0.08-0.89 ng/g for steroids and 0.09-2.84 ng/g for corticosteroids.

  10. Speciation of heavy metals by modified BCR sequential extraction procedure in different depths of sediments from Sungai Buloh, Selangor, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Nemati, Keivan, E-mail: keivan_nemati@yahoo.com [Environmental Research Group, Department of Chemistry, University of Malaya (UM), Kuala Lumpur 50603 (Malaysia); Bakar, Nor Kartini Abu; Abas, Mhd. Radzi; Sobhanzadeh, Elham [Environmental Research Group, Department of Chemistry, University of Malaya (UM), Kuala Lumpur 50603 (Malaysia)

    2011-08-15

    Highlights: {yields} A BCR sequential extraction procedure was applied for measurement of heavy metals in Sungai Buloh sediments in different depths. {yields} The amounts of CF and percentage of RAC was measured in this study too. {yields} Highest CF was obtained for Cd, Co, Pb and Zn in these samples. {yields} Zn at S3 and Cd at S3-S7 showed a high risk for the sediment samples. There were no elements of very high risk conditions in the selected samples. - Abstract: The sequential extraction procedure proposed by the European Standard, Measurements and Testing (SM and T) program, formerly the Community Bureau of Reference (BCR), was applied for partitioning of heavy metals (HMs) in river sediments collected along the course of Sungai Buloh and the Straits of Malacca in Selangor, Malaysia. Eight elements (V, Pb, Cd, Cr, Co, Ni, Cu and Zn) from seven stations (S1-S7) and at different depths were analyzed using the modified BCR Sequential Extraction Procedure (SEP) in combination with ICP-MS to obtain the metal distribution patterns in this region. The results showed that heavy metal contaminations at S2 and S3 was more severe than at other sampling sites, especially for Zn, Cu, Ni and Pb. Nevertheless, the element concentrations from top to bottom layers decreased predominantly. The samples from the Straits of Malacca (S4-S7) the highest contamination factors obtained were for Co, Zn and Pb while the lowest were found for V and Cr, similar to Sungai Buloh sediments. The sediments showed a low risk for V, Cr, Cu and Pb with RAC values of less than 10%, but medium risk for Co, Zn (except S3), Cd at S1 and S2 and Ni at S1, S3 and S5. Zn at S3 and Cd at S3-S7 showed high risk to our sediment samples. There is not any element of very high risk conditions in the selected samples.

  11. Effects of aerosol collection and extraction procedures on the optical properties of water-soluble organic compounds

    Science.gov (United States)

    Mladenov, N.; Alados-Arboledas, L.; Olmo Reyes, F. J.; Reche, I.

    2009-12-01

    Water-soluble organic compounds (WSOC) are routinely collected using active and passive aerosol samplers and, after extraction in water, analyzed using UV-vis absorbance and fluorescence techniques. These analyses provide important information regarding the chemical character and sources of aerosols worldwide. To evaluate the effects of various aerosol collection and processing methods on the optical properties of WSOC, two-dimensional absorption spectra from 200 to 900 nm and three-dimensional fluorescence excitation-emission spectra (EEMs) from 240 to 450 nm excitation and 300 to 560 nm emission were analyzed in samples obtained simultaneously with different procedures. Samples included: milli-Q purified water passed through 140 mm diameter glass fiber and quartz fiber filters used in high volume PM10 aerosol samplers, 47 mm glass fiber filters used for organic matter analyses, and mixed cellulose 0.2 micron and 0.015 micron filters used for bacterial and viral filtration, respectively; milli-Q purified water rinsed in plastic buckets used for passive wet and dry deposition collection; and WSOC samples extracted from filters by soaking, sonication, and agitation. Parallel factor analysis (PARAFAC) modeling of WSOC was performed to quantify the influence of various collection and extraction procedures on fluorescence signatures. All filters examined were found to leach some amount of fluorescent compounds (Figure 1). Mixed cellulose filters, especially those with small pore size, leached substantially more amino acid-like and humic-like material than other filters, whereas leaching from quartz fiber filters used for high volume aerosol collection was minimal (Figure 1). Fluorescence intensities of filter leachates decreased with increased rinsing of filters, indicating that rinsing with purified water prior to filtration is advisable, even for pre-combusted filters. Dissolved organic carbon concentrations of WSOC extracted from filters by sonication, agitation

  12. Quality Control on the Determination of 16 PAHs in Soil Using ASE-SPE/GC-MS%ASE-SPE/GC-MS测定土壤中16种PAHs质量控制研究

    Institute of Scientific and Technical Information of China (English)

    许鹏军; 张烃; 任玥; 齐丽; 杨文龙; 黄业茹

    2012-01-01

    The analytical method for 16 USEPA priority polycyclic aromatic hydrocarbons(PAHs) in soil was optimized in this study, and an integrated quality control (QC) system was established to resolve the problems occurring in PAHs analysis, such as the lower recoveries of benzo ( a) pyrene ( BaP) , unsatisfactory clean-up efficiency for samples in complex matrix, volatilization loss and environmental background of naphthalene ( Nap ) and phenanthrene ( Phe ). The analysis procedure commenced with accelerated solvent extraction ( ASE ) , followed by solid phase extraction ( SPE) clean-up and gradual condensation in vacuum. Gas chromatography - mass spectrometry ( GC - MS) was used for measurement. Deuterated benzo (a) pyrene (BaP - dl2) was used as an indicator of recovery in analysis. Three normal phase SPE materials were attempted to separate PAHs in samples, the results indicated that BaP was degraded when passing through florisil. Isotope dilution quantification was recommended to reduce the uncertainty of BaP analysis. Alumina was unsuitable for clean-up as for its strong adsorption to PAHs, but silica gel was proved to be the appropriate SPE material among the three candidates. The detection limits for the instrument and the analytical method were in the ranges of 0. 26 -5. 7 pg and 0. 067 -0. 97 ng/g(dry weight) , respectively. Recoveries of PAHs in spiked soil ranged from 71% to 122% , with RSDs of 1. 6% - 8. 3% . The method was applied in the analysis of 7 farmland soil samples collected from electronic waste combustion area. The concentrations of PAHs were in the range of 28 - 283 ng/g( dry weight) , the recoveries of BaP - dl2 ranged from 90% to 124% , which all fell within the acceptable range set by the QC system.%优化了土壤中16种优控多环芳烃( PAHs)的分析方法,建立了一套完备的质量控制体系,解决了PAHs分析中常见的技术难点,如苯并(a)芘(BaP)回收率低,基质复杂的样品净化效果不理想,萘(Nap)和菲(Phe)挥

  13. A novel procedure for total nucleic acid extraction from small numbers of Eimeria species oocysts.

    Science.gov (United States)

    Kaya, Galip; Dale, Colin; Maudlin, Ian; Morgan, Kenton

    2007-01-01

    A series of experiments were performed in an attempt to extract genomic DNA from a small number of Eimerian oocysts. Sonication, ammonia, ethanol and lysozyme were all found to be unsuitable for the digestion of Eimeria oocysts. The chemicals and enzyme given were not capable of either disruption or digestion of oocysts for nucleic acid extraction. They had the capability of penetrating the oocyst wall but could not break-up the oocyst wall. It is impossible to obtain nucleic acid from Eimeria oocysts if the wall is not broken-up. In this study oocyst disruption was achieved using a simple but highly effective treatment regime involving sodium hypochlorite treatment, osmotic shock and proteinase K digestion. Following the disruption of the oocyst walls, a commercially available nucleic acid purification kit (Wizard DNA Purification Kit, Promega) can be used to prepare high quality nucleic acid.

  14. Development and validation of a nylon6 nanofibers mat-based SPE coupled with HPLC method for the determination of docetaxel in rabbit plasma and its application to the relative bioavailability study.

    Science.gov (United States)

    Xu, Qian; Zhang, Niping; Yin, Xueyan; Wang, Min; Shen, Yanyan; Xu, Shi; Zhang, Ling; Gu, Zhongze

    2010-09-15

    A simple and sensitive HPLC method was established and validated for the determination of docetaxel (DTX) in rabbit plasma. Biosamples were spiked with paclitaxel (PCX) as an internal standard (I.S.) and pre-treated by solid-phase extraction (SPE). The SPE procedure followed a simple protein digestion was based on nylon6 electrospun nanofibers mats as sorbents. Under optimized conditions, target analytes in 500 microL of plasma sample can be completely extracted by only 2.5mg nylon6 nanofibers mat and eluted by 100 microL solvent. The HPLC separation was obtained on C18 column and UV detector was used to quantify the target analytes. The extraction recovery was more than 85%; the standard curve was linear over the validated concentrations range of 10-5000 ng/mL and the limit of detection was 2 ng/mL. The inter-day coefficient of variation (CV%) of the calibration standards was below 5.0% and the mean accuracy was in the range of 92.8-113.4%. Moreover, analysing quality control plasma samples in 3 days, the results showed that the method was precise and accurate, for the intra- and inter-day CV% within 10% and the accuracy from 96.0% to 114.0%. The developed and validated method was successfully applied to relative bioavailability study for the preclinical evaluation of a new injectable DTX-sulfobutyl ether beta-cyclodextrin (DTX-SBE-beta-CD) inclusion complex freeze-dried powder (test preparation), compared with the reference preparation (DTX injection, Taxotere) in healthy rabbits. On the basis of the mean AUC(0-t) and AUC(0-infinity), the relative bioavailability of the test preparation was found to be 113.1%.

  15. Optimization of pressurized liquid extraction using a multivariate chemometric approach and comparison of solid-phase extraction cleanup steps for the determination of polycyclic aromatic hydrocarbons in mosses.

    Science.gov (United States)

    Foan, L; Simon, V

    2012-09-21

    A factorial design was used to optimize the extraction of polycyclic aromatic hydrocarbons (PAHs) from mosses, plants used as biomonitors of air pollution. The analytical procedure consists of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) cleanup, in association with analysis by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). For method development, homogeneous samples were prepared with large quantities of the mosses Isothecium myosuroides Brid. and Hypnum cupressiforme Hedw., collected from a Spanish Nature Reserve. A factorial design was used to identify the optimal PLE operational conditions: 2 static cycles of 5 min at 80 °C. The analytical procedure performed with PLE showed similar recoveries (∼70%) and total PAH concentrations (∼200 ng g(-1)) as found using Soxtec extraction, with the advantage of reducing solvent consumption by 3 (30 mL against 100mL per sample), and taking a fifth of the time (24 samples extracted automatically in 8h against 2 samples in 3.5h). The performance of SPE normal phases (NH(2), Florisil, silica and activated aluminium) generally used for organic matrix cleanup was also compared. Florisil appeared to be the most selective phase and ensured the highest PAH recoveries. The optimal analytical procedure was validated with a reference material and applied to moss samples from a remote Spanish site in order to determine spatial and inter-species variability.

  16. Minimally invasive surgical technique integrating multiple procedures with large specimen extraction via inguinal hernia orifice

    OpenAIRE

    Mani, Vishnu R.; Ahmed, Leaque

    2015-01-01

    While laparoscopic surgery can be performed using small skin incisions, any resected specimen must still be able to fit through these opening. For procedures, such as cholecystectomies and appendectomies, this is not usually a problem; however, for large specimens such as bowel or large tumors, this becomes problematic. Currently, the standard technique is to attempt piecemeal removal of the specimen or enlarge one of the laparoscopic incisions, effectively creating a mini laparotomy. Creatin...

  17. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING SOLID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.20)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting and concentrating solid food samples for persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, substituted phenols, and...

  18. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING LIQUID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.19)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting, and concentrating liquid food samples for neutral persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phenols.

  19. Comparison of DNA extraction kits and modification of DNA elution procedure for the quantitation of subdominant bacteria from piggery effluents with real‐time PCR

    National Research Council Canada - National Science Library

    Desneux, Jérémy; Pourcher, Anne‐Marie

    2014-01-01

    Four commercial DNA extraction kits and a minor modification in the DNA elution procedure were evaluated for the quantitation of bacteria in pig manure samples. The PowerSoil ® , PowerFecal ® , NucleoSpin...

  20. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING SOLID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.20)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting and concentrating solid food samples for persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, substituted phenols, and...

  1. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING LIQUID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.19)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting, and concentrating liquid food samples for neutral persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phenols.

  2. HPLC-NMR revisited: Using time-slice HPLC-SPE-NMR with database assisted dereplication

    DEFF Research Database (Denmark)

    Johansen, Kenneth; Wubshet, Sileshi Gizachew; Nyberg, Nils

    2013-01-01

    Time based trapping of chromatographically separated compounds on to solid-phase extraction cartridges (SPE) and subsequent elution to NMR-tubes was done to emulate the function of HPLC–NMR for dereplication purposes. Sufficient mass sensitivity was obtained by the use of a state-of-the-art HPLC......–SPE–NMR-system with a cryogenically cooled probe head, designed for 1.7 mm NMR-tubes. The resulting 1H NMR spectra (600 MHz) were evaluated against a database of previously acquired and prepared spectra. The in-house developed matching algorithm, based on partitioning of the spectra and allowing for changes in the chemical shifts...... and analogues. The database matching of the resulting spectra positively identified expected compounds, while the number of false positives was few and easily recognized....

  3. An automatic procedure to extract galaxy clusters from CRoNaRio catalogues

    CERN Document Server

    Puddu, E; Longo, G; Paolillo, M; Scaramella, R; Testa, V; Gal, R R; De Carvalho, R R; Djorgovski, S G

    1999-01-01

    We present preliminary results of a simple peak finding algorithm applied to catalogues of galaxies, extracted from the Second Palomar Sky Survey in the framework of the CRoNaRio project. All previously known Abell and Zwicky clusters in a test region of 5x5 sq. deg. are recovered and new candidate clusters are also detected. This algorithm represents an alternative way of searching for galaxy clusters with respect to that implemented and tested at Caltech on the same type of data (Gal et al. 1998).

  4. Speciation of heavy metals by modified BCR sequential extraction procedure in different depths of sediments from Sungai Buloh, Selangor, Malaysia.

    Science.gov (United States)

    Nemati, Keivan; Abu Bakar, Nor Kartini; Abas, Mhd Radzi; Sobhanzadeh, Elham

    2011-08-15

    The sequential extraction procedure proposed by the European Standard, Measurements and Testing (SM&T) program, formerly the Community Bureau of Reference (BCR), was applied for partitioning of heavy metals (HMs) in river sediments collected along the course of Sungai Buloh and the Straits of Malacca in Selangor, Malaysia. Eight elements (V, Pb, Cd, Cr, Co, Ni, Cu and Zn) from seven stations (S1-S7) and at different depths were analyzed using the modified BCR Sequential Extraction Procedure (SEP) in combination with ICP-MS to obtain the metal distribution patterns in this region. The results showed that heavy metal contaminations at S2 and S3 was more severe than at other sampling sites, especially for Zn, Cu, Ni and Pb. Nevertheless, the element concentrations from top to bottom layers decreased predominantly. The samples from the Straits of Malacca (S4-S7) the highest contamination factors obtained were for Co, Zn and Pb while the lowest were found for V and Cr, similar to Sungai Buloh sediments. The sediments showed a low risk for V, Cr, Cu and Pb with RAC values of less than 10%, but medium risk for Co, Zn (except S3), Cd at S1 and S2 and Ni at S1, S3 and S5. Zn at S3 and Cd at S3-S7 showed high risk to our sediment samples. There is not any element of very high risk conditions in the selected samples.

  5. A dipole-assisted solid-phase extraction microchip combined with inductively coupled plasma-mass spectrometry for online determination of trace heavy metals in natural water.

    Science.gov (United States)

    Shih, Tsung-Ting; Hsu, I-Hsiang; Chen, Shun-Niang; Chen, Ping-Hung; Deng, Ming-Jay; Chen, Yu; Lin, Yang-Wei; Sun, Yuh-Chang

    2015-01-21

    We employed a polymeric material, poly(methyl methacrylate) (PMMA), for fabricating a microdevice and then implanted the chlorine (Cl)-containing solid-phase extraction (SPE) functionality into the PMMA chip to develop an innovative on-chip dipole-assisted SPE technique. Instead of the ion-ion interactions utilized in on-chip SPE techniques, the dipole-ion interactions between the highly electronegative C-Cl moieties in the channel interior and the positively charged metal ions were employed to facilitate the on-chip SPE procedures. Furthermore, to avoid labor-intensive manual manipulation, a programmable valve manifold was designed as an interface combining the dipole-assisted SPE microchip and inductively coupled plasma-mass spectrometry (ICP-MS) to achieve the fully automated operation. Under the optimized operation conditions for the established system, the detection limits for each analyte ion were obtained based on three times the standard deviation of seven measurements of the blank eluent solution. The limits ranged from 3.48 to 20.68 ng L(-1), suggesting that this technique appears uniquely suited for determining the levels of heavy metal ions in natural water. Indeed, a series of validation procedures demonstrated that the developed method could be satisfactorily applied to the determination of trace heavy metals in natural water. Remarkably, the developed device was durable enough to be reused more than 160 times without any loss in its analytical performance. To the best of our knowledge, this is the first study reporting on the combination of a dipole-assisted SPE microchip and elemental analysis instrument for the online determination of trace heavy metal ions.

  6. AVAILABILITY OF COPPER AND ZINC IN SOILS EVALUATED BY SEQUENTIAL EXTRACTION PROCEDURE (BCR

    Directory of Open Access Journals (Sweden)

    Lucilia Alves Linhares

    2009-07-01

    Full Text Available In environmental studies, knowledge of the chemical forms of copper and zinc and the relationships with the levels available, are important for predicting the elements behavior in the soil-plant system. To assess the distribution of copper and zinc in soils of Minas Gerais State and their relations with their availability, an experiment was carried out on samples from six natural soils at two depths. The soil samples were incubated with the elements of interest and subjected to sequential extraction for separation of the elements in six fractions defined operationally. The results showed that the technique provided valuable information regarding the interaction of copper and zinc in soil and their speciation in various fractions of soils. There was a larger distribution of zinc in the exchangeable fraction and residual, while copper was preferably associated to more stable chemical forms, that is, related to reducible and residual forms. The nearly null extractions of copper and zinc from the soluble fraction and the exchangeable Argilúvico Chernosol (soil 2 and Tb eutrophic Haplic Cambisol (soil 3 systems correspond to the soil-metal system with the largest retention and lower availability of the elements in these soils. The predominance of copper and zinc associated mainly with the soluble and exchangeable fractions in Cambisol (soil 4 and latosol orthic Quartzarenic Neosol (soil 6 showed increased mobility and availability of the metals in more acidic and sandy soil when compared with the other soils.

  7. [Study on modes of occurrence of bromine in coals using sequential chemical extraction procedure].

    Science.gov (United States)

    Peng, Bing-Xian; Wu, Dai-She; Li, Ping

    2011-07-01

    Modes of occurrence of bromine in eight coals from Sichuan and Chongqing were studied using inductively coupled plasma spectrometry and sequential chemical extraction. The results showed that the bromine mainly occur the water-soluble, ion exchangeable, carbonate, Fe-Mn oxides and organic fraction in these coals, which average total extraction rate was 88.2%. In bituminous coal and anthracite, the mean relative amount was 22.3% and 20.0% for organic bromine, 14.0% and 19.2% for the bromine of carbonate bound and almost equal for the bromine from water soluble and Fe-Mn oxidizes. The ion exchangeable bromine may be mainly adsorbed to organic matter in these coals. The relative amount of bromine in various modes of occurrence may not be very closely related to its sedimentary environment during the formation of coal. Bromine in coals from Sichuan and Chongqing should be paid more attention because its potential leachable rate was 36.62% - 86.80% and potential leachable content was 7.092- 20.10 microg/g.

  8. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DERMAL WIPE AND SURFACE WIPE SAMPLES FOR ANALYSIS OF POLAR ORGANIC POLLUTANTS (SOP-5.27)

    Science.gov (United States)

    The method for extracting and preparing a dermal or surface wipe sample for analysis of acidic persistent organic pollutants is summarized in this standard operating procedure. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mas...

  9. NEAR FIELD MODELING OF SPE1 EXPERIMENT AND PREDICTION OF THE SECOND SOURCE PHYSICS EXPERIMENTS (SPE2)

    Energy Technology Data Exchange (ETDEWEB)

    Antoun, T; Xu, H; Vorobiev, O; Lomov, I

    2011-10-20

    Motion along joints and fractures in the rock has been proposed as one of the sources of near-source shear wave generation, and demonstrating the validity of this hypothesis is a focal scientific objective of the source physics experimental campaign in the Climax Stock granitic outcrop. A modeling effort has been undertaken by LLNL to complement the experimental campaign, and over the long term provide a validated computation capability for the nuclear explosion monitoring community. The approach involves performing the near-field nonlinear modeling with hydrodynamic codes (e.g., GEODYN, GEODYN-L), and the far-field seismic propagation with an elastic wave propagation code (e.g., WPP). the codes will be coupled together to provide a comprehensive source-to-sensor modeling capability. The technical approach involves pre-test predictions of each of the SPE experiments using their state of the art modeling capabilities, followed by code improvements to alleviate deficiencies identified in the pre-test predictions. This spiral development cycle wherein simulations are used to guide experimental design and the data from the experiment used to improve the models is the most effective approach to enable a transition from the descriptive phenomenological models in current use to the predictive, hybrid physics models needed for a science-based modeling capability for nuclear explosion monitoring. The objective of this report is to describe initial results of non-linear motion predictions of the first two SPE shots in the Climax Stock: a 220-lb shot at a depth of 180 ft (SPE No.1), and a 2570-lb shot at a depth of 150 ft (SPE No.2). The simulations were performed using the LLNL ensemble granite model, a model developed to match velocity and displacement attenuation from HARDHAT, PILE DRIVER, and SHOAL, as well as Russian and French nuclear test data in granitic rocks. This model represents the state of the art modeling capabilities as they existed when the SPE campaign was

  10. A Highly Sensitive Multicommuted Flow Analysis Procedure for Photometric Determination of Molybdenum in Plant Materials without a Solvent Extraction Step.

    Science.gov (United States)

    Santos, Felisberto G; Reis, Boaventura F

    2017-01-01

    A highly sensitive analytical procedure for photometric determination of molybdenum in plant materials was developed and validated. This procedure is based on the reaction of Mo(V) with thiocyanate ions (SCN(-)) in acidic medium to form a compound that can be monitored at 474 nm and was implemented employing a multicommuted flow analysis setup. Photometric detection was performed using an LED-based photometer coupled to a flow cell with a long optical path length (200 mm) to achieve high sensitivity, allowing Mo(V) determination at a level of μg L(-1) without the use of an organic solvent extraction step. After optimization of operational conditions, samples of digested plant materials were analyzed employing the proposed procedure. The accuracy was assessed by comparing the obtained results with those of a reference method, with an agreement observed at 95% confidence level. In addition, a detection limit of 9.1 μg L(-1), a linear response (r = 0.9969) over the concentration range of 50-500 μg L(-1), generation of only 3.75 mL of waste per determination, and a sampling rate of 51 determinations per hour were achieved.

  11. A Highly Sensitive Multicommuted Flow Analysis Procedure for Photometric Determination of Molybdenum in Plant Materials without a Solvent Extraction Step

    Directory of Open Access Journals (Sweden)

    Felisberto G. Santos

    2017-01-01

    Full Text Available A highly sensitive analytical procedure for photometric determination of molybdenum in plant materials was developed and validated. This procedure is based on the reaction of Mo(V with thiocyanate ions (SCN− in acidic medium to form a compound that can be monitored at 474 nm and was implemented employing a multicommuted flow analysis setup. Photometric detection was performed using an LED-based photometer coupled to a flow cell with a long optical path length (200 mm to achieve high sensitivity, allowing Mo(V determination at a level of μg L−1 without the use of an organic solvent extraction step. After optimization of operational conditions, samples of digested plant materials were analyzed employing the proposed procedure. The accuracy was assessed by comparing the obtained results with those of a reference method, with an agreement observed at 95% confidence level. In addition, a detection limit of 9.1 μg L−1, a linear response (r=0.9969 over the concentration range of 50–500 μg L−1, generation of only 3.75 mL of waste per determination, and a sampling rate of 51 determinations per hour were achieved.

  12. Influence of crisp values on the object-based data extraction procedure from LiDAR data

    Science.gov (United States)

    Tomljenovic, Ivan; Rousell, Adam

    2014-05-01

    . The purpose of this study is to identify to what extent the use of explicit boundary values has on the overall building footprint dataset extracted. By performing the analysis multiple times using differing threshold values for rules, it is possible to compare the resultant datasets and thus identify the impact of using such classification procedures. If a significant difference is found between the resultant datasets, this would highlight that the use of such crisp methods in the extraction processes may not be optimal and that a future enhancement to the method would be to consider the use of fuzzy classification methods.

  13. Ultra-Trace Determination of Methyl Carbamate and Ethyl Carbamate in Local Wines by GC-FID Following Pre concentration with C18-SPE

    Directory of Open Access Journals (Sweden)

    Supawadee Sarawan

    2014-09-01

    Full Text Available An analytical method is described for ultra-trace determination of methyl carbamate and ethyl carbamate in locally produced fruit wines. The quantitative analysis involves with dichloromethane extraction followed by 30-fold preconcentration using C18 SPE prior to measurement by capillary GC-FID. Under the optimized conditions, a good linearity of their calibration curves was obtained in the range of 0.1-50.0 mg/L with r2 > 0.994. LOD and LOQ were 3.3-16.7 µg/L and 11.1-55.6 µg/L, respectively. The averaged recovery of these carbamates was ranged of 82.2-95.2% with RSD < 8.76%. The procedure was applied to determine both carbamate residues in various local wine samples. It was found that the concentration range of methyl carbamate (6.9-24.1 µg/L was rather fluctuated and higher than that of ethyl carbamate (2.6-4.3 µg/L, suggesting that is a certain residual background contamination naturally occurring in the wine fermentation.

  14. Preparation of molecularly imprinted polymers using theanine as dummy template and its application as SPE sorbent for the determination of eighteen amino acids in tobacco.

    Science.gov (United States)

    Zhu, Fengling; Wang, Jing; Zhu, Lijun; Tan, Lanlan; Feng, Guanglin; Liu, Shaomin; Dai, Ya; Wang, Hua

    2016-04-01

    In this paper, a novel dummy template molecularly imprinted polymer (DMIP) based on a vinyl-SiO2 microspheres surface for the simultaneous selective recognition and enrichment of 18 amino acids was prepared via a surface molecular imprinting technique using theanine as a dummy template. Compared to the imprinted polymers prepared using traditional polymerization techniques, the obtained DMIPs exhibited a regular spherical shape and were relatively monodisperse. The maximal sorption capacity (Qmax) of the resulting DMIPs for the 18 amino acids was up to 1444.3 mg g(-1). A kinetic binding study showed that the sorption capacity reached 85.40% of Qmax in 25 min and sorption equilibrium at 30 min. The imprint factors of the sorbents ranged from 2.86 to 6.9 for the 18 amino acids, which indicated that the DMIP sorbents have high selectivity. An HPLC-UV method for the simultaneous determination of 18 amino acids in tobacco and tobacco smoke was developed using the DMIPs as sorbents for solid phase extraction (SPE) in the sample pretreatment procedure. Under the optimum experimental conditions, the materials had enrichment factors of up to 200 for the amino acids, and the recoveries of the 18 amino acids in tobacco smoke were in the range from 79% to 104% with relative standard deviations of less than 7.4%. It indicated that the obtained DMIP sorbents could specifically recognize the amino acids from complicated samples.

  15. An improved chloroplast DNA extraction procedure for whole plastid genome sequencing.

    Science.gov (United States)

    Shi, Chao; Hu, Na; Huang, Hui; Gao, Ju; Zhao, You-Jie; Gao, Li-Zhi

    2012-01-01

    Chloroplast genomes supply valuable genetic information for evolutionary and functional studies in plants. The past five years have witnessed a dramatic increase in the number of completely sequenced chloroplast genomes with the application of second-generation sequencing technology in plastid genome sequencing projects. However, cost-effective high-throughput chloroplast DNA (cpDNA) extraction becomes a major bottleneck restricting the application, as conventional methods are difficult to make a balance between the quality and yield of cpDNAs. We first tested two traditional methods to isolate cpDNA from the three species, Oryza brachyantha, Leersia japonica and Prinsepia utihis. Both of them failed to obtain properly defined cpDNA bands. However, we developed a simple but efficient method based on sucrose gradients and found that the modified protocol worked efficiently to isolate the cpDNA from the same three plant species. We sequenced the isolated DNA samples with Illumina (Solexa) sequencing technology to test cpDNA purity according to aligning sequence reads to the reference chloroplast genomes, showing that the reference genome was properly covered. We show that 40-50% cpDNA purity is achieved with our method. Here we provide an improved method used to isolate cpDNA from angiosperms. The Illumina sequencing results suggest that the isolated cpDNA has reached enough yield and sufficient purity to perform subsequent genome assembly. The cpDNA isolation protocol thus will be widely applicable to the plant chloroplast genome sequencing projects.

  16. Ibuprofen metabolite profiling using a combination of SPE/column-trapping and HPLC-micro-coil NMR.

    Science.gov (United States)

    Djukovic, Danijel; Appiah-Amponsah, Emmanuel; Shanaiah, Narasimhamurthy; Gowda, G A Nagana; Henry, Ian; Everly, Mike; Tobias, Brian; Raftery, Daniel

    2008-06-09

    Solid-phase extraction and column-trapping preconcentration are combined to enhance HPLC-nuclear magnetic resonance (HPLC-NMR) and applied to metabolite profiling in biological samples. Combining the two signal enhancement techniques improved the NMR signal substantially such that we were able to identify 2-hydroxyibuprofen, carboxyibuprofen, and unmetabolized ibuprofen molecules from a small urine sample after a therapeutic dose of ibuprofen. The hyphenated SPE/column-trapping method resulted in an excellent overall signal enhancement of up to 90-fold.

  17. SPE-HPLC法测定水中的酚类化合物

    Institute of Scientific and Technical Information of China (English)

    刘晓武

    2015-01-01

    Phenol compounds especially chlorophenol and nitrophenol compounds in water were determined by SPE-HPLC method. The solid phase extraction (SPE)column was firstly activated by 4 mL methanol and 4 mL pure water, phenol compounds in the sample was absorbed by SPE column, eluted by acetonitrile, and then concentrated to 1 mL. The condition of the HPLC was as follows:pure water and acetonitrile was used as mobile phase and gradient eluted from 8:2 to 2:8, the velocity of flow was 1.0 mL/min. ODS-C18 was used to separate the phenol compounds, the wavelength of the VWD was 285 nm. The linearity of the standard curve was higher than 0.999 0, the detection limits of the phenol compounds was below the requiring of the standard for drinking water quality, the average spike recovery was 70%~90%.%建立了一种固相萃取—高效液相色谱法,测定水中的酚类化合物,特别是氯酚和硝基酚几种酚类化合物。吸附前使用4 mL甲醇和4 mL纯水活化固相萃取小柱(SPE),样品通过SPE时酚类化合物被吸附,后用乙腈洗脱,收集洗脱液浓缩至1 mL。以V 水∶V 乙腈为8∶2梯度淋洗,V 水∶V 乙腈为2∶8结束,流速1.0 mL/min,以ODS-C18分离酚类化合物,检测器波长为285 nm。实验结果表明,标准曲线线性关系均大于0.9990;检出限均小于《生活饮用水卫生标准》的要求;平均加标回收率在70%~90%之间。

  18. Simultaneous analysis of some club drugs in whole blood using solid phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Castro, André L; Tarelho, Sónia; Silvestre, Armando; Teixeira, Helena M

    2012-02-01

    The use of psychoactive substances to improve social relations and increase body energy, in Rave Culture, has raised many legal and health public concerns, both for illicit trade and consumption. Therefore, forensic toxicology plays an important role in this area, mainly linked to the detection and quantitation of these substances, both in vivo and in post-mortem samples. In fact, at the moment, forensic sciences have been under public authorities' scrutiny and critical look, due to the increasing attention of the media and public opinion, always applying for the use of scientific knowledge to help solving forensic cases. However, forensic toxicology results are only reliable to solve legal cases if all the analytical methodologies used are appropriately validated. In this work, a methodology for the extraction and analysis of 7-aminoflunitrazepam, buprenorphine, flunitrazepam, ketamine, methadone, phencyclidine (PCP) and d-propoxyphene was developed for whole blood samples, with solid phase extraction (SPE), using OASIS(®) MCX SPE columns, and gas chromatography coupled to mass spectrometry. The procedure presented here proved to be reliable, specific, selective and sensitive, with good LODs and LOQs and good precision.The adoption of a SPE procedure with an automatic SPE extraction device, allowed an increased level of automation in sample treatment, being contemporarily less time-consuming, increasing productiveness, and allowing good recovery and appropriate selectivity being, also, simple and reproducible. The simultaneous detection and quantitation of all compounds by the same extraction and detection methodology is crucial and has a great potential for forensic toxicology and clinical analysis.

  19. An improved chloroplast DNA extraction procedure for whole plastid genome sequencing.

    Directory of Open Access Journals (Sweden)

    Chao Shi

    Full Text Available BACKGROUND: Chloroplast genomes supply valuable genetic information for evolutionary and functional studies in plants. The past five years have witnessed a dramatic increase in the number of completely sequenced chloroplast genomes with the application of second-generation sequencing technology in plastid genome sequencing projects. However, cost-effective high-throughput chloroplast DNA (cpDNA extraction becomes a major bottleneck restricting the application, as conventional methods are difficult to make a balance between the quality and yield of cpDNAs. METHODOLOGY/PRINCIPAL FINDINGS: We first tested two traditional methods to isolate cpDNA from the three species, Oryza brachyantha, Leersia japonica and Prinsepia utihis. Both of them failed to obtain properly defined cpDNA bands. However, we developed a simple but efficient method based on sucrose gradients and found that the modified protocol worked efficiently to isolate the cpDNA from the same three plant species. We sequenced the isolated DNA samples with Illumina (Solexa sequencing technology to test cpDNA purity according to aligning sequence reads to the reference chloroplast genomes, showing that the reference genome was properly covered. We show that 40-50% cpDNA purity is achieved with our method. CONCLUSION: Here we provide an improved method used to isolate cpDNA from angiosperms. The Illumina sequencing results suggest that the isolated cpDNA has reached enough yield and sufficient purity to perform subsequent genome assembly. The cpDNA isolation protocol thus will be widely applicable to the plant chloroplast genome sequencing projects.

  20. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Margaret [National Security Technologies, LLC, Las Vegas, NV (United States). Nevada Test Site; Obi, Curtis [National Security Technologies, LLC, Las Vegas, NV (United States). Nevada Test Site

    2015-01-26

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and far-field data that are available.

  1. Determination of umckalin in commercial tincture and phytopreparations containing Pelargonium sidoides by HPLC: comparison of sample preparation procedures.

    Science.gov (United States)

    Franco, L; de Oliveira, B H

    2010-06-15

    Roots of Pelargonium sidoides D.C. are used for the production of phytomedicines. Current quality control of phytopreparations containing P. sidoides extracts has been made in terms of total phenolics content. In this work we describe the development and validation of an HPLC method for the analysis of P. sidoides tincture and commercial syrup phytopreparations using umckalin (7-hydroxy-5,6-dimethoxycoumarin) as chemical marker. Two sample preparation procedures, liquid-liquid extraction (LLE) and solid-phase extraction (SPE) were also developed and compared. The samples were analyzed by RP-HPLC and the two methods were then validated and compared. The repeatability of the two procedures showed coefficients of variation (CV) of 1.2% for SPE procedure, and 1.3% for LLE. Recovery for both methods was higher than 95.2%. The linearity showed correlation coefficients better than 0.999 for both methods. The detection and quantification limit were 0.0098 and 0.0298microgmL(-1), respectively. The validated procedure was then used for the analysis of tincture and five batches of two commercial phytopreparations containing P. sidoides tincture.

  2. Liquid-liquid extraction procedure exploiting multicommutation in flow system for the determination of molybdenum in plants

    Energy Technology Data Exchange (ETDEWEB)

    Comitre, Ana Lucia D.; Reis, Boaventura F

    2003-03-10

    A liquid-liquid extraction flow analysis procedure for the spectrophotometric determination of molybdenum in plants at {mu}g l{sup -1} level is described. The flow network comprised a set of solenoid valves assembled to implement the multicommutation approach under microcomputer control. Radiation source (LED, 475 nm), detector (photodiode) and separation chamber were nested together with the flow cell comprising a compact unit. The consumption of reagents (potassium thiocyanate and stannous chloride) and also extracting solvent (isoamyl alcohol) were optimized to 32 mg and 200 {mu}l per determination, respectively. Accuracy was assessed by comparing results with those obtained with ICP-OES and no significant difference at 95% confidence level was observed. Other favorable characteristics such as a linear response ranging from 25 to 150 {mu}g l{sup -1} molybdenum (r=0.999); detection limit of 4.6 {mu}g l{sup -1} sample throughput of 25 determinations per hour and relative standard deviation of 2.5% (n=10) were also achieved.

  3. The use of a sequential extraction procedure for heavy metal analysis of house dusts by atomic absorption spectrometry.

    Science.gov (United States)

    Altundag, Huseyin; Dundar, Mustafa Sahin; Doganci, Secil; Celik, Muhammed; Tuzen, Mustafa

    2013-01-01

    In general, dust is considered as house or street dust. Indoor dust, as a contamination source, has been studied for many years. In this work, the original Community Bureau of Reference of the European Commission (BCR) three-stage sequential extraction procedure was applied to the fractionation of Cr, Cu, Fe, Mn, Pb, and Zn in 20 house dust samples from five different areas of Sakarya, Turkey. Acetic acid, hydroxylammonium chloride, and hydrogen peroxide plus ammonium acetate were used for the first, second, and third steps of the BCR method, respectively. The extracts were analyzed for the studied heavy metals using flame atomic absorption spectrometry. Validation of the results was performed by using a standard reference material (BCR 701 Sediment) to certify the experimental results obtained and to evaluate the reliability of the method used. The elemental loadings typically increased in magnitude according to the area order: Izmit Caddesi>Ankara Caddesi >Erenler>Karaman>Korucuk. The results were in agreement with values reported in the literature.

  4. A one-step extraction procedure for the screening of cocaine, amphetamines and cannabinoids in postmortem blood samples.

    Science.gov (United States)

    Pelição, Fabrício Souza; Peres, Mariana Dadalto; Pissinate, Jauber Fornaciari; De Martinis, Bruno Spinosa

    2014-01-01

    A gas chromatography-mass spectrometric (GC-MS) method was developed and validated for the simultaneous detection and quantification in postmortem whole blood samples of cocaine (COC), amphetamines (AMPs) and cannabis; the main drugs involved in cases of impaired driving in Brazil. The analytes were extracted by solid-phase extraction by means of Bond-Elute Certify cartridges, derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide at 80°C for 30 min and analyzed by GC-MS. Linearity ranged from 10 to 500 ng/mL, except for ecgonine methyl ester, for which linearity ranged from 10 to 100 ng/mL. Inter- and intra-day imprecision ranged from 2.8 to 18.4% and from 1.5 to 14.9%, respectively. Accuracy values lay between 86.9 and 104.4%. The limit of quantitation for all drugs was 10 ng/mL and recoveries were >74% for all analytes, except for cannabinoids, which showed poor recovery (∼30%). The developed method was applied to real samples collected from deceased victims due to traffic accidents. These samples were selected according to the results obtained in immunoassay screening on collected urine samples. Five samples were positive for the presence of COC and metabolites, four samples were positive for cannabinoids, six samples were positive for AMPs and two samples were drug negative. Some samples were positive for more than one class of drug. Results obtained from whole blood samples showed good agreement with urine screening. The developed method proved capable of quantifying all three classes of drugs of abuse proposed in this study, through a one-step extraction procedure.

  5. Determination of diniconazole in agricultural samples by sol-gel immunoaffinity extraction procedure coupled with HPLC and ELISA.

    Directory of Open Access Journals (Sweden)

    Zhenjiang Liu

    Full Text Available BACKGROUND: In the European Union (EU, the use of diniconazole-M is no longer authorized. However, residues of diniconazole-M occur in various plant commodities. METHODOLOGY/PRINCIPAL FINDINGS: A selective and simple analytical method for the trace level determination of diniconazole in soil, fruit, vegetables and water samples was developed based on immunoaffinity extraction followed by Enzyme-linked immunosorbent assay (ELISA and the high-performance liquid chromatography (HPLC analysis. The ELISA was based on monoclonal antibodies highly specific to diniconazole and was a fast, cost-effective, and selective screening method for the detection of diniconazole. The results of the ELISA correlated well with gas chromatography (GC results, with the correlation coefficient of 0.9879 (n = 19. A simple gel permeation chromato- graphy clean-up method was developed to purify extracts from matrices containing high amounts of fat and natural pigments, without the need for a large dilution of the sample. The immunoaffinity column (IAC capacity was 0.180 mg g(-1. The columns could be re-used approximately 20 times with no significant alteration in capacity. The recoveries from complex samples were in the range of 89.2% to 96.1% with a relative standard deviation (RSD of 0.770%-6.11% by ELISA. The results were in good agreement with those obtained by HPLC method. CONCLUSION/SIGNIFICANCE: The IAC extraction procedure coupled with HPLC and ELISA analysis could be also used as alternative effective analytical methods for the determination of diniconazole concentrations in complex samples.

  6. Development of an automated sequential injection on-line solvent extraction-back extraction procedure as demonstrated for the determination of cadmium with detection by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection (SI) on-line solvent extraction-back extraction separation/preconcentration procedure is described. Demonstrated for the assay of cadmium by electrothermal atomic absorption spectrometry (ETAAS), the analyte is initially complexed with ammonium pyrrolidinedithioc......An automated sequential injection (SI) on-line solvent extraction-back extraction separation/preconcentration procedure is described. Demonstrated for the assay of cadmium by electrothermal atomic absorption spectrometry (ETAAS), the analyte is initially complexed with ammonium....../preconcentration process of the ensuing sample. An enrichment factor of 21.4, a detection limit of 2.7 ng/l, along with a sampling frequency of 13s/h were obtained at a sample flow rate of 6.0mlmin/sup -1/. The precision (R.S.D.) at the 0.4 mug/l level was 1.8% as compared to 3.2% when quantifying the organic extractant...

  7. Study of the water-rock interaction in Tsengwenshi groundwater system (southern Taiwan) using BCR sequential extraction procedure

    Science.gov (United States)

    Teng, J. Y.

    2012-04-01

    The heavy metals in groundwater seriously risk the human wealth, agriculture and the aquaculture, especially, if the water is the major source of daily use. Generally, in spite of anthropogenic source, the heavy metals in groundwater are released during water-rock interaction. However, there are many mineral phases being capable of releasing heavy metals. It would need a sequential extraction procedure to identify the source mineral phase in the aquifer. In addition, the geochemical reactions after the release of heavy metals are also important to modify the concentrations. In this study, the rare earth elements are used to be a natural tracer for this purpose. The study area, Tsengwenshi watershed in southern Taiwan, is an alluvial fan with all kinds of land uses and is notorious of arsenic contamination. The groundwaters sampled in this study show that arsenic is enriched in deep aquifer (depth>150m), which is composed of sediments deposited in the last glacial period (18 ka). Based on this conceptual model, the results of BCR sequential extraction procedure are categorized into shallow aquifer (depthheavy metals in two groups can be subsequently obtained to take account of extensive water-rock interaction in the groundwater system. The results show that arsenic and other heavy metals are mostly binding with Fe-Mn oxides. To compare the ratios between deep and shallow aquifers for all heavy metals, the pattern of groundwaters does not show the similar type with those of extracted phases from soils. It is believed that the released heavy metals were strongly modified by the geochemical reactions during the transportation in the groundwater system. In addition, the analysis results of the rare earth elements demonstrates that almost all groundwaters with high arsenic do not have Ce negative anomaly; and, on the contrary, those with low arsenic are generally characterized by strong negative anomaly. Generally, the Ce negative anomaly is a prominent indicator of

  8. Rapid analysis of six sweeteners in wine by dispersive solid-phase extraction and ultra-fast liquid chromatography coupled with tandem mass spectrometry%葡萄酒中6种甜味剂的dSPE-UFLC-MS/MS快速确证检测

    Institute of Scientific and Technical Information of China (English)

    陈晓红; 朱浩; 周丽新; 赵永纲; 金米聪

    2014-01-01

    目的 建立一种简便、快速的葡萄酒中安赛蜜、糖精、甜蜜素、阿斯巴甜、甜菊糖苷和纽甜的分散固相萃取-液相色谱/串联质谱(dSPE-UFLC-MS/MS)定性定量分析方法.方法 样品以新型磁性纳米材料为吸附剂进行分散固相萃取,利用UFLC-ESI-MS/MS进行分离和串联质谱测定,采用保留时间结合三离子定性原则进行确证.结果 磁性纳米材料是一种高效的分散固相萃取吸附剂,可有效去除葡萄酒中的干扰基质;电喷雾电离可获得稳定可靠的二级质谱裂解碎片离子,安赛蜜、糖精、甜蜜素、阿斯巴甜、甜菊糖苷和纽甜的定量离子对分别为m/z 162→82、m/z 182→42、m/z 178→80、m/z 293→200、m/z 803→641、m/z 377→200,6种甜味剂的精密度范围为1.1% ~4.0%,回收率范围为83.4% ~ 104.0%,定量检出限范围为0.1~5.0 μg/L.结论 建立的方法快速、灵敏、准确,适用于葡萄酒中安赛蜜、糖精、甜蜜素、阿斯巴甜、甜菊糖苷和纽甜的含量确证分析.

  9. Premature sperm activation and defective spermatogenesis caused by loss of spe-46 function in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Wei-Siang Liau

    Full Text Available Given limited resources for motility, sperm cell activation must be precisely timed to ensure the greatest likelihood of fertilization. Like those of most species, the sperm of C. elegans become active only after encountering an external signaling molecule. Activation coincides with spermiogenesis, the final step in spermatogenesis, when the spherical spermatid undergoes wholesale reorganization to produce a pseudopod. Here, we describe a gene involved in sperm activation, spe-46. This gene was identified in a suppressor screen of spe-27(it132ts, a sperm-expressed gene whose product functions in the transduction of the spermatid activation signal. While spe-27(it132ts worms are sterile at 25°C, the spe-46(hc197I; spe-27(it132tsIV double mutants regain partial fertility. Single nucleotide polymorphism mapping, whole genome sequencing, and transformation rescue were employed to identify the spe-46 coding sequence. It encodes a protein with seven predicted transmembrane domains but with no other predicted functional domains or homology outside of nematodes. Expression is limited to spermatogenic tissue, and a transcriptional GFP fusion shows expression corresponds with the onset of the pachytene stage of meiosis. The spe-46(hc197 mutation bypasses the need for the activation signal; mutant sperm activate prematurely without an activation signal in males, and mutant males are sterile. In an otherwise wild-type genome, the spe-46(hc197 mutation induces a sperm defective phenotype. In addition to premature activation, spe-46(hc197 sperm exhibit numerous defects including aneuploidy, vacuolization, protruding spikes, and precocious fusion of membranous organelles. Hemizygous worms [spe-46(hc197/mnDf111] are effectively sterile. Thus, spe-46 appears to be involved in the regulation of spermatid activation during spermiogenesis, with the null phenotype being an absence of functional sperm and hypomorphic phenotypes being premature spermatid activation

  10. Simple SPE-HPLC determination of some common drugs and herbicides of environmental concern by pulsed amperometry.

    Science.gov (United States)

    Rivoira, L; De Carlo, R M; Cavalli, S; Bruzzoniti, M C

    2015-01-01

    In this work the electrochemical behavior of substances of environmental concern [bentazone, atrazine, carbamazepine, phenytoin and its metabolite 5-(4-hydroxyphenyl)-5-phenylhydantoin, HPPH] on a glassy carbon working electrode (Ag/AgCl reference electrode) was studied with the aim to develop a HPLC method coupled with amperometric detection. Constant potential (DC), pulsed amperometric detection modes were studied. For the pulsed mode, several waveforms were set and investigated. Detection conditions were optimized as a function of eluent pH. In order to reduce the limits of detection and to analyze natural water samples, a SPE protocol was optimized to be coupled to the developed procedure. For this aim, five sorbents of different physico-chemical characteristics were tested optimizing a recovery procedure for each of the cartridge evaluated. At the optimized SPE conditions, recoveries were included in the range (R=90.2-100.5% for all the analytes, with excellent reproducibility (<%, n=3). The method detection limits obtained by pulsed amperometry after the SPE protocol (preconcentration factor 100) were 113 ng L(-1) (0.47 nmol L(-1)), 67 ng L(-1) (0.25 nmol L(-1)), 234 ng L(-1) (1.1 nmol L(-1)), for bentazone, HPPH and carbamazepine, respectively. Robustness of the method was assessed for each analyte at a concentration level corresponding to about three times the limit of detection, through the evaluation of intra-day (n=13) and inter-day tests (4 days, n=52). Finally the method was successfully applied for the analysis of a river sample (Po River, Turin, Italy).

  11. Direct continuous supercritical fluid extraction as a novel method of wine analysis. Comparison with conventional indirect extraction and implications for wine variety identification.

    Science.gov (United States)

    Karásek, Pavel; Planeta, Josef; Varad'ová Ostrá, Elena; Mikesová, Milena; Goliás, Jan; Roth, Michal; Vejrosta, Jirí

    2003-06-20

    Direct supercritical fluid extraction (SFE) of wines with carbon dioxide was compared to SFE of the sorbent used for solid-phase extraction of the same wine samples (SPE-SFE). Compared to SPE-SFE, the direct SFE results in amore specific and representative gas chromatographic fingerprint of the wine sample. The multivariate statistical processing of the direct SFE-GC data provides a clear-cut and sharp discrimination among the individual wine varieties while the discrimination based on the SPE-SFE-GC data is relatively poor. This finding reflects the adverse effects of additional analyte-sorbent interactions and sorption/desorption steps involved in SPE-SFE.

  12. Solid Polymer Electrolyte (SPE) fuel cell technology, program review, phase 2

    Science.gov (United States)

    1976-01-01

    The purpose of the solid polymer electrolyte (SPE) fuel cell program is to advance the SPE fuel cell technology in four target areas. These areas are: (1) reduced fuel cell costs; (2) reduced fuel cell weight; (3) improved fuel cell efficiency; and (4) increased systems compatibility.

  13. Novel molecularly imprinted polymers with carbon nanotube as matrix for selective solid-phase extraction of emodin from kiwi fruit root.

    Science.gov (United States)

    Yang, Xiao; Zhang, Zhaohui; Li, Jiaxing; Chen, Xing; Zhang, Minlei; Luo, Lijuan; Yao, Shouzhuo

    2014-02-15

    In this paper, we present a novel surface imprinting technique for the preparation of molecularly imprinted polymers/multi-walled carbon nanotubes (MIPs/MWNTs) for extraction of emodin from kiwi fruit root. The MIPs/MWNTs were characterised by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy (FT-IR). The properties involving adsorption dynamics, static adsorption, and selective recognition capacity were evaluated. The MIPs/MWNTs exhibited good site accessibility in which it only took 60 min to achieve adsorption equilibrium and highly selective recognition for the template emodin. Furthermore, the performance of the MIPs/MWNTs as solid phase extraction (SPE) material was investigated in detail. The proposed MIPs/MWNTs-SPE procedure for emodin exhibited satisfactory recoveries ranging from 89.2% to 93.8% for real samples. It was used for the purification and enrichment of emodin from kiwi fruit root successfully.

  14. Comparison of solid phase extraction, saponification and gel permeation chromatography for the clean-up of microwave-assisted biological extracts in the analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Navarro, P; Cortazar, E; Bartolomé, L; Deusto, M; Raposo, J C; Zuloaga, O; Arana, G; Etxebarria, N

    2006-09-22

    The feasibility of different clean-up procedures was studied for the determination of polycyclic aromatic hydrocarbons (PAHs) in biota samples such as oysters, mussels and fish liver. In this sense, once the samples were extracted--essentially with acetone and in a microwave system--and before they could be analysed by gas chromatography-mass spectrometry (GC-MS), three different approaches were studied for the clean-up step: solid phase extraction (SPE), microwave-assisted saponification (MAS) and gel permeation chromatography (GPC). The main aim of this work was to maximise the recoveries of PAHs and to minimise the presence of interfering compounds in the last extract. In the case of SPE, Florisil cartridges of 1, 2 and 5 g, and silica cartridges of 5 g were studied. In that case, and with oysters and mussels, microwave-assisted extraction and 5 g Florisil cartridges provided good results. In addition, the concentrations obtained for Standard Reference Material (SRM) NIST 2977 (mussel tissue) were in good agreement with the certified values. In the case of microwave-assisted saponification, the extracts were not as clean as those obtained with 5 g Florisil and this fact lead to overestimate the concentration of the heaviest PAHs. Finally, the cleanest extracts were obtained by GPC. The method was successfully applied to mussels, oysters and hake liver, and the results obtained for NIST 2977 (mussel tissue) were within the confidence interval of the certified reference material for most of the certified analytes.

  15. Application of dispersive liquid-liquid microextraction coupled with vortex-assisted hydrophobic magnetic nanoparticles based solid-phase extraction for determination of aflatoxin M1 in milk samples by sensitive micelle enhanced spectrofluorimetry.

    Science.gov (United States)

    Amoli-Diva, Mitra; Taherimaslak, Zohreh; Allahyari, Mehdi; Pourghazi, Kamyar; Manafi, Mohammad Hanif

    2015-03-01

    An efficient, simple and fast low-density solvent based dispersive liquid-liquid microextraction (LDS-DLLME) followed by vortex-assisted dispersive solid phase extraction (VA-D-SPE) has been developed as a new approach for extraction and preconcentration of aflatoxin M1 in milk samples prior to its micelle enhanced spectrofluorimetic determination. In this LDS-DLLME coupled VA-D-SPE method, milk samples were first treated with methanol/water (80:20, v/v) after removing the fat layer. This solvent was directly used as the dispersing solvent in DLLME along with using 1-heptanol (as a low-density solvent with respect to water) as the extracting solvent. In VA-D-SPE approach, hydrophobic oleic acid modified Fe3O4 nanoparticles were used to retrieve the analyte from the DLLME step. It is considerably that the target of VA-D-SPE was 1-heptanol rather than the aflatoxin M1 directly. The main parameters affecting the efficiency of LDS-DLLME and VA-D-SPE procedures and signal enhancement of aflatoxin M1 were investigated and optimized. Under the optimum conditions, the method was linear in the range from 0.02 to 200 µg L(-1) with the correlation coefficient (R(2)) of 0.9989 and detection limit of 13 ng L(-1). The intra-day precision was 2.9 and 4.3% and the inter-day precision was 2.1 and 3.3% for concentration of 2 and 50 µg L(-1) respectively. The developed method was applied for extraction and preconcentration of AFM1 in three commercially available milk samples and the results were compared with the official AOAC method.

  16. Comparison of two sample preparation procedures for HPLC determination of ochratoxin A

    Directory of Open Access Journals (Sweden)

    Vuković Gorica L.

    2009-01-01

    Full Text Available In preparation of samples for chromatographic determination of ochratoxin A, two types of columns were used for sample cleanup (SPE and immunoaffinity columns. The first method consisted of liquid-liquid extraction with a mixture of chloroform and phosphoric acid, followed by ion-exchange cleanup on Waters Oasis MAX columns. The sec­ond method consisted of extraction with a mixture of water and methanol, followed by LCTech OtaCLEAN immunoaf­finity column cleanup. Recoveries of the methods were determined at three levels in three repetitions for maize flour, and they were 84% (%RSD = 19.2 for the first method of sample preparation and 101% (%RSD = 2.2 for the second method. Values of LOQ for OTA were 0.25 and 1.00 μg/kg for the IAC and SPE clean-up procedures, respectively. Both methods comply with present regulations, but the MAX sample clean-up procedure should be used as an alternative, since the immunoaffinity column clean-up procedure is characterized by better reproducibility, accuracy, and efficiency.

  17. Acetonitrile extraction and dual-layer solid phase extraction clean-up for pesticide residue analysis in propolis.

    Science.gov (United States)

    Oellig, Claudia

    2016-05-06

    Propolis is a very complex mixture of substances that is produced by honey bees and is known to be a rather challenging matrix for residue analysis. Besides resins, flavonoids and phenols, high amount of wax is co-extracted resulting in immense matrix effects. Therefore a suitable clean-up is crucial and indispensable. In this study, a reliable solid phase extraction (SPE) clean-up was developed for pesticide residue analysis in propolis. The clean-up success was quickly and easily monitored by high-performance thin-layer chromatography with different detection possibilities. The final method consists of the extraction of propolis with acetonitrile according to the QuEChERS method followed by an effective extract purification on dual-layer SPE cartridges with spherical hydrophobic polystyrene-divinylbenzene resin/primary secondary amine as sorbent and a mixture of toluene/acetone (95:5, v/v) for elution. Besides fat-soluble components like waxes, flavonoids, and terpenoids, more polar compounds like organic acids, fatty acids, sugars and anthocyanins were also removed to large extent. Method performance was assessed by recovery experiments at spiking levels of 0.5 and 1mg/kg (n=5) for fourteen pesticides that are relevant for propolis. Mean recoveries determined by HPLC-MS against solvent standards were between 40 and 101%, while calculation against matrix-matched standards provided recoveries of 79-104%. Precision of recovery, assessed by relative standard deviations, were below 9%. Thus, the developed dual-layer SPE clean-up enables the reliable pesticide residue analysis in propolis and provides a suitable alternative to time-consuming clean-up procedures proposed in literature.

  18. The annual frequency of root fillings, tooth extractions and pulp-related procedures in Danish adults during 1977-2003

    DEFF Research Database (Denmark)

    Bjørndal, L.; Reit, C.

    2004-01-01

    endodontic epidemiology, frequency of root fillings, pulp capping, stepwise excavation, tooth extractions......endodontic epidemiology, frequency of root fillings, pulp capping, stepwise excavation, tooth extractions...

  19. Influence of processing procedure on the quality of Radix Scrophulariae: a quantitative evaluation of the main compounds obtained by accelerated solvent extraction and high-performance liquid chromatography.

    Science.gov (United States)

    Cao, Gang; Wu, Xin; Li, Qinglin; Cai, Hao; Cai, Baochang; Zhu, Xuemei

    2015-02-01

    An improved high-performance liquid chromatography with diode array detection combined with accelerated solvent extraction method was used to simultaneously determine six compounds in crude and processed Radix Scrophulariae samples. Accelerated solvent extraction parameters such as extraction solvent, temperature, number of cycles, and analysis procedure were systematically optimized. The results indicated that compared with crude Radix Scrophulariae samples, the processed samples had lower contents of harpagide and harpagoside but higher contents of catalpol, acteoside, angoroside C, and cinnamic acid. The established method was sufficiently rapid and reliable for the global quality evaluation of crude and processed herbal medicines.

  20. Determination of polychlorinated biphenyls and organochlorine pesticides in small volumes of human blood by high-throughput on-line SPE-LVI-GC-HRMS.

    Science.gov (United States)

    Wittsiepe, Jürgen; Nestola, Marco; Kohne, Matthias; Zinn, Peter; Wilhelm, Michael

    2014-01-15

    A fully automated and robust method featuring on-line solid-phase extraction (SPE) and large volume injection (LVI) gas chromatographic (GC) high resolution mass spectrometry (HRMS) is used to determine polychlorinated biphenyls (PCBs) and organochlorine pesticides, such as penta- and hexachlorobenzene (PeCBz, HxCBz), hexachlorocyclohexane isomers (HCH) and 4,4'-dichlorodiphenyldichloroethene (a metabolite of dichlorodiphenyltrichloroethane (DDT)), with only 200μl of human blood, serum or plasma. After spiking the sample with (13)C-labeled internal standards and precipitating the proteins, the sample is passed through a 10mm×2.0mm ID SPE cartridge filled with C18 material that adsorbs the analytes. After washing and drying, the cartridge is extracted with hexane/dodecane (99/1, v/v); the extract is directly injected into a LVI where GC/HRMS analysis follows. The fully automated system utilizes a robotic autosampler and a modular SPE system including two high-pressure syringe pumps, an automatic SPE cartridge exchanger unit and 6 switchable valves. All sample preparation steps are performed within 20min during the GC run of a previous sample, limiting the throughput with only the GC runtime. The contents are quantified using the isotope dilution method. Due to laboratory air contamination problems, we achieved LOQs of 0.017 (PeCBz), 0.009 (HxCBz), 0.007 (HCH), 0.016 (DDE), while for the six indicator PCBs, we achieved values of 0.030 (PCB-28), 0.044 (PCB-52), 0.024 (PCB-101), 0.009 (PCB-138), 0.015 (PCB-153) and 0.008 (PCB-180)μg/l serum. Under clean laboratory air conditions, these values may be improved. This method is recommended when high throughput is desirable and/or only small amounts of material are available, such as during studies involving children. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Fractionation of heavy metals in liquefied chromated copper arsenate 9-treated wood sludge using a modified BCR-sequential extraction procedure.

    Science.gov (United States)

    Pan, Hui; Hse, Chung-Yun; Gambrell, Robert; Shupe, Todd F

    2009-09-01

    Chromated copper arsenate (CCA)-treated wood was liquefied with polyethylene glycol/glycerin and sulfuric acid. After liquefaction, most CCA metals (98% As, 92% Cr, and 83% Cu) were removed from liquefied CCA-treated wood by precipitation with calcium hydroxide. The original CCA-treated wood and liquefied CCA-treated wood sludge were fractionated by a modified Community Bureau of Reference (BCR) sequential extraction procedure. The purpose of the BCR-sequential extraction used in this study was to examine the availability of CCA metals in treated wood for reuse. Both As and Cr had a slightly higher concentration in the sludge sample than in original CCA-treated wood. The sequential extraction showed that As and Cr were principally existed in an oxidizable fraction (As, 67%; Cr, 88%) in original CCA-treated wood. Only 1% of both As and Cr were extracted by hot nitric acid with the last extraction step. The distribution of As and Cr changed markedly in liquefied CCA-treated wood sludge. The amount of As in the exchangeable/acid extractable fraction increased from 16% to 85% while the amount of Cr increased from 3% to 54%. Only about 3% of As was present in the oxidizable fraction. However, there was still about 34% of Cr in the same fraction. Based on these results from sequential extraction procedures, it can be concluded that the accessibilities of CCA metals increase markedly by the liquefaction-precipitation process.

  2. Assessment of metal species in river Ganga sediment at Varanasi, India using sequential extraction procedure and SEM-EDS.

    Science.gov (United States)

    Pandey, Mayank; Pandey, Ashutosh Kumar; Mishra, Ashutosh; Tripathi, B D

    2015-09-01

    Aim of the present study was to assess impact of urban drains over river water and sediments by physico-chemical and metal analysis. Metal speciation (Sequential Extraction Procedure) and elemental composition analysis (SEM-EDS) was used to quantify metal pollution load in river sediments. Metal speciation analysis showed dominance of available and labile fractions of all heavy metals (Cr, Ni, Cu, Zn, Cd and Pb) except Mn and Fe which were dominant in residual forms. Cluster analysis (CA), Principal Components Analysis (PCA) and Partial Least Square Regression (PLSR) were applied as source receptor modeling for pollutants. Results classified river stretch into three zones i.e. moderately, severely and extremely polluted, on the basis of pollutant concentration released from anthropogenic sources. SEM-EDS study revealed the elemental composition percentage in river sediments. Pollution Load Index (PLI) varied from 1.8 (S1)-3.9 (S15). The Geo accumulation index (GAI) was found highest for Cd (6.88-8.97) and Pb (2.41-3.24).

  3. 信息动态%DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOIL BY ASE-GPC.SPE PURIFICATION AND HPLC DETECTION

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A new method using ASE combined with solid-phase extraction and GPC cleanup followed by HPLCtandem UV and fluorescence detection has been established for the quantitative determination of 16 PAHs in soils. In the method, the samples were extracted by ASE with acetone: dichloromethane (V:V, 50:50 )at 120 ℃, and dissolved in 9 mL hexane: ethyl acetate ( V: V, 50:50 ) after taking the extract to dryness with evaporation at 25 ℃. Then the extract was injected into GPC column with hexane:ethyl acetate( V: V,50:50)as the mobile phase at a flow rate of 5 mL·min-1 and GPC vacuum was 130 mbr/140 mbr. The 1340-3380 s fraction was collected for subsequent analysis. The portions collected from GPC were dissolved in 2 mL dichloromethane after taking the extract to dryness with nitrogen gas. Then the 2 mL extractions were purified by SPE using Florisil cartridges, eluted with 5 mL dichloromethane. Finally, the extraction was collected from SPE and dissolved in acetonitrile after taking it to dryness with nitrogen gas. The correlation coefficient of each PAH was r2 >0.99, the recovery fell within 62.9%-118.9%, and the relative standard derivation of PAHs was between 0.6% and 19.9%.

  4. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/....

  5. Highly specific purification of N-glycans using phosphate-based derivatization as an affinity tag in combination with Ti{sup 4+}-SPE enrichment for mass spectrometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying [Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Key Laboratory of Glycoconjugates Research Ministry of Public Health, Fudan University, Shanghai 200032 (China); Peng, Ye; Bin, Zhichao [Department of Chemistry, Fudan University, Shanghai 200032 (China); Wang, Huijie [Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Lu, Haojie, E-mail: luhaojie@fudan.edu.cn [Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Department of Chemistry, Fudan University, Shanghai 200032 (China); Key Laboratory of Glycoconjugates Research Ministry of Public Health, Fudan University, Shanghai 200032 (China)

    2016-08-31

    N-linked protein glycosylation is involved in regulation of a wide variety of cellular processes and associated with numerous diseases. Highly specific identification of N-glycome remains a challenge while its biological significance is acknowledged. The relatively low abundance of glycan in complex biological mixtures, lack of basic sites for protonation, and suppression by other highly abundant proteins/peptides lead to the particularly poor detection sensitivity of N-glycans in the MS analysis. Therefore, the highly specific purification procedure becomes a crucial step prior to MS analysis of the N-glycome. Herein, a novel N-glycans enrichment approach based on phosphate derivatization combined with Ti{sup 4+}-SPE (solid phase extraction) was developed. Briefly, in this strategy, N-glycans were chemically labeled with a phospho-group at their reducing ends, such that the Ti{sup 4+}-SPE microspheres were able to capture the phospho-containing glycans. The enrichment method was developed and optimized using model oligosaccharides (maltoheptaose DP7 and sialylated glycan A1) and also glycans from a standard glycoprotein (asialofetuin, ASF). This method experimentally showed high derivatization efficiency (almost 100%), excellent selectivity (analyzing DP7 in the digests of bovine serum albumin at a mass ratio of 1:100), high enriching recovery (90%), good reproducibility (CV<15%) as well as high sensitivity (LOD at fmol level). At last, the proposed method was successfully applied in the profiling of N-glycome in human serum, in which a total of 31 N-glycan masses were identified. - Graphical abstract: A selective enrichment method for the N-glycome is reported. N-glycans were chemically labeled with a phosphate derivatization reagent (AMS), then the phospho-containing glycans were enriched using Ti{sup 4+}-microspheres. - Highlights: • A highly specific N-glycans purification method based on phosphate derivatization combined with Ti{sup 4+}-SPE was developed

  6. Quantification of neonicotinoid insecticide residues in soils from cocoa plantations using a QuEChERS extraction procedure and LC-MS/MS

    DEFF Research Database (Denmark)

    Dankyi, Enock; Gordon, Christopher; Carboo, Derick

    2014-01-01

    of neonicotinoids in the environment extremely important. The present study was aimed at assessing the levels of five major neonicotinoids in soils from cocoa farmlands in Ghana. Extraction and cleanup of analytes were performed by use of a method based on the original QuEChERS procedure after optimizing salts...

  7. Dispersive liquid-liquid microextraction coupled with dispersive micro-solid-phase extraction for the fast determination of polycyclic aromatic hydrocarbons in environmental water samples.

    Science.gov (United States)

    Shi, Zhi-Guo; Lee, Hian Kee

    2010-02-15

    A new two-step microextraction technique, combining dispersive liquid-liquid microextraction (DLLME) and dispersive microsolid-phase extraction (D-micro-SPE), was developed for the fast gas chromatographic-mass spectrometric determination of polycyclic aromatic hydrocarbons (PAHs) in environmental samples. A feature of the new procedure lies in that any organic solvent immiscible with water can be used as extractant in DLLME. A special apparatus, such as conical-bottom test tubes, and tedious procedures of centrifugation, refrigeration of the solvent, and then thawing it, associated with classical DLLME or similar techniques are not necessary in the new procedure, which potentially lends itself to possible automation. In the present D-micro-SPE approach, hydrophobic magnetic nanoparticles were used to retrieve the extractant of 1-octanol in the DLLME step. It is noteworthy that the target of D-micro-SPE was the 1-octanol rather than the PAHs. Because of the rapid mass transfer associated with the DLLME and the D-micro-SPE steps, fast extraction could be achieved. Parameters affecting the extraction efficiency were investigated in detail. The optimal conditions were as follows: vortex at 3200 rpm in the DLLME step for 2 min and in D-micro-SPE for 1 min and then desorption by sonication for 4 min with acetonitrile as the solvent. The results demonstrated that enrichment factors ranging from 110- to 186-fold were obtained for the analytes. The limits of detection and the limits of quantification were in the range of 11.7-61.4 pg/mL and 0.04-0.21 ng/mL, respectively. The linearities were 0.5-50, 1-50, or 2-50 ng/mL for different PAHs. Finally, the two-step extraction method was successfully used for the fast determination of PAHs in river water samples. This two-step method, combining two different and efficient miniaturized techniques, provides a fast means of sample pretreatment for environmental water samples.

  8. Analyses of Indole Compounds in Sugar Cane (Saccharum officinarum L. Juice by High Performance Liquid Chromatography and Liquid Chromatography-Mass Spectrometry after Solid-Phase Extraction

    Directory of Open Access Journals (Sweden)

    Jean Wan Hong Yong

    2017-03-01

    Full Text Available Simultaneous quantitative analysis of 10 indole compounds, including indole-3-acetic acid (IAA, one of the most important naturally occurring auxins and some of its metabolites, by high performance liquid chromatography (HPLC and liquid chromatography-mass spectrometry (LC-MS after solid-phase extraction (SPE was reported for the first time. The analysis was carried out using a reverse phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid modified by methanol. Furthermore, a novel SPE procedure was developed for the pre-concentration and purification of indole compounds using C18 SPE cartridges. The combination of SPE, HPLC, and LC-MS was applied to screen for the indole compounds present in sugar cane (Saccharum officinarum L. juice, a refreshing beverage with various health benefits. Finally, four indole compounds were successfully detected and quantified in sugar cane juice by HPLC, which were further unequivocally confirmed by LC-MS/MS experiments operating in the multiple reaction monitoring (MRM mode.

  9. Determination of heavy metals and their speciation in street dusts by inductively coupled plasma-optical emission spectrometry after a Community Bureau of Reference sequential extraction procedure.

    Science.gov (United States)

    Altundag, Huseyin; Imamoglu, Mustafa; Doganci, Secil; Baysal, Erkan; Albayrak, Sinem; Tuzen, Mustafa

    2013-01-01

    Sequential selective extraction techniques are commonly used to fractionate the solid-phase forms of metals in soils. This procedure provides measurements of extractable metals from media, such as acetic acid (0.11 M), hydroxyl ammonium chloride (0.1 M), hydrogen peroxide (8.8 M) plus ammonium acetate (1 M), and aqua regia stages of the sequential extraction procedure. In this work, the extractable Pb, Cu, Mn, Sr, Ni, V, Fe, Zn, and Cr were evaluated in street dust samples from Sakarya, Turkey, between May and October 2009 using the three-step sequential extraction procedure described by the Community Bureau of Reference (BCR, now the Standards, Measurements, and Testing Programme) of the European Union. The sampling sites were divided into 10 categories; a total of 50 street dusts were analyzed. The determination of multielements in the samples was performed by inductively coupled plasma-optical emission spectrometry. Validation of the proposed method was performed using BCR 701 certified reference material. The results showed good agreement between the obtained and the certified values for the metals analyzed.

  10. Electrothermal atomic absorption spectrometric determination of vanadium in extracts of soil and sewage sludge certified reference materials after fractionation by means of the Communities Bureau of Reference modified sequential extraction procedure

    Science.gov (United States)

    Žemberyová, M.; Jankovič, R.; Hagarová, I.; Kuss, H.-M.

    2007-05-01

    A modified three-step sequential extraction procedure proposed by the Commission of European Communities Bureau of Reference (BCR) was applied to certified reference materials of three different soil groups (rendzina, luvisol, cambisol) and sewage sludge of different composition originating from a municipal water treatment plant in order to assess potential mobility and the distribution of vanadium in the resulting fractions. Analysis of the extracts was carried out by electrothermal atomic absorption spectrometry with Zeeman background correction using transversely heated graphite atomizers. Extracts showed significant matrix interferences which were overcome by the standard addition technique. The original soil and sludge certified reference materials (CRMs) and the extraction residue from the sequential extraction were decomposed by a mixture of HNO 3-HClO 4-HF in an open system. The content of V determined after decomposition of the samples was in very good agreement with the certified total values. The accuracy of the sequential extraction procedure was checked by comparing the sum of the vanadium contents in the three fractions and in the extraction residue with the certified total content of V. The amounts of vanadium leached were in good correlation with the certified total contents of V in the CRMs of soils and sewage sludge. In the soils examined, vanadium was present almost entirely in the mineral lattice, while in the sewage sludge samples 9-14% was found in the oxidizable and almost 25% in the reducible fractions. The recovery ranged from 93-106% and the precision (RSD) was below 10%.

  11. Ionic liquid based dispersive liquid-liquid microextraction coupled with micro-solid phase extraction of antidepressant drugs from environmental water samples.

    Science.gov (United States)

    Ge, Dandan; Lee, Hian Kee

    2013-11-22

    Ionic liquid-dispersive liquid-liquid microextraction combined with micro-solid phase extraction (IL-DLLME-μ-SPE), and high-performance liquid chromatography (HPLC) was developed for the determination of tricyclic antidepressants (TCAs) in water samples. Two hundred microliters of an organic solvent (as disperser solvent) and 20 μl of 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate were injected into a 5.0 ml sample for sonication-assisted DLLME. After this, a μ-SPE device, containing a novel material zeolite imidazolate framework 4 (ZIF-4), was added into the sample solution and 1 min of vortex-assisted extraction was performed. After 5 min of sonication-assisted desorption, 10 μl of desorption solvent was injected into a HPLC system for analysis. A characteristic property of DLLME-VA-μ-SPE is that any organic solvent and solid sorbent immiscible with water can be used. Special apparatus, or conical-bottom test tubes, and tedious procedures conventionally associated with DLLME such as centrifugation, or refrigeration of solvent are not necessary in the present approach. A novel material, ZIF-4 was employed as μ-SPE sorbent. Under the optimized conditions, the calibration curves were linear in the range of 1-1000 μg/L. The relative standard deviations and the limits of detection were in the range of 1.5% and 7.8% and 0.3 and 1 μg/L, respectively. The relative recoveries of canal water samples, spiked with drugs, were in the range of 94.3% and 114.7%. The results showed that IL-DLLME-μ-SPE was suitable for the determination of TCAs in water samples.

  12. Feasibility of the direct coupling of solid-phase extraction-pipette tips with a programmed-temperature vaporiser for gas chromatographic analysis of drugs in plasma

    NARCIS (Netherlands)

    van Hout, M.W J; van Egmond, W.M A; Franke, J.P.; de Zeeuw, R.A; de Jong, G.J.

    2002-01-01

    Solid-phase extraction-pipette tips (SPE-PTs) were used for micro solid-phase extraction of lidocaine and diazepam from plasma. Off-line extraction was followed by on-line desorption. On-line desorption was carried out by direct coupling of the SPE-PTs with the liner of the programmed-temperature va

  13. Clavibacter michiganensis subsp. michiganensis, Bacterial Canker of Tomato: 2. Comparison of the Effectiveness of Extraction Procedures and Sensitivity of Methods for Detection in Tomato Seeds

    Directory of Open Access Journals (Sweden)

    Svetlana Milijašević

    2007-01-01

    Full Text Available Two seed extraction procedures, used for detection of Clavibacter michiganensis subsp. michiganensis (Cmm in artifficially infested tomato seed lots, were evaluated. A comparison of the efficiency of pathogen detection by using different extraction methods showed that a grinding procedure was more effective than soaking seed samples. The extraction by grinding resulted in a higher number of samples with Cmm colonies than did the method that included soaking. The detection threshold of Cmm in relation to seed sample size wasevaluated by adding different numbers of artificially infested seeds to uninfected samples of 2000 or 5000 seeds. Four detection methods were simultaneously compared for their sensitivity in Cmm detection in seeds: isolation on semiselective media (mSCM, D2ANX, mCNS, direct PCR from seed material, Bio-PCR with initial culturing of bacteria on NBY agar prior to PCR, and Enrichment PCR. The pathogen was detected in samples of 2000 seeds containing one, five and ten infested seeds, in at least two out of three replicates by threedetection methods (selective plating, direct PCR and Bio-PCR, using the grinding extraction method with an addition of centrifugation step. In samples of 5000 seeds, five infested seeds were detected in all replicates by the same detection methods. Similar resultswere obtained by the soaking extraction method. In Enrichment PCR, positive results were obtained only in samples of 2000 seeds containing five and ten infested seeds regardless of the extraction method.

  14. Enantiomeric resolution of ibuprofen and flurbiprofen in human plasma by SPE-chiral HPLC methods.

    Science.gov (United States)

    Ali, Imran; Hussain, Iqbal; Saleem, Kishwar; Aboul-Enein, Hassan Y

    2012-07-01

    Chiral analysis of profens in human plasma is an important area of research due to different pharmaceutical activities of their enantiomers. The solid phase extraction of ibuprofen and flurbiprofen from human plasma was carried out on C18 cartridges by using phosphate buffer (50 mM, pH 6.0) followed by elution with methanol. Chiral-HPLC was performed on AmyCoat RP (150 mm x 46 mm, 3 μm particle size) column by using different combinations of water-acetonitrile-trifluoro acetic acid at 1.5 mLmin-1 flow rate. The detection was achieved at 236 and 254 nm for ibuprofen and flurbiprofen, respectively with 27±1°C as working temperature. The chromatographic parameters i.e. retention (k), separation (α) and resolution (Rs) factors ranged from 4.54-14.42, 1.10-1.30 and 1.01-1.49, respectively. The binding differences of enantiomers of ibuprofen and flurbiprofen were 4.4 and 5.2, respectively. These values suggest that S-(+)- enantiomer of flurbiprofen is more active than ibuprofen due to low enantiomeric difference of the later drug. The developed SPE-Chiral HPLC methods were validated, which are selective, efficient and reproducible.

  15. Reproducibility of the BCR sequential extraction procedure in a long-term study of the association of heavy metals with soil components in an upland catchment in Scotland.

    Science.gov (United States)

    Bacon, Jeffrey R; Hewitt, Irene J; Cooper, Patricia

    2005-01-20

    Humic iron podzol soils from three different plots at the Glensaugh Research Station, Aberdeenshire have been sampled on an annual basis since 1990 and analysed using both total digestion and the original BCR sequential extraction procedure. Particular care was required during the oxidation of these organic soils to prevent loss of material. The residue from the sequential extraction was analysed so that the values for total concentration derived from the total digestion and from the sum of the concentrations in the fractions of the extraction procedure could be compared. The comparison was good for all three soils indicating that not only did the sequential extraction give good recovery but that this was reproducible over a period of several years. The proportion of metals extractable at each step remained relatively constant thereby demonstrating the reproducibility of the procedure and the stability of the metals in the soils over the time scale of the sampling used. Whereas the total concentrations of Cr, Cu and Ni were highest in the soil from a roadside plot, this was not the case for Cd, Pb and Zn. In the case of Pb, concentrations in soils (0-25-cm depth) well away from the road were over 100 mg/kg and well above the expected background level. The distribution of metals between each of the extracted fractions varied not only between each metal but also between each of the three soils indicating that both metal and soil influenced the measured distribution. The distribution of Pb in the roadside soil was different from those in the other two soils and over 10% was extracted in the first, acetic acid soluble, fraction.

  16. Enhancement of Alcohol Metabolism by Sprouted Peanut Extract in SD Rats

    OpenAIRE

    Seo, Ji Yeon; Kim, Seong Soon; Kim, Jong-Sang

    2014-01-01

    Excessive ethanol intake is known to induce a number of physiological symptoms, including headache, dizziness and vertigo. In this study, we investigated the attenuation effect of sprouted peanut extract (SPE) on ethanol-induced hangover in male Sprague-Dawley rats. The animals were divided into five groups: the control group, which was administered ethanol only; the ethanol plus SPE experimental groups, which were administered ethanol and 100, 200, or 400 mg SPE/kg b.w.; and the positive con...

  17. Application of solid phase extraction with the use of silica modified with polyaniline film for pretreatment of samples from plant material before HPLC determination of triterpenic acids.

    Science.gov (United States)

    Sowa, Ireneusz; Wójciak-Kosior, Magdalena; Rokicka, Kamila; Kocjan, Ryszard; Szymczak, Grażyna

    2014-05-01

    The new sorbent based on silica gel coated with a film of polyaniline (Si-PANI) was obtained in a process of in situ polymerization directly on carrier particles and its potential application for pretreatment of plant material samples with the use of solid phase extraction (SPE) was investigated. Parameters such as cartridge conditioning, the volume and concentration of the sample, the type and volume of the elution solvent were optimized and compared with parameters obtained for RP-18 and aminopropyl silica cartridges. The high recovery values above 97% after the SPE procedure with the use of Si-PANI cartridges proves their utility for analysis of triterpenic acids. The sorbent tested was successfully used for clean-up of extracts from Salvia officinalis L., Syzygium aromaticum (L.) Merrill., and Origanum vulgare L. prior to HPLC-DAD determination of oleanolic, ursolic and betulinic acid. The efficiency of sample purification was verified by monitoring of chromatograms in the region between 190 nm and 400 nm during the gradient elution. The fewest components or their lowest concentrations were observed for all the investigated samples after the SPE procedures.

  18. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ziming, E-mail: wangziming@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  19. IRTF SpeX Observations of Orbital Object

    Science.gov (United States)

    Buckalew, B.; Abercromby, K.; Cowardin, H.

    Presented herein are the results of the Infrared Telescope Facility (IRTF) spectral observations of orbiting objects taken between 2006-2008. The data collected using the SpeX infrared spectrograph cover the wavelength range 1-8 ?m. Overall, data were collected on twenty different orbiting objects at or near the geosynchronous (GEO) regime. Four of the objects were controlled spacecraft, seven were non-controlled spacecraft, five were rocket bodies, and the final four were cataloged as debris pieces. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared focusing on features from hydrocarbons due to paint, silicon, and the beginning of thermal emission from the debris itself. The spacecraft, both the controlled and non-controlled, show distinct features due to solar panels while the rocket bodies do not. The variations in signature between the types of rocket bodies show a presence of metals instead of solar panels showing that one can distinguish most spacecraft from rocket bodies through the infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give an excellent idea as to the materials on the surface of the objects. Further remote data collection as well as updating the models to include noise, surface roughness, and material degradation is necessary to make a better assessment of material types. However, based on the current state of the comparison between the observations and the laboratory data, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft, rocket bodies, or debris.

  20. The optimization of essential oils supercritical CO2 extraction from Lavandula hybrida through static-dynamic steps procedure and semi-continuous technique using response surface method.

    Science.gov (United States)

    Kamali, Hossein; Aminimoghadamfarouj, Noushin; Golmakani, Ebrahim; Nematollahi, Alireza

    2015-01-01

    The aim of this study was to examine and evaluate crucial variables in essential oils extraction process from Lavandula hybrida through static-dynamic and semi-continuous techniques using response surface method. Essential oil components were extracted from Lavandula hybrida (Lavandin) flowers using supercritical carbon dioxide via static-dynamic steps (SDS) procedure, and semi-continuous (SC) technique. Using response surface method the optimum extraction yield (4.768%) was obtained via SDS at 108.7 bar, 48.5°C, 120 min (static: 8×15), 24 min (dynamic: 8×3 min) in contrast to the 4.620% extraction yield for the SC at 111.6 bar, 49.2°C, 14 min (static), 121.1 min (dynamic). The results indicated that a substantial reduction (81.56%) solvent usage (kg CO2/g oil) is observed in the SDS method versus the conventional SC method.

  1. An improved protocol and a new grinding device for extraction of genomic DNA from microorganisms by a two-step extraction procedure.

    Science.gov (United States)

    Zhang, S S; Chen, D; Lu, Q

    2012-05-21

    Current protocols to extract genomic DNA from microorganisms are still laborious, tedious and costly, especially for the species with thick cell walls. In order to improve the effectiveness of extracting DNA from microbial samples, a novel protocol, defined as two-step extraction method, along with an improved tissue-grinding device, was developed. The protocol included two steps, disruption of microbial cells or spores by grinding the sample together with silica sand in a new device and extraction of DNA with an effective buffer containing cell lysis chemicals. The device was prepared by using a commercial electric mini-grinder, adapted with a grinding stone, and a sample cup processed by lathing from a polytetrafluoroethylene rod. We tested the method with vegetative cells of four microbial species and two microbial spores that have thick cell walls and are therefore hard to process; these included Escherichia coli JM109, Bacillus subtilis WB600, Sacchromyces cerevisiae INVSc1, Trichoderma viride AS3.3711, and the spores of S. cerevisiae and T. viride, respectively, representing Gram-positive bacteria, Gram-negative bacteria, yeast, filamentous fungi. We found that this new method and device extracted usable quantities of genomic DNA from the samples. The DNA fragments that were extracted exceeded 23 kb. The target sequences up to about 5 kb were successfully and exclusively amplified by PCR using extracted DNA as the template. In addition, the DNA extraction was finalized within 1.5 h. Thus, we conclude that this two-step extraction method is an effective and improved protocol for extraction of genomic DNA from microbial samples.

  2. Pre-shot simulations of far-field ground motion for the Source Physics Experiment (SPE) Explosions at the Climax Stock, Nevada National Security Site: SPE2

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R J; Rodgers, A; Walter, W; Ford, S; Xu, H; Matzel, E; Myers, S; Petersson, N A; Sjogreen, B; Hauk, T; Wagoner, J

    2011-10-18

    The Source Physics Experiment (SPE) is planning a 1000 kg (TNT equivalent) shot (SPE2) at the Nevada National Security Site (NNSS) in a granite borehole at a depth (canister centroid) of 45 meters. This shot follows an earlier shot of 100 kg in the same borehole at a depth 60 m. Surrounding the shotpoint is an extensive array of seismic sensors arrayed in 5 radial lines extending out 2 km to the north and east and approximately 10-15 to the south and west. Prior to SPE1, simulations using a finite difference code and a 3D numerical model based on the geologic setting were conducted, which predicted higher amplitudes to the south and east in the alluvium of Yucca Flat along with significant energy on the transverse components caused by scattering within the 3D volume along with some contribution by topographic scattering. Observations from the SPE1 shot largely confirmed these predictions although the ratio of transverse energy relative to the vertical and radial components was in general larger than predicted. A new set of simulations has been conducted for the upcoming SPE2 shot. These include improvements to the velocity model based on SPE1 observations as well as new capabilities added to the simulation code. The most significant is the addition of a new source model within the finite difference code by using the predicted ground velocities from a hydrodynamic code (GEODYN) as driving condition on the boundaries of a cube embedded within WPP which provides a more sophisticated source modeling capability linked directly to source site materials (e.g. granite) and type and size of source. Two sets of SPE2 simulations are conducted, one with a GEODYN source and 3D complex media (no topography node spacing of 5 m) and one with a standard isotropic pre-defined time function (3D complex media with topography, node spacing of 5 m). Results were provided as time series at specific points corresponding to sensor locations for both translational (x,y,z) and rotational

  3. UA-SPE-HPLC快速分离法测定乳饮料中的硫氰酸钠的研究%Ultrasonic-assisted Solid Phase Extraction for Separation and Determination of Sodium Thiocyanate in Dairy Beverage by High Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    张丽媛; 姚笛; 贾鹏宇; 王颖; 李秀波

    2014-01-01

    建立超声辅助萃取-固相净化-高效液相色谱法测定乳饮料中硫氰酸钠的方法,重点研究了乳饮料的样品前处理方法,采用乙腈加三氯乙酸作为蛋白沉淀剂,有效实现对各类乳饮料的样品中蛋白质的沉淀和硫氰酸钠的提取。方法在0.05~50 mg·kg-1具有良好的线性关系,硫氰酸钠的日内精密度3.29%~5.56%,日间精密度4.32%~6.45%;不同乳饮料的回收率范围变化为87.73%~106.37%。此方法中硫氰酸钠检出限是0.024 mg·kg-1。%Ultrasonic-assisted solid phase extraction method was developed to determine sodium thiocyanate of dairy beverage by high-performance liquid chromatography,which studied importantly the sample pretreatment. Using acetonitrile and trichloroacetic acid as precipitate protein, the precipitate protein and extraction of the sodium thiocyanate contaminant could be achieved effectively,and the calibration curve was linear in the range of 0.05-50 mg·kg-1,intra-day precision of 3.29%to 5.56%,inter-day precision of sodium thiocyanate of 4.32% to 6.45% and the recoveries of different dairy beverage range of 87.73% to 106.37%. Sodium thiocyanate of detection limits was 0.024 mg·kg-1 by this method .

  4. MULTILEVEL MONTE CARLO (MLMC) SIMULATIONS: PERFORMANCE RESULTS FOR SPE10 (XY SLICES)

    Energy Technology Data Exchange (ETDEWEB)

    Kalchev, Delyan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-02-26

    In this report we first describe a generic multilevel Monte Carlo method and then illustrate its superior performance over a traditional single-level Monte Carlo method for second order elliptic PDEs corresponding to two-dimensional layers in (x, y)-direction of the Tenth SPE Comparative Solution project (SPE 10) which gives high-contrast permeability coefficients. The SPE10 data set is used as a coarse level in the Monte Carlo method and the respective permeability coefficient k (provided in the SPE10 dataset) is used as a mean in the simulation. The actual coefficients are drawn based on a KL-expansion assuming that the log-mean is perturbed by a log-normal distributed samples.

  5. Reflection processing of the large-N seismic data from the Source Physics Experiment (SPE)

    Energy Technology Data Exchange (ETDEWEB)

    Paschall, Olivia C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-18

    The purpose of the SPE is to develop a more physics-based model for nuclear explosion identification to understand the development of S-waves from explosion sources in order to enhance nuclear test ban treaty monitoring.

  6. Study of extraction procedures for protein analysis in plankton samples by OFFGEL electrophoresis hyphenated with Lab-on-a-chip technology.

    Science.gov (United States)

    García-Otero, Natalia; Barciela-Alonso, Ma Carmen; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

    2013-10-15

    Extraction procedures for protein analysis from plankton samples were studied. OFFGEL electrophoresis combined with Lab-on-a-chip technology has been applied for protein analysis in plankton samples. BCR-414 (plankton) certified reference material from the European Commission was used to evaluate the protein extraction procedures. Three protein extraction procedures were studied: (1) by using Tris-HCl buffer containing a protease inhibitor cocktail, (2) urea/triton X-100 buffer extraction, and (3) using the phenol/sodium dodecyl sulphate method after different washing steps with 10% trichloroacetic acid/acetone solution and methanol. The pellet of proteins obtained was dried and then dissolved in the OFFGEL buffer. Proteins were separated according to their isoelectric points by OFFGEL electrophoresis. This separation was performed using 24 cm, pH 3-10 IPG Dry Strips. The proteins present in each liquid fraction (24 fractions) were separated according to their molecular weight using a microfluidic Lab-on-a-chip electrophoresis with the Protein 80 LabChip kit. This kit allows for the separation of proteins with a molecular weight ranging from 5 to 80 kDa. Taking into account the intensity and the number of the protein bands obtained, the protein extraction procedure using the phenol/sodium dodecyl sulphate after different wash steps with 10% trichloroacetic acid/acetone solution was selected. The developed method was applied for protein determination in a fresh marine plankton sample. The proteins found in this sample have a molecular weight ranging from 6.4 to 57.3 kDa, and the proteins with highest molecular weight were in the OFFGEL fractions with an isoelectric point ranging from 4.40 to 8.60. The concentration of proteins were calculated using external calibration with Bovine Serum Albumin, and the protein concentrations varied from 50.0 to 925.9 ng µL(-1).

  7. Optimization of Ultrasound-assisted Extraction Procedure to Determine Astaxanthin in Xanthophyllomyces dendrorhous by Box-Behnken Designn

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-11-01

    Full Text Available An ultrasonic-assisted extraction method has been developed for the effective extraction of astaxanthin from Xanthophyllomyces dendrorhous. Single-factor experiment design was employed to optimize the disruption temperature, disruption time, ethanol concentration, extraction time. The ethanol concentration was 60% ethanol in ethyl lactate and temperature for disrupting (40-60°C, time for disrupting extraction time (15-35 min, extraction time (20-40 min were used for further optimization of extraction conditions. The optimal conditions for the ultrasound-assisted extraction of astaxanthin were determined using Response Surface Methodology (RSM by Box-Behnken design. The optimal extraction conditions were that the yeast was disrupted at 49.08°C for 26.09 min under ultrasound irradiation of 200 W and then extracted for 32.43 min. Under optimal conditions, the astaxanthin content was 1472.85±43.64 &mug/g DW. This study introduces a simple, green and highly efficient method for extraction of astaxanthin fromX. dendrorhous

  8. Development of sample preparation method for auxin analysis in plants by vacuum microwave-assisted extraction combined with molecularly imprinted clean-up procedure.

    Science.gov (United States)

    Hu, Yuling; Li, Yuanwen; Zhang, Yi; Li, Gongke; Chen, Yueqin

    2011-04-01

    A novel sample preparation method for auxin analysis in plant samples was developed by vacuum microwave-assisted extraction (VMAE) followed by molecularly imprinted clean-up procedure. The method was based on two steps. In the first one, conventional solvent extraction was replaced by VMAE for extraction of auxins from plant tissues. This step provided efficient extraction of 3-indole acetic acid (IAA) from plant with dramatically decreased extraction time, furthermore prevented auxins from degradation by creating a reduced oxygen environment under vacuum condition. In the second step, the raw extract of VMAE was further subjected to a clean-up procedure by magnetic molecularly imprinted polymer (MIP) beads. Owing to the high molecular recognition ability of the magnetic MIP beads for IAA and 3-indole-butyric acid (IBA), the two target auxins in plants can be selectively enriched and the interfering substance can be eliminated by dealing with a magnetic separation procedure. Both the VMAE and the molecularly imprinted clean-up conditions were investigated. The proposed sample preparation method was coupled with high-performance liquid chromatogram and fluorescence detection for determination of IAA and IBA in peas and rice. The detection limits obtained for IAA and IBA were 0.47 and 1.6 ng/mL and the relative standard deviation were 2.3% and 2.1%, respectively. The IAA contents in pea seeds, pea embryo, pea roots and rice seeds were determined. The recoveries were ranged from 70.0% to 85.6%. The proposed method was also applied to investigate the developmental profiles of IAA concentration in pea seeds and rice seeds during seed germination.

  9. Phenotypic comparison of samdc and spe mutants reveals complex relationships of polyamine metabolism in Ustilago maydis.

    Science.gov (United States)

    Valdés-Santiago, Laura; Cervantes-Chávez, José Antonio; Winkler, Robert; León-Ramírez, Claudia G; Ruiz-Herrera, José

    2012-03-01

    Synthesis of spermidine involves the action of two enzymes, spermidine synthase (Spe) and S-adenosylmethionine decarboxylase (Samdc). Previously we cloned and disrupted the gene encoding Spe as a first approach to unravel the biological function of spermidine in Ustilago maydis. With this background, the present study was designed to provide a better understanding of the role played by Samdc in the regulation of the synthesis of this polyamine. With this aim we proceeded to isolate and delete the gene encoding Samdc from U. maydis, and made a comparative analysis of the phenotypes of samdc and spe mutants. Both spe and samdc mutants behaved as spermidine auxotrophs, and were more sensitive than the wild-type strain to different stress conditions. However, the two mutants displayed significant differences: in contrast to spe mutants, samdc mutants were more sensitive to LiCl stress, high spermidine concentrations counteracted their dimorphic deficiency, and they were completely avirulent. It is suggested that these differences are possibly related to differences in exogenous spermidine uptake or the differential location of the respective enzymes in the cell. Alternatively, since samdc mutants accumulate higher levels of S-adenosylmethionine (SAM), whereas spe mutants accumulate decarboxylated SAM, the known opposite roles of these metabolites in the processes of methylation and differentiation offer an additional attractive hypothesis to explain the phenotypic differences of the two mutants, and provide insights into the additional roles of polyamine metabolism in the physiology of the cell.

  10. An automated and simultaneous solid-phase extraction of delta 9-tetrahydrocannabinol and 11-nor-9-carboxy-delta 9-tetrahydrocannabinol from whole blood using the Zymark RapidTrace with confirmation and quantitation by GC-EI-MS.

    Science.gov (United States)

    D'Asaro, J A

    2000-01-01

    A sensitive, reliable, and automated solid-phase extraction (SPE) method was developed for the simultaneous extraction, confirmation, and quantitation of delta9-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-delta9-tetrahydrocannabinol (THCCOOH) from whole blood. The extraction was performed on the Zymark RapidTrace SPE Workstation with a reduced solvent volume SPE copolymer cartridge. Quantitative analysis was completed on a benchtop gas chromatograph-mass spectrometer using electron ionization mode with selected ion monitoring of three ions for each analyte. The limits of quantitation for THC and THCCOOH were 2 ng/mL and 1 ng/mL, respectively. The limits of detection for THC and THCCOOH were 1.6 ng/mL and 0.8 ng/mL, respectively. Extensive method validation is presented including extraction recoveries, within-run precision, day-to-day precision, linearity, and carryover. This procedure is used routinely in the laboratory on blood samples screened positive for cannabinoids.

  11. A Rapid Centrifugation-Assisted Solid-Phase Extraction and Liquid Chromatography Method for Determination of Loureirin A and Loureirin B of Dragon's Blood Capsules in Rat Plasma and Urine After Oral Administration.

    Science.gov (United States)

    Chen, Xiaoshuang; Li, Gaofeng; Ma, Shangfang; Hu, Xujia

    2015-07-01

    A simple, sensitive and rapid centrifugation-assisted solid-phase extraction (SPE) with high-performance liquid chromatography (SPE-HPLC) method was developed for simultaneous determination of the metabolites loureirin A and loureirin B from Dragon's blood in rat plasma and urine. The development of the extraction procedure included optimization of some important extraction phases. After evaluation, the metabolites of Dragon's blood were extracted by centrifugation-assisted SPE and separated by using HPLC. This method showed good linearity (r(2) > 0.99), and in the rat plasma and urine, the recoveries were 93.1 and 95.7% for loureirin A and were 90.1 and 94.2% for loureirin B. The relative standard deviation (RSD) values of intraday and interday precision in rat plasma and urine for loureirin A were <3.84 and 2.01%, respectively. The RSD values of the intraday and interday precision in rat plasma and urine for loureirin B were below 4.25 and 5.83%, respectively. Thus, the established method is suitable for metabolism studies of loureirin A and loureirin B in rat plasma and urine. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Introduction of agarose gel as a green membrane in electromembrane extraction: An efficient procedure for the extraction of basic drugs with a wide range of polarities.

    Science.gov (United States)

    Tabani, Hadi; Asadi, Sakine; Nojavan, Saeed; Parsa, Mitra

    2017-05-12

    Developing green methods for analyte extraction is one of the most important topics in the field of sample preparation. In this study, for the first time, agarose gel was used as membrane in electromembrane extraction (EME) without using any organic solvent, for the extraction of four model basic drugs (rivastigmine (RIV), verapamil (VER), amlodipine (AML), and morphine (MOR)) with a wide polarity window (log P from 0.43 to 3.7). Different variables playing vital roles in the proposed method were evaluated and optimized. As a driving force, a 25V electrical field was applied to make the analyte migrate from sample solution with pH 7.0, through the agarose gel 3% (w/v) with 5mm thickness, into an acceptor phase (AP) with pH 2.0. The best extraction efficiency was obtained with an extraction duration of 25min. With this new methodology, MOR with high polarity (log P=0.43) was efficiently extracted without using any carrier or ion pair reagents. Limits of detection (LODs) and quantification (LOQs) were in the ranges of 1.5-1.8ngmL(-1) and 5.0-6.0ngmL(-1), respectively. Finally, the proposed method was successfully applied to determine concentrations of the model drugs in the wastewater sample. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Metal speciation of environmental samples using SPE and SFC-AED analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, S.C.; Burford, M.D.; Robson, M. [Leeds Univ. (United Kingdom)] [and others

    1995-12-31

    Due to growing public concern over heavy metals in the environment, soil, water and air particulate samples azre now routinely screened for their metal content. Conventional metal analysis typically involves acid digestion extraction and results in the generation of large aqueous and organic solvent waste. This harsh extraction process is usually used to obtain the total metal content of the sample, the extract being analysed by atomic emission or absorption spectroscoply techniques. A more selective method of metal extraction has been investigated which uses a supercritical fluid modified with a complexing agent. The relatively mild extraction method enables both organometallic and inorganic metal species to be recovered intact. The various components from the supercritical fluid extract can be chromatographically separated using supercritical fluid chromatography (SFC) and positive identification of the metals achieved using atomic emission detection (AED). The aim of the study is to develop an analytical extraction procedure which enables a rapid, sensitive and quantitative analysis of metals in environmental samples, using just one extraction (eg SFE) and one analysis (eg SFC-AED) procedure.

  14. Development of a selective solid phase extraction method for nitro musk compounds in environmental waters using a molecularly imprinted sorbent.

    Science.gov (United States)

    Lopez-Nogueroles, Marina; Lordel-Madeleine, Sonia; Chisvert, Alberto; Salvador, Amparo; Pichon, Valérie

    2013-06-15

    A powerful analytical method for the determination of the family of the nitro musk compounds at trace level in environmental waters-river, sea, and water from a treatment plant-is presented. The method is based on the use of molecularly imprinted silica (MIS) as sorbent for solid phase extraction (SPE) used for the clean-up and the concentration step of the target analytes previous to their determination by gas chromatography-mass spectrometry. The optimized extraction procedure allowed extraction recoveries between 61% and 87% using the MIS. The comparison with a non-imprinted silica (NIS) sorbent, for which extraction recoveries between 8% and 26% were obtained, showed the high selectivity of the MIS for the nitro musks. Moreover, high enrichment factors, ranging between 580 and 827, were achieved. The imprinted sorbent was compared to a conventional polymeric SPE sorbent for the extraction of the target compounds from environmental waters, showing high selectivity of the MIS and its clean-up potential. For the first time, the five nitro musk compounds were selectively extracted with an imprinted material.

  15. Analytical performance of two miniaturised extraction methods for triclosan and methyltriclosan, in fish roe and surimi samples.

    Science.gov (United States)

    Gonzalo-Lumbreras, R; Sanz-Landaluze, J; Cámara, C

    2014-03-01

    A new and reliable miniaturised QuEChERS-based extraction method combined with a dispersive SPE cleanup procedure for extracting triclosan and methyltriclosan from fish roe and surimi samples was proposed. The effectiveness of different extraction/partition conditions for QuEChERS method was systematically investigated, and the use of acetonitrile extraction solvent and MgSO4, PSA, C18 and Florisil as cleanup reagents was recommended in the final method. Other method based on ultrasonic extraction with ethylacetate and clean-up with SPE was also evaluated for these samples. Different polymeric and silica sorbents for clean up were tested and the combination of Florisil and PSA was finally selected. The performance of these miniaturised sample preparation methods combined with GC-MS with quadrupole detection were compared. Extraction efficiency as well as cleaning effectiveness, laboriousness and speed were taken as criteria for method evaluation. Satisfactory validation parameters, such as linearity, recovery, precision and LODs and LOQs for both developed analytical methods were obtained from fish roe and surimi samples. Finally, both methods were applied to real samples. The sensitivity of the proposed methods was good enough to ensure reliable determination of target analytes at concentration levels commonly found in this kind of samples.

  16. Determination of acrylamide in coffee and coffee products by GC-MS using an improved SPE clean-up.

    Science.gov (United States)

    Soares, C; Cunha, S; Fernandes, J

    2006-12-01

    An improved gas chromatography-mass spectrometry (GC-MS) method to determine acrylamide (AA) in coffee and coffee products was developed. The method was based on two main purification steps: the first with ethanol and Carrez solutions in order to precipitate polysaccharides and proteins, respectively; and the second with a layered solid-phase extraction (SPE) column which proved to be efficient in the elimination of the main chromatographic interferences. The method is applicable to a wide range of coffee products. Twenty-six samples of different coffee products were analysed. The levels of AA were in the range 11.4-36.2 microg l-1 for 'espresso coffee' and 200.8-229.4 microg l-1 for coffee blends with cereals. The results indicate that the presence of cereals significantly increased the levels of AA.

  17. Análise de fármacos em águas por SPE-UPLC-ESI-MS/MS

    Directory of Open Access Journals (Sweden)

    Vanessa de Jesus Gaffney

    2014-01-01

    Full Text Available A method was developed for the analysis of 31 pharmaceutical compounds in Lisbon's drinking water system, using solid-phase extraction (SPE and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS. The method was validated through estimation of the linearity range, method detection and quantification limits, matrix effects, precision and accuracy. The method detection and quantification limit ranges were 0.009-10 and 0.03-33 ng/L, respectively. Analytes were quantified in water samples collected from the EPAL (Empresa Portuguesa das Águas Livres S.A. supply system. Carbamazepine, atenolol, sulfadiazine, sulfamethazine, sulfapyridine, sulfamethoxazole, acetaminophen, caffeine and erythromycin were quantified in the analysed samples.

  18. Effective determination of a pharmaceutical, sulpiride, in river water by online SPE-LC-MS using a molecularly imprinted polymer as a preconcentration medium.

    Science.gov (United States)

    Kubo, Takuya; Kuroda, Kenta; Tominaga, Yuichi; Naito, Toyohiro; Sueyoshi, Kenji; Hosoya, Ken; Otsuka, Koji

    2014-02-01

    We report an effective and a quantitative analysis method for one of pharmaceuticals, sulpiride, in river water by online solid phase extraction (SPE) connected with liquid chromatography-mass spectrometry (LC-MS) using a molecularly imprinted polymer as a preconcentration medium. The polymer prepared with a pseudo template molecule showed the selective retention ability based on the interval recognition of functional groups in sulpiride. Also, the imprinted polymer provided an effective concentration of a trace level of sulpiride in offline SPE with dual washing processes using water and acetonitrile, although another imprinted polymer prepared by an authentic method using sulpiride and methacrylic acid as a template and a functional monomer, respectively, showed the selective adsorption only in organic solvents. Furthermore, we employed the imprinted polymer as the preconcentration column of online SPE-LC-MS and the results supposed that the proposed system allowed the quantitative analysis of sulpiride with high sensitivity and recovery (10ng/L at 96%). Additionally, the determination of sulpiride in real river water without an additional spiking was effectively achieved by the system.

  19. A novel SPE-HPLC method for simultaneous determination of selected sulfonated phthalocyanine zinc complexes in mouse plasma following cassette dosing.

    Science.gov (United States)

    Jiang, Zhou; Shao, Jingwei; Chen, Meili; Wang, Jian; Jia, Lee

    2013-08-07

    Sulfonated phthalocyanine zinc complexes (ZnPcSn) are a mixture of polymolecules with different number of the sulfonic groups. They are typical photosensitizers for photodynamic therapy (PDT). Analysis of the sulfonic phthalocyanine complexes in blood is a global technical challenge to developing this kind of photosensitizers into clinics. To circumvent the problem, we aimed at developing a novel solid-phase extraction (SPE)-HPLC method, which was primarily composed of (1) the SPE material that has both the aliphatic benzene group and hydrophilic ethylenediamino group bonded to the silica surface typically for retaining those hydrophobic compounds with some degree of hydrophilic anionic (negatively charged) functionality; and (2) the RP-Amide C16 HPLC column packed with palmitamidopropylsilane for both reversed-phase and anion exchange separation. The method was validated in terms of recovery, precision and accuracy for pharmacokinetic study with the photosensitizer following its intravenous cassette dosing to mice. The present study is the first report on using an SPE-HPLC mode to simultaneously determine the phthalocyanine-based polymolecule photosensitizer in blood. The study will aid in clinical development of photosensitizers.

  20. Deparaffinization with mineral oil: a simple procedure for extraction of high-quality DNA from archival formalin-fixed paraffin-embedded samples.

    Science.gov (United States)

    Heikal, Nahla; Nussenzveig, Roberto H; Agarwal, Archana M

    2014-09-01

    Extracting DNA from formalin-fixed paraffin-embedded (FFPE) archival samples remains difficult. Successful polymerase chain reactions (PCR) with DNA extracted from FFPE samples is still very low. We extracted DNA from 12 recent and old archival FFPE bone marrow trephine biopsies by use of a simple protocol on the basis of deparaffinization with molecular biology-grade mineral oil followed by DNA extraction with the Qiagen FFPE kit. Comparison of this deparaffinization method with standard protocols, for example, xylene or Hemo-D with subsequent rehydration using graded ethanols, was investigated. The quality and quantity of extracted DNA were tested by a combination of ultraviolet spectroscopy, analysis on a Caliper LabChip GX, and real-time PCR combined with high-resolution melt analysis. Highest quality PCR-amplifiable DNA was obtained by deparaffinization with mineral oil, whereas more variable results were obtained for the other 2 deparaffinization procedures. This result was confirmed by real-time PCR and high-resolution melt analysis. Besides improvements in the quality of extracted DNA, use of mineral oil for deparaffinization has the added benefit of decreased time (20 vs. 75 min) and a significant reduction of hands-on labor (1 step vs. multiple hands-on centrifugation and decanting steps).

  1. Influence of the extraction procedure on the antioxidative activity of lentil seed extracts in a β-carotene-linoleate model system

    Directory of Open Access Journals (Sweden)

    Chavan, U.

    2001-04-01

    Full Text Available Phenolic compounds were extracted from lentil seeds using three solvent systems: 80% (v/v acetone, 80% (v/v methanol, and 80% (v/v ethanol. Each extract was subsequently separated into two fractions by chromatoghraphy on a column with Toyo Pearl HW-40 using water (fraction I and methanol (fraction II for elution. Antioxidative activity of extracts and their respective fractions were examined in a β-carotene-linoleate model system. All three extracts exhibited similar antioxidant activity. Considering the level of phenolic compounds in extracts it seems that phenolic compounds from the acetone extract were less active than those from either the methanolic and ethanolic ones. Because the content of phenolics was about 16-fold lower in fraction I of the methanolic and ethanolic extracts compared to fraction II, the phenolics in fraction I of the methanol and ethanol extracts from lentil seeds are much more active than these in fraction II. A stronger antioxidant activity of fraction I from the acetone extract compared to the crude acetone extract was observed during the latter incubation stage. The reason was a relatively high level of phenolic compounds in this fraction. UV spectra confirmed that the phenolic compounds from the acetone extract were different compared to methanolic and ethanolic extracts.Los compuestos fenólicos fueron extraídos de semillas de lenteja usando tres sistemas de disolventes: acetona del 80% (v/v, metanol del 80% (v/v, y etanol del 80% (v/v. Cada extracto fue separado posteriormente en dos fracciones por cromatografía en columna con Toyo Pearl HW-40 usando agua (fracción I y metanol (fracción II para la elución. La actividad antioxidante de los extractos y de sus fracciones respectivas fueron examinadas en un sistema modelo β-caroteno-linoleato. Los tres extractos exhibieron actividad antioxidante similar. Atendiendo al nivel de compuestos fenólicos en los extractos parece que los compuestos del extracto

  2. The Influence of DNA Extraction Procedure and Primer Set on the Bacterial Community Analysis by Pyrosequencing of Barcoded 16S rRNA Gene Amplicons.

    Science.gov (United States)

    Starke, Ingo C; Vahjen, Wilfried; Pieper, Robert; Zentek, Jürgen

    2014-01-01

    In this study, the effect of different DNA extraction procedures and primer sets on pyrosequencing results regarding the composition of bacterial communities in the ileum of piglets was investigated. Ileal chyme from piglets fed a diet containing different amounts of zinc oxide was used to evaluate a pyrosequencing study with barcoded 16S rRNA PCR products. Two DNA extraction methods (bead beating versus silica gel columns) and two primer sets targeting variable regions of bacterial 16S rRNA genes (8f-534r versus 968f-1401r) were considered. The SEED viewer software of the MG-RAST server was used for automated sequence analysis. A total of 5.2 × 10(5) sequences were used for analysis after processing for read length (150 bp), minimum sequence occurrence (5), and exclusion of eukaryotic and unclassified/uncultured sequences. DNA extraction procedures and primer sets differed significantly in total sequence yield. The distribution of bacterial order and main bacterial genera was influenced significantly by both parameters. However, this study has shown that the results of pyrosequencing studies using barcoded PCR amplicons of bacterial 16S rRNA genes depend on DNA extraction and primer choice, as well as on the manner of downstream sequence analysis.

  3. The Influence of DNA Extraction Procedure and Primer Set on the Bacterial Community Analysis by Pyrosequencing of Barcoded 16S rRNA Gene Amplicons

    Directory of Open Access Journals (Sweden)

    Ingo C. Starke

    2014-01-01

    Full Text Available In this study, the effect of different DNA extraction procedures and primer sets on pyrosequencing results regarding the composition of bacterial communities in the ileum of piglets was investigated. Ileal chyme from piglets fed a diet containing different amounts of zinc oxide was used to evaluate a pyrosequencing study with barcoded 16S rRNA PCR products. Two DNA extraction methods (bead beating versus silica gel columns and two primer sets targeting variable regions of bacterial 16S rRNA genes (8f-534r versus 968f-1401r were considered. The SEED viewer software of the MG-RAST server was used for automated sequence analysis. A total of 5.2×105 sequences were used for analysis after processing for read length (150 bp, minimum sequence occurrence (5, and exclusion of eukaryotic and unclassified/uncultured sequences. DNA extraction procedures and primer sets differed significantly in total sequence yield. The distribution of bacterial order and main bacterial genera was influenced significantly by both parameters. However, this study has shown that the results of pyrosequencing studies using barcoded PCR amplicons of bacterial 16S rRNA genes depend on DNA extraction and primer choice, as well as on the manner of downstream sequence analysis.

  4. Evaluating the mobility of toxic metals in untreated industrial wastewater sludge using a BCR sequential extraction procedure and a leaching test.

    Science.gov (United States)

    Kazi, T G; Jamali, M K; Kazi, G H; Arain, M B; Afridi, H I; Siddiqui, A

    2005-09-01

    The distribution and speciation of toxic metals in industrial wastewater sludge (IWS) was investigated. In this work, the modified BCR three-stage sequential extraction procedure was applied to the fractionation of Cr Pb Ni, and Cd in untreated industrial wastewater sludge from industrial sites in Hyderabad (Pakistan). The extracts were analyzed using electrothermal atomic absorption spectrometry. The procedure was evaluated using a certified reference material for soil mixed with sewage sludge BCR 483. The results from the partitioning study indicate that more easily mobilized forms (acid exchangeable) of Cd were dominant. The oxidizable fraction was dominant for all four toxic metals. Metal recovery was good, with metal recovered through the extractant steps and the total metal determined after microwave digestion. Lixiviation tests (DIN 38414-S4) were used to evaluate the leaching of toxic species from IWS, and it was observed that levels of leachable toxic metals were low compared to the amount of metal extracted in the exchangeable fraction of the BCR protocol.

  5. Differences in SpeB protease activity among group A streptococci associated with superficial, invasive, and autoimmune disease.

    Science.gov (United States)

    Ly, Anhphan T; Noto, John P; Walwyn, Odaelys L; Tanz, Robert R; Shulman, Stanford T; Kabat, William; Bessen, Debra E

    2017-01-01

    The secreted cysteine proteinase SpeB is an important virulence factor of group A streptococci (GAS), whereby SpeB activity varies widely among strains. To establish the degree to which SpeB activity correlates with disease, GAS organisms were recovered from patients with pharyngitis, impetigo, invasive disease or acute rheumatic fever (ARF), and selected for analysis using rigorous sampling criteria; >300 GAS isolates were tested for SpeB activity by casein digestion assays, and each GAS isolate was scored as a SpeB-producer or non-producer. Highly significant statistical differences (p < 0.01) in SpeB production are observed between GAS recovered from patients with ARF (41.5% SpeB-non-producers) compared to pharyngitis (20.5%), invasive disease (16.7%), and impetigo (5.5%). SpeB activity differences between pharyngitis and impetigo isolates are also significant, whereas pharyngitis versus invasive isolates show no significant difference. The disproportionately greater number of SpeB-non-producers among ARF-associated isolates may indicate an altered transcriptional program for many rheumatogenic strains and/or a protective role for SpeB in GAS-triggered autoimmunity.

  6. SPE coupled with dispersive liquid-liquid microextraction followed by GC with flame ionization detection for the determination of ultra-trace amounts of benzodiazepines.

    Science.gov (United States)

    Ghobadi, Masoomeh; Yamini, Yadollah; Ebrahimpour, Behnam

    2014-02-01

    SPE combined with dispersive liquid-liquid microextration was used for the extraction of ultra-trace amounts of benzodiazepines (BZPs) including, diazepam, midazolam, and alprazolam, from ultra-pure water, tap water, fruit juices, and urine samples. The analytes were adsorbed from large volume samples (60 mL) onto octadecyl silica SPE columns. After the elution of the desired compounds from sorbents with 2.0 mL acetone, 0.5 mL of eluent containing 40.0 μL chloroform was injected rapidly into 4.5 mL pure water. After extraction and centrifugation, 2 μL of the sedimented phase was injected into a GC equipped with a flame ionization detector. Several parameters affecting this process were investigated and optimized. Under the optimal conditions, LODs ranged from 0.02 to 0.05 μg/L, a linear dynamic range of 0.1-100 μg/L and relative SDs in the range of 4.4-10.7% were attained. Very high preconcentration factors ranging from 3895-7222 were achieved. The applicability of the method for the extraction of BZPs from different types of complicated matrices, such as tap water, fruit juices, and urine samples, was studied. The obtained results reveal that the proposed method is a good technique for the extraction and determination of BZPs in complex matrices.

  7. Multivariate optimization of cloud point extraction procedure for zinc determination in aqueous extracts of medicinal plants by flame atomic absorption spectrometry.

    Science.gov (United States)

    Kolachi, N F; Kazi, T G; Khan, S; Wadhwa, S K; Baig, J A; Afridi, H I; Shah, A Q; Shah, F

    2011-10-01

    Cloud point extraction method has been developed for preconcentration of trace quantities of zinc (Zn) in aqueous extract of medicinal plants and blood samples of liver cancer patients using flame atomic absorption spectrometry. The Zn in aqueous extracts of medicinal plants (MPs) was complexed with 2-methyl-8-hydroxyquinoline (quinaldine) and 1-(2-pyridylazo)-2-naphthol (PAN) separately and entrapped in a non-ionic surfactant Triton X-114. After centrifugation, the surfactant-rich phase was diluted with 0.25mL acidic ethyl alcohol. The multivariate strategy was applied to estimate the optimum values of experimental variables (pH, time temperature, ligands and surfactant concentrations). Interactions between analytical factors and their optimal levels were investigated by two level factorial designs. Student's t-test on the results of factorial design with 16 runs for Zn extraction, demonstrated that the factors, ligands concentrations, pH and temperature were statistically significant. The accuracy was assessed by analysis of certified reference materials, namely, BCR 101 (spruce needles), Clincheck control-lyophilized human whole blood. Enhancement factor of 30 and 26 were achieved for the preconcentration of Zn by 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2), respectively. The relative standard deviation for six replicate determinations of Zn at 10μg/L level using 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2) were 5%, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Multiwalled carbon nanotubes as a sorbent material for the solid phase extraction of lead from urine and subsequent determination by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Peña Crecente, Rosa M.; Lovera, Carlha Gutiérrez; García, Julia Barciela; Méndez, Jennifer Álvarez; Martín, Sagrario García; Latorre, Carlos Herrero, E-mail: carlos.herrero@usc.es

    2014-11-01

    The determination of lead in urine is a way of monitoring the chemical exposure to this metal. In the present paper, a new method for the Pb determination by electrothermal atomic absorption spectrometry (ETAAS) in urine at low levels has been developed. Lead was separated from the undesirable urine matrix by means of a solid phase extraction (SPE) procedure. Oxidized multiwalled carbon nanotubes have been used as a sorbent material. Lead from urine was retained at pH 4.0 and was quantitatively eluted using a 0.7 M nitric acid solution and was subsequently measured by ETAAS. The effects of parameters that influence the adsorption–elution process (such as pH, eluent volume and concentration, sampling and elution flow rates) and the atomic spectrometry conditions have been studied by means of different factorial design strategies. Under the optimized conditions, the detection and quantification limits obtained were 0.08 and 0.26 μg Pb L{sup −1}, respectively. The results demonstrate the absence of a urine matrix effect and this is the consequence of the SPE process carried out. Therefore, the developed method is useful for the analysis of Pb at low levels in real samples without the influence of other urine components. The proposed method was applied to the determination of lead in urine samples of unexposed healthy people and satisfactory results were obtained (in the range 3.64–22.9 μg Pb L{sup −1}). - Highlights: • Lead determination in urine using a solid phase extraction procedure followed by ETAAS • Carbon nanotubes as SPE adsorbent for Pb in urine • Matrix elimination for the Pb determination in urine by using SPE based on carbon nanotubes • The detection limit was 0.08 μg Pb L{sup −1}.

  9. APPLICATION OF EMPORE C-8 EXTRACTION DISKS FOR SCREENING URINE IN SYSTEMATIC TOXICOLOGICAL ANALYSIS

    NARCIS (Netherlands)

    ENSING, K; FRANKE, JP; TEMMINK, A; CHEN, XH; DEZEEUW, RA

    1992-01-01

    Solid-phase extraction (SPE) by means of disposable columns has become a widely accepted technique for sample pretreatment in toxicology, both for directed analyses and for screening analyses. However, the sample capacity in SPE is usually limited to a few millilitres. Therefore, we have investigate

  10. SPE HG-AAS method for the determination of inorganic arsenic in rice--results from method validation studies and a survey on rice products.

    Science.gov (United States)

    Rasmussen, Rie R; Qian, Yiting; Sloth, Jens J

    2013-09-01

    The present paper describes the development, validation and application of a method for inorganic arsenic (iAs) determination in rice samples. The separation of iAs from organoarsenic compounds was done by off-line solid-phase extraction (SPE) followed by hydride generation atomic absorption spectrometry (HG-AAS) detection. This approach was earlier developed for seafood samples (Rasmussen et al., Anal Bioanal Chem 403:2825-2834, 2012) and has in the present work been tailored for rice products and further optimised for a higher sample throughput and a lower detection limit. Water bath heating (90 °C, 60 min) of samples with dilute HNO3 and H2O2 solubilised and oxidised all iAs to arsenate (As(V)). Loading of buffered sample extracts (pH 6 ± 1) followed by selective elution of arsenate from a strong anion exchange SPE cartridge enabled the selective iAs quantification by HG-AAS, measuring total arsenic (As) in the SPE eluate. The in-house validation gave mean recoveries of 101-106% for spiked rice samples and in two reference samples. The limit of detection was 0.02 mg kg(-1), and repeatability and intra-laboratory reproducibility were less than 6 and 9%, respectively. The SPE HG-AAS method produced similar results compared to parallel high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (ICP-MS) analysis. The SPE separation step was tested collaboratively, where the laboratories (N = 10) used either HG-AAS or ICP-MS for iAs determination in a wholemeal rice powder. The trial gave satisfactory results (HorRat value of 1.6) and did not reveal significant difference (t test, p > 0.05) between HG-AAS and ICP-MS quantification. The iAs concentration in 36 rice samples purchased on the Danish retail market varied (0.03-0.60 mg kg(-1)), with the highest concentration found in a red rice sample.

  11. Development of a simple extraction and clean-up procedure for determination of organochlorine pesticides in soil using gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rashid, A; Nawaz, S; Barker, H; Ahmad, I; Ashraf, M

    2010-04-23

    A procedure based on QuEChERS extraction and a simultaneous liquid-liquid partition clean-up was developed. The procedure involved extraction of hydrated soil samples using acetonitrile and clean-up by liquid-liquid partition into n-hexane. The hexane extracts produced were clean and suitable for determination using gas chromatography-tandem mass spectrometry (GC-MS/MS). The method was validated by analysis of soil samples, spiked at five levels between 1 and 200 microg kg(-1). The recovery values were generally between 70 and 100% and the relative standard deviation values (%RSDs) were at or below 20%. The procedure was validated for determination of 19 organochlorine (OC) pesticides. These were hexachlorobenzene (HCB), alpha-HCH, beta-HCH, gamma-HCH, heptachlor, heptachlor epoxide (trans), aldrin, dieldrin, chlordane (trans), chlordane (cis), oxychlordane, alpha-endosulfan, beta-endosulfan, endosulfan sulfate, endrin, p,p'-DDT, o,p'-DDT, p,p'-DDD and p,p'-DDE. The method achieved low limits of detection (LOD; typically 0.3 microg kg(-1)) and low limits of quantification (LOQ; typically 1.0 microg kg(-1)). The method performance was also assessed using five fortified soil samples with different physico-chemical properties and the method performance was consistent for the different types of soil samples. The proposed method was compared with an established procedure based on Soxtec extraction. This comparison was carried out using six soil samples collected from regions of Pakistan with a history of intensive pesticide use. The results of this comparison showed that the two procedures produced results with good agreement. The proposed method produced cleaner extracts and therefore led to lower limits of quantification. The proposed method was less time consuming and safer to use. The six samples tested during this comparison showed that soils from cotton growing regions contained a number of persistent OC residues at relatively low levels (<10 microg kg(-1)). These

  12. A nanoparticle-based solid-phase extraction procedure followed by spectrofluorimetry to determine carbaryl in different water samples

    Energy Technology Data Exchange (ETDEWEB)

    Tabrizi, Ahad Bavili, E-mail: a.bavili@tbzmed.ac.ir, E-mail: abavilitabrizia@gmail.com [Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Rashidi, Mohammad Reza [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, (Iran, Islamic Republic of); Ostadi, Hadi [Department of Chemistry, Payam-e-noor University, Ardabil Branch, Ardabil (Iran, Islamic Republic of)

    2014-04-15

    In this study, a new method based on Fe{sub 3}O{sub 4} magnetite nanoparticles (MNPs) has been developed for the extraction, preconcentration and determination of trace amounts of carbaryl from environmental water samples. Fe{sub 3}O{sub 4} MNPs were synthesized and modified by the surfactant sodium dodecyl sulfate (SDS), then successfully applied for the extraction of carbaryl and its determination by spectrofluorimetry. Main factors affecting the adsolubilization of carbaryl such as the amount of SDS, pH value, standing time, desorption solvent and maximal extraction volume were optimized. Under the selected conditions, carbaryl could be quantitatively extracted. Acceptable recoveries (84.5-91.9%) and relative standard deviations (6.2%) were achieved in analyzing spiked water samples. A concentration factor of 20 was achieved by the extraction of 100 mL of environmental water samples. The limit of detection and quantification were found to be 2.1 and 6.9 μg L{sup -1}, respectively. The proposed method was successfully applied for the extraction and determination of carbaryl in environmental water samples. (author)

  13. Novel surface dummy molecularly imprinted silica as sorbent for solid-phase extraction of bisphenol A from water samples.

    Science.gov (United States)

    Hu, Xiaolei; Wu, Xiao; Yang, Fanfan; Wang, Qiang; He, Chiyang; Liu, Shaorong

    2016-01-01

    A novel surface molecularly imprinted silica composite was prepared by a dummy-template imprinting strategy for the solid-phase extraction (SPE) of bisphenol A (BPA). 2,2-Bis(4-hydroxyphenyl) hexafluoropropane (BPAF) was chosen as the template molecule, and a hybrid technique was used for imprinting procedure. The imprinted silica was characterized by FT-IR spectroscopy, scanning electron microscope, thermo-gravimetric analysis, and nitrogen adsorption-desorption isotherms. The static binding test verified that the imprinted silica had much higher recognition ability for BPA than the non-imprinted silica, and the kinetic adsorption test presented the fast binding kinetics of the surface imprinted silica for BPA. When used as a SPE sorbent, the imprinted silica showed high extraction efficiencies and high enrichment factor for BPA. Based on the imprinted silica, a SPE-HPLC-UV method was developed and successfully applied to the detection of BPA in BPA-spiked lake water, tap water and drinking water samples with a high recovery of 97.3-106.0%, a RSD of 1.2-3.8% (n=3) and a limit of detection (S/N=3) of 0.3 ng/mL. The analysis results of a certified BPA sample also demonstrated the reliability of present method. The new surface dummy molecularly imprinted silica completely avoided the interference of the residual template molecules and greatly improved the binding kinetic of the target molecules. Therefore, it can be used as a good sorbent for SPE of BPA in environmental water samples.

  14. Fast determination of seven synthetic pigments from wine and soft drinks using magnetic dispersive solid-phase extraction followed by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Chen, Xiao-Hong; Zhao, Yong-Gang; Shen, Hao-Yu; Zhou, Li-Xin; Pan, Sheng-Dong; Jin, Mi-Cong

    2014-06-13

    A novel, simple and sensitive method based on the use of magnetic dispersive solid-phase extraction (M-dSPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) was developed to determine seven synthetic pigments (tartrazine, amaranth, carmine, sunset yellow, allura red, brilliant blue and erythrosine) in wines and soft drinks. An amino-functionalized low degrees of cross-linking magnetic polymer (NH2-LDC-MP) was synthesized via suspension polymerization, and characterized by transmission electron microscopy (TEM). The NH2-LDC-MP was used as the M-dSPE sorbent to remove the matrix from the solution, and the main factors affecting the extraction were investigated in detail. The obtained results demonstrated the higher extraction capacity of NH2-LDC-MP with recoveries between 84.0 and 116.2%. The limits of quantification (LOQs) for the seven synthetic pigments were between 1.51 and 5.0μg/L in wines and soft drinks. The developed M-dSPE UFLC-MS/MS method had been successfully applied to the real wines and soft drinks for food-safety risk monitoring in Zhejiang Province, China. The results showed that sunset yellow was in three out of thirty soft drink samples (2.95-42.6μg/L), and erythrosine in one out of fifteen dry red wine samples (3.22μg/L), respectively. It was confirmed that the NH2-LDC-MP was a kind of highly effective M-dSPE materials for the pigments analyses.

  15. Toxicological screening of human plasma by on-line SPE-HPLC-DAD: identification and quantification of acidic and neutral drugs.

    Science.gov (United States)

    Mut, Ludmila; Grobosch, Thomas; Binscheck-Domaß, Torsten; Frenzel, Wolfgang

    2016-03-01

    A multi-analyte screening method for the quantification of 50 acidic/neutral drugs in human plasma based on on-line solid-phase extraction (SPE)-HPLC with photodiode array detection (DAD) was developed, validated and applied for clinical investigation. Acetone and methanol for protein precipitation, three different SPE materials (two electro-neutral, one strong anion-exchange, one weak cation-exchange) for on-line extraction, five HPLC-columns [one C18 (GeminiNX), two phenyl-hexyl (Gemini C6 -Phenyl, Kinetex Phenyl-Hexyl) and two pentafluorophenyl (LunaPFP(2), KinetexPFP)] for analytical separation were tested. For sample pre-treatment, acetone in the ratio 1:2 (plasma:acetone) showed a better baseline and fewer matrix peaks in the chromatogram than methanol. Only the strong anion-exchanger SPE cartridge (StrataX-A, pH 6) allowed the extraction of salicylic acid. Analytical separation was carried out on a Gemini C6 -Phenyl column (150 × 4.6 mm, 3 µm) using gradient elution with acetonitrile-water 90:10 (v/v) and phosphate buffer (pH 2.3). Linear calibration curves with correlation coefficients r ≥ 0.9950/0.9910 were obtained for 46/four analytes. Additionally, this method allows the quantification of 23 analytes for therapeutic drug monitoring. Limits of quantitation ranged from 0.1 (amobarbital) to 23 mg/L (salicylic acid). Inter-/intra-day precisions of quality control samples (low/high) were better than 13% and accuracy (bias) ranged from -14 to 10%. A computer-assisted database was created for automated detection of 223 analytes of toxicological interests. Four cases of multi-drug intoxications are presented.

  16. Electric field-assisted solid phase extraction and cleanup of ionic compounds in complex food matrices: Fluoroquinolones in eggs.

    Science.gov (United States)

    Ribeiro, Cyntia Cabral; Orlando, Ricardo Mathias; Rohwedder, Jarbas José Rodrigues; Reyes, Felix Guillermo Reyes; Rath, Susanne

    2016-05-15

    The use of electric fields as additional driving forces in sample preparation techniques is an innovative approach that is environmentally friendly, straightforward, and able to overcome several limitations of conventional sample preparation procedures. In this work, the advantages of electric field-assisted solid phase extraction (E-SPE) using syringe-type cartridges were demonstrated for the extraction of four fluoroquinolones (FQs) in their anionic forms. The FQs were extracted from eggs and subsequently determined by UHPLC-MS/MS. The use of electric fields during the washing and final elution steps resulted in a significant improvement of the extraction efficiencies for almost all FQs when compared to conventional SPE. Intra- and inter-day assays showed coefficients of variation below 10%. The better cleanup also resulted in the appearance of less precipitated matter in the final eluate, as well as reduced matrix effects. The results showed that the electrophoretic forces derived from electric fields are a promising way of significantly increasing the extraction efficiency of ionic analytes, while minimizing matrix effects associated with complex samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Application of HPLC-DAD after SPE/QuEChERS with ZrO2-based sorbent in d-SPE clean-up step for pesticide analysis in edible oils.

    Science.gov (United States)

    Tuzimski, Tomasz; Rejczak, Tomasz

    2016-01-01

    In this study, the solid-phase extraction/quick, easy, cheap, effective, rugged and safe (SPE/QuEChERS) technique was adapted to develop a simple sample treatment for multi-residue pesticide analysis of edible oils. The proposed method is based on liquid-liquid partitioning with acetonitrile followed by dispersive solid phase extraction using zirconia-coated silica particles for extract purification. To evaluate the described method, 21 pesticides belonging to different chemical classes were analysed using high performance liquid chromatography with diode-array detection (HPLC-DAD). For validation purposes, recovery studies were performed at 75 ng g(-1), 125 ng g(-1), 250 ng g(-1), 500 ng g(-1) and 1000 ng g(-1) levels. Recoveries were over the range of 50-130% for most of the analytes, with relative standard deviations less than 15% being observed. HPLC-DAD provided suitable linearity, precision and accuracy. The validated method was successfully applied to the analysis of edible oil samples selected from the market.

  18. Trace enrichment and characterization of polyphenols in Bistort Rhizoma using weak anion-exchange solid phase extraction and high performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Wang, Shao-Teng; Yang, Hua; Gao, Wen; Li, Hui-Jun; Li, Ping

    2016-02-05

    The analysis of trace constituents in herbal medicines has always been a challenge due to complex matrices and structural diversities. In this work, a pH-sensitive solid phase extraction (SPE) procedure capable of enriching trace polyphenols in Bistort Rhizoma (BR) was proposed and preliminary chemical characterization was accomplished by high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS). A weak anion-exchange SPE column packed with divinylbenzene/vinylpyrrolidone bonding quaternary amine group was employed for anionic extraction, and the target fraction was obtained by eluting with acidic methanol (apparent pH 1.9). On the other hand, the MS/MS fragmentation rules of four reference polyphenols in negative ion mode were outlined. Using these rules, a total of 31 polyphenols including 20 benzoyl derivatives and 11 caffeoyl derivatives were screened out from BR extract, of which 26 trace members were found for the first time in this herb. Those findings demonstrated that the anion-exchange SPE could enhance the detection capability and selectivity for plant polyphenols in the LC-MS analysis and the strategy for deducing structures could be applied for analysis of polyphenols in BR and other herbal medicines.

  19. Development of a sample preparation procedure of sewage sludge samples for the determination of polycyclic aromatic hydrocarbons based on selective pressurized liquid extraction.

    Science.gov (United States)

    Pena, Maria Teresa; Casais, Maria Carmen; Mejuto, Maria Carmen; Cela, Rafael

    2010-01-22

    An automated, simple and sensitive method based on selective pressurized liquid extraction (SPLE) was developed for the analysis of polycyclic aromatic hydrocarbons in sewage sludge samples. The new sample preparation procedure consists of on-line clean-up by inclusion of sorbents in the extraction cell, and combines elevated temperatures and pressures with liquid solvents to achieve fast and efficient removal of target analytes from complex sewage sludge matrices. The effects of various operational parameters (e.g. sample pretreatment, extraction solvent, temperature, pressure, static time, etc.) on the performance of SPLE procedure were carefully investigated, obtaining the best results when SPLE conditions were fixed at 140 degrees C, 1500 psi, static time of 5 min and n-hexane as extraction solvent. A new programmed temperature vaporization-gas chromatography-tandem mass spectrometry method based on large volume injection (PTV-LVI-GC-MS/MS) was also developed and analytical determinations were performed by high performance liquid chromatography coupled with fluorescence detection and GC-MS/MS. The extraction yields for the different compounds obtained by SPLE ranged from 84.8% to 106.6%. Quantification limits obtained for all of these studied compounds (between 0.0001 and 0.005 microg g(-1), dry mass) were well below the regulatory limits for all compounds considered. To test the accuracy of the SPLE technique, the optimized methodology was applied to the analysis of a certified reference material (sewage sludge (BCR088)) and a reference material (sewage sludge (RTC-CNS312-04)), with excellent results.

  20. Water-compatible dummy molecularly imprinted resin prepared in aqueous solution for green miniaturized solid-phase extraction of plant growth regulators.

    Science.gov (United States)

    Wang, Mingyu; Chang, Xiaochen; Wu, Xingyu; Yan, Hongyuan; Qiao, Fengxia

    2016-08-01

    A water-compatible dummy molecularly imprinted resin (MIR) was synthesized in water using melamine, urea, and formaldehyde as hydrophilic monomers of co-polycondensation. A triblock copolymer (PEO-PPO-PEO, P123) was used as porogen to dredge the network structure of MIR, and N-(1-naphthyl) ethylenediamine dihydrochloride, which has similar shape and size to the target analytes, was the dummy template of molecular imprinting. The obtained MIR was used as the adsorbent in a green miniaturized solid-phase extraction (MIR⬜mini-SPE) of plant growth regulators, and there was no organic solvent used in the entire MIR⬜mini-SPE procedure. The calibration linearity of MIR⬜mini-SPE⬜HPLC method was obtained in a range 5⬜250ngmL(↙1) for IAA, IPA, IBA, and NAA with correlation coefficient (r) Ⱕ0.9998. Recoveries at three spike levels are in the range of 87.6⬜100.0% for coconut juice with relative standard deviations Ⱔ8.1%. The MIR⬜mini-SPE method possesses the advantages of environmental friendliness, simple operation, and high efficiency, so it is potential to apply the green pretreatment strategy to extraction of trace analytes in aqueous samples.

  1. Glyoxal-Urea-Formaldehyde Molecularly Imprinted Resin as Pipette Tip Solid-Phase Extraction Adsorbent for Selective Screening of Organochlorine Pesticides in Spinach.

    Science.gov (United States)

    Yang, Chen; Lv, Tianwei; Yan, Hongyuan; Wu, Gaochan; Li, Haonan

    2015-11-01

    A new kind of glyoxal-urea-formaldehyde molecularly imprinted resin (GUF-MIR) was synthesized by a glyoxal-urea-formaldehyde (GUF) gel imprinting method with 4,4'-dichlorobenzhydrol as a dummy template. The obtained GUF-MIR was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) and applied as a selective adsorbent of miniaturized pipet tip solid-phase extraction (PT-SPE) for the separation and extraction of three organochlorine pesticides (dicofol (DCF), dichlorodiphenyl dichloroethane (DDD), and tetradifon) in spinach samples. The proposed pretreatment procedures of spinach samples involved only 5.0 mg of GUF-MIR, 0.7 mL of MeOH-H2O (1:1, v/v) (washing solvent), and 0.6 mL of cyclohexane-ethyl acetate (9:1, v/v) (elution solvent). In comparison with other adsorbents (such as silica gel, C18, NH2-silica gel, and neutral alumina (Al2O3-N)), GUF-MIR showed higher adsorption and purification capacity for DCF, DDD, and tetradifon in aqueous solution. The average recoveries at three spiked levels ranged from 89.1% to 101.9% with relative standard deviations (RSDs) ≤ 7.1% (n = 3). The presented GUF-MIR-PT-SPE method combines the advantages of molecularly imprinted polymers (MIPs), GUF, and PT-SPE and can be used in polar solutions with high affinity and selectivity to the analytes in complex samples.

  2. Ionic liquid molecularly imprinted polymers for application in pipette-tip solid-phase extraction coupled with gas chromatography for rapid screening of dicofol in celery.

    Science.gov (United States)

    Yan, Hongyuan; Yang, Chen; Sun, Yunyun; Row, Kyung Ho

    2014-09-26

    A new type of ionic liquid molecularly imprinted polymers (IL-MIPs) synthesized by precipitation polymerization using 1-allyl-3-methylimidazolium bromide as an auxiliary solvent and α-chloro-dichlorodiphenyltrichloroethane (α-chloro-DDT) as the template was applied as a selective sorbent of minimized pipette tip-solid-phase extraction (PT-SPE) for rapid isolation and extraction of dicofol (DCF) from celery samples. The pretreatment procedure of celery samples involved only 2.0mg of IL-MIPs, 0.8 mL of acetonitrile-water (ACN-H2O; 1:1, v/v) (washing solvent), and 1.0 mL of acetone-10% acetic acid (HOAc) (elution solvent). Compared with molecularly imprinted polymers (MIPs), ionic liquid-non-imprinted polymers (IL-NIPs) and conventional sorbents such as C18, Si, NH2, and Al2O3-N, IL-MIPs showed higher adsorption and purification capacity to DCF in aqueous solution. Good linearity for DCF was observed in the range from 2.3 to 232.5 ng g(-1) (r(2)=0.9995). The average recoveries at three spiking levels ranged from 86.6% to 101.9% with relative standard deviations (RSDs) of ≤ 6.5% (n=3). The presented IL-MIPs-PT-SPE-GC/ECD method combines the advantages of MIPs, IL, and PT-SPE, and can be used in aqueous conditions with high affinity and selectivity to analytes of complex samples.

  3. Screening for illicit and medicinal drugs in whole blood using fully automated SPE and UHPLC-TOF-MS with data-independent acquisition

    DEFF Research Database (Denmark)

    Pedersen, Anders Just; Dalsgaard, Petur Weihe; Rode, Andrej Jaroslav

    2013-01-01

    A broad forensic screening method for 256 analytes in whole blood based on a fully automated SPE robotic extraction and UHPLC-TOF-MS with data-independent acquisition has been developed. The limit of identification was evaluated for all 256 compounds and 95 of these compounds were validated with ......-MS screening of blood samples constitutes a practical way for screening traffic cases, with the exception of THC, which should be handled in a separate method. This article is protected by copyright. All rights reserved....

  4. An Optimized High Throughput Clean-Up Method Using Mixed-Mode SPE Plate for the Analysis of Free Arachidonic Acid in Plasma by LC-MS/MS

    OpenAIRE

    Wan Wang; Suzi Qin; Linsen Li; Xiaohua Chen; Qunjie Wang; Junfu Wei

    2015-01-01

    A high throughput sample preparation method was developed utilizing mixed-mode solid phase extraction (SPE) in 96-well plate format for the determination of free arachidonic acid in plasma by LC-MS/MS. Plasma was mixed with 3% aqueous ammonia and loaded into each well of 96-well plate. After washing with water and methanol sequentially, 3% of formic acid in acetonitrile was used to elute arachidonic acid. The collected fraction was injected onto a reversed phase column at 30°C with mobile pha...

  5. Phenylboronic Acid Solid Phase Extraction Cleanup and Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry for the Determination of Florfenicol Amine in Fish Muscles.

    Science.gov (United States)

    Sin, Della Wai-Mei; Ho, Clare; Wong, Yiu-Tung

    2015-01-01

    Florfenicol (FFC) residues in foods are regulated as the sum of florfenicol and its metabolites measured as florfenicol amine (FFA). An isotope dilution LC-MS/MS method utilizing phenylboronic acid (PBA) SPE cleanup is established for the accurate determination of FFA in fish muscles (i.e., salmon and tilapia) after acid catalyzed hydrolysis. Comparisons of the PBA SPE cleanup procedure with other cleanup procedures such as mixed-mode cationic (MCX) SPE and solid supported liquid-liquid extraction were performed. Quantification of FFA in fish muscles was accomplished by using matrix-matched calibration with FFA-D3 as the internal standard. The method was validated with FFA fortified fish muscles at three different levels (50, 100, and 200 μg/kg). Conversion of FFC to FFA by acid catalyzed hydrolysis was evaluated and found to be ≥88%. The recoveries of FFA in fish muscles at the three fortification levels ranged from 89 to 106%, and RSDs were ≤9% in all cases. The LOD values in salmon and tilapia muscles were 0.13 and 1.64 μg/kg, respectively. The LOQ values in salmon and tilapia muscles were 0.29 and 4.13 μg/kg, respectively. This method is suitable for the application in routine control of FFC in fishes according to its residue definition.

  6. Comparison of extraction procedures for the determination of arsenic and other elements in lobster tissue by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Brisbin, Judith A; Caruso, Joseph A

    2002-07-01

    A variety of extraction procedures were evaluated for the extraction of arsenic and other analytes from lobster tissue samples using inductively coupled plasma mass spectrometry (ICP-MS) detection. Soxhlet, room temperature mixing, sonication, microwave assisted, supercritical carbon dioxide and subcritical water extractions were evaluated for a variety of solvent systems and optimum conditions determined using a partially defatted Lobster Hepatopancreas marine certified reference material, TORT-2 (National Research Council of Canada). The solubility trends and solvents into which the analytes extracted gave an indication as to the polar/non-polar nature of the compounds present. Analytes that prefer water are probably more polar or inorganic, while those preferring methanol solutions are less polar or organic in nature. Arsenic, cadmium, cobalt, molybdenum and selenium were probably all present in TORT-2 in both polar inorganic and non-polar organic forms. While TORT-2 may have contained similar amounts of selenium in both forms, the results suggested that more of the arsenic was present as less polar or more organic compounds, and cobalt existed mainly as more polar or inorganic species. Most of the extraction techniques suggested that, although there may be some less polar organic forms present, more of the cadmium was probably present as polar inorganic compounds. Additionally, most techniques indicated that molybdenum was possibly all less polar or more organic in nature. In general, microwave assisted extraction (MAE) yielded comparable or improved recoveries for all of the analytes monitored and usually required less solvent. Additionally, MAE proved to be the mildest, fastest, least complicated and most reproducible extraction technique evaluated. MAE at 75 degrees C for 2 min exposure time yielded quantitative recovery of arsenic from TORT-2. These conditions were evaluated for lobster tissue samples purchased from a local restaurant. Separate evaluation

  7. Rapid 96-well plates DNA extraction and sequencing procedures to identify genome-wide transposon insertion sites in a difficult to lyse bacterium: Lactobacillus casei.

    Science.gov (United States)

    Scornec, Hélène; Tichit, Magali; Bouchier, Christiane; Pédron, Thierry; Cavin, Jean-François; Sansonetti, Philippe J; Licandro-Seraut, Hélène

    2014-11-01

    Random transposon mutagenesis followed by adequate screening methods is an unavoidable procedure to characterize genetics of bacterial adaptation to environmental changes. We have recently constructed a mutant library of Lactobacillus casei and we aimed to fully annotate it. However, we have observed that, for L. casei which is a difficult to lyse bacterium, methods used to identify the transposon insertion site in a few mutants (transposon rescue by restriction and recircularization or PCR-based methods) were not transposable for a larger number because they are too time-consuming and sometimes not reliable. Here, we describe a method for large-scale and reliable identification of transposon insertion sites in a L. casei mutant library of 9250 mutants. DNA extraction procedure based on silica membranes in 96-column format was optimized to obtain genomic DNA from a large number of mutants. Then reliable direct genomic sequencing was improved to fit the obtained genomic DNA extracts. Using this procedure, readable and identifiable sequences were obtained for 87% of the L. casei mutants. This method extends the applications of a library of this type, reduces the number of insertions needed to be screened, and allows selection of specific mutants from an arrayed and stored mutant library. This method is applicable to any already existing mutant library (obtained by transposon or insertional mutagenesis) and could be useful for other bacterial species, especially for highly lysis-resistant bacteria species such as lactic acid bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. A Highly Sensitive Multicommuted Flow Analysis Procedure for Photometric Determination of Molybdenum in Plant Materials without a Solvent Extraction Step

    OpenAIRE

    Felisberto G. Santos; Boaventura F. Reis

    2017-01-01

    A highly sensitive analytical procedure for photometric determination of molybdenum in plant materials was developed and validated. This procedure is based on the reaction of Mo(V) with thiocyanate ions (SCN−) in acidic medium to form a compound that can be monitored at 474 nm and was implemented employing a multicommuted flow analysis setup. Photometric detection was performed using an LED-based photometer coupled to a flow cell with a long optical path length (200 mm) to achieve high sensit...

  9. Tooth extraction

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007630.htm Tooth extraction To use the sharing features on this page, please enable JavaScript. A tooth extraction is a procedure to remove a tooth from ...

  10. Micro-solid phase extraction with liquid chromatography-tandem mass spectrometry for the determination of aflatoxins in coffee and malt beverage.

    Science.gov (United States)

    Khayoon, Wejdan Shakir; Saad, Bahruddin; Salleh, Baharuddin; Manaf, Normaliza Hj Abdul; Latiff, Aishah A

    2014-03-15

    A single step extraction-cleanup procedure using porous membrane-protected micro-solid phase extraction (μ-SPE) in conjunction with liquid chromatography-tandem mass spectrometry for the extraction and determination of aflatoxins (AFs) B1, B2, G1 and G2 from food was successfully developed. After the extraction, AFs were desorbed from the μ-SPE device by ultrasonication using acetonitrile. The optimum extraction conditions were: sorbent material, C8; sorbent mass, 20mg; extraction time, 90 min; stirring speed, 1,000 rpm; sample volume, 10 mL; desorption solvent, acetonitrile; solvent volume, 350 μL and ultrasonication period, 25 min without salt addition. Under the optimum conditions, enrichment factor of 11, 9, 9 and 10 for AFG2, AFG1, AFB2 and AFB1, respectively were achieved. Good linearity and correlation coefficient was obtained over the concentration range of 0.4-50 ng g(-1) (r(2) 0.9988-0.9999). Good recoveries for AFs ranging from 86.0-109% were obtained. The method was applied to 40 samples involving malt beverage (19) and canned coffee (21). No AFs were detected in the selected samples.

  11. COMPARISON OF COMMERCIAL DNA KITS AND TRADITIONAL DNA EXTRACTION PROCEDURE IN PCR DETECTION OF PORK IN DRY/FERMENTED SAUSAGES

    Directory of Open Access Journals (Sweden)

    Ivona Djurkin Kušec

    2015-09-01

    Full Text Available In the present study four commercially available DNA extraction kits (Wizard® Genomic DNA Purification Kit, High Pure PCR Template Kit, DNeasy mericon Food and GeneJET PCR Purification Kit, as well as standard phenol/chloroform isolation technique have been evaluated regarding their concentration, purity and suitability for amplification of porcine DNA in dry/fermented sausages. The isolates were assessed for quantity and quality using spectrophotometer (IMPLEN GmbH, Germany. To verify template usability and quality of isolated DNA, the polymerase chain reaction (PCR targeting at porcine cytochrome b by species specific primers was used. The comparison of extraction methods revealed satisfactory efficiency and purity of all extraction kits, while with standard phenol/chloroform isolation method high concentrations of DNA with low A260/280 were obtained. However, all the investigated techniques proved to be suitable for identification of porcine DNA in dry/fermented sausage. Thus, the standard phenol/chloroform DNA extraction method, as the cost-effective one, can be recommended as a good alternative to more expensive isolation kits when investigating the presence of pork DNA in dry/ fermented meat products.

  12. Solid Phase Extraction for Monitoring of Occupational Exposure to Cr (III

    Directory of Open Access Journals (Sweden)

    S.J. Shahtaheri

    2007-01-01

    Full Text Available Chromium is an important constituent widely used in different industrial processes for production of various synthetic materials. For evaluation of workers’ exposure to trace toxic metal of Cr (III, environmental and biological monitoring are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to analysis. The use of solid-phase extraction (SPE has grown and is a fertile technique of sample preparation as it provides better results than those produced by liquid-liquid extraction (LLE. SPE using mini columns filled with XAD-4 resin was optimized regarding to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume, elution volume, amount of resins, and sample matrix interferences. Chromium was retained on solid sorbent and was eluted with 2 M HNO3 followed by simple determination of analytes by using flame atomic absorption spectrometery. Obtained recoveries of metal ion were more than 92%. The optimized procedure was also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Through this study, suitable results were obtained for relative standard deviation, therefore, it is concluded that, this optimized method can be considered to be successful in simplifying sample preparation for trace residue analysis of Cr in different matrices for evaluation of occupational and environmental exposures. To evaluate occupational exposure to chromium, 16 urine samples were taken, prepared, and analyzed based on optimized procedure.

  13. HPLC-SPE-NMR for combinatorial biosynthetic investigations – expanding the landscape of diterpene structural diversity

    DEFF Research Database (Denmark)

    Kongstad, Kenneth Thermann; Andersen-Ranberg, Johan; Hamberger, Björn Robert

    In this work, the analytical technique, HPLC-HRMS-SPE-NMR was used for the first time in combination with combinatorial biosynthetic investigations in N. benthamiana. This efficient setup allowed for identification of several diterpene synthase (diTPS) combinations responsible for stereospecific ......In this work, the analytical technique, HPLC-HRMS-SPE-NMR was used for the first time in combination with combinatorial biosynthetic investigations in N. benthamiana. This efficient setup allowed for identification of several diterpene synthase (diTPS) combinations responsible for...

  14. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

    Science.gov (United States)

    Savinell, R. F.; Fritts, S. D.

    1988-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  15. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

    Science.gov (United States)

    Savinell, R. F.; Fritts, S. D.

    1988-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  16. "In situ" extraction of essential oils by use of Dean-Stark glassware and a Vigreux column inside a microwave oven: a procedure for teaching green analytical chemistry.

    Science.gov (United States)

    Chemat, Farid; Perino-Issartier, Sandrine; Petitcolas, Emmanuel; Fernandez, Xavier

    2012-08-01

    One of the principal objectives of sustainable and green processing development remains the dissemination and teaching of green chemistry in colleges, high schools, and academic laboratories. This paper describes simple glassware that illustrates the phenomenon of extraction in a conventional microwave oven as energy source and a process for green analytical chemistry. Simple glassware comprising a Dean-Stark apparatus (for extraction of aromatic plant material and recovery of essential oils and distilled water) and a Vigreux column (as an air-cooled condenser inside the microwave oven) was designed as an in-situ extraction vessel inside a microwave oven. The efficiency of this experiment was validated for extraction of essential oils from 30 g fresh orange peel, a by-product in the production of orange juice. Every laboratory throughout the world can use this equipment. The microwave power is 100 W and the irradiation time 15 min. The method is performed at atmospheric pressure without added solvent or water and furnishes essential oils similar to those obtained by conventional hydro or steam distillation. By use of GC-MS, 22 compounds in orange peel were separated and identified; the main compounds were limonene (72.1%), β-pinene (8.4%), and γ-terpinene (6.9%). This procedure is appropriate for the teaching laboratory, does not require any special microwave equipment, and enables the students to learn the skills of extraction, and chromatographic and spectroscopic analysis. They are also exposed to a dramatic visual example of rapid, sustainable, and green extraction of an essential oil, and are introduced to successful sustainable and green analytical chemistry.

  17. Integrated and convenient procedure for protein extraction from formalin-fixed, paraffin-embedded tissues for LC-MS/MS analysis.

    Science.gov (United States)

    Lai, Xianyin; Schneider, Bryan P

    2014-11-01

    Because fresh-frozen tissue samples associated with long-term clinical data and of rare diseases are often unobtainable at the present time, formalin-fixed paraffin-embedded (FFPE) tissue samples are considered a highly valuable resource for researchers. However, protein extraction from FFPE tissues faces challenges of deparaffinization and cross-link reversion. Current procedures for protein extraction from FFPE tissue require separate steps and toxic solvents, resulting in inconvenience in protein extraction. To overcome these limitations, an integrated method was developed using nontoxic solvents in four types of FFPE tissues. The average amount of proteins from three replicates of bladder, kidney, liver, and lung FFPE tissues were 442.6, 728.9, 736.4, and 694.7 μg with CVs of 7.5, 5.8, 2.4, and 4.5%, respectively. Proteomic analysis showed that 348, 417, 607, and 304 unique proteins were identified and quantified without specification of isoform by a least two peptides from bladder, kidney, liver, and lung FFPE tissue samples, respectively. The analysis of individual protein CV demonstrated that 97-99% of the proteins were quantified with a CV ≤ 30%, verifying the reproducibility of the integrated protein extraction method. In summary, the developed method is high-yield, reproducible, convenient, simple, low cost, nonvolatile, nonflammable, and nontoxic.

  18. The loss of essential oil components induced by the Purge Time in the Pressurized Liquid Extraction (PLE) procedure of Cupressus sempervirens.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Czapczyńska, Natalia B; Wianowska, Dorota

    2012-05-30

    The influence of different Purge Times on the effectiveness of Pressurized Liquid Extraction (PLE) of volatile oil components from cypress plant matrix (Cupressus sempervirens) was investigated, applying solvents of diverse extraction efficiencies. The obtained results show the decrease of the mass yields of essential oil components as a result of increased Purge Time. The loss of extracted components depends on the extrahent type - the greatest mass yield loss occurred in the case of non-polar solvents, whereas the smallest was found in polar extracts. Comparisons of the PLE method with Sea Sand Disruption Method (SSDM), Matrix Solid-Phase Dispersion Method (MSPD) and Steam Distillation (SD) were performed to assess the method's accuracy. Independent of the solvent and Purge Time applied in the PLE process, the total mass yield was lower than the one obtained for simple, short and relatively cheap low-temperature matrix disruption procedures - MSPD and SSDM. Thus, in the case of volatile oils analysis, the application of these methods is advisable.

  19. The optimization of essential oils supercritical CO 2 extraction from Lavandula hybrida through static-dynamic steps procedure and semi-continuous technique using response surface method

    Directory of Open Access Journals (Sweden)

    Hossein Kamali

    2015-01-01

    Full Text Available Aim: The aim of this study was to examine and evaluate crucial variables in essential oils extraction process from Lavandula hybrida through static-dynamic and semi-continuous techniques using response surface method. Materials and Methods: Essential oil components were extracted from Lavandula hybrida (Lavandin flowers using supercritical carbon dioxide via static-dynamic steps (SDS procedure, and semi-continuous (SC technique. Results: Using response surface method the optimum extraction yield (4.768% was obtained via SDS at 108.7 bar, 48.5° C , 120 min (static: 8×15, 24 min (dynamic: 8×3 min in contrast to the 4.620% extraction yield for the SC at 111.6 bar, 49.2° C , 14 min (static, 121.1 min (dynamic. Conclusion: The results indicated that a substantial reduction (81.56% solvent usage (kg CO 2 /g oil is observed in the SDS method versus the conventional SC method.

  20. Determination of cocaine in postmortem human liver exposed to overdose. Application of an innovative and efficient extraction/clean up procedure and gas chromatography-mass spectrometry analysis.

    Science.gov (United States)

    Magalhães, Elisângela Jaqueline; Ribeiro de Queiroz, Maria Eliana Lopes; Penido, Marcus Luiz de Oliveira; Paiva, Marco Antônio Ribeiro; Teodoro, Janaína Aparecida Reis; Augusti, Rodinei; Nascentes, Clésia Cristina

    2013-09-27

    A simple and efficient method was developed for the determination of cocaine in post-mortem samples of human liver via solid-liquid extraction with low temperature partitioning (SLE-LTP) and analysis by gas chromatography coupled to mass spectrometry (GC-MS). The extraction procedure was optimized by evaluating the influence of the following variables: pH of the extract, volume and composition of the extractor solvent, addition of a sorbent material (PSA: primary-secondary amine) and NaCl to clean up and increase the ionic strength of the extract. A bovine liver sample that was free of cocaine was used as a blank for the optimization of the SLE-LTP extraction procedure. The highest recovery was obtained when crushed bovine liver (2g) was treated with 2mL of ultrapure water plus 8mL of acetonitrile at physiological pH (7.4). The results also indicated no need for using PSA and NaCl. The complete analytical procedure was validated for the following figures of merit: selectivity, lower limit of quantification (LLOQ), calibration curve, recovery, precision and accuracy (for within-run and between-run experiments), matrix effect, dilution integrity and stability. The within-run and between-run precision (at four levels) varied from 2.1% to 9.4% and from 4.0% to 17.0%, respectively. A maximum deviation of 11.62% for the within-run and between-run accuracies in relation to the nominal concentrations was observed. Moreover, the LLOQ value for cocaine was 50.0ngg(-1) whereas no significant effects were noticed in the assays of dilution integrity and stability. To assess its overall performance, the optimized method was applied to the analysis of eight human liver samples collected from individuals who died due to the abusive consumption of cocaine. Due to the existence of a significant matrix effect, a blank human liver was used to construct a matrix-matched analytical curve. The concentrations of cocaine found in these samples ranged from 333.5 to 5969ngg(-1). Copyright

  1. Liquid chromatography/tandem mass spectrometric bioanalysis using normal-phase columns with aqueous/organic mobile phases - a novel approach of eliminating evaporation and reconstitution steps in 96-well SPE.

    Science.gov (United States)

    Naidong, Weng; Shou, Wilson Z; Addison, Thomas; Maleki, Saber; Jiang, Xiangyu

    2002-01-01

    Bioanalytical methods using automated 96-well solid-phase extraction (SPE) and liquid chromatography with electrospray tandem mass spectrometry (LC/MS/MS) are widely used in the pharmaceutical industry. SPE methods typically require manual steps of drying of the eluates and reconstituting of the analytes with a suitable injection solvent possessing elution strength weaker than the mobile phase. In this study, we demonstrated a novel approach of eliminating these two steps in 96-well SPE by using normal-phase LC/MS/MS methods with low aqueous/high organic mobile phases, which consisted of 70-95% organic solvent, 5-30% water, and small amount of volatile acid or buffer. While the commonly used SPE elution solvents (i.e. acetonitrile and methanol) have stronger elution strength than a mobile phase on reversed-phase chromatography, they are weaker elution solvents than a mobile phase for normal-phase LC/MS/MS and therefore can be injected directly. Analytical methods for a range of polar pharmaceutical compounds, namely, omeprazole, metoprolol, fexofenadine, pseudoephedrine as well as rifampin and its metabolite 25-desacetyl-rifampin, in biological fluids, were developed and optimized based on the foregoing principles. As a result of the time saving, a batch of 96 samples could be processed in one hour. These bioanalytical LC/MS/MS methods were validated according to "Guidance for Industry - Bioanalytical Method Validation" recommended by the Food and Drug Administration (FDA) of the United States.

  2. Polydopamine decorated 3D nickel foam for extraction of sixteen polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cai, Ying; Yan, Zhihong; Yang, Ming; Huang, Xiaoying; Min, Weiping; Wang, Lijia; Cai, Qingyun

    2016-12-23

    In this work, polydopamine coated 3D nickel foam (NF-PDA) was prepared and applied as sorbent for the solid phase extraction (SPE) of 16 polycyclic aromatic hydrocarbons (PAHs) from water samples. NF-PDA were synthesized by situ oxidative self-polymerization procedure and characterized by using the techniques of scanning electron microscopy (SEM), energy dispersive spectrum analysis (EDS) and X-ray photoelectron spectroscopy (XPS). Its performance was evaluated by the SPE of 16 PAHs from water samples, followed by gas chromatography-mass spectrometrical (GC-MS) analysis. The effects of the main experimental parameters (i.e. sorbent amount, desorption solvent, extraction time, water sample volume, elution volume, elution time, ionic strength and samle solution pH.) that could affect the extraction efficiencies were investigated. The results demonstrated that the NF-PDA had an excellent adsorption capability for the compounds. The methodology was validated for river water and wastewater, obtaining recoveries ranging from 89.6 to 97.5% with relative standard deviation values lower than 7.3% and limits of detection in the range 2.3-16.5ng/L.

  3. Estudo de compostos orgânicos em lixiviado de aterros sanitários por EFS e CG/EM Study of organic compounds in landfill leachate by SPE and GC/MSD

    Directory of Open Access Journals (Sweden)

    Irajá do Nascimento Filho

    2001-08-01

    Full Text Available The main purpose of this work was the qualitative study of organic compounds in landfill leachate. The samples were collected from a sanitary landfill located at Gravataí, a southern Brazilian city, that receive both, industrial and domestic refuse. The samples were submitted to solid phase extraction (SPE with XAD-4 resin as the stationary phase. The instrumental analysis was performed by Gas Chromatography with a Mass Spectrometry Detector (GC/MSD. The compounds achieved in the SPE extracts were tentatively identified by the GC/MS library. It was found several oxygen and nitrogen compounds like carboxylic acids, ketones, amines and amides. Sulfur compounds and phthalate esters are also identified.

  4. Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids

    NARCIS (Netherlands)

    Schellen, A.; Ooms, B.; Lagemaat, D. van de; Vreeken, R.; Dongen, W.D. van

    2003-01-01

    A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS sys

  5. Analysis of human urine metabolites using SPE and NMR spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Nuclear magnetic resonance (NMR) spectroscopic analysis of metabonome/metabolome has widespread applications in biomedical science researches. However, most of NMR resonances for urinary metabolites remain to be fully assigned. In the present study, human urine samples from two healthy volunteers were pre-treated with C18 solid-phase extraction and the resultant 5 sub-fractions were subjected to one- and two-dimensional NMR studies, including 1H J-Resolved, 1H-1H COSY, 1H-1H TOCSY, 1H-13C HSQC, and HMBC 2D NMR. More than 70 low molecular weight metabolites were identified, and complete assignments of 1H and 13C resonances including many complex coupled spin systems were obtained.

  6. A simple procedure for the extraction of DNA from long-term formalin-preserved brain tissues for the detection of EBV by PCR.

    Science.gov (United States)

    Hassani, Asma; Khan, Gulfaraz

    2015-12-01

    Long-term formalin fixed brain tissues are potentially an important source of material for molecular studies. Ironically, very few protocols have been published describing DNA extraction from such material for use in PCR analysis. In our attempt to investigate the role of Epstein-Barr virus (EBV) in the pathogenesis of multiple sclerosis (MS), extracting PCR quality DNA from brain samples fixed in formalin for 2-22 years, proved to be very difficult and challenging. As expected, DNA extracted from these samples was not only of poor quality and quantity, but more importantly, it was frequently found to be non-amplifiable due to the presence of PCR inhibitors. Here, we describe a simple and reproducible procedure for extracting DNA using a modified proteinase K and phenol-chloroform methodology. Central to this protocol is the thorough pre-digestion washing of the tissues in PBS, extensive digestion with proteinase K in low SDS containing buffer, and using low NaCl concentration during DNA precipitation. The optimized protocol was used in extracting DNA from meninges of 26 MS and 6 non-MS cases. Although the quality of DNA from these samples was generally poor, small size amplicons (100-200 nucleotides) of the house-keeping gene, β-globin could be reliably amplified from all the cases. PCR for EBV revealed positivity in 35% (9/26) MS cases, but 0/6 non-MS cases. These findings indicate that the method described here is suitable for PCR detection of viral sequences in long-term formalin persevered brain tissues. Our findings also support a possible role for EBV in the pathogenesis of MS.

  7. Assessment of bioavailable metals in the sediments of Yamuna flood plain using two different single extraction procedures

    Directory of Open Access Journals (Sweden)

    Sudesh Chaudhary

    2016-01-01

    Full Text Available Though flood plains are considered as most fertile areas across the world but they have come under severe stress due to the flow of untreated domestic and industrial effluents and therefore, needed attention for its characterisation and subsequent treatment plans. The sediment samples, collected at 0–15, 15–35 and 30–60 cm depth levels during pre and post monsoon season from east and west sides of the river Yamuna around the national capital region of Delhi, were assessed for bioavailability of lead (Pb, zinc (Zn and nickel (Ni using Ethylene Diamine Tetra Acetic Acid (EDTA and acetic acid. The average concentrations of Zn (25 ± 6 mg kg−1 and Pb (33 ± 6 mg kg−1 leached in EDTA were higher than that of in acetic acid (Zn: 22 ± 6 mg kg−1; Pb: 24 ± 5 mg kg−1 whereas Ni (24 ± 6 mg kg−1 leached more in acetic acid compared to EDTA (Ni: 21 ± 4 mg kg−1. The bioavailable concentrations of metals were comparable among 0–15 and 15–35 cm depth samples but decreased in 35–60 cm depth samples. The post monsoon samples contained lower amounts of total metals in comparison to pre-monsoon samples, an indication of washout/dilution effects of flood/high water flow during monsoon season. The percentages of metals, with reference to their respective total concentrations, in the flood plain sediments as extracted by EDTA were in the range of 14–47% for Pb, 17–54% for Zn, and 15–39% for Ni. The Zn, Ni and Pb were soluble in acetic acid in the range of 12–39%, 16.7–36.5% and 14–36%, respectively. The chemical nature of extracting agent affected the metal leaching. Acetic acid, a weak acid, extracted the metals that were present in exchangeable fraction and easily movable whereas EDTA, hexa-dentate complexing agent, extracted metals from carbonate and organically bound fractions of the sediment samples. This could result in metal accumulation in the floodplains, biomagnification, adverse

  8. Surface Signature Characterization at SPE through Ground-Proximal Methods: Methodology Change and Technical Justification

    Energy Technology Data Exchange (ETDEWEB)

    Schultz-Fellenz, Emily S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-09

    A portion of LANL’s FY15 SPE objectives includes initial ground-based or ground-proximal investigations at the SPE Phase 2 site. The area of interest is the U2ez location in Yucca Flat. This collection serves as a baseline for discrimination of surface features and acquisition of topographic signatures prior to any development or pre-shot activities associated with SPE Phase 2. Our team originally intended to perform our field investigations using previously vetted ground-based (GB) LIDAR methodologies. However, the extended proposed time frame of the GB LIDAR data collection, and associated data processing time and delivery date, were unacceptable. After technical consultation and careful literature research, LANL identified an alternative methodology to achieve our technical objectives and fully support critical model parameterization. Very-low-altitude unmanned aerial systems (UAS) photogrammetry appeared to satisfy our objectives in lieu of GB LIDAR. The SPE Phase 2 baseline collection was used as a test of this UAS photogrammetric methodology.

  9. Proceedings of the 1992 SPE oil and gas economics, finance and management conference

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    This volume contains the proceedings of the SPE 1992 Oil and Gas Economics, Finance and Management Conference. Topics covered include: Iran's petroleum industry, planning and control of reserves, natural gas supply and demand. petroleum investment and exploration contracts, and project financing.

  10. HPLC-SPE-NMR for combinatorial biosynthetic investigations – Expanding the landscape of diterpene structural diversity

    DEFF Research Database (Denmark)

    Kongstad, Kenneth Thermann; Andersen-Ranberg, Johan; Hamberger, Björn Robert;

    In this work, the analytical technique, HPLC-HRMS-SPE-NMR was used for the first time in combination with combinatorial biosynthetic investigations in N. benthamiana. This efficient setup allowed for identification of several diterpene synthase (diTPS) combinations responsible for stereospecific...

  11. Selective extraction of chromium(VI) using a leaching procedure with sodium carbonate from some plant leaves, soil and sediment samples

    Energy Technology Data Exchange (ETDEWEB)

    Elci, Latif, E-mail: elci@pamukkale.edu.tr [Department of Chemistry, Pamukkale University, 20017 Denizli (Turkey); Divrikli, Umit; Akdogan, Abdullah; Hol, Aysen; Cetin, Ayse [Department of Chemistry, Pamukkale University, 20017 Denizli (Turkey); Soylak, Mustafa [Department of Chemistry, Erciyes University, 38039 Kayseri (Turkey)

    2010-01-15

    Speciation of chromium in some plant leaves, soil and sediment samples was carried out by selective leaching of Cr(VI) using a sodium carbonate leaching procedure. Total chromium from the samples was extracted using aqua regia and oxidative acid digestion, respectively. The concentrations of chromium species in the extracts were determined using by graphite furnace atomic absorption spectrometry (GFAAS). Uncoated graphite furnace tubes were used as an atomizer. Due to the presence of relatively high amounts of Na{sub 2}CO{sub 3} in the resulting samples, the possible influences of Na{sub 2}CO{sub 3} on the absorbance signals were checked. There is no interference of Na{sub 2}CO{sub 3} on the chromium absorbance up to 0.1 mol L{sup -1} Na{sub 2}CO{sub 3}. A limit of detection (LOD) for determination of Cr(VI) in 0.1 Na{sub 2}CO{sub 3} solution by GFAAS was found to be 0.93 {mu}g L{sup -1}. The procedure was applied to environmental samples. The relative standard deviation, R.S.D. as precision for 10 replicate measurements of 20 {mu} L{sup -1} Cr in processed soil sample was 4.2%.

  12. Extraction procedure may not be feasible for cadmium analysis of tissues, such as horse kidney cortex, having a very high cadmium content

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.G. (The Karenlinska Inst., Stockholm, Sweden); Lind, B.; Piscator, M.; Sundstedt, K.; Akerberg, S.

    1981-12-01

    In the light of the discrepancy between data on cadmium in horse kidney in the U.S. and what has been reported in Europe the present authors have tested the analytical procedure used by Penumarthy et al. (1980). Cadmium in reference pig kidney and horse kidney cortex was determined by flame atomic absorption spectrophotometry after wet digestion, dissolving of the residue in water, complexing with APDC and extraction into MIBK. The ratio between the measured amount (minus blank) and the calculated amount of cadmium in the samples was 86% for blank with addition of 0.5 ..mu..g cadmium and 91% for low-level pig kidney cortex with or without the addition of 0.5 ..mu..g cadmium. The ratio was unacceptably low for horse kidney cortex having a concentration of greater than or equal to 117 ..mu..g/g dry wt. Concentrations of this magnitude are also found in human kidney and in human and horse liver. Data of Penumarthy et al. (1980) are also unusual in that the average cadmium concentration was 3.4 ..mu..g/g wet wt in horse liver and 2.5 ..mu..g/g in horse kidney. As a rule, cadmium concentration in kidney exceeds that in liver by a factor of 2-15. The capacity of the extraction procedure appears to be insufficient at high and intermediate cadmium levels. 1 table (JMT)

  13. Streptococcal pyogenic exotoxin B (SpeB) boosts the contact system via binding of a-1 antitrypsin

    DEFF Research Database (Denmark)

    Meinert Niclasen, Louise; Olsen, Johan G; Dagil, Robert

    2011-01-01

    The Streptococcus pyogenes cysteine protease SpeB (streptococcal pyrogenic exotoxin B) is important for the invasive potential of the bacteria, but its production is down-regulated following systemic infection. This prompted us to investigate if SpeB potentiated the host immune response after...

  14. Cleanup and analysis of sugar phosphates in biological extracts by using solid phase extraction and anion-exchange chromatography with pulsed amperometric detection

    DEFF Research Database (Denmark)

    Smith, Hans Peter; Cohen, A.; Buttler, T.

    1998-01-01

    A cleanup method based on anion-exchange solid-phase extraction (SPE) was developed to render biological extracts suitable for the analysis of hexose phosphates with a modified anion-exchange chromatography method and pulsed amperometric detection. The method was applied to cell extracts of Sacch......A cleanup method based on anion-exchange solid-phase extraction (SPE) was developed to render biological extracts suitable for the analysis of hexose phosphates with a modified anion-exchange chromatography method and pulsed amperometric detection. The method was applied to cell extracts...... of Saccharomyces cerevisiae obtained by using cold methanol as quenching agent and chloroform as extraction solvent. It was shown that pretreatment of the cell extract with SPE markedly improved the quality of the liquid chromatography analysis with recoveries of the sugar phosphates close to 100%. Furthermore...

  15. Simultaneous analysis of diazepam and its metabolites in rat plasma and brain tissue by HPLC-UV and SPE.

    Science.gov (United States)

    Mercolini, Laura; Mandrioli, Roberto; Iannello, Carmelina; Matrisciano, Francesco; Nicoletti, Ferdinando; Raggi, Maria Augusta

    2009-11-15

    Diazepam is frequently used as an adjuvant during antidepressant therapy. Recently, some studies have suggested that the treatment with benzodiazepines could have different efficacy in depressed patients as opposed to non-depressed ones. To clarify the matter, a study is currently underway, regarding the drug metabolism in rats. In order to obtain a more complete and significant set of data, the main diazepam metabolites have also been considered, namely: nordiazepam, temazepam and oxazepam. A feasible and reliable HPLC method has been developed for the simultaneous determination of these compounds in plasma and brain tissue of rats. The method has been applied to "normal" rats and to genetic rat models of depression in order to estimate drug metabolism in different breeds. Analyte separation was achieved on a C8 reversed phase column using an acidic phosphate buffer/acetonitrile mixture as the mobile phase. The detection wavelength was 238 nm. An original sample pre-treatment, based on solid-phase extraction (SPE) was developed in order to eliminate endogenous interference, using only 250 microL of matrix (brain homogenate or plasma) for a complete analysis. The method has been validated with good results in terms of precision, extraction yield, sensitivity, selectivity and accuracy on both matrices and has been successfully applied to samples from some rats subjected to the preliminary study. The obtained data will hopefully contribute to the clarification of possible differences between depressed and non-depressed subjects with respect to benzodiazepine biotransformation.

  16. Multiplexed Colorimetric Solid-Phase Extraction

    Science.gov (United States)

    Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.

    2009-01-01

    Multiplexed colorimetric solid-phase extraction (MC-SPE) is an extension of colorimetric solid-phase extraction (C-SPE) an analytical platform that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water. In CSPE, analytes are extracted and complexed on the surface of an extraction membrane impregnated with a colorimetric reagent. The analytes are then quantified directly on the membrane surface using a handheld diffuse reflectance spectrophotometer. Importantly, the use of solid-phase extraction membranes as the matrix for impregnation of the colorimetric reagents creates a concentration factor that enables the detection of low concentrations of analytes in small sample volumes. In extending C-SPE to a multiplexed format, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple sample syringes have been designed, enabling the simultaneous determination of multiple analytes. Separate, single analyte membranes, placed in a readout cartridge create unique, analyte-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. In a demonstration, MC-SPE was used to measure the pH of a sample and quantitate Ag(I) and Ni(II).

  17. From soil to leaves--aluminum fractionation by single step extraction procedures in polluted and protected areas.

    Science.gov (United States)

    Frankowski, Marcin; Zioła-Frankowska, Anetta; Siepak, Jerzy

    2013-09-30

    The paper presents the fractionation of aluminum in the samples of soil and plants of different species using a selective single-step extraction method. The study was conducted in the area located near a chemical plant, which for many years served as a post-crystallization leachate disposal site storing chemical waste (sector I), and in the area around the site: in Wielkopolski National Park, Rogalin Landscape Park and toward the infiltration ponds at the "Dębina" groundwater well-field for the city of Poznań (Poland) (sector II). The results of aluminum fractionation in samples of soil, leaves and plants showed heavy pollution with aluminum, especially in the water soluble aluminum fraction - Alsw (maximum concentration of aluminum in soil extract was 234.8 ± 4.8 mg kg(-1), in the leaves of Betula pendula it was 107.4 ± 1.8 mg kg(-1) and in the plants of Artemisia vulgaris (root) and Medicago sativa (leaves) it amounted to 464.7 ± 10.7 mg kg(-1)and 146.8 ± 1.2 mg kg(-1) respectively). In addition, the paper presents the problem of organic aluminum fractionation in biological samples and it shows the relationship between aluminum concentration in soil and the analysed woody and herbaceous species.

  18. Preconcentration procedure using cloud point extraction in the presence of electrolyte for cadmium determination by flame atomic absorption spectrometry

    Science.gov (United States)

    Coelho, Luciana Melo; Arruda, Marco Aurélio Zezzi

    2005-06-01

    This paper describes a micelle-mediated phase separation in the presence of electrolyte as a preconcentration method for cadmium determination by flame atomic absorption spectrometry (FAAS). Cadmium was complexed with ammonium O,O-diethyldithiophosphate (DDTP) in an acidic medium (0.32 mol l- 1 HCl) using Triton X-114 as surfactant and quantitatively extracted into a small volume (about 20 μl) of the surfactant-rich phase after centrifugation. The chemical variables that affect the cloud point extraction, such as complexing time (0 20 min), Triton X114 concentration (0.043 0.87% w/v) and complexing agent concentration (0.01 0.1 mol l- 1), were investigated. The cloud point is formed in the presence of NaCl at room temperature (25 °C), and the electrolyte concentration (0.5 5% w/v) was also investigated. Under optimized conditions, only 8 ml of sample was used in the presence of 0.043% w/v Triton X-114 and 1% (w/v) NaCl. This method permitted limits of detection and quantification of 0.9 μg l- 1 and 2.9 μg l- 1 Cd, respectively, and a linear calibration range from 3 to 400 μg l- 1 Cd. The proposed method was applied to Cd determination in physiological solutions (containing 0.9% (w/v) of NaCl), mineral water, lake water and cigarette samples (tobacco).

  19. Multivariate optimization of an ultrasound-assisted extraction procedure for Cu, Mn, Ni and Zn determination in ration to chickens.

    Science.gov (United States)

    Barros, Joélia M; Bezerra, Marcos A; Valasques, Gisseli S; Do Nascimento Jr, Baraquízio B; Souza, Anderson S; De Aragão, Nádia M

    2013-09-01

    In this work, multivariate optimization techniques were used to develop a method based on the ultrasound-assisted extraction for copper, manganese, nickel and zinc determination from rations for chicken nutrition using flame atomic absorption spectrometry. The proportions of extracting components (2.0 mol.L-1 nitric, hydrochloric and acetic acid solutions) were optimized using centroid-simplex mixture design. The optimum proportions of this mixture taken as percentage of each component were respectively 20%, 37% and 43%. Variables of method (sample mass, sonication time and final acid concentration) were optimized using Doehlert design. The optimum values found for these variables were respectively 0.24 g, 18s and 3.6 mol.L-1. The developed method allows copper, manganese, nickel and zinc determination with quantification limits of 2.82; 4.52; 10.7; e 9.69 µg.g-1, and precision expressed as relative standard deviation (%RSD, 25 µg.g-1, N = 5) of 5.30; 2.13; 0.88; and 0.83%, respectively. This method was applied in the analytes determination from chicken rations collected from specialized commerce in Jequié city (Bahia State/Brazil). Application of paired t-test at the obtained results, in a confidence level of 95%, does not show significant difference between the proposed method and the microwave-assisted digestion.

  20. Multivariate optimization of an ultrasound-assisted extraction procedure for Cu, Mn, Ni and Zn determination in ration to chickens

    Directory of Open Access Journals (Sweden)

    JOELIA M. BARROS

    2013-09-01

    Full Text Available In this work, multivariate optimization techniques were used to develop a method based on the ultrasound-assisted extraction for copper, manganese, nickel and zinc determination from rations for chicken nutrition using flame atomic absorption spectrometry. The proportions of extracting components (2.0 mol.L–1 nitric, hydrochloric and acetic acid solutions were optimized using centroid-simplex mixture design. The optimum proportions of this mixture taken as percentage of each component were respectively 20%, 37% and 43%. Variables of method (sample mass, sonication time and final acid concentration were optimized using Doehlert design. The optimum values found for these variables were respectively 0.24 g, 18s and 3.6 mol.L–1. The developed method allows copper, manganese, nickel and zinc determination with quantification limits of 2.82; 4.52; 10.7; e 9.69 µg.g–1, and precision expressed as relative standard deviation (%RSD, 25 µg.g–1, N = 5 of 5.30; 2.13; 0.88; and 0.83%, respectively. This method was applied in the analytes determination from chicken rations collected from specialized commerce in Jequié city (Bahia State/Brazil. Application of paired t-test at the obtained results, in a confidence level of 95%, does not show significant difference between the proposed method and the microwave-assisted digestion.

  1. On-line coupling of solid-phase extraction with mass spectrometry for the analysis of biological samples. II. Determination of clenbuterol in urine using multiple-stage mass spectrometry in an ion-trap mass spectrometer

    NARCIS (Netherlands)

    van Hout, MWJ; Hofland, CM; Niederlander, HAG; de Jong, GJ

    2000-01-01

    Solid-phase extraction (SPE) was coupled to ion-trap mass spectrometry to determine clenbuterol in urine. For SPE a cartridge exchanger was used and, after extraction, the eluate was directly introduced into the mass spectrometer, For two types of cartridges, i.e. C-18 and polydivinylbenzene (PDVB),

  2. Pharmacological effects of saw palmetto extract in the lower urinary tract

    Institute of Scientific and Technical Information of China (English)

    Mayumi SUZUKI; Yoshihiko ITO; Tomomi FUJINO; Masayuki ABE; Satomi ONOUE; Keizo UMEGAKI; Hiroshi NOGUCHI; Shizuo YAMADA

    2009-01-01

    Saw palmetto extract (SPE), an extract from the ripe berries of the American dwarf palm, has been widely used as a thera-peutic remedy for urinary dysfunction due to benign prostatic hyperplasia (BPH) in Europe. Numerous mechanisms of action have been proposed for SPE, including the inhibition of 5α-reductase. Today, α1-adrenoceptor antagonists and muscarinic cholinoceptor antagonists are commonly used in the treatment of men with voiding symptoms secondary to BPH. The improvement of voiding symptoms in patients taking SPE may arise from its binding to pharmacologically rel-evant receptors in the lower urinary tract, such as α1-adrenoceptors, muscarinic cholinoceptors, 1,4-dihyropyridine recep-tors and vanilloid receptors. Furthermore, oral administration of SPE has been shown to attenuate the up-regulation of α1-adrenoceptors in the rat prostate induced by testosterone. Thus, SPE at clinically relevant doses may exert a direct effect on the pharmacological receptors in the lower urinary tract, thereby improving urinary dysfunction in patients with BPH and an overactive bladder. SPE does not have interactions with co-administered drugs or serious adverse events in blood biochemical parameters, suggestive of its relative safety, even with long-term intake. Clinical trials (placebo-controlled and active-controlled trials) of SPE conducted in men with BPH were also reviewed. This review should contribute to the under-standing of the pharmacological effects of SPE in the treatment of patients with BPH and associated lower urinary tract symptoms (LUTS).

  3. Time-Dependent Moment Tensors of the First Four Source Physics Experiments (SPE) Explosions

    Science.gov (United States)

    Yang, X.

    2015-12-01

    We use mainly vertical-component geophone data within 2 km from the epicenter to invert for time-dependent moment tensors of the first four SPE explosions: SPE-1, SPE-2, SPE-3 and SPE-4Prime. We employ a one-dimensional (1D) velocity model developed from P- and Rg-wave travel times for Green's function calculations. The attenuation structure of the model is developed from P- and Rg-wave amplitudes. We select data for the inversion based on the criterion that they show consistent travel times and amplitude behavior as those predicted by the 1D model. Due to limited azimuthal coverage of the sources and the mostly vertical-component-only nature of the dataset, only long-period, diagonal components of the moment tensors are well constrained. Nevertheless, the moment tensors, particularly their isotropic components, provide reasonable estimates of the long-period source amplitudes as well as estimates of corner frequencies, albeit with larger uncertainties. The estimated corner frequencies, however, are consistent with estimates from ratios of seismogram spectra from different explosions. These long-period source amplitudes and corner frequencies cannot be fit by classical P-wave explosion source models. The results motivate the development of new P-wave source models suitable for these chemical explosions. To that end, we fit inverted moment-tensor spectra by modifying the classical explosion model using regressions of estimated source parameters. Although the number of data points used in the regression is small, the approach suggests a way for the new-model development when more data are collected.

  4. Analysis of the Source Physics Experiment SPE4 Prime Using State-Of Parallel Numerical Tools.

    Science.gov (United States)

    Vorobiev, O.; Ezzedine, S. M.; Antoun, T.; Glenn, L.

    2015-12-01

    This work describes a methodology used for large scale modeling of wave propagation from underground chemical explosions conducted at the Nevada National Security Site (NNSS) fractured granitic rock. We show that the discrete natures of rock masses as well as the spatial variability of the fabric of rock properties are very important to understand ground motions induced by underground explosions. In order to build a credible conceptual model of the subsurface we integrated the geological, geomechanical and geophysical characterizations conducted during recent test at the NNSS as well as historical data from the characterization during the underground nuclear test conducted at the NNSS. Because detailed site characterization is limited, expensive and, in some instances, impossible we have numerically investigated the effects of the characterization gaps on the overall response of the system. We performed several computational studies to identify the key important geologic features specific to fractured media mainly the joints characterized at the NNSS. We have also explored common key features to both geological environments such as saturation and topography and assess which characteristics affect the most the ground motion in the near-field and in the far-field. Stochastic representation of these features based on the field characterizations has been implemented into LLNL's Geodyn-L hydrocode. Simulations were used to guide site characterization efforts in order to provide the essential data to the modeling community. We validate our computational results by comparing the measured and computed ground motion at various ranges for the recently executed SPE4 prime experiment. We have also conducted a comparative study between SPE4 prime and previous experiments SPE1 and SPE3 to assess similarities and differences and draw conclusions on designing SPE5.

  5. Ochratoxin A in raisins and currants: basic extraction procedure used in two small marketing surveys of the occurrence and control of the heterogeneity of the toxins in samples.

    Science.gov (United States)

    Möller, T E; Nyberg, M

    2003-11-01

    A basic extraction procedure for analysis of ochratoxin A (OTA) in currants and raisins is described, as well as the occurrence of OTA and a control of heterogeneity of the toxin in samples bought for two small marketing surveys 1999/2000 and 2001/02. Most samples in the surveys were divided into two subsamples that were individually prepared as slurries and analysed separately. The limit of quantification for the method was estimated as 0.1 microg kg(-1) and recoveries of 85, 90 and 115% were achieved in recovery experiments at 10, 5 and 0.1 microg kg(-1), respectively. Of all 118 subsamples analysed in the surveys, 96 (84%) contained ochratoxin A at levels above the quantification level and five samples (4%) contained more than the European Community legislation of 10 microg kg(-1). The OTA concentrations found in the first survey were in the range Big differences were often achieved between individual subsamples of the original sample, which indicate a wide heterogeneous distribution of the toxin. Data from the repeatability test as well as recovery experiments from the same slurries showed that preparation of slurries as described here seemed to give a homogeneous and representative sample. The extraction with the basic sodium bicarbonate-methanol mixture used in the surveys gave similar or somewhat higher OTA values on some samples tested in a comparison with a weak phosphoric acid water-methanol extraction mixture.

  6. Screening procedure for detection of non-steroidal anti-inflammatory drugs and their metabolites in urine as part of a systematic toxicological analysis procedure for acidic drugs and poisons by gas chromatography-mass spectrometry after extractive methylation.

    Science.gov (United States)

    Maurer, H H; Tauvel, F X; Kraemer, T

    2001-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used as analgesic and anti-rheumatic drugs, and they are often misused. A gas chromatographic-mass spectrometric (GC-MS) screening procedure was developed for their detection in urine as part of a systematic toxicological analysis procedure for acidic drugs and poisons after extractive methylation. The compounds were separated by capillary GC and identified by computerized MS in the full-scan mode. Using mass chromatography with the ions m/z 119, 135, 139, 152, 165, 229, 244, 266, 272, and 326, the possible presence of NSAIDs and their metabolites could be indicated. The identity of positive signals in such mass chromatograms was confirmed by comparison of the peaks underlying full mass spectra with the reference spectra recorded during this study. This method allowed the detection of therapeutic concentrations of acemetacin, acetaminophen (paracetamol), acetylsalicylic acid, diclofenac, diflunisal, etodolac, fenbufen, fenoprofen, flufenamic acid, flurbiprofen, ibuprofen, indometacin, kebuzone, ketoprofen, lonazolac, meclofenamic acid, mefenamic acid, mofebutazone, naproxen, niflumic acid, phenylbutazone, suxibuzone, tiaprofenic acid, tolfenamic acid, and tolmetin in urine samples. The overall recoveries of the different NSAIDs ranged between 50 and 80% with coefficients of variation of less than 15% (n = 5), and the limits of detection of the different NSAIDs were between 10 and 50 ng/mL (S/N = 3) in the full-scan mode. Extractive methylation has proved to be a versatile method for STA of various acidic drugs, poisons, and their metabolites in urine. It has also successfully been used for plasma analysis.

  7. Comparison of DNA extraction kits and modification of DNA elution procedure for the quantitation of subdominant bacteria from piggery effluents with real-time PCR.

    Science.gov (United States)

    Desneux, Jérémy; Pourcher, Anne-Marie

    2014-08-01

    Four commercial DNA extraction kits and a minor modification in the DNA elution procedure were evaluated for the quantitation of bacteria in pig manure samples. The PowerSoil(®), PowerFecal(®), NucleoSpin(®) Soil kits and QIAamp(®) DNA Stool Mini kit were tested on raw manure samples and on lagoon effluents for their ability to quantify total bacteria and a subdominant bacteria specific of pig manure contamination: Lactobacillus amylovorus. The NucleoSpin(®) Soil kit (NS kit), and to a lesser extent the PowerFecal(®) kit were the most efficient methods. Regardless of the kit utilized, the modified elution procedure increased DNA yield in the lagoon effluent by a factor of 1.4 to 1.8. When tested on 10 piggery effluent samples, compared to the QIAamp kit, the NS kit combined with the modified elution step, increased by a factor up to 1.7 log10 the values of the concentration of L. amylovorus. Regardless of the type of manure, the best DNA quality and the highest concentrations of bacteria were obtained using the NS kit combined with the modification of the elution procedure. The method recommended here significantly improved quantitation of subdominant bacteria in manure. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  8. A novel solid phase extraction procedure on Amberlite XAD-1180 for speciation of Cr(III), Cr(VI) and total chromium in environmental and pharmaceutical samples.

    Science.gov (United States)

    Narin, Ibrahim; Kars, Ayse; Soylak, Mustafa

    2008-01-31

    Due to the toxicity of chromium, species depend on their chemical properties and bioavailabilities, speciation of chromium is very important in environmental samples. A speciation procedure for chromium(III), chromium(VI) and total chromium in environmental samples is presented in this work, prior to flame atomic absorption spectrometric determination of chromium. The procedure is based on the adsorption of Cr(III)-diphenylcarbazone complex on Amberlite XAD-1180 resin. After oxidation of Cr(III), the developed solid phase extraction system was applied to determinate the total chromium. Cr(III) was calculated as the difference between the total Cr content and the Cr(VI) content. The analytical conditions for the quantitative recoveries of Cr(VI) on Amberlite XAD-1180 resin were investigated. The effects of some alkaline, earth alkaline, metal ions and also some anions were also examined. Preconcentration factor was found to be 75. The detection limits (LOD) based on three times sigma of the blank (N: 21) for Cr(VI) and total chromium were 7.7 and 8.6 microg/L, respectively. Satisfactory results for the analysis of total chromium in the stream sediment (GBW7310) certified reference material for the validation of the presented method was obtained. The procedure was applied to food, water and pharmaceutical samples successfully.

  9. Fertilization in C. elegans requires an intact C-terminal RING finger in sperm protein SPE-42

    Directory of Open Access Journals (Sweden)

    Rumbley Jon N

    2011-02-01

    Full Text Available Abstract Background The C. elegans sperm protein SPE-42, a membrane protein of unknown structure and molecular function, is required for fertilization. Sperm from worms with spe-42 mutations appear normal but are unable to fertilize eggs. Sequence analysis revealed the presence of 8 conserved cysteine residues in the C-terminal cytoplasmic domain of this protein suggesting these residues form a zinc-coordinating RING finger structure. Results We made an in silico structural model of the SPE-42 RING finger domain based on primary sequence analysis and previously reported RING structures. To test the model, we created spe-42 transgenes coding for mutations in each of the 8 cysteine residues predicted to coordinate Zn++ ions in the RING finger motif. Transgenes were crossed into a spe-42 null background and protein function was measured by counting progeny. We found that all 8 cysteines are required for protein function. We also showed that sequence differences between the C-terminal 29 and 30 amino acids in C. elegans and C. briggsae SPE-42 following the RING finger domain are not responsible for the failure of the C. briggsae SPE-42 homolog to rescue C. elegans spe-42 mutants. Conclusions The results suggest that a bona fide RING domain is present at the C-terminus of the SPE-42 protein and that this motif is required for sperm-egg interactions during C. elegans fertilization. Our structural model of the RING domain provides a starting point for further structure-function analysis of this critical region of the protein. The C-terminal domain swap experiment suggests that the incompatibility between the C. elegans and C. briggsae SPE-42 proteins is caused by small amino acid differences outside the C-terminal domain.

  10. The Immunoglobulin-like Gene spe-45 Acts during Fertilization in Caenorhabditis elegans like the Mouse Izumo1 Gene.

    Science.gov (United States)

    Nishimura, Hitoshi; Tajima, Tatsuya; Comstra, Heather Skye; Gleason, Elizabeth J; L'Hernault, Steven W

    2015-12-21

    The Caenorhabditis elegans spe-9 class genes, which show specific or predominant expression in the male germline, are indispensable for fertilization [1, 2]. However, due to the rapid evolution of genes involved in reproduction, we do not currently know if there are spe-9 class genes in mammals that play similar roles during fertilization to those found in C. elegans. In mice, the Izumo1 gene encodes a sperm-specific transmembrane (TM) protein with a single immunoglobulin (Ig)-like domain that is absolutely required for gamete fusion [3, 4]. In this study, we hypothesized that C. elegans has a new member of the spe-9 class genes coding for an IZUMO1-like protein. We screened C. elegans microarray data [5, 6] to identify male germline-enriched genes that encode membrane proteins with Ig-like domains. A deletion (tm3715) in one such gene (F28D1.8) caused hermaphrodites to show a male germline-dependent self-sterility, so we have named it spe-45. Mutant spe-45 worms seemed to normally undergo spermatogenesis (spermatid production by meiosis) and spermiogenesis (spermatid activation into actively motile spermatozoa). spe-45 mutant spermatozoa, however, could not complete gamete fusion, which is a characteristic of all spe-9 class mutants [1, 2]. Moreover, spe-45 self-sterile worms were rescued by a transgene expressing chimeric SPE-45 protein in which its Ig-like domain was replaced by the Ig-like domain from mouse IZUMO1. Hence, C. elegans SPE-45 and mouse IZUMO1 appear to have retained a common function(s) that is required during fertilization.

  11. Utilizing ion-pairing hydrophilic interaction chromatography solid phase extraction for efficient glycopeptide enrichment in glycoproteomics

    DEFF Research Database (Denmark)

    Mysling, Simon; Palmisano, Giuseppe; Højrup, Peter;

    2010-01-01

    Glycopeptide enrichment is a prerequisite to enable structural characterization of protein glycosylation in glycoproteomics. Here we present an improved method for glycopeptide enrichment based on zwitter-ionic hydrophilic interaction chromatography solid phase extraction (ZIC-HILIC SPE...

  12. Preconcentration procedure using cloud point extraction in the presence of electrolyte for cadmium determination by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Melo Coelho, Luciana [Departamento de Quimica Analitica, Universidade Estadual de Campinas (Unicamp), Cidade Universitaria ' Zeferino Vaz' , 13084-971, Campinas, Sao Paulo (Brazil); Arruda, Marco Aurelio Zezzi [Departamento de Quimica Analitica, Universidade Estadual de Campinas (Unicamp), Cidade Universitaria ' Zeferino Vaz' , 13084-971, Campinas, Sao Paulo (Brazil)]. E-mail: zezzi@iqm.unicamp.br

    2005-06-30

    This paper describes a micelle-mediated phase separation in the presence of electrolyte as a preconcentration method for cadmium determination by flame atomic absorption spectrometry (FAAS). Cadmium was complexed with ammonium O,O-diethyldithiophosphate (DDTP) in an acidic medium (0.32 mol l{sup -} {sup 1} HCl) using Triton X-114 as surfactant and quantitatively extracted into a small volume (about 20 {mu}l) of the surfactant-rich phase after centrifugation. The chemical variables that affect the cloud point extraction, such as complexing time (0-20 min), Triton X114 concentration (0.043-0.87% w/v) and complexing agent concentration (0.01-0.1 mol l{sup -} {sup 1}), were investigated. The cloud point is formed in the presence of NaCl at room temperature (25 deg. C), and the electrolyte concentration (0.5-5% w/v) was also investigated. Under optimized conditions, only 8 ml of sample was used in the presence of 0.043% w/v Triton X-114 and 1% (w/v) NaCl. This method permitted limits of detection and quantification of 0.9 {mu}g l{sup -} {sup 1} and 2.9 {mu}g l{sup -} {sup 1} Cd, respectively, and a linear calibration range from 3 to 400 {mu}g l{sup -} {sup 1} Cd. The proposed method was applied to Cd determination in physiological solutions (containing 0.9% (w/v) of NaCl), mineral water, lake water and cigarette samples (tobacco)

  13. Microwave-assisted extraction and ultrasonic slurry sampling procedures for cobalt determination in geological samples by electrothermal atomic absorption spectroscopy.

    Science.gov (United States)

    Felipe-Sotelo, M; Carlosena, A; Fernández, E; López-Mahía, P; Muniategui, S; Prada, D

    2004-06-17

    Slurry sampling is compared to microwave-assisted acid digestion for cobalt determination in soil/sediment samples by electrothermal atomic absorption spectrometry (ETAAS). Furnace temperature programs and appropriate amounts of three chemical modifiers were optimised in order to get the highest signals and good separations between the atomic and background signals. Using nitric acid (0.5% (v/v)) as liquid medium, no chemical modifier was needed. The detection limit, based on integrated absorbance, was 0.04mugg(-1) for digests and slurries. Within-batch precision and analytical recoveries were satisfactory for both procedures. Accuracy was tested by analysing a reference soil and a sediment from IRMM. The methods were further compared employing a set of roadside soils and estuarine sediments. As no significant differences (95% confidence) were found, practical analytical properties were suggested in order to select one of them.

  14. Evaluation of an automated high-volume extraction method for viral nucleic acids in comparison to a manual procedure with preceding enrichment.

    Science.gov (United States)

    Hourfar, M K; Schmidt, M; Seifried, E; Roth, W K

    2005-08-01

    Nucleic acid extraction still harbours the potential for improvements in automation and sensitivity of nucleic acid amplification technology (NAT) testing. This study evaluates the feasibility of a novel automated high-volume extraction protocol for NAT minipool testing in a blood bank setting. The chemagic Viral DNA/RNA Kit special for automated purification of viral nucleic acids from 9.6 ml of plasma by using the chemagic Magnetic Separation Module I was investigated. Analytical sensitivity for hepatitis C virus (HCV), human immunodeficiency virus-1 (HIV-1), hepatitis B virus (HBV), hepatitis A virus (HAV) and parvovirus B19 (B19) was compared to our present manual procedure that involves virus enrichment by centrifugation. Chemagic technology allows automation of the viral DNA/RNA extraction process. Viral nucleic acids were bound directly to magnetic beads from 9.6-ml minipools. By combining the automated magnetic beads-based extraction technology with our in-house TaqMan polymerase chain reaction (PCR) assays, 95% detection limits were 280 IU/ml for HCV, 4955 IU/ml for HIV-1, 249 IU/ml for HBV, 462 IU/ml for HAV and 460 IU/ml for B19, calculated for an individual donation in a pool of 96 donors. The detection limits of our present method were 460 IU/ml for HCV, 879 IU/ml for HIV-1, 90 IU/ml for HBV, 203 IU/ml for HAV and 314 IU/ml for B19. The 95% detection limits obtained by using the chemagic method were within the regulatory requirements for blood donor screening. The sensitivities detected for HCV, HBV, HAV and B19 were found to be in a range similar to that of the manual purification method. Sensitivity for HIV-1, however, was found to be inferior for the chemagic method in this study.

  15. In situ assessment of phyto and zooavailability of trace elements: A complementary approach to chemical extraction procedures.

    Science.gov (United States)

    Pauget, Benjamin; Faure, Olivier; Conord, Cyrille; Crini, Nadia; de Vaufleury, Annette

    2015-07-15

    For an accurate risk assessment of sites contaminated by trace elements (TE), measurements of bioavailability must be performed. This is routinely achieved using the standardized 0.01M CaCl2 method. However, the suitability of chemical extractions as proxies of bioavailability is questionable. We analyzed the correlations between chemically estimated TE bioavailability and TE actually accumulated by coupling plant and snails bioindicators. Results showed a better correlation between plant TE contents and CaCl2 fraction while total soil concentration better explained snail TE contents. However in both cases chemical measures were not suitable to predict TE accumulation and bioavailability. Considering the soil properties only improve the estimation of Cr, Ni and Pb accumulation by plants while for snails, TE contents in viscera were dependent both on soil and plant contents and soil properties. It highlights the complementarities of biomonitoring methods to assess bioavailability. This dual approach allows a "physiologically defined" evaluation of bioavailability. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. NEATTILL: A simplified procedure for nucleic acid extraction from arrayed tissue for TILLING and other high-throughput reverse genetic applications

    Directory of Open Access Journals (Sweden)

    Mohan Vijee

    2010-01-01

    Full Text Available Abstract Background TILLING (Targeting Induced Local Lesions in Genomes is a reverse genetics procedure for identifying point mutations in selected gene(s amplified from a mutagenized population using high-throughput detection platforms such as slab gel electrophoresis, capillary electrophoresis or dHPLC. One essential pre-requisite for TILLING is genomic DNA isolation from a large population for PCR amplification of selected target genes. It also requires multiplexing of genomic DNA isolated from different individuals (pooling in typically 8-fold pools, for mutation scanning, and to minimize the number of PCR amplifications, which is a strenuous and long-drawn-out work. We describe here a simplified procedure of multiplexing, NEATTILL (Nucleic acid Extraction from Arrayed Tissue for TILLING, which is rapid and equally efficient in assisting mutation detection. Results The NEATTILL procedure was evaluated for the tomato TILLING platform and was found to be simpler and more efficient than previously available methods. The procedure consisted of pooling tissue samples, instead of nucleic acid, from individual plants in 96-well plates, followed by DNA isolation from the arrayed samples by a novel protocol. The three variants of the NEATTILL procedure (vast, in-depth and intermediate can be applied across various genomes depending upon the population size of the TILLING platform. The 2-D pooling ensures the precise confirmation of the coordinates of the positive mutant line while scanning complementary plates. Choice of tissue for arraying and nucleic acid isolation is discussed in detail with reference to tomato. Conclusion NEATTILL is a convenient procedure that can be applied to all organisms, the genomes of which have been mutagenized and are being scanned for multiple alleles of various genes by TILLING for understanding gene-to-phenotype relationships. It is a time-saving, less labour intensive and reasonably cost-effective method. Tissue

  17. High sensitivity measurements of active oxysterols with automated filtration/filter backflush-solid phase extraction-liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Roberg-Larsen, Hanne; Strand, Martin Frank; Grimsmo, Anders; Olsen, Petter Angell; Dembinski, Jennifer L; Rise, Frode; Lundanes, Elsa; Greibrokk, Tyge; Krauss, Stefan; Wilson, Steven Ray

    2012-09-14

    Oxysterols are important in numerous biological processes, including cell signaling. Here we present an automated filtration/filter backflush-solid phase extraction-liquid chromatography-tandem mass spectrometry (AFFL-SPE-LC-MS/MS) method for determining 24-hydroxysterol and the isomers 25-hydroxycholesterol and 22S-hydroxycholesterol that enables simplified sample preparation, high sensitivity (~25 pg/mL cell lysis sample) and low sample variability. Only one sample transfer step was required for the entire process of cell lysis, derivatization and determination of selected oxysterols. During the procedure, autoxidation of cholesterol, a potential/common problem using standard analytical methods, was found to be negligible. The reversed phase AFFL-SPE-LC-MS/MS method utilizing a 1mm inner diameter column was validated, and used to determine levels of the oxysterol analytes in mouse fibroblast cell lines SSh-LII and NIH-3T3, and human cancer cell lines, BxPC3, HCT-15 and HCT-116. In BxPC3 cells, the AFFL-SPE-LC-MS/MS method was used to detect significant differences in 24S-OHC levels between vimentin+ and vimentin- heterogenous sub-populations. The methodology also allowed monitoring of significant alterations in 24S-OHC levels upon delivery of the Hedgehog (Hh) antagonist MS-0022 in HCT-116 colorectal carcinoma cell lines.

  18. On-cartridge derivatisation using a calixarene solid-phase extraction sorbent for facile, sensitive and fast determination of formaldehyde in beer.

    Science.gov (United States)

    Deng, Zhifen; Hu, Kai; Zhang, Yongming; Zhao, Wenjie; Wang, Fei; Guo, Ling; Zhang, Wenfen; He, Juan; Huang, Yanjie; Zhang, Shusheng

    2016-11-15

    This work demonstrates the successful application of an on-cartridge derivatisation procedure for facile, fast and sensitive determination of formaldehyde in beer by HPLC-UV. The derivatisation and solid-phase extraction (SPE) were integrated into a novel calixarene SPE sorbent: tetraazacalix[2]arene[2]triazine bonded silica gel. Specifically, 2,4-dinitrophenylhydrazine was adsorbed onto the sorbent in advance, based on the charge-transfer interaction between the macrocyclic molecule and nitrobenzenes. The method was optimised and validated: under the optimal conditions of derivatisation, SPE and HPLC separation, good linearity was obtained in the range of 0.080-3.2μgmL(-1) with a correlation coefficient of 0.9939, the limit of detection was 3.0ngmL(-1) (S/N=3), the limit of quantification was 10ngmL(-1) (S/N=10), and the recovery level using this method was desirable at 75-84%. The developed method was successfully applied to determine formaldehyde content in real beer samples; the results were in the range of 0.11-1.1μgmL(-1).

  19. A new procedure combining GC-MS with accelerated solvent extraction for the analysis of phthalic acid esters in contaminated soils

    Institute of Scientific and Technical Information of China (English)

    Tingting MA; Ying TENG; Peter CHRISTIE; Yongming LUO; Yongshan CHEN; Mao YE

    2013-01-01

    An optimized procedure based on gas chromatography-mass spectrometry (GC-MS) combined with accelerated solvent extraction (ASE) is developed for the analysis of six phthalic acid esters (PAEs), which are priority soil pollutants nominated by United States Environmental Protection Agency (USEPA). Quantification of PAEs in soil employs ultrasonic extraction (UE) (USEPA 3550) and ASE (USEPA 3545), followed by clean up procedures involving three different chromatography columns and two combined elution methods. GC-MS conditions under selected ion monitoring (SIM) mode are described and quality assurance and quality control (QA/ QC) criteria with high accuracy and sensitivity for target analytes were achieved. Method reliability is assured with the use of an isotopically labeled PAE, di-n-butyl phthalate-d4 (DnBP-D4), as a surrogate, and benzyl benzoate (BB) as an internal standard, and with the analysis of certified reference materials (CRM). QA/QC for the developed procedure was tested in four PAE-spiked soils and one PAE-contaminated soil. The four spiked soils were originated from typical Chinese agricultural fields and the contaminated soil was obtained from an electronic waste dismantling area. Instrument detection limits (IDLs) for the six PAEs ranged 0.10-0.31 μg·L-1 and method detection limits (MDLs) of the four spiked soils varied from a range of 20-70 μg· kg -1 to a range of 90-290 μg· kg-1. Lineal-iVy of response between 20 μg· L-1 and 2mg.L~ was also established and the correlation coefficients (R) were a11〉0.998. Spiked soil matrix showed relative recovery rates between 75 and 120% for the six target compounds and about 93% for the surrogate substance. The developed procedure is anticipated to be highly applicable for field surveys of soil PAE pollution in China.

  20. Simultaneous determination of six resorcylic acid lactones in feed using liquid chromatography-tandem mass spectrometry and multi-walled carbon nanotubes as a dispersive solid phase extraction sorbent.

    Science.gov (United States)

    Ying, Yong-Fei; Wu, Yin-Liang; Wen, Yi; Yang, Ting; Xu, Xiu-Qin; Wang, Yi-Zhen

    2013-09-13

    A simple and cost-effective pre-treatment procedure was developed for six resorcylic acid lactones (RALs) in feed using dispersive solid phase extraction (dSPE) with multi-walled carbon nanotubes (MWCNTs). The sample was analysed after purification by ultra-high performance liquid chromatography-negative electrospray ionisation tandem mass spectrometry (UHPLC-ESI-MS/MS). After extraction with acetonitrile/water (80:20, v/v) and dilution with water, a dSPE procedure was carried out with MWCNTs. The pH value of the extract, the extraction time for MWCNTs, the type and amount of MWCNTs and the type of eluent were optimised to increase the sample throughput and the sensitivity. The samples were quantified using the internal standard zearalenone-D6. The absolute recoveries of the target compounds from feed samples were most efficient when using 100mg of MWCNTs with an outer diameter of less than 8nm and a length of 10-30μm, and ethyl acetate was shown to be the most suitable solvent for desorbing the target compounds from the MWCNTs. The mean recoveries from fortified swine mixed feed samples ranged from 95.3% to 107.2% and had relative standard deviations lower than 10%; the limits of detection and quantification for RALs were in the ranges of 0.20-0.29μg/kg and 0.54-0.78μg/kg, respectively.

  1. Tea bag filter paper as a novel protective membrane for micro-solid phase extraction of butachlor in aqueous samples.

    Science.gov (United States)

    Pelden, Tshering; Thammaknet, Chongdee; Thavarungkul, Panote; Kanatharana, Proespichaya

    2014-01-01

    An innovative, cost-effective, simple, and environmental friendly tea bag filter paper protected micro-solid phase extraction (μ-SPE) technique was developed for the first time with the aim to miniaturize and minimize the use of organic solvents for the extraction and determination of butachlor in aqueous samples. The μ-SPE device was produced by packing 3.0 mg of an easily synthesized new sorbent, hydroxyl-functionalized polypyrrole (OH-PPY), inside a small tea bag filter paper sachet (1.0 cm × 0.5 cm) that served as a protective envelope. Both the extraction and desorption procedures were facilitated by sonication. Due to the high porosity and the fast water absorption of the tea bag filter paper, the analyte could easily diffuse through and enhance the interaction with the sorbent. Under the optimized conditions for the GC-ECD and the μ-SPE, the limit of detection (S/N ≥ 3) was 2.0 μg L(-1) while the limit of quantitation (S/N ≥ 10) was 10.0 μg L(-1). The recoveries of the butachlor spiked at 0.050, 0.10, and 0.50 μg mL(-1) ranged from 77.9 ± 3.0 to 112.5 ± 2.9%. The proposed method was successfully applied for the determination of butachlor in water samples from paddy cultivation sites. The levels found were from non-detectable to 24.71 ± 0.37 μg L(-1).

  2. Determination of artificial sweeteners in sewage sludge samples using pressurised liquid extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ordoñez, Edgar Y; Quintana, José Benito; Rodil, Rosario; Cela, Rafael

    2013-12-13

    An analytical method for the determination of six artificial sweeteners in sewage sludge has been developed. The procedure is based on pressurised liquid extraction (PLE) with water followed by solid-phase extraction (SPE) and subsequent liquid chromatography-tandem mass spectrometry analysis. After optimisation of the different PLE parameters, extraction with aqueous 500mM formate buffer (pH 3.5) at 80°C during a single static cycle of 21min proved to be best conditions. After a subsequent SPE, quantification limits, referred to dry weight (dw) of sewage sludge, ranged from 0.3ng/g for acesulfame (ACE) to 16ng/g for saccharin (SAC) and neohespiridine dihydrochalcone. The trueness, expressed as recovery, ranged between 72% and 105% and the precision, expressed as relative standard deviation, was lower than 16%. Moreover, the method proved its linearity up to the 2μg/g range. Finally, the described method was applied to the determination of the artificial sweeteners in primary and secondary sewage sludge from urban wastewater treatment plants. Four of the six studied artificial sweeteners (ACE, cyclamate, SAC and sucralose) were found in the samples at concentrations ranging from 17 to 628ng/g dw.

  3. Simultaneous determination of polycyclic aromatic hydrocarbons and benzene, toluene, ethylbenzene and xylene in water samples using a new sampling strategy combining different extraction modes and temperatures in a single extraction solid-phase microextraction-gas chromatography-mass spectrometry procedure.

    Science.gov (United States)

    Bianchin, Joyce Nunes; Nardini, Giuliana; Merib, Josias; Dias, Adriana Neves; Martendal, Edmar; Carasek, Eduardo

    2012-04-13

    This study proposes a new optimization approach for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene isomers (BTEX) from water samples using the solid-phase microextraction technique followed by gas chromatography-mass spectrometry (GC-MS) separation and detection. The objective of the study was to achieve compromise extraction conditions, suitable for all semi-volatile and volatile compounds, under which the amount extracted is maximized for all analytes. This was achieved by careful optimization of the fiber coating, salting-out effect, extraction time and temperature and extraction mode (headspace or direct immersion). With the optimized fiber coating - PDMS/DVB 65 μm - the other selected factors were optimized using a response surface methodology through central composite designs. As expected, the optimized results for each class of analytes varied significantly, probably due to the differences in their volatility and the equilibrium constants for the analyte/fiber coating. In order to overcome this issue, a new optimization approach was proposed based on a combination of extraction modes and extraction temperatures in a single extraction procedure. The final optimized procedure was: 48 min of extraction in direct immersion mode with the sample maintained at 80 °C followed by a further 32 min of headspace extraction with the sample temperature kept at 10 °C. The proposed procedure was compared with conventional methods based on the use of a single extraction mode and temperature (80 min of headspace extraction at 60 °C or 80 min of direct immersion extraction at 50 °C). The newly proposed method was shown to be more attractive as it extracted higher amounts of both semi-volatile and volatile compounds in a single extraction procedure compared to the conventional approaches. The optimized method was validated and excellent results were obtained.

  4. DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOIL BY ASE-GPC-SPE PURIFICATION AND HPLC DETECTION%快速溶剂(ASE)提取、凝胶渗透色谱(GPC)联合固相萃取(SPE)净化,高效液相色谱法测定土壤中的多环芳烃

    Institute of Scientific and Technical Information of China (English)

    张茜; 刘潇威; 罗铭; 王璐; 李红; 王迪; 徐亚平

    2011-01-01

    A new method using ASE combined with solid-phase extraction and GPC cleanup followed by HPLCtandem UV and fluorescence detection has been established for the quantitative determination of 16 PAHs in soils. In the method, the samples were extracted by ASE with acetone: dichloromethane (V:V, 50:50 )at 120 ℃, and dissolved in 9 mL hexane: ethyl acetate ( V: V, 50:50 ) after taking the extract to dryness with evaporation at 25 ℃. Then the extract was injected into GPC column with hexane:ethyl acetate( V: V,50:50)as the mobile phase at a flow rate of 5 mL·min-1 and GPC vacuum was 130 mbr/140 mbr. The 1340-3380 s fraction was collected for subsequent analysis. The portions collected from GPC were dissolved in 2 mL dichloromethane after taking the extract to dryness with nitrogen gas. Then the 2 mL extractions were purified by SPE using Florisil cartridges, eluted with 5 mL dichloromethane. Finally, the extraction was collected from SPE and dissolved in acetonitrile after taking it to dryness with nitrogen gas. The correlation coefficient of each PAH was r2 >0.99, the recovery fell within 62.9%-118.9%, and the relative standard derivation of PAHs was between 0.6% and 19.9%.%建立了采用快速溶剂提取(ASE),固相萃取(SPE)与凝胶渗透色谱(GPC)协同净化方法,使用高效液相色谱-紫外-荧光检测器(HPLC-UV-FLD)串联检测土壤中多环芳烃类化合物多残留的检测方法.通过对加速溶剂提取仪提取条件,凝胶渗透色谱和固相萃取净化条件的优化,确定土壤中多环芳烃类化合物多残留的前处理方法:提取溶剂为丙酮:二氯甲烷(V:V,50:50),提取温度120℃,GPC在线浓缩系统真空腔真空度为130mbr/140mbr,弗罗里硅土固相萃取柱净化,5mL二氯甲烷作为洗脱剂.方法回收率在62.9%-118.9%之间,RSD为0.6%-19.9%.

  5. Dispersive micro-solid phase extraction based on self-assembling, ionic liquid-coated magnetic particles for the determination of clofentezine and chlorfenapyr in environmental water samples.

    Science.gov (United States)

    Peng, Bing; Zhang, Jiaheng; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang

    2013-11-21

    Two ionic liquid-coated-Fe3O4 magnetic particles (IL-Fe3O4 MPs) were developed for use in two types of dispersive micro-solid phase extraction (D-μ-SPE) for the high-performance liquid chromatographic analysis of clofentezine and chlorfenapyr in environmental water samples. Self-assembling IL-Fe3O4 MPs were used in D-μ-SPE as adsorbents. Two D-μ-SPE extraction methods, namely, direct dispersive micro-solid phase extraction (d-D-μ-SPE) and in situ solvent formation-based dispersive micro-solid phase extraction (ISF-D-μ-SPE), were proposed, using [C8MIM][PF6] to extract analytes through two pathways. Lower IL doses were required in the extraction process compared with those in other IL-based methods. Fe3O4 MPs can also be recycled and reused after extraction and are thus environmentally friendly. These newly developed methods were demonstrated to be feasible for use in the quantitation of clofentezine and chlorfenapyr at trace levels, with lower limit of detection values ranging from 0.4 to 0.5 ng mL(-1) for d-D-μ-SPE and 0.4 ng mL(-1) for ISF-D-μ-SPE. Finally, relative standard deviations of less than 6.0% were obtained.

  6. Evaluation of SPE and GCR Radiation Effects in Inflatable, Space Suit and Composite Habitat Materials Project

    Science.gov (United States)

    Waller, Jess M.; Nichols, Charles

    2016-01-01

    The radiation resistance of polymeric and composite materials to space radiation is currently based on irradiating materials with Co-60 gamma-radiation to the equivalent total ionizing dose (TID) expected during mission. This is an approximation since gamma-radiation is not truly representative of the particle species; namely, Solar Particle Event (SPE) protons and Galactic Cosmic Ray (GCR) nucleons, encountered in space. In general, the SPE and GCR particle energies are much higher than Co-60 gamma-ray photons, and since the particles have mass, there is a displacement effect due to nuclear collisions between the particle species and the target material. This effort specifically bridges the gap between estimated service lifetimes based on decades old Co-60 gamma-radiation data, and newer assessments of what the service lifetimes actually are based on irradiation with particle species that are more representative of the space radiation environment.

  7. Hindlimb suspension and SPE-like radiation impairs clearance of bacterial infections.

    Directory of Open Access Journals (Sweden)

    Minghong Li

    Full Text Available A major risk of extended space travel is the combined effects of weightlessness and radiation exposure on the immune system. In this study, we used the hindlimb suspension model of microgravity that includes the other space stressors, situational and confinement stress and alterations in food intake, and solar particle event (SPE-like radiation to measure the combined effects on the ability to control bacterial infections. A massive increase in morbidity and decrease in the ability to control bacterial growth was observed using 2 different types of bacteria delivered by systemic and pulmonary routes in 3 different strains of mice. These data suggest that an astronaut exposed to a strong SPE during extended space travel is at increased risk for the development of infections that could potentially be severe and interfere with mission success and astronaut health.

  8. Optimization of a cloud point extraction procedure with response surface methodology for the quantification of dissolved iron in produced water from the petroleum industry using FAAS.

    Science.gov (United States)

    Gondim, Tamyris A; Guedes, Jhonyson A C; Ribeiro, Livia P D; Lopes, Gisele S; Matos, Wladiana O

    2017-01-30

    The characterization of inorganic elements in the produced water (PW) samples is a difficult task because of the complexity of the matrix. This work deals with a study of a methodology for dissolved Fe quantification in PW from oil industry by flame atomic absorption spectrometry (FAAS) after cloud point extraction (CPE). The procedure is based on the CPE using PAN as complexing agent and Triton X-114 as surfactant. The best conditions for Fe extraction parameters were studied using a Box-Behnken design. The proposed method presented a LOQ of 0.010μgmL(-1) and LOD of 0.003μgmL(-1). The precision of the method was evaluated in terms of repeatability, obtaining a coefficient of variation of 2.54%. The accuracy of the method was assessed by recovery experiments of Fe spiked that presented recovery of 103.28%. The method was applied with satisfactory performance to determine Fe by FAAS in PW samples.

  9. Determination of salicylic acid using a magnetic iron oxide nanoparticle-based solid-phase extraction procedure followed by an online concentration technique through micellar electrokinetic capillary chromatography.

    Science.gov (United States)

    Chang, Yu-Hsuan; Huang, Chang-Wei; Fu, Shih-Feng; Wu, Mei-Yao; Wu, Tsunghsueh; Lin, Yang-Wei

    2017-01-06

    In this study, a magnetic iron oxide nanoparticle-based solid-phase extraction procedure combined with the online concentration and separation of salicylic acid (SA) through micellar electrokinetic chromatography-UV detection (MEKC-UV) was developed. Under optimal experimental conditions, a good linearity in the range of 0.01-100μmolL(-1) was obtained with a coefficient of correlation of 0.9999. The detection sensitivity of the proposed method exhibited an approximately 1026-fold improvement compared with a single MEKC method without online concentration, and the detection limit (S/N=3) was 3.80nmolL(-1). The repeatability of the method was evaluated using intraday and interday RSDs (11.5% and 17.0%, respectively). The method was used to determine SA concentrations in tobacco leaves (Nicotiana tabacum L. cv. Samsun) from the NN genotype, nn genotype, and Nt-NahG mutant strains, as well as in shampoo and ointment samples. Rapid extraction and separation (<50min), acceptable repeatability (RSD<17.0%), and high spiked recoveries (95.8%-102.4%) were observed for plants, detergents, and pharmaceuticals.

  10. Ion suppression in the determination of clenbuterol in urine by solid-phase extraction atmospheric pressure chemical ionisation ion-trap mass spectrometry

    NARCIS (Netherlands)

    van Hout, M.W.J.; Niederlander, H.A G; de Zeeuw, R.A.; de Jong, G.J.

    2003-01-01

    Ion suppression effects were observed during the determination of clenbuterol in urine with solid-phase extraction/multiple-stage ion-trap mass spectrometry (SPE/MS3), despite the use of atmospheric pressure chemical ionisation. During SPE, a polymeric stationary phase (polydivinylbenzene) was appli

  11. 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...

  12. Preparation of polydopamine-coated magnetic nanoparticles for dispersive solid-phase extraction of water-soluble synthetic colorants in beverage samples with HPLC analysis.

    Science.gov (United States)

    Chai, Weibo; Wang, Huijuan; Zhang, Ying; Ding, Guosheng

    2016-01-01

    A facile and sensitive dispersive solid-phase extraction (D-SPE) method for the extraction and enrichment of four representative synthetic colorants prior to high performance liquid chromatography analysis was introduced. As highly efficient adsorbents, polydopamine-coated Fe3O4 nanoparticles (Fe3O4@PDA NPs) were prepared by a simple and green procedure. Several factors affecting the extraction efficiency, mainly including the polymerization time of dopamine, pH of the sample solution, the amount of adsorbent, extraction time and the desorption conditions, were systematically studied. Under the optimized conditions, the enrichment factors for the four colorants were both higher than 176. The limits of detection (LODs) for the established d-SPE-HPLC method were found to be 0.20-0.25μgL(-1), which were lower than most chromatographic methods previously reported for synthetic colorant analysis. When used for quantitative analysis, wide linearity ranges (1-500μgL(-1) for amaranth and Ponceau 4R, and 0.80-500μgL(-1) for sunset yellow and allure red) were achieved with good correlation (R(2)≥0.9995). The developed method was also successfully applied to the analysis of colorants in beverage samples with satisfactory results, demonstrating its reliability and feasibility in real sample analysis.

  13. Determination of vitamin A (retinol) in infant and medical nutritional formulas with AOAC method 992.06 using a modified extraction procedure: single-laboratory validation.

    Science.gov (United States)

    Thompson, Linda B; Schimpf, Karen J; Stiner, Lisa A; Schmitz, Daniel J

    2010-01-01

    The applicability of AOAC Official Method 992.06, vitamin A (retinol) in milk-based infant formula can be extended to specialty infant formulas, and medical and adult nutritional products with a few minor modifications to the sample preparation procedure. Currently, AOAC Official Method 992.06 is only applicable to milk-based infant formulas containing >500 IU vitamin A per reconstituted quart. When this method is used as written to test specialty infant formulas, vitamin A recoveries are low compared to results generated with alternate validated vitamin A methods. AOAC Method 992.06 vitamin A recoveries can be improved significantly in specialty infant formulas if the amount of potassium hydroxide used during the saponification step is doubled. With this one minor modification to the sample preparation procedure, AOAC Method 992.06 demonstrates acceptable precision and accuracy for the quantitation of vitamin A (retinol) in specialty infant formulas, milk- and soy-based infant formulas, and adult and medical nutritionals. Because increasing the amount of potassium hydroxide can cause emulsions to form, 2-4 mL aliquots of reagent alcohol may need to be added to some samples to separate the organic and aqueous layers during the extraction step. A single-laboratory validation of these modifications was completed. During validation, 15 different product matrixes were analyzed. The intermediate precision averaged 2.70% RSD, and spike recovery data averaged 96.3%.

  14. Statistical design-principal component analysis optimization of a multiple response procedure using cloud point extraction and simultaneous determination of metals by ICP OES.

    Science.gov (United States)

    Bezerra, Marcos A; Bruns, Roy E; Ferreira, Sergio L C

    2006-11-24

    A procedure has been developed for the simultaneous determination of traces amounts of Cd, Cr, Cu, Mn, Ni and Pb from saline oil-refinery effluents and digested vegetable samples using inductively coupled plasma optical emission spectrometry (ICP OES). The procedure is based on cloud point extraction (CPE) of these metals as 2-(bromo-2-pyridylazo)-5-diethyl-amino-phenol (Br-PADAP) complexes into a micellar phase of octylphenoxypolyethoxyethanol (Triton X-114). Optimization of the procedure was performed by response surface methodology (RSM) using a Doehlert design. Principal components (PC) were used to simplify the multiple response analysis. A response surface for the first PC score is useful in determining the optimum conditions for the Cd, Cr, Cu, Mn and Pb determinations whereas the second PC is highly correlated with the Ni response. Improvement factors of 22, 36, 46, 25, 65 and 39, along with limits of detection (3sigma(B)) of 0.081, 0.79, 0.38, 0.83, 0.28 and 0.69 microg L(-1), and precision expressed as relative standard deviation (%R.S.D., n=8, 20.0 microg L(-1)) of 1.5, 2.2, 3.5, 2.6, 2.5 and 2.5 were achieved for Cd, Cr, Cu, Mn, Ni and Pb, respectively. The accuracy was evaluated by spike tests in oil-refinery effluent samples and analysis of a vegetable certified reference material (NIST 1571, orchard leaves). Results found were in agreement with certified values.

  15. Simultaneous determination of isoflavones and resveratrols for adulteration detection of soybean and peanut oils by mixed-mode SPE LC-MS/MS.

    Science.gov (United States)

    Zhao, Xin; Ma, Fei; Li, Peiwu; Li, Guangming; Zhang, Liangxiao; Zhang, Qi; Zhang, Wen; Wang, Xiupin

    2015-06-01

    To ensure authenticity of vegetable oils, isoflavones (genistein, genistin, daidzein and daidzin) and resveratrols (cis-resveratrol and trans-resveratrol) were selected as the putative markers for adulteration of soybean and peanut oils. Firstly, mixed mode solid-phase extraction coupled with liquid chromatography tandem mass spectrometry (mixed-mode SPE LC-MS/MS) method was developed to analyze isoflavones and resveratrols in vegetable oils. The concentration of marker compounds in vegetable oils were 0.08-1.47mgkg(-1) for daidzein, ND-78.9μgkg(-1) for daidzin, 0.40-5.89mgkg(-1) for genistein, 1.2-114.9μgkg(-1) for genistin, 3.1-85.0μgkg(-1) for trans-resveratrol and 1.9-51.0μgkg(-1) for cis-resveratrol, which are compatible with the raw materials for oil press. Additionally, the applicability of this method has been successfully tested in thirteen vegetable oils from the market. Mixed-mode SPE LC-MS/MS method can simultaneously detect isoflavones and resveratrols in vegetable oils and assess adulteration and quality of soybean and peanut oils.

  16. Evaluation of metal-organic framework 5 as a new SPE material for the determination of polycyclic aromatic hydrocarbons in environmental waters.

    Science.gov (United States)

    Yang, Shaolei; Chen, Chunyan; Yan, Zhihong; Cai, Qingyun; Yao, Shouzhuo

    2013-04-01

    Metal-organic frameworks, a new class of materials with high surface area and great porosity, have been widely applied in gas sorption. It is generally known that metal-organic framework 5 cannot be applied in aqueous phase since it is water sensitive. However, this work reveals that the derived material of metal-organic framework 5 is a good SPE sorbent that can be applied to aqueous phases. Metal-organic framework 5 was prepared and used as a SPE sorbent for the determination of polycyclic aromatic hydrocarbons in environmental matrices coupling with HPLC. The water treatment induced changes in the properties were investigated in detail. Even though metal-organic framework 5 is conversed to a second phase after water treatment, it still shows high extraction ability. Under the optimized experimental conditions, good sensitivity levels were achieved with low LODs ranging from 0.4 to 4.0 ng L(-1) and a linearity of 0.004-20 μg L(-1) (R(2) > 0.996) for the investigated polycyclic aromatic hydrocarbons. The method has been validated in the analysis of real water samples with recoveries in the range of 80.2-120.2% and RSDs in the range of 0.5-11.7%.

  17. An RP-HPLC-UV method with SPE for cefotaxime in all-in-one total parenteral nutritional admixtures: application to stability studies.

    Science.gov (United States)

    Iqbal, Muhammad Shahid; Bahari, Mohd Baidi; Darwis, Yusrida; Iqbal, Muhammad Zahid; Hayat, Amer; Venkatesh, Gantala

    2013-01-01

    A simple and selective RP-HPLC-UV method with SPE was developed and validated for the quantification of cefotaxime in all-in-one total parenteral nutrition (AIO-TPN) admixtures. Chromatographic separation was achieved on a 5 pm particle size C18 DB column (250 x 4.6 mm id) using the mobile phase ammonium acetate (25 mM, pH 4.0)-50% acetonitrile in methanol (80 + 20, v/v). The flow rate was 0.9 mL/min and the detection wavelength was 254 nm. The analyte was extracted from AIO-TPN admixtures by means of an SPE method. The cefotaxime calibration curve was linear over a concentration range of 100-1400 microg/mL with a correlation coefficient of > or = 0.9994. The intraday accuracy and precision for cefotaxime were cefotaxime in the presence of micronutrients together with low and high concentrations of macronutrients in AIO-TPN admixtures. Cefotaxime was degraded by 13.00 and 26.05% at room temperature (25 +/- 2 degrees C) after 72 h in low and high macronutrient concentration formulations of AIO-TPN admixtures, respectively. The values of cefotaxime degradation rates for low and high macronutrient concentration formulations of AIO-TPN admixtures were -0.164 and -0.353, respectively. These results indicated that there was a higher rate of degradation in the AIO-TPN admixture formulations containing high concentrations of macronutrients.

  18. Determination of furanochromones and pyranocoumarins in drugs and Ammi visnaga fruits by combined solid-phase extraction-high-performance liquid chromatography and thin-layer chromatography-high-performance liquid chromatography.

    Science.gov (United States)

    Zgórka, G; Dragan, T; Głowniak, K; Basiura, E

    1998-02-27

    A new, simple and rapid solid-phase extraction method for the determination of furanochromones and pyranocoumarins in Ammi visnaga L. fruits and pharmaceuticals by reversed-phase high-performance liquid chromatography (RP-HPLC) was developed. The isolation of compounds examined was carried out on octadecyl BakerBond SPE columns using various concentrations of methanol, acetonitrile and tetrahydrofuran in water. High and reproducible recoveries were obtained. To compare the results of quantitative analysis a preparative TLC procedure was also elaborated and carried out.

  19. The micronutrient element zinc modulates sperm activation through the SPE-8 pathway in Caenorhabditis elegans.

    Science.gov (United States)

    Liu, Zhiyu; Chen, Lianwan; Shang, Yunlong; Huang, Ping; Miao, Long

    2013-05-01

    Immotile spermatids produced in the testis must undergo a series of poorly understood morphological, physiological and biochemical processes called sperm activation to become motile, fertilization-competent spermatozoa. In Caenorhabditis elegans, the spe-8 group contains sperm-specific genes active in both males and hermaphrodites, although their activity is required only for hermaphrodite self-sperm activation. The activating signal upstream of the SPE-8 signaling cascade remains unknown. Here, we show that the micronutrient zinc is sufficient to trigger sperm activation in vitro, and that extracellular zinc induces the intracellular redistribution of labile zinc. We demonstrate that other activating signals promote the similar redistribution of labile zinc, indicating that zinc might have first and/or second messenger roles during sperm activation. Moreover, zinc-induced sperm activation is SPE-8 pathway dependent. Labile zinc was enriched in the spermatheca, the normal site for self-sperm activation in hermaphrodites. High levels of zinc were also found in the secretory cells in the male gonad, suggesting that zinc might be secreted from these cells during copulation and become a component of seminal fluid, to modulate sperm activation post-copulation. These data indicate that zinc regulates sperm activation in both male and hermaphrodite C. elegans, a finding with important implications for understanding hermaphroditic evolution.

  20. Developments in coupled solid-phase extraction-capillary electrophoresis 2013-2015.

    Science.gov (United States)

    Ramautar, Rawi; Somsen, Govert W; de Jong, Gerhardus J

    2016-01-01

    An overview of the design and application of coupled solid-phase extraction-capillary electrophoresis (SPE-CE) systems reported in the literature between July 2013 and June 2015 is provided in this paper. The present article is a continuation of our previous review papers on this topic which covered the time period 2000-2013 (Electrophoresis 2008, 29, 108-128; Electrophoresis 2010, 31, 44-54; Electrophoresis 2012, 33, 243-250; Electrophoresis 2014, 35, 128-137). The use of in-line and on-line SPE-CE approaches is treated and outlined in this review. Recent advancements, such as, for example, the use of aptamers as affinity material for in-line SPE-CE, the use of a bead string design for in-line fritless SPE-CE, and new interfacing techniques for the on-line coupling of SPE to CE, are outlined. Selected examples demonstrate the applicability of the coupled SPE-CE systems for biomedical, pharmaceutical, environmental, and food studies. A complete overview of the recent SPE-CE studies is given in table format, providing information on sample type, SPE sorbent, coupling mode, detection mode, and LOD. Finally, some general conclusions and perspectives are provided.

  1. Uudised : ER annab välja In Spe albumi. Krummi-nimeline preemia. EMA raamatukogu sai annetuse / Tiia Teder

    Index Scriptorium Estoniae

    Teder, Tiia, 1959-

    1999-01-01

    Eesti Raadio annab välja ans. In Spe CD-plaadi. Ansambli ajaloost, tegevusest. H. Krummi nimelisest kultuuripreemiast. 16. dets. sai EMA raamatukogu kingituseks T. Valjakka noodi- ja raamatukogu. Teistest annetajatest

  2. Uudised : ER annab välja In Spe albumi. Krummi-nimeline preemia. EMA raamatukogu sai annetuse / Tiia Teder

    Index Scriptorium Estoniae

    Teder, Tiia, 1959-

    1999-01-01

    Eesti Raadio annab välja ans. In Spe CD-plaadi. Ansambli ajaloost, tegevusest. H. Krummi nimelisest kultuuripreemiast. 16. dets. sai EMA raamatukogu kingituseks T. Valjakka noodi- ja raamatukogu. Teistest annetajatest

  3. Ultra-preconcentration and determination of selected pharmaceutical and personal care products in different water matrices by solid-phase extraction combined with dispersive liquid-liquid microextraction prior to ultra high pressure liquid chromatography tandem mass spectrometry analysis.

    Science.gov (United States)

    Celano, Rita; Piccinelli, Anna Lisa; Campone, Luca; Rastrelli, Luca

    2014-08-15

    Pharmaceutical and personal care products (PPCPs) are one of the most important classes of emerging contaminants. The potential of ecological and environmental impacts associated with PPCPs are of particular concern because they continually penetrate the aquatic environment. This work describes a novel ultra-preconcentration technique for the rapid and highly sensitive analysis of selected PPCPs in environmental water matrices at ppt levels. Selected PPCPs were rapidly extracted and concentrated from large volumes of aqueous solutions (500 and 250mL) by solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME) and then analyzed using UHPLC-MS/MS. Experimental parameters were carefully investigated and optimized to achieve the best SPE-DLLME efficiency and higher enrichment factors. The best results were obtained using the ternary mixture acetonitrile/methanol/dichloromethane 3:3:4, v/v/v, both as SPE eluent and DLLME extractant/dispersive mixture. DLLME aqueous solution (5% NaCl, 10mgL(-1) TBAB) was also modified to improve the extraction efficiency of more hydrophilic PPCPs. Under the optimal conditions, an exhaustive extraction for most of the investigated analytes (recoveries >70%), with a precision (RSD <10%) and very high enrichment factors were attained for different aqueous matrices (drinking, sea, river and wastewater). Method detection and quantification limits were at very low ppt levels and below 1 and 3ngL(-1), respectively, for 15 of selected PPCPs. The proposed analytical procedure offers numerous advantages such as the simplicity of operation, rapidity, a high enrichment factor and sensitivity. So it is suitable for monitoring and studies of occurrence of PPCPs in different environmental compartments.

  4. Optimisation of an extraction procedure for determination of total water-soluble Zn, Pb a,d Cd and their species in soils from a mining area

    Energy Technology Data Exchange (ETDEWEB)

    Svete, P.; Milacic, R. [Jozef Stefan Institute, Ljubljana (Slovenia). Dept. of Environmental Sciences; Pihlar, B. [Ljubljana Univ., Ljubljana (Slovenia). Fac of Chemistry and Chemical Technology

    2000-06-01

    The parameters influencing the extraction efficiency of total water-soluble Zn, Pb and Cd in various soil samples from a lead and zinc mining area were investigated. Water was added to moist soil sample and the mixture shaken in a classical shaker. Variations of the solution volume to soil weight ratio, and of extraction time were studied in order to develop an optimum extraction procedure for determination of total water-soluble Zn, Pb and Cd. The influence of filtration of the extracts through membrane filters of various pore size was investigated as well. Speciation of Zn, Pb and Cd was also performed in aqueous soil extracts using column chelating ion-exchange (Chelex-100 resin) - flame atomic absorption spectrometry (FAAS) technique. Positively charged species and labile complexes of Zn, Pb and Cd were retained on the column and after elution with nitric acid determined by FAAS. Comparative analyses of the total metal concentrations in the soil samples indicated that the percentage of total water soluble Zn, Pb and Cd in samples analyses in these extracts by the chelating ion-exchange - FAAS technique demonstrated that Zn, Pb and Cd exist in the form of positively charged species or weak labile metal complexes. [Italian] Si sono studiati i parametri che influenzano l'efficienza di estrazione delle forme completamente solubili di Zn, Pb e Cd in vari campioni di terreno provenienti da un'area mineraria di piombo e zinco. E' stata addizionata acqua per bagnare i terreni e la sospensione e' stata mantenuta in agitazione. Si sono studiate le variazioni del rapporto tra volume di soluzione e peso del terreno e del tempo di estrazione per sviluppare una procedura ottimizzata di estrazione per la determinazione delle frazioni totalmente solubili in acuqa di Zn, Pb e Cd. Si e' pure studiata l'influenza della filtrazione degli estratti attraverso membrane di diversa porosita'. Si e' poi effettuata la speciazione di Zn, Pb e Cd

  5. SPE/UPLC法检测血中吗啡、苯丙胺类及氯胺酮%The simultaneous analysis of morphine,amphetamines and ketamine in whole blood by SPE/UPLC

    Institute of Scientific and Technical Information of China (English)

    张小婷; 孙立敏; 刘娟; 徐淑云

    2011-01-01

    Objective To establish a solid phase extraction (SPE)/UPLC method for the determination of morphine,amphetamines and ketamine in whole blood simultaneously. Methods Morphine, MA, MDMA,MDA,ketamine were extracted from whole blood using Agilent SCX 3cc (60mg)extraction cartridges and detected by UPLC-PDA. Qualitative and quantitative analysis was obtained by retention time and UVspectrum. Results The recoveries for morphine, MA, MIDMA, MDA, ketamine were 81. 4% ± 2. 51%,88.2% ±2.48% ,91. 8% ± 2.03% ,93. 8% ± 1.46% ,74. 8% ± 2. 27% respectively, The correlation coefficient of linear calibration curve was over 0. 999 within concentration range 0.08 ~ 100μg/mL,0.4 ~100μg/mL,0.2 ~ 75 μg/ml,0.3 ~ 75 μg/mL, 0.4 ~ 100 μg/mL respectively. The limits of qualification were 30pg,200pg, 80pg, 100pg, 200pg respectively. Conclusion The method was simple, rapid and accurate for qualitative and quantitative analysis of morphine,amphetamines, ketamine in whole blood simultaneously.%目的 建立SPE/UPLC方法在同一条件下同时检测血中吗啡、苯丙胺类及氯胺酮.方法 采用SCX 3cc(60mg)固相萃取柱萃取血中吗啡、MA、MDMA、MDA及氯胺酮,用超高效液相色谱(UPLC)-二极管阵列检测器(PDA)检测,结合保留时间和紫外光谱进行定性、定量分析,对实验各环节进行优化,并进行实际案例检测.结果 吗啡、MA、MDMA、MDA、氯胺酮的固相萃取提取回收率分别为81.4%±2.51%、88.2%±2.48%、91.8%±2.03%、93.8%±1.46%、74.8%±2.27%,峰面积和质量浓度的线性关系良好(r>0.999),线性范围分别为0.08~100μg/mL、0.4~100μg/mL、0.2~75μg/mL、0.3~75μg/mL、0.4~100μg/mL,检出限分别为30pg、200pg、80pg、100pg、200pg.结论 本文所建方法适用于血中吗啡、苯丙胺类、氯胺酮常见毒品的筛选及定量分析.

  6. A high-throughput solid-phase extraction microchip combined with inductively coupled plasma-mass spectrometry for rapid determination of trace heavy metals in natural water.

    Science.gov (United States)

    Shih, Tsung-Ting; Hsieh, Cheng-Chuan; Luo, Yu-Ting; Su, Yi-An; Chen, Ping-Hung; Chuang, Yu-Chen; Sun, Yuh-Chang

    2016-04-15

    Herein, a hyphenated system combining a high-throughput solid-phase extraction (htSPE) microchip with inductively coupled plasma-mass spectrometry (ICP-MS) for rapid determination of trace heavy metals was developed. Rather than performing multiple analyses in parallel for the enhancement of analytical throughput, we improved the processing speed for individual samples by increasing the operation flow rate during SPE procedures. To this end, an innovative device combining a micromixer and a multi-channeled extraction unit was designed. Furthermore, a programmable valve manifold was used to interface the developed microchip and ICP-MS instrumentation in order to fully automate the system, leading to a dramatic reduction in operation time and human error. Under the optimized operation conditions for the established system, detection limits of 1.64-42.54 ng L(-1) for the analyte ions were achieved. Validation procedures demonstrated that the developed method could be satisfactorily applied to the determination of trace heavy metals in natural water. Each analysis could be readily accomplished within just 186 s using the established system. This represents, to the best of our knowledge, an unprecedented speed for the analysis of trace heavy metal ions. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Copper and zinc fractionation in apple orchard soil in the village of Bukevje (Croatia) using the revised four-step BCR extraction procedure.

    Science.gov (United States)

    Medunić, Gordana; Juranović Cindrić, Iva; Lovrenčić Mikelić, Ivanka; Tomašić, Nenad; Balen, Dražen; Oreščanin, Višnja; Kampić, Štefica; Ivković, Ivana

    2013-12-01

    The aim of this study was to establish the fractionation of copper and zinc in a small apple orchard using the revised (four-step) Bureau Communautaire de Référence (BCR) sequential extraction procedure and assess their potential mobility in soil. Soil samples were collected at the depth of 10 cm to 25 cm, sixteen from the orchard and five control samples from a meadow located some 200 m away from the orchard. As the distribution of trace-element concentrations in the control samples was normal, they were used for comparison as background levels. We also determined soil mineralogical composition, carbonate content, soil pH, cation exchange capacity, and soil organic matter. The extraction yields of Cu and Zn from the control soil were lower than from the orchard soil (25% vs. 34% and 47% vs. 52%, respectively), which pointed to natural processes behind metal bonding in the control soil and greater influence of man-made activities in the orchard soil. Compared to control, the orchard soil had significantly higher concentrations of total Cu (P=0.0009), possibly due to the application of Cu-based fungicides. This assumption was further supported by greater speciation variability of Cu than of zinc, which points to different origins of the two, Cu from pesticides and Zn from the parent bedrock. Copper levels significantly better (P=0.01) correlated with the oxidisable fraction of the orchard soil than of control soil. Residual and organically bound copper and zinc constituted the most important fractions in the studied soils. However, the use of Cu-based fungicides in the apple orchard did not impose environmental and health risk from Cu exposure.

  8. Human Health Risk Assessment Based on Toxicity Characteristic Leaching Procedure and Simple Bioaccessibility Extraction Test of Toxic Metals in Urban Street Dust of Tianjin, China

    Science.gov (United States)

    Yu, Binbin; Wang, Yu; Zhou, Qixing

    2014-01-01

    The potential ecological and human health risk related with urban street dust from urban areas of Tianjin, China was quantitatively analyzed using the method of toxicity characteristic leaching procedure (TCLP) and simple bioaccessibility extraction test (SBET). In the study, Hakason index, Nemerow index (P), the hazard index (HI) and the cancer risk index (RI) were calculated to assess the potential risk. The sequence of potential ecological risk based on Hakason index was arsenic (As) > cadmium (Cd) > lead (Pb) > copper (Cu) > chromium (Cr), in particular, As and Cd were regarded as high polluted metals. While the results of extraction of TCLP were assessed using P, the sequence was As > Pb > Cd > Cr > Cu, which mean that As and Pb should be low polluted, and Cd, Cr and Cu would barely not polluted. For human health, total carcinogenic risk for children and adults was 2.01×10−3 and 1.05×10−3, respectively. This could be considered to be intolerable in urban street dust exposure. The sequence in the hazard quotient (HQ) of each element was As > Cr > Pb > Cu > Cd. The HI value of these toxic metals in urban street dust for children and adults was 5.88×10−1 and 2.80×10−1, respectively. According to the characters of chemistry, mobility, and bioavailability of metals in urban street dust, we estimated the hazards on the environment and human health, which will help us to get more reasonable information for risk management of metals in urban environment. PMID:24651129

  9. Human health risk assessment based on toxicity characteristic leaching procedure and simple bioaccessibility extraction test of toxic metals in urban street dust of Tianjin, China.

    Directory of Open Access Journals (Sweden)

    Binbin Yu

    Full Text Available The potential ecological and human health risk related with urban street dust from urban areas of Tianjin, China was quantitatively analyzed using the method of toxicity characteristic leaching procedure (TCLP and simple bioaccessibility extraction test (SBET. In the study, Hakason index, Nemerow index (P, the hazard index (HI and the cancer risk index (RI were calculated to assess the potential risk. The sequence of potential ecological risk based on Hakason index was arsenic (As > cadmium (Cd > lead (Pb > copper (Cu > chromium (Cr, in particular, As and Cd were regarded as high polluted metals. While the results of extraction of TCLP were assessed using P, the sequence was As > Pb > Cd > Cr > Cu, which mean that As and Pb should be low polluted, and Cd, Cr and Cu would barely not polluted. For human health, total carcinogenic risk for children and adults was 2.01 × 10(-3 and 1.05 × 10(-3, respectively. This could be considered to be intolerable in urban street dust exposure. The sequence in the hazard quotient (HQ of each element was As > Cr > Pb > Cu > Cd. The HI value of these toxic metals in urban street dust for children and adults was 5.88 × 10(-1 and 2.80 × 10(-1, respectively. According to the characters of chemistry, mobility, and bioavailability of metals in urban street dust, we estimated the hazards on the environment and human health, which will help us to get more reasonable information for risk management of metals in urban environment.

  10. Antioxidative properties of defatted dabai pulp and peel prepared by solid phase extraction.

    Science.gov (United States)

    Khoo, Hock Eng; Azlan, Azrina; Ismail, Amin; Abas, Faridah

    2012-08-14

    Solid phase extraction (SPE) using Sep-Pak® cartridges is one of the techniques used for fractionation of antioxidant compounds in waste of dabai oil extraction (defatted dabai parts). The aim of this study was to determine the phenolic compounds and antioxidant capacity in crude extracts and several SPE fractions from methanolic extract of defatted dabai pulp and peel. Based on SPE, Sep-Pak® cyanopropyl and C₁₈ cartridges were used to fractionate the antioxidant-rich crude extracts into water and methanolic fractions. Analyzed using LC-MS, flavonoids, anthocyanins, saponin derivatives and other unknown antioxidative compounds were detected in the defatted dabai crude extracts and their SPE fractions. Anthocyanins were the major phenolic compounds identified in the defatted dabai peel and detected in most of the SPE fractions. Methanolic fractions of defatted dabai parts embraced higher total phenolics and antioxidant capacity than water fractions. This finding also revealed the crude extracts of defatted dabai peel have the most significant antioxidant properties compared to the methanolic and water fractions studied. The crude extract of defatted dabai parts remain as the most potent antioxidant as it contains mixture of flavonoids, anthocyanins and other potential antioxidants.

  11. A Rapid Method for the Quantitative Determination of 34 Pesticides in Nonalcoholic Carbonated Beverages Using Liquid-Liquid Extraction Coupled to Dispersive Solid-Phase Cleanup Followed by Gas Chromatography with Tandem Mass Spectrometry.

    Science.gov (United States)

    Rai, Satyajeet; Gullapalli, Madhuri Devi; Srivastava, Anshuman; Shaik, Hussain; Siddiqui, Mohammed Haris; Mudiam, Mohana Krishna Reddy

    2017-05-01

    An economical, rapid, and sensitive multiresidue method using liquid-liquid extraction (LLE) coupled with dispersive SPE (dSPE) cleanup was developed for the quantitative determination of 34 multiclass multiresidue (MCMR) pesticides (14 organochlorines, eight organophosphates, 10 synthetic pyrethroids, and two herbicides) in nonalcoholic carbonated beverages (cola, orange, lemon-lime, and citra) using GC with tandem MS. The procedure mainly involved LLE by dichloromethane and dSPE cleanup in the presence of magnesium sulfate, primary secondary amine, and C18. The RSD of the developed method was found to be less than 14%. The LOD and LOQ values for all the analyzed pesticides were found in the ranges of 0.001-0.027 μg/L and 0.004-0.088 μg/L, respectively. The LOQ levels of the pesticides analyzed were found to be well below the recommended limit by the European Union (0.1 μg/L in water). The mean recoveries of pesticides in different nonalcoholic carbonated beverages (cola, orange, lemon-lime, and citra) were found to be in the range of 79-111%, with RSDs less than 11%. The validation data prove that the method can be acceptable to regulatory agencies for the routine analysis of MCMR pesticides in nonalcoholic carbonated beverages.

  12. Determination of propoxur in environmental samples by automated solid-phase extraction followed by flow-injection analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Ruiz, Tomas [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain)]. E-mail: tpr@um.es; Martinez-Lozano, Carmen [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain); Garcia, Maria Dolores [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain)

    2007-02-19

    A sensitive method for the analysis of propoxur in environmental samples has been developed. It involves an automated solid-phase extraction (SPE) procedure using a Gilson Aspec XLi and flow-injection analysis (FI) with chemiluminescence (CL) detection. The FI-CL system relies on the photolysis of propoxur by irradiation using a low-pressure mercury lamp (main spectral line 254 nm). The resultant methylamine is subsequently detected by CL using tris(2,2'-bipyridyl)ruthenium(III), which is on-line generated by photo-oxidation of the ruthenium(II) complex in the presence of peroxydisulfate. The linear concentration range of application was 0.05-5 {mu}g mL{sup -1} of propoxur, with a detection limit of 5 ng mL{sup -1}. The repeatability was 0.82% expressed as relative standard deviation (n = 10) and the reproducibility, studied on 5 consecutive days, was 2.1%. The sample throughput was 160 injection per hour. Propoxur residues below ng mL{sup -1} levels could be determined in environmental water samples when an SPE preconcentration device was coupled on-line with the FI system. This SPE-FI-CL arrangement provides a detection limit as low as 5 ng L{sup -1} using only 500 mL of sample. In the analysis of fruits and vegetables, the detection limit was about 10 {mu}g kg{sup -1}.

  13. Determination of propoxur in environmental samples by automated solid-phase extraction followed by flow-injection analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection.

    Science.gov (United States)

    Pérez-Ruiz, Tomás; Martínez-Lozano, Carmen; García, María Dolores

    2007-02-19

    A sensitive method for the analysis of propoxur in environmental samples has been developed. It involves an automated solid-phase extraction (SPE) procedure using a Gilson Aspec XLi and flow-injection analysis (FI) with chemiluminescence (CL) detection. The FI-CL system relies on the photolysis of propoxur by irradiation using a low-pressure mercury lamp (main spectral line 254 nm). The resultant methylamine is subsequently detected by CL using tris(2,2'-bipyridyl)ruthenium(III), which is on-line generated by photo-oxidation of the ruthenium(II) complex in the presence of peroxydisulfate. The linear concentration range of application was 0.05-5 microg mL(-1) of propoxur, with a detection limit of 5 ng mL(-1). The repeatability was 0.82% expressed as relative standard deviation (n=10) and the reproducibility, studied on 5 consecutive days, was 2.1%. The sample throughput was 160 injection per hour. Propoxur residues below ng mL(-1) levels could be determined in environmental water samples when an SPE preconcentration device was coupled on-line with the FI system. This SPE-FI-CL arrangement provides a detection limit as low as 5 ng L(-1) using only 500 mL of sample. In the analysis of fruits and vegetables, the detection limit was about 10 microg kg(-1).

  14. Carbon and Oxygen Isotope Measurements of Ordinary Chondrite (OC) Meteorites from Antarctica Indicate Distinct Carbonate Species Using a Stepped Acid Extraction Procedure

    Science.gov (United States)

    Evans, Michael E.

    2015-01-01

    The purpose of this study is to characterize the stable isotope values of terrestrial, secondary carbonate minerals from five Ordinary Chondrite (OC) meteorites collected in Antarctica. These samples were identified and requested from NASA based upon their size, alteration history, and collection proximity to known Martian meteorites. They are also assumed to be carbonate-free before falling to Earth. This research addresses two questions involving Mars carbonates: 1) characterize terrestrial, secondary carbonate isotope values to apply to Martian meteorites for isolating in-situ carbonates, and 2) increase understanding of carbonates formed in cold and arid environments with Antarctica as an analog for Mars. Two samples from each meteorite, each approximately 0.5 grams, were crushed and dissolved in pure phosphoric acid for 3 sequential reactions: a) R times 0 for 1 hour at 30 degrees Centigrade (fine calcite extraction), b) R times 1 for 18 hours at 30 degrees Centigrade (course calcite extraction), and c) R times 2 for 3 hours at 150 degrees Centigrade (siderite and/or magnesite extraction). CO (sub 2) was distilled by freezing with liquid nitrogen from each sample tube, then separated from organics and sulfides with a TRACE GC using a Restek HayeSep Q 80/100 6 foot 2 millimeter stainless column, and then analyzed on a Thermo MAT 253 Isotope Ratio Mass Spectrometer (IRMS) in Dual Inlet mode. This system was built at NASA/JSC over the past 3 years and proof-tested with known carbonate standards to develop procedures, assess yield, and quantify expected error bands. Two distinct species of carbonates are found: 1) calcite, and 2) non-calcite carbonate (future testing will attempt to differentiate siderite from magnesite). Preliminary results indicate the terrestrial carbonates are formed at approximately sigma (sup 13) C equal to plus 5 per mille, which is consistent with atmospheric CO (sub 2) sigma (sup 13) C equal to minus 7 per mille and fractionation of plus

  15. Fully automated trace level determination of parent and alkylated PAHs in environmental waters by online SPE-LC-APPI-MS/MS.

    Science.gov (United States)

    Ramirez, Cesar E; Wang, Chengtao; Gardinali, Piero R

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds that enter the environment from natural and anthropogenic sources, often used as markers to determine the extent, fate, and potential effects on natural resources after a crude oil accidental release. Gas chromatography-mass spectrometry (GC-MS) after liquid-liquid extraction (LLE+GC-MS) has been extensively used to isolate and quantify both parent and alkylated PAHs. However, it requires labor-intensive extraction and cleanup steps and generates large amounts of toxic solvent waste. Therefore, there is a clear need for greener, faster techniques with enough reproducibility and sensitivity to quantify many PAHs in large numbers of water samples in a short period of time. This study combines online solid-phase extraction followed by liquid chromatography (LC) separation with dopant-assisted atmospheric pressure photoionization (APPI) and tandem MS detection, to provide a one-step protocol that detects PAHs at low nanograms per liter with almost no sample preparation and with a significantly lower consumption of toxic halogenated solvents. Water samples were amended with methanol, fortified with isotopically labeled PAHs, and loaded onto an online SPE column, using a large-volume sample loop with an auxiliary LC pump for sample preconcentration and salt removal. The loaded SPE column was connected to an UPLC pump and analytes were backflushed to a Thermo Hypersil Green PAH analytical column where a 20-min gradient separation was performed at a variable flow rate. Detection was performed by a triple-quadrupole MS equipped with a gas-phase dopant delivery system, using 1.50 mL of chlorobenzene dopant per run. In contrast, LLE+GC-MS typically use 150 mL of organic solvents per sample, and methylene chloride is preferred because of its low boiling point. However, this solvent has a higher environmental persistence than chlorobenzene and is considered a carcinogen. The automated system is capable of

  16. A novel procedure to measure the antioxidant capacity of Yerba maté extracts Procedimento padronizado para avaliar a capacidade antioxidante dos extratos de erva-mate

    Directory of Open Access Journals (Sweden)

    Vanessa Graciela Hartwig

    2012-03-01

    Full Text Available Yerba maté extracts have in vitro antioxidant capacity attributed to the presence of polyphenolic compounds, mainly chlorogenic acids and dicaffeoylquinic acid derivatives. DPPH is one of the most used assays to measure the antioxidant capacity of pure compounds and plant extracts. It is difficult to compare the results between studies because this assay is applied in too many different conditions by the different research groups. Thus, in order to assess the antioxidant capacity of yerba maté extracts, the following procedure is proposed: 100 µL of an aqueous dilution of the extracts is mixed in duplicate with 3.0 mL of a DPPH 'work solution in absolute methanol (100 µM.L-1, with an incubation time of 120 minutes in darkness at 37 ± 1 °C, and then absorbance is read at 517 nm against absolute methanol. The results should be expressed as ascorbic acid equivalents or Trolox equivalents in mass percentage (g% dm, dry matter in order to facilitate comparisons. The AOC of the ethanolic extracts ranged between 12.8 and 23.1 g TE % dm and from 9.1 to 16.4 g AAE % dm. The AOC determined by the DPPH assay proposed in the present study can be related to the total polyphenolic content determined by the Folin-Ciocalteu assay.Extratos de erva-mate têm a sua capacidade antioxidante in vitro atribuída à presença de compostos polifenólicos, principalmente ácidos clorogênicos e derivados do ácido dicafeoilquínico. Embora DPPH seja um dos ensaios mais utilizados para avaliar a capacidade antioxidante dos compostos puros e extratos de plantas, o fato de que há uma padronização pobre na sua aplicação torna as comparações entre os diferentes extratos muito difíceis. Visando conseguir uma técnica padronizada para medir a capacidade antioxidante de extratos de erva-mate, propomos o seguinte procedimento: 100 µL de uma diluição do extrato aquoso são misturados em duplicata, com 3,0 mL de uma solução de trabalho de DPPH em metanol absoluto

  17. Selective solid-phase extraction using molecular imprinted polymer sorbent for the analysis of florfenicol in food samples.

    Science.gov (United States)

    Sadeghi, Susan; Jahani, Moslem

    2013-11-15

    A molecularly imprinted polymer (MIP) for the selective solid phase extraction (SPE) of florfenicol (FF) was prepared using FF as template and 4-vinyl pyridine (4-VP) as functional monomer. For comparison, non-imprinted polymer (NIP) was synthesized in the absence of FF. The synthesized polymers were characterised by infrared spectroscopy (IR), scanning electron microscopy (SEM), thermogravimetry analysis (TGA) and differential thermal analysis (DTA). A molecularly imprinted solid phase extraction (MISPE) procedure was performed in column method by spectrophotometry detection technique. The prepared FF-MIP showed higher adsorption capacity than the non-imprinted polymer (NIP) and the maximum static adsorption capacities of FF on the MIP and the NIP were 4.32 and 2.88mgg(-1), respectively. Kinetics of the adsorption was fast and the adsorption equilibrium was achieved in 30min. The accuracy of the developed method was satisfactory for determination of FF in fish, chicken meat and honey samples.

  18. 固相萃取高效液相色谱法测定水中微囊藻毒素%Determination of Microcystin-LR in Water by SPE and HPLC

    Institute of Scientific and Technical Information of China (English)

    李保珍; 谢树莲

    2012-01-01

    The enrichment and detection of microcystin-LR were performed by the solid phase extraction (SPE) and high performance liquid chromatography (HPLC). The microcystin-LR was extracted with 80% aqueous methanol (m/V) stirring for 2 h at room temperature when the fluid solid ratio was 1 : 50. The supernatant was obtained after centrifugation (20 min, 8 000 r/min). The methanol in the extract was removed by the rotary evaporator, and the color was removed by the protein isoelectric point precipitation process. SPE was used for the microcystin-LR concentration and partial purification. The microcystin-LR was identified and quantified by HPLC. The method has good accuracy, precision, recovery rate, high extraction rate and low impurity content. The minimum detection limit was 0. 1 mg/L. The method is suitable for analyzing the trace microcystin-LR in water.%建立了采用固相萃取法(SPE)富集、HPLC法检测微囊藻毒素(MC - LR)的分析方法,采用80%的甲醇溶液按1:50的质量体积比,在室温下磁力搅拌抽提2h,于8 000 r/min转速下离心20 min,取出上清液,利用旋转蒸发仪脱除提取液中的甲醇,采用蛋白质等电点沉淀法进一步去除色素,最后利用SPE富集纯化MC - LR.该方法具有较好的测定准确度、精密度和回收率,且提取率高、藻毒素中杂质含量低,检测限为0.1 mg/L,适用于分析水体中的痕量MC - LR.

  19. [Determination of alkyl-phenols in textiles by in-tube capillary solid-phase extraction-gas chromatography].

    Science.gov (United States)

    Zhang, Luohong; Du, Ting; Zhong, Jiayu

    2015-10-01

    An in-tube capillary solid-phase extraction (SPE) -gas chromatography (GC) method was developed for confirmation and quantitative determination of octylphenol (OP) and nonylphenol (NP) in textiles. To make the in-tube capillary SPE column, the best SPE cartridge was chosen from four kinds of SPE cartridges. The adsorbent in the cartridge was used as the filling material to make the in-tube capillary SPE column. The nature, volume used, flow rate and adsorption capacity of the eluent were compared. Finally, the in-tube capillary solid-phase extraction was combined with gas chromatography to detect the alkyl phenols (APs). Abselut NEXUS extraction cartridge was chosen as the best solid phase extractant. The optimal in-tube capillary SPE extraction conditions were as follows: 1.2 μL methanol and 1.2 μL ultra-pure water for activating the extraction column, 1.2 μL methanol for eluting, 0.4 μL/min for solution loading. The method showed a good linear relationship in the low concentration range, and the enrichment ratios for the APs were about 100 times. The detection limits of octylphenol and nonylphenol were 3.7 μg/L and 4.5 μg/L, respectively. The recoveries of octylphenol were 85.6%-98.2%, and those of nonylphenol were 83.8%-95.7%. The experimental results demonstrated that the method is simple, rapid, and useful for detecting APs in textiles.

  20. One-pot synthesized functionalized mesoporous silica as a reversed-phase sorbent for solid-phase extraction of endocrine disrupting compounds in milks.

    Science.gov (United States)

    Gañán, Judith; Morante-Zarcero, Sonia; Pérez-Quintanilla, Damián; Marina, María Luisa; Sierra, Isabel

    2016-01-08

    A new procedure for the determination of 12 naturally occurring hormones and some related synthetic chemicals in milk, commonly used as growth promoters in cattle, is reported. The method is based on liquid-liquid extraction followed by solid-phase extraction (SPE) using a new one-pot synthesized ordered mesoporous silica (of the SBA-15 type) functionalized with octadecyl groups (denoted as SBA-15-C18-CO) as reversed-phase sorbent. The analytes were eluted with methanol and then submitted to HPLC with diode array detection. Under optimal conditions, the method quantification limit for the analytes ranged from 0.023 to 1.36μg/mL. The sorbent affored the extraction of estrone, 17β-estradiol, estriol, progesterone, hexestrol, diethylstilbestrol, 4-androstene-3,17-dione, ethinylestradiol, 17α-methyltestosterone, nandrolone, prednisolone and testosterone with mean recoveries ranging from 72% to 105% (except for diethylstilbestrol) with RSDextraction methods, therefore SBA-15-C18-CO mesoporous silica possess a high potential as a reversed-phase sorbent for SPE of the 12 mentioned endocrine disrupting compounds in milk samples.

  1. Application of microwave-assisted micro-solid-phase extraction for determination of parabens in human ovarian cancer tissues.

    Science.gov (United States)

    Sajid, Muhammad; Basheer, Chanbasha; Narasimhan, Kothandaraman; Choolani, Mahesh; Lee, Hian Kee

    2015-09-01

    Parabens (alkyl esters of p-hydroxybenzoic acid) are widely used as preservatives in food, cosmetics and pharmaceutical products. However, weak estrogenicity of some parabens has been reported in several studies, which provided the impetus for this work. Here, a simple and efficient analytical method for quantifying parabens in cancer tissues has been developed. This technique involves the simultaneous use of microwave-assisted solvent extraction (MASE) and micro-solid phase extraction (μ-SPE), in tandem with high performance liquid chromatography (HPLC/UV) analysis for the determination of parabens. The pollutants studied included four parabens (methyl, ethyl, propyl and butyl parabens). Optimization of the experimental parameters for MASE and μ-SPE was performed. Good relative standard deviation (%RSD) ranged from 0.09 to 2.81% and high enrichment factors (27-314) were obtained. Coefficients of determination (r(2)) up to 0.9962 were obtained across a concentration range of 5.0-200ngg(-1). The method detection limits for parabens ranged from 0.005 to 0.0244ngg(-1). The procedure was initially tested on prawn samples to demonstrate its feasibility on a complex biological matrix. Preliminary studies on human ovarian cancer (OC) tissues showed presence of parabens. Higher levels of parabens were detected in malignant ovarian tumor tissues compared to benign tumor tissue samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Colourimetric solid-phase extraction coupled with fibre optic reflectance spectroscopy for determination of ascorbic acid in pharmaceutical formulations.

    Science.gov (United States)

    Filik, Hayati; Aksu, Duygu; Giray, Derya; Apak, Reşat

    2012-06-01

    A redox colourimetric solid-phase extraction (C-SPE) procedure for the determination of ascorbic acid (AA) in pharmaceutical formulations was proposed. Iron (III)-2,2'-dipyridyl (Fe(III)-Bpy) reagent solution was used as a colouring reagent for AA and the immobilization of the redox product onto Amberlite XAD-16 resin was achieved. The analyte in the sample reacted with a solid sorbent loaded with the colourimetric reagent (Fe(III)-Bpy) and then quantified directly on the sorbent surface by using a fibre optic reflectance spectrometer (FORS). The amount of AA was reflectometrically determined in a few seconds with a total sample workup and readout time of ∼10 min using only 10-ml sample volumes. The limit of detection (LOD) and quantification (LOQ) values were 0.18 and 0.6 mg L(-1), respectively, and the linear dynamic range for AA extended up to 8.8 mg L(-1). The C-SPE for different extractions (n = 5) gave a relative standard deviation (RSD) of 2.9% at 5.28 mg L(-1) AA level.

  3. Comparison of liquid-liquid extraction-thin layer chromatography with solid-phase extraction-high-performance thin layer chromatography in detection of urinary morphine.

    Science.gov (United States)

    Ahadi, Ali; Partoazar, Alireza; Abedi-Khorasgani, Mohammad-Hassan; Shetab-Boushehri, Seyed Vahid

    2011-09-01

    Liquid-liquid extraction-thin layer chromatography (LLE-TLC) has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction (SPE) is gradually replacing the traditional LLE method. High performance thin layer chromatography (HPTLC) has several advantages over TLC. The present work studied the higher efficiency of a new SPE-HPTLC method over that of a routine LLE-TLC method, in extraction and detection of urinary morphine. Fifty-eight urine samples, primarily identified as morphine-positive samples by a strip test, were re-screened by LLE-TLC and SPE-HPTLC. The results of LLE-TLC and SPE-HPTLC were then compared with each other. The results showed that the SPE-HPTLC detected 74% of total samples as morphine-positive samples whereas the LLE-TLC detected 48% of the same samples. We further discussed the effect of codeine abuse on TLC analysis of urinary morphine. Regarding the importance of morphine detection in urine, the present combined SPE-HPTLC method is suggested as a replacement method for detection of urinary morphine by many reference laboratories.

  4. Solid phase extractive preconcentration of uranium(VI) using quinoline-8-ol anchored chloromethylated polymeric resin beads.

    Science.gov (United States)

    Praveen, R S; Metilda, P; Daniel, S; Rao, T Prasada

    2005-10-31

    A new chelating polymeric sorbent has been developed using Merrifield chloromethylated resin anchored with quinoline-8-ol (HQ). The modified polymeric resin was characterized by FT-IR spectroscopy and elemental analysis. The HQ anchored resin showed superior binding affinity for U(VI) over Th(IV) and La(III). The influence of various physicochemical parameters on the recovery of U(VI) were optimized by both static and dynamic methods. The phase exchange kinetic studies performed for U(VI) revealed that XAD-16. The developed HQ anchored polymeric resin is highly selective as none of the extraneous species were found to have any deleterious effect. Solid phase extraction (SPE) studies performed using HQ anchored polymeric resin offered enrichment factor of 100 and the lowest concentration below which recoveries become non-quantitative is 5mugl(-1). The accuracy of the developed SPE method in conjunction with Arsenazo III procedure was tested by analyzing marine sediment (MESS-3) and soil (IAEA-Soil 7) reference materials. Furthermore, the above procedure has been successfully employed for the analysis of real soil and sediment samples.

  5. Accelerated solvent extraction combined with solid phase extraction for the determination of organophosphate esters from sewage sludge compost by UHPLC-MS/MS.

    Science.gov (United States)

    Pang, Long; Yang, Peijie; Ge, Liming; Du, Jingjing; Zhang, Hongzhong

    2017-02-01

    Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, are regarded as emerging pollutants. OPEs are prone to concentrate into residual activated sludge, which might cause secondary pollution if not suitably treated. Composting is an economical and effective approach to make sewage sludge stable and harmless. Therefore, it is essential to develop a novel method for analyzing OPEs in sewage sludge compost samples. However, in the composting process, large amounts of amendments are doped into the sludge to adjust the carbon-nitrogen ratio. Amendment has a strong capacity for adsorption and thus induces a decrease of extraction efficiency. This study developed a novel procedure for determining OPEs in compost samples. Accelerated solvent extraction (ASE) and solid phase extraction (SPE) were used for extracting and concentrating the OPEs from sewage sludge compost samples, and then analyzed by UHPLC-MS/MS. Some parameters were optimized in this study, mainly including the extraction solvent type, extraction temperature, static extraction time, extraction cycles, and flush volume. Under the optimal conditions, the proposed method showed good linearity between 0.50 and 100 μg kg(-1) with regression coefficients in the range of 0.9984-0.9998. Detection limits were in the range of 0.02-3 μg kg(-1) with standard deviations ranging from 2 to 6%. Acceptable recoveries between 56 and 119% for samples spiked at different concentration levels were achieved. In contrast, the recoveries merely ranged from 24 to 58% by using ultrasonic-assisted extraction. Graphical abstract A comparison of recoveries between ultrasonic-assisted extraction (UAS) and accelerated solvent extraction (ASE) for organophosphate esters from sewage sludge compost samples.

  6. Srv mediated dispersal of streptococcal biofilms through SpeB is observed in CovRS+ strains.

    Directory of Open Access Journals (Sweden)

    Kristie L Connolly

    Full Text Available Group A Streptococcus (GAS is a human specific pathogen capable of causing both mild infections and severe invasive disease. We and others have shown that GAS is able to form biofilms during infection. That is to say, they form a three-dimensional, surface attached structure consisting of bacteria and a multi-component extracellular matrix. The mechanisms involved in regulation and dispersal of these GAS structures are still unclear. Recently we have reported that in the absence of the transcriptional regulator Srv in the MGAS5005 background, the cysteine protease SpeB is constitutively produced, leading to increased tissue damage and decreased biofilm formation during a subcutaneous infection in a mouse model. This was interesting because MGAS5005 has a naturally occurring mutation that inactivates the sensor kinase domain of the two component regulatory system CovRS. Others have previously shown that strains lacking covS are associated with decreased SpeB production due to CovR repression of speB expression. Thus, our results suggest the inactivation of srv can bypass CovR repression and lead to constitutive SpeB production. We hypothesized that Srv control of SpeB production may be a mechanism to regulate biofilm dispersal and provide a mechanism by which mild infection can transition to severe disease through biofilm dispersal. The question remained however, is this mechanism conserved among GAS strains or restricted to the unique genetic makeup of MGAS5005. Here we show that Srv mediated control of SpeB and biofilm dispersal is conserved in the invasive clinical isolates RGAS053 (serotype M1 and MGAS315 (serotype M3, both of which have covS intact. This work provides additional evidence that Srv regulated control of SpeB may mediate biofilm formation and dispersal in diverse strain backgrounds.

  7. Apparent Explosion Moments from Rg Waves Recorded on SPE: Implications for the Late-Time Damage Source Model

    Science.gov (United States)

    Patton, H. J.; Larmat, C. S.; Rougier, E.

    2016-12-01

    Seismic moments for chemical shots making up Phase I of the Source Physics Experiments (SPE) are estimated from 6 Hz Rg waves under the assumption that the shots are pure explosions. These apparent explosion moments are compared to moments determined using the Reduced Displacement Potential (RDP) method applied to free field data. LIDAR/photogrammetry observations, strong ground motions on the free surface near ground zero, and moment tensor inversion results are evidence in support of the fourth shot SPE-4P being essentially a pure explosion. The apparent moment for SPE-4P is 9 × 1010 Nm in good agreement with the RDP moment 8 × 1010 Nm. In stark contrast, apparent moments for the first three shots are three to four times smaller than RDP moments. Data show that spallation occurred on these shots, as well as permanent deformations detected with ground-based LIDAR. As such, the source medium suffered late-time damage. The late-time damage source model predicts destructive interference between Rg waves radiated by explosion and damage sources, which reduces amplitudes and explains why apparent moments are smaller than RDP moments based on compressional energy emitted directly from the source. SPE-5 was conducted at roughly the same yield-scaled burial depth as SPE-2 and -3, but with five times the yield. As such, the damage source model predicts less reduction of apparent moment. At this writing, preliminary results from Rg interferometry and RDP moments confirm this prediction. SPE-6 is scheduled for the fall of 2016, and it should have the strongest damage source of all SPE shots. The damage model predicts that the polarity of Rg waves could be reversed. Realization of this prediction will be strong confirmation of the late-time damage source model. This abstract has a Los Alamos National Laboratory Unlimited Release Number LA-UR-16-25709.

  8. Microwave-assisted extraction and ultrasonic extraction to determine polycyclic aromatic hydrocarbons in needles and bark of Pinus pinaster Ait. and Pinus pinea L. by GC-MS.

    Science.gov (United States)

    Ratola, Nuno; Lacorte, Sílvia; Barceló, Damià; Alves, Arminda

    2009-01-15

    Two different extraction strategies (microwave-assisted extraction (MAE) and ultrasonic extraction (USE)) were tested in the extraction of the 16 US Environmental Protection Agency (EPA) polycyclic aromatic hydrocarbons (PAHs) from pine trees. Extraction of needles and bark from two pine species common in the Iberian Peninsula (Pinus pinaster Ait. and Pinus pinea L.) was optimized using two amounts of sample (1g and 5 g) and two PAHs spiking levels (20 ng/g and 100 ng/g). In all cases, the clean-up procedure following extraction consisted in solid-phase extraction (SPE) with alumina cartridges. Quantification was done by gas chromatography (GC) with mass spectrometry (MS), using five deuterated PAH surrogate standards as internal standards. Limits of detection were globally below 0.2 ng/g. The method was robust for the matrices studied regardless of the extraction procedures. Recovery values between 70 and 130% were reached in most cases, except for high molecular weight PAHs (indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene and benzo[ghi]perylene). A field study with naturally contaminated samples from eight sites (four in Portugal and four in Catalonia, Spain) showed that needles are more suitable biomonitors for PAHs, yielding concentrations from 2 to 17 times higher than those found in bark. The levels varied according to the sampling site, with the sum of the individual PAH concentrations between 213 and 1773 ng/g (dry weight). Phenanthrene was the most abundant PAH, followed by fluoranthene, naphthalene and pyrene.

  9. Methodologies for the Extraction of Phenolic Compounds from Environmental Samples: New Approaches

    Directory of Open Access Journals (Sweden)

    Cristina Mahugo Santana

    2009-01-01

    Full Text Available Phenolic derivatives are among the most important contaminants present in the environment. These compounds are used in several industrial processes to manufacture chemicals such as pesticides, explosives, drugs and dyes. They also are used in the bleaching process of paper manufacturing. Apart from these sources, phenolic compounds have substantial applications in agriculture as herbicides, insecticides and fungicides. However, phenolic compounds are not only generated by human activity, but they are also formed naturally, e.g., during the decomposition of leaves or wood. As a result of these applications, they are found in soils and sediments and this often leads to wastewater and ground water contamination. Owing to their high toxicity and persistence in the environment, both, the US Environmental Protection Agency (EPA and the European Union have included some of them in their lists of priority pollutants. Current standard methods of phenolic compounds analysis in water samples are based on liquid–liquid extraction (LLE while Soxhlet extraction is the most used technique for isolating phenols from solid matrices. However, these techniques require extensive cleanup procedures that are time-intensive and involve expensive and hazardous organic solvents, which are undesirable for health and disposal reasons. In the last years, the use of news methodologies such as solid-phase extraction (SPE and solid-phase microextraction (SPME have increased for the extraction of phenolic compounds from liquid samples. In the case of solid samples, microwave assisted extraction (MAE is demonstrated to be an efficient technique for the extraction of these compounds. In this work we review the developed methods in the extraction and determination of phenolic derivatives in different types of environmental matrices such as water, sediments and soils. Moreover, we present the new approach in the use of micellar media coupled with SPME process for the

  10. Design and test status for life support applications of SPE oxygen generation systems. [Solid Polymer Electrolyte

    Science.gov (United States)

    Titterington, W. A.; Erickson, A. C.

    1975-01-01

    An advanced six-man rated oxygen generation system has been fabricated and tested as part of a NASA/JSC technology development program for a long lived, manned spacecraft life support system. Details of the design and tests results are presented. The system is based on the Solid Polymer Electrolyte (SPE) water electrolysis technology and its nominal operating conditions are 2760 kN/sq m (400 psia) and 355 K (180 F) with an electrolysis module current density capability up to 350 mA/sq cm (326 ASF). The system is centered on a 13-cell SPE water electrolysis module having a single cell active area of 214 sq cm (33 sq in) and it incorporates instrumentation and controls for single pushbutton automatic startup/shutdown, component fault detection and isolation, and self-contained sensors and controls for automatic safe emergency shutdown. The system has been tested in both the orbital cyclic and continuous mode of operation. Various parametric tests have been completed to define the system capability for potential application in spacecraft environmental systems.

  11. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

    Science.gov (United States)

    This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

  12. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DRINKING WATER SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP 5.23)

    Science.gov (United States)

    The method for extracting and preparing a drinking water sample for analysis of atrazine is summarized in this SOP. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/ mass spectrometry.

  13. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

    Science.gov (United States)

    This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

  14. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DRINKING WATER SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP 5.23)

    Science.gov (United States)

    The method for extracting and preparing a drinking water sample for analysis of atrazine is summarized in this SOP. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/ mass spectrometry.

  15. EPA Method 525.3 - Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS)

    Science.gov (United States)

    Method 525.3 is an analytical method that uses solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) for the identification and quantitation of 125 selected semi-volatile organic chemicals in drinking water.

  16. Extraction of mono- and dicarboxylic acids from a curative water.

    Science.gov (United States)

    Franke, C; Weil, L; Niessner, R

    1995-09-01

    A method for the analysis of mono- and dicarboxylic acids from water is presented. For this purpose two techniques, a C(18) solid phase extraction (SPE) and a combination method of liquid-liquid extraction (LLE) and aminopropyl SPE, were tested. With the combination method all analytes, short-chain mono- and long-chain dicarboxylic acids, could be analysed in one approach. The C(18) SPE was not suitable for short-chain mono- but for dicarboxylic acids. Concentrations in the investigated water ranged from 315 mg/l (butanoic acid) to 2.9 mg/l (octanoic acid). Dicarboxylic acids were found from 5 mg/l (octanedioic acid) to 0.5 mg/l (dodecanedioic acid).

  17. Molecular imprinted polymer for solid-phase extraction of flavonol aglycones from Moringa oleifera extracts.

    Science.gov (United States)

    Pakade, Vusumzi; Cukrowska, Ewa; Lindahl, Sofia; Turner, Charlotta; Chimuka, Luke

    2013-02-01

    Molecular imprinted polymer produced using quercetin as the imprinting compound was applied for the extraction of flavonol aglycones (quercetin and kaempferol) from Moringa oleifera methanolic extracts obtained using heated reflux extraction method. Identification and quantification of these flavonols in the Moringa extracts was achieved using high performance liquid chromatography with ultra violet detection. Breakthrough volume and retention capacity of molecular imprinted polymer SPE was investigated using a mixture of myricetin, quercetin and kaempferol. The calculated theoretical number of plates was found to be 14, 50 and 8 for myricetin, quercetin and kaempferol, respectively. Calculated adsorption capacities were 2.0, 3.4 and 3.7 μmol/g for myricetin, quercetin and kaempferol, respectively. No myricetin was observed in Moringa methanol extracts. Recoveries of quercetin and kaempferol from Moringa methanol extracts of leaves and flowers ranged from 77 to 85% and 75 to 86%, respectively, demonstrating the feasibility of using the developed molecularly imprinted SPE method for quantitative clean-up of both of these flavonoids. Using heated reflux extraction combined with molecularly imprinted SPE, quercetin concentrations of 975 ± 58 and 845 ± 32 mg/kg were determined in Moringa leaves and flowers, respectively. However, the concentrations of kaempferol found in leaves and flowers were 2100 ± 176 and 2802 ± 157 mg/kg, respectively. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Effect of DNA extraction procedure, repeated extraction and ethidium monoazide (EMA)/propidium monoazide (PMA) treatment on overall DNA yield and impact on microbial fingerprints for bacteria, fungi and archaea in a reference soil.

    Science.gov (United States)

    Wagner, Andreas O; Praeg, Nadine; Reitschuler, Christoph; Illmer, Paul

    2015-09-01

    Different DNA extraction protocols were evaluated on a reference soil. A wide difference was found in the total extractable DNA as derived from different extraction protocols. Concerning the DNA yield phenol-chloroform-isomyl alcohol extraction resulted in high DNA yield but also in a remarkable co-extraction of contaminants making PCR from undiluted DNA extracts impossible. By comparison of two different extraction kits, the Macherey&Nagel SoilExtract II kit resulted in the highest DNA yields when buffer SL1 and the enhancer solution were applied. The enhancer solution not only significantly increased the DNA yield but also the amount of co-extracted contaminates, whereas additional disintegration strategies did not. Although a three times repeated DNA extraction increased the total amount of extracted DNA, microbial fingerprints were merely affected. However, with the 5th extraction this changed. A reduction of total DGGE band numbers was observed for archaea and fungi, whereas for bacteria the diversity increased. The application of ethidium monoazide (EMA) or propidium monoazide (PMA) treatment aiming on the selective removal of soil DNA derived from cells lacking cell wall integrity resulted in a significant reduction of total extracted DNA, however, the hypothesized effect on microbial fingerprints failed to appear indicating the need for further investigations.

  19. A Fully Automated Radiosynthesis of [18F]Fluoroethyl-Diprenorphine on a Single Module by Use of SPE Cartridges for Preparation of High Quality 2-[18F]Fluoroethyl Tosylate

    Directory of Open Access Journals (Sweden)

    Gjermund Henriksen

    2013-06-01

    Full Text Available We have developed a new method for automated production of 2-[18F]fluoroethyl tosylate ([18F]FETos that enables 18F-alkylation to provide PET tracers with high chemical purity. The method is based on the removal of excess ethylene glycol bistosylate precursor by precipitation and subsequent filtration and purification of the filtrate by means of solid phase extraction cartridges (SPE. The method is integrated to a single synthesis module and thereby provides the advantage over previous methods of not requiring HPLC purification, as demonstrated by the full radiosynthesis of the potent opioid receptor PET tracer [18F]fluoroethyldiprenorphine.

  20. Dual high-resolution inhibition profiling and HPLC-HRMS-SPE-NMR analysis for identification of α-glucosidase and radical scavenging inhibitors in Solanum americanum Mill

    DEFF Research Database (Denmark)

    Silva, Eder Lana e; Almeida-Lafetá, Rita C.; Borges, Ricardo Moreira

    2017-01-01

    Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α......-glucosidase/radical scavenging inhibition profiling. The high-resolution biochromatograms obtained by this technique were used to target subsequent structural elucidation by HPLC-HRMS-SPE-NMR analysis towards the bioactive constituents. This led to identification of 4-hydroxybenzoic acid ( 1 ) and 3-indolecarboxylic acid ( 6...

  1. Determination of Reductones, Furans and Organic Acids in Aqueous Model Matrices Using Solid-Phase Extraction and Gas Chromatography/Mass Spectrometry

    National Research Council Canada - National Science Library

    MORI, Masataka; ITO, Kenji

    2004-01-01

    ...: reductones, furans and volatile organic acids, in aqueous model matrices. The SPE procedures were optimized mainly on the pH-dependency of the analytes with regard to their adsorption characteristics...

  2. High-performance liquid chromatography - Ultraviolet method for the determination of total specific migration of nine ultraviolet absorbers in food simulants based on 1,1,3,3-Tetramethylguanidine and organic phase anion exchange solid phase extraction to remove glyceride.

    Science.gov (United States)

    Wang, Jianling; Xiao, Xiaofeng; Chen, Tong; Liu, Tingfei; Tao, Huaming; He, Jun

    2016-06-17

    The glyceride in oil food simulant usually causes serious interferences to target analytes and leads to failure of the normal function of the RP-HPLC column. In this work, a convenient HPLC-UV method for the determination of the total specific migration of nine ultraviolet (UV) absorbers in food simulants was developed based on 1,1,3,3-tetramethylguanidine (TMG) and organic phase anion exchange (OPAE) SPE to efficiently remove glyceride in olive oil simulant. In contrast to the normal ion exchange carried out in an aqueous solution or aqueous phase environment, the OPAE SPE was performed in the organic phase environments, and the time-consuming and challenging extraction of the nine UV absorbers from vegetable oil with aqueous solution could be readily omitted. The method was proved to have good linearity (r≥0.99992), precision (intra-day RSD≤3.3%), and accuracy(91.0%≤recoveries≤107%); furthermore, the lower limit of quantifications (0.05-0.2mg/kg) in five types of food simulants(10% ethanol, 3% acetic acid, 20% ethanol, 50% ethanol and olive oil) was observed. The method was found to be well suited for quantitative determination of the total specific migration of the nine UV absorbers both in aqueous and vegetable oil simulant according to Commission Regulation (EU) No. 10/2011. Migration levels of the nine UV absorbers were determined in 31 plastic samples, and UV-24, UV-531, HHBP and UV-326 were frequently detected, especially in olive oil simulant for UV-326 in PE samples. In addition, the OPAE SPE procedure was also been applied to efficiently enrich or purify seven antioxidants in olive oil simulant. Results indicate that this procedure will have more extensive applications in the enriching or purification of the extremely weak acidic compounds with phenol hydroxyl group that are relatively stable in TMG n-hexane solution and that can be barely extracted from vegetable oil.

  3. Mixed hemimicelles SPE based on CTAB-coated Fe3O4/SiO2 NPs for the determination of herbal bioactive constituents from biological samples.

    Science.gov (United States)

    Zhu, Li; Pan, Di; Ding, Li; Tang, Fei; Zhang, Qianli; Liu, Qian; Yao, Shouzhuo

    2010-03-15

    In this paper, a solid-phase extraction (SPE) method based on mixed hemimicelles of cetyltrimethyl ammonium bromide (CTAB) on silica-coated magnetic nanoparticles (MNPs) is developed for extraction and preconcentration of compounds from the biological samples. We selected rhein and emodin which are the major active anthraquinones of rhubarb as model analytes. A high performance liquid chromatography-fluorescence detection (HPLC/FLD) method was developed for the determination of rhein and emodin in urine and serum samples. The main factors influencing the extraction efficiency including the amount of surfactant, the concentration of MNPs, the shaking time and the desorption ability of organic solvents were investigated and optimized. No interferences were caused by proteins or endogenous compounds in urine and serum samples. Good linearities (r(2)>0.9995) for all calibration curves were obtained, and the limits of detection (LODs) for rhein and emodin were 0.2 and 0.5 ng/mL in urine samples and 7 and 10 ng/mL in serum samples, respectively. Satisfactory recoveries (92.76-109.90% and 97.53-107.72% for rhein and emodin) in the biological matrices were achieved. Copyright (c) 2009. Published by Elsevier B.V.

  4. Simultaneous determination of 30 hormones illegally added to anti-ageing functional foods using UPLC-MS/MS coupled with SPE clean-up.

    Science.gov (United States)

    He, Xiaoqin; Xi, Cunxian; Tang, Bobin; Wang, Guomin; Chen, Dongdong; Peng, Tao; Mu, Zhaode

    2014-01-01

    A novel analytical method employing solid-phase extraction (SPE) coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 30 hormones in anti-ageing functional foods (capsules, powders and tablets). The analytes were extracted with acetic acid-acetonitrile (1-99 v/v), methanol and acetone, respectively. The extract was purified using a combined column, followed by analyte detection with electrospray ionisation in positive- or negative-ion modes. The results indicated that the 30 compounds had good linear correlations in the range of 1-1000 μg kg⁻¹, and the correlation coefficients were above 0.99. The limits of detection (LOD) and limits of quantification (LOQ) were 0.03-2 and 0.1-5 μg kg⁻¹, respectively. The average recovery of 30 compounds at the three spiked levels varied from 74.7% to 124.1%, and the relative standard deviation (RSD) was 2.4-15.0%. This method was applied to the analysis of hormones in 14 real samples of which seven hormones (such as estrone, dienestrol) were detected in four samples, but the remainder of the hormones were not detected. The developed method is sensitive, efficient, reliable and applicable to real samples.

  5. VizieR Online Data Catalog: New SpeX Observations of M7-L6 Dwarfs (Bardalez+, 2014)

    Science.gov (United States)

    Bardalez Gagliuffi, D. C.; Burgasser, A. J.; Gelino, C. R.; Looper, D. L.; Nicholls, C. P.; Schmidt, S. J.; Cruz, K.; West, A. A.; Gizis, J. E.; Metchev, S.

    2017-05-01

    The SpeX Prism Library is composed of low-resolution (λ/Δλ=75-120) spectra acquired with the SpeX 0.8-2.5 um spectrograph, mounted on the 3.0 m NASA Infrared Telescope Facility (IRTF), located in Mauna Kea, HI (Rayner et al. 2003PASP..115..362R). All spectra were obtained using the prism-dispersed SpeX mode, which continuously samples wavelengths between 0.75 and 2.5 um at a dispersion of 20-30 Å/pixel. The library includes close to 2000 sources, both previously published data (e.g., Burgasser et al. 2010, J/ApJ/710/1142; Chiu et al. 2006, J/AJ/131/2722; Cruz et al. 2003, J/AJ/126/2421) and 530 new spectra acquired between 2000 November and 2013 December. (2 data files).

  6. Comparison of SPE, IFE, and FLC in Monitoring Patients with Multiple Myeloma After Autologous Stem Cell Transplantation.

    Science.gov (United States)

    Li, Wei; Zhou, Jia-Zi; Chang, Hui-Rong; Dai, Li-Jun; Zhu, Zi-Ling; Feng, Yu-Feng; Gong, Fei-Ran; Wu, De-Pei

    2015-12-01

    Conventionally, serum protein electrophoresis (SPE) and serum immunofixation electrophoresis (IFE) are used as primary methods to diagnose and monitor multiple myeloma (MM). Recently, serum-free light chain (FLC) assay has been incorporated into hematological screening programs for myeloma. The purpose of this study is to compare the performance of the three methods in monitoring MM patients after autologous stem cell transplantation (ASCT). SPE, serum IFE and serum FLC assay were performed on 38 MM patients who underwent ASCT. In total, four patients had unexpected protein bands (UPBs) and 13 patients had relapsed after ASCT. Our results indicate that IFE is more sensitive than SPE and FLC assay in detection of UPBs and relapse. The results of IFE may provide useful information in advance of patient relapse.

  7. [Determination of 30 organochlorine pesticides in animal-originated food products using combined purification by gel permeation chromatography and solid-phase extraction coupled with gas chromatography-mass spectrometry].

    Science.gov (United States)

    Du, Juan; Lü, Bing; Zhu, Pan; Miao, Hong; Wu, Yongning

    2013-08-01

    A new analytical method was developed for the determination of 30 organochlorine pesticides (OCPs) in animal-originated food, including pork, chicken, fish and shrimp. The combined purification by gel permeation chromatography (GPC) and solid-phase extraction (SPE) were established by optimizing different fraction collection times. The detection conditions can be achieved by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring (SIM). Isotopic internal standards were used for the quantitative determination of the 30 OCPs. The sample pretreatment procedure was based on acetonitrile extraction and combined purification of GPC and Florisil SPE cartridge. The experimental results showed that the linear ranges for 30 OCPs were 5.0 - 500.0 microg/L, the correlation coefficients were better than 0.996, and the method detection limits (MDLs) of the 30 OCPs were 0.2 - 2.7 microg/kg. The spiked recoveries at three levels of 5.0, 10.0 and 20.0 microg/kg using pork, chicken, fish and shrimp samples as blank matrices were in the range of 55.0% - 119.1%, the relative standard deviations (RSDs) were in the range of 0.4% - 15.0%. The method has the advantages of wide linear range, high sensitivity and efficient clean-up procedure, and consistent with the demand of pesticide routine analysis.

  8. Efficiency of Polyphenol Extraction from Artificial Honey Using C18 Cartridges and Amberlite® XAD-2 Resin: A Comparative Study

    OpenAIRE

    Chua Yung An; Md. Murad Hossain; Fahmida Alam; Md. Asiful Islam; Md. Ibrahim Khalil; Nadia Alam; Siew Hua Gan,

    2016-01-01

    A comparative study of the extraction efficiency of nine known polyphenols [phenolic acids (benzoic acid, dihydroxybenzoic acid, gallic acid, trans-cinnamic acid, and vanillic acid) and flavonoids (naringenin, naringin, quercetin, and rutin)] was conducted by deliberately adding the polyphenols to an artificial honey solution and performing solid phase extraction (SPE). Two SPE methods were compared: one using Amberlite XAD-2 resin and another one using a C18 cartridge. A gradient high perfor...

  9. Edible seaweed as future functional food: Identification of α-glucosidase inhibitors by combined use of high-resolution α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR.

    Science.gov (United States)

    Liu, Bingrui; Kongstad, Kenneth T; Wiese, Stefanie; Jäger, Anna K; Staerk, Dan

    2016-07-15

    Crude chloroform, ethanol and acetone extracts of nineteen seaweed species were screened for their antioxidant and α-glucosidase inhibitory activity. Samples showing more than 60% α-glucosidase inhibitory activity, at a concentration of 1 mg/ml, were furthermore investigated using high-resolution α-glucosidase inhibition profiling combined with high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HR-bioassay/HPLC-HRMS-SPE-NMR). The results showed Ascophyllum nodosum and Fucus vesicolosus to be rich in antioxidants, equaling a Trolox equivalent antioxidant capacity of 135 and 108 mM Troloxmg(-1) extract, respectively. HR-bioassay/HPLC-HRMS-SPE-NMR showed the α-glucosidase inhibitory activity of A. nodosum, F. vesoculosus, Laminaria digitata, Laminaria japonica and Undaria pinnatifida to be caused by phlorotannins as well as fatty acids - with oleic acid, linoleic acid and eicosapentaenoic acid being the most potent with IC50 values of 0.069, 0.075 and 0.10 mM, respectively, and showing a mixed-type inhibition mode.

  10. Solid-phase/supercritical-fluid extraction for liquid chromatography of phenolic compounds in freshwater microalgae and selected cyanobacterial species.

    Science.gov (United States)

    Klejdus, B; Kopecký, J; Benesová, L; Vacek, J

    2009-01-30

    In the present paper a new extraction technique based on the combination of solid-phase/supercritical-fluid extraction (SPE/SFE) with subsequent reversed-phase HPLC is described. The SPE/SFE extractor was originally constructed from SPE-cartridge incorporated into the SFE extraction cell. Selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acid), hydroxybenzaldehydes (4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde) and cinnamic acid derivatives (o-coumaric, p-coumaric, caffeic, ferulic, sinapic and chlorogenic acid) were extracted. Cyclic addition of binary extraction solvent system based on methanol:water (1:1, v/v) and methanol/ammonia aqueous solution was used for extraction at 40MPa and 80 degrees C. The p-hydroxybenzoic, protocatechuic, vanillic, syringic, caffeic and chlorogenic acid; 4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde were identified by HPLC-electrospray mass spectrometry in SPE/SFE extracts of acid hydrolyzates of microalga (Spongiochloris spongiosa) and cyanobacterial strains (Spirulina platensis, Anabaena doliolum, Nostoc sp., and Cylindrospermum sp.). For the identification and quantification of the compounds the quasi-molecular ions [M-H](-) and specific fragments were analysed by quadrupole mass spectrometry analyzer. Our analysis showed that the microalgae and cyanobacteria usually contained phenolic acids or aldehydes at microg levels per gram of lyophilized sample. The proposed SPE/SFE extraction method would be useful for the analysis of different plant species containing trace amount of polar fraction of phenols.

  11. Elevated urinary levels of carcinogenic N-nitrosamines in patients with urinary tract infections measured by isotope dilution online SPE LC–MS/MS

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chiung-Wen [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Shih, Ying-Ming [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Division of Chest Medicine, Department of Internal Medicine, Changhua Christian Hospital, Changhua 500, Taiwan (China); Liu, Hung-Hsin [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Chiang, Yi-Chen [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); School of Public Health, Xiamen University, Xiamen 361102, Fujian (China); Chen, Chih-Ming [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Chao, Mu-Rong, E-mail: chaomurong@gmail.com [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China)

    2016-06-05

    Highlights: • Nine N-nitrosamines in urine were quantified by LC–MS/MS. • N-nitrosodiphenylamine was firstly identified in human urine. • UTI patients had much higher N-nitrosamines concentrations than healthy subjects. • N-nitrosamines were dramatically decreased after antibiotic treatment. • NDMA was correlated with the pH, WBC esterase activity or nitrite in UTI patients. - Abstract: N-nitrosamines (NAms) are well-documented for their carcinogenic potential. Human exposure to NAms may arise from the daily environment and endogenous formation via the reaction of secondary amines with nitrites or from bacteria infection. We describe the use of isotope dilution online solid-phase extraction (SPE) LC–MS/MS to quantify nine NAms in human urine. This method was validated and further applied to healthy subjects and patients with urinary tract infection (UTI). N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPYR) and N-nitrosomorpholine (NMOR) were analyzed with an APCI source, while N-nitrosodiethylamine (NDEA), N-nitrosopiperidine (NPIP), N-nitrosodi-n-propylamine (NDPA), N-nitrosodibutylamine (NDBA) and N-nitrosodiphenylamine (NDPhA) were quantified with an ESI source, due to their effect on the sensitivity and chromatography. NDMA was the most abundant N-nitrosamine, while NDPhA was firstly identified in human. UTI patients had three to twelve-fold higher concentrations for NDMA, NPIP, NDEA, NMOR and NDBA in urine than healthy subjects, and the NAms were significantly decreased after antibiotics treatment. NDMA concentrations were also significantly correlated with the pH value, leukocyte esterase activity or nitrite in urines of UTI patients. Our findings by online SPE LC–MS/MS method evidenced that UTI patients experienced various NAms exposures, especially the potent carcinogen NDMA, which was likely induced by bacteria infection.

  12. Investigation of different extraction procedures for the determination of major and trace elements in coal by ICP-AES and ion chromatography

    Directory of Open Access Journals (Sweden)

    Tasić Aleksandra M.

    2016-01-01

    Full Text Available This paper presents the extraction of major and trace elements from a coal sample, in deionized water, by using three different extraction techniques. Rotary mixing and ultrasonic extraction were examined for different extraction times, while the microwave assisted extraction was performed at different temperatures. Metal concentrations (Na, K, Ca, Mg, Al, Fe, Mn, Be, Cd, Co, Cr, Hg, As, Ni, Se, Sb and Pb in a solution were determined by employing the inductively coupled plasma atomic emission spectrometry; whereas the results obtained for Na, K, Ca and Mg were compared employing ion chromatography. Comparing the rotary and ultrasonic-assisted extraction it is shown that the former is more efficient for the determination of Fe, Na and Pb, whereas the latter one has proven more efficient for the determination of Co and Cr ions. Microwave-assisted extraction has proven the most efficient method for any elements tested in coal. In addition, sequential extraction of elements was done using microwave digestion. The results of sequential extraction experiments indicated associations of investigated elements with a mineral phase and organic matrix. Sequential extraction provided information on possible leaching of As, Cd, Co, Cr, Ni, Pb, Fe and Mn in environmental conditions. [Projekat Ministarstva nauke Republike Srbije, br. 172030

  13. Graphene-modified TiO2 nanotube arrays as an adsorbent in micro-solid phase extraction for determination of carbamate pesticides in water samples.

    Science.gov (United States)

    Zhou, Qingxiang; Fang, Zhi

    2015-04-15

    Graphene is a good adsorbent for organic pollutants, especially for compounds containing benzene rings. When used in TiO2 nanotube arrays for micro-solid phase extraction (μ-SPE), the combination of graphene's strong adsorptive properties with its good separation capabilities results in excellent sample preconcentration performance. In the present study, graphene-modified TiO2 nanotube arrays were prepared by electrodeposition using a cyclic voltammetric reduction method. Four carbamate pesticides, including metolcarb, carbaryl, isoprocarb, and diethofencarb, were used as model analytes to validate the enrichment properties of the prepared adsorbent in μ-SPE. Factors affecting the enrichment efficiency of the μ-SPE procedure were optimized and included sample pH, elution solvents, salting-out effect, adsorption time and desorption time. Under optimal conditions, graphene-modified TiO2 nanotube arrays exhibited excellent enrichment efficiency for carbamate pesticides. The detection limits of these carbamate pesticides ranged from 2.27 to 3.26 μg L(-1). The proposed method was validated using four environmental water samples, and yields of pesticides recovered from spiked test samples of the four analytes were in the range of 83.9-108.8%. These results indicate that graphene-modified TiO2 nanotube arrays exhibit good adsorption to the target pollutants, and the method described in this work could be used as a faster and easier alternative procedure for routine analysis of carbamate pesticides in real water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Lessons Learned from Near Field Modeling and Data Collected at the SPE Chemical Explosions in Jointed Rock Masses

    Science.gov (United States)

    Vorobiev, O.; Ezzedine, S. M.; Hurley, R.; Antoun, T.; Glenn, L.

    2016-12-01

    This work describes the near-field modeling of wave propagation from underground chemicalexplosions conducted at the Nevada National Security Site (NNSS) in fractured granitic rock. Lab testsperformed on granite samples excavated from various locations at the SPE site have shown littlevariability in mechanical properties. Granite at this scale can be considered as an isotropic medium. Wehave shown, however, that on the scale of the pressure waves generated during chemical explosions(tens of meters), the effective mechanical properties may vary significantly and exhibit both elastic andplastic anisotropies due to local variations in joint properties such as spacing orientation, joint aperture,cohesion and saturation. Since including every joint in a discrete fashion in computational model is notfeasible, especially for large-scale calculations ( 1.5 km domain), we have developed a computationaltechnique to upscale mechanical properties for various scales (frequencies) using geophysicalcharacterization conducted during recent SPE tests at the NNSS. Stochastic representation of thesefeatures based on the field characterizations has been implemented into LLNL's Geodyn-L hydrocode.Scale dependency in mechanical properties is important in order to understand how the ground motionscales with yield. We hope that such an approach will not only provide a better prediction of theground motion observed in the SPE (where the yield varies from 100 kg to few tons of TNT equivalent)but also will allow us to extrapolate results of the SPE to sources with bigger yields. We have validatedour computational results by comparing the measured and computed ground motion at various rangesfor experiments of various yields (SPE1-SPE5). Using the new model we performed severalcomputational studies to identify the most important mechanical properties of the rock mass specific tothe SPE site and to understand their roles in the observed ground motion in the near-field. We willpresent a series

  15. Solid phase extraction method for the study of black carbon cycling in dissolved organic carbon using radiocarbon

    OpenAIRE

    2015-01-01

    © 2015 Elsevier B.V.. Radiocarbon analysis is a powerful tool for understanding the cycling of individual components within carbon pools, such as black carbon (BC) in dissolved organic carbon (DOC). Radiocarbon (δ14C) measurements of BC in DOC provide insight into one source of aged, recalcitrant DOC. We report a modified solid phase extraction (SPE) method to concentrate 43±6% of DOC (SPE-DOC) from seawater. We used the Benzene Polycarboxylic Acid (BPCA) method to isolate BC from SPE-DOC (SP...

  16. Synthesis of mimic molecularly imprinted ordered mesoporous silica adsorbent by thermally reversible semicovalent approach for pipette-tip solid-phase extraction-liquid chromatography fluorescence determination of estradiol in milk.

    Science.gov (United States)

    Wang, Lu; Yan, Hongyuan; Yang, Chunliu; Li, Zan; Qiao, Fengxia

    2016-07-22

    A mimic molecularly imprinted ordered mesoporous silica (MIOMS) adsorbent was prepared utilizing a thermally reversible semicovalent approach. The thermally reversible covalent template-monomer complex was firstly synthesized by employing 4,4'-sulfonyldiphenol (BPS) and (3-isocyanatopropyl) triethoxysilane (ICPTES) as template and monomer, respectively. The template-monomer complex was incorporated into ordered mesoporous silica via a simple self-assembly process. The adsorption experiment illustrated that the imprint-removed silica (MIOMS-ir) had higher special recognition ability (250μgg(-1)) for estradiol (E2) than the non-imprinted silica (NIOMS-ir) (25μgg(-1)). MIOMS-ir was applied as an adsorbent in pipette-tip solid-phase extraction (PT-SPE) coupled with liquid chromatography-fluorescence detector (LC-FLD) for determination of E2 in milk samples. Under the optimized conditions, only 3mg of the adsorbent, 0.3mL of water as washing solvent, and 0.5mL of acetonitrile-acetic acid (96:4, v/v) as elution solvent were used in the pretreatment procedure of milk samples. Good calibration linearity was obtained in a range of 25ngL(-1) to 1000ngL(-1), and the recoveries at three spiked levels were ranged from 95.4% to 107.0% with relative standard deviations (RSDs) ≤3.1% (n=3). The proposed MIOMS-ir-PT-SPE-LC-FLD method combined the advantages of PT-SPE and ordered mesoporous material such as ease assembly, low cost, high extraction efficiency and large specific surface area, so it is a potential pretreatment strategy for the extraction and determination of E2 in complex milk samples.

  17. Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

    Science.gov (United States)

    Han, Dandan; Row, Kyung Ho

    2011-01-01

    A simple solid-phase extraction (SPE) method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC) for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998) for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1) was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction. PMID:21673926

  18. Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2011-03-01

    Full Text Available A simple solid-phase extraction (SPE method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998 for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1 was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.

  19. A comprehensive method for extraction and quantitative analysis of sterols and secosteroids from human plasma.

    Science.gov (United States)

    McDonald, Jeffrey G; Smith, Daniel D; Stiles, Ashlee R; Russell, David W

    2012-07-01

    We describe the development of a method for the extraction and analysis of 62 sterols, oxysterols, and secosteroids from human plasma using a combination of HPLC-MS and GC-MS. Deuterated standards are added to 200 μl of human plasma. Bulk lipids are extracted with methanol:dichloromethane, the sample is hydrolyzed using a novel procedure, and sterols and secosteroids are isolated using solid-phase extraction (SPE). Compounds are resolved on C₁₈ core-shell HPLC columns and by GC. Sterols and oxysterols are measured using triple quadrupole mass spectrometers, and lathosterol is measured using GC-MS. Detection for each compound measured by HPLC-MS was ∪ 1 ng/ml of plasma. Extraction efficiency was between 85 and 110%; day-to-day variability showed a relative standard error of <10%. Numerous oxysterols were detected, including the side chain oxysterols 22-, 24-, 25-, and 27-hydroxycholesterol, as well as ring-structure oxysterols 7α- and 4β-hydroxycholesterol. Intermediates from the cholesterol biosynthetic pathway were also detected, including zymosterol, desmosterol, and lanosterol. This method also allowed the quantification of six secosteroids, including the 25-hydroxylated species of vitamins D₂ and D₃. Application of this method to plasma samples revealed that at least 50 samples could be extracted in a routine day.

  20. In vivo monitoring of quantum dots in the extracellular space using push-pull perfusion sampling, online in-tube solid phase extraction, and inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Su, C K; Huang, C W; Yang, C S; Wang, Y J; Sun, Y C

    2010-09-01

    To monitor the dynamic changes of extracellular quantum dots (QDs) in vivo in the livers of anesthetized rats, we developed an automatic online analytical system comprising push-pull perfusion (PPP) sampling, the established in-tube solid phase extraction (SPE) procedure, and inductively coupled plasma mass spectrometry (ICPMS). The method takes advantage of the retention of QDs onto the interior surface of a polytetrafluoroethylene (PTFE) tube as a means of extracting the QDs from complicated push-pull perfusates. For the injected QDs present in the liver extracellular fluid (ECF) at low picomolar levels, a temporal resolution of 10 min was required to collect sufficient amounts of QDs to meet the sensitivity requirements of the ICPMS system. To the best of our knowledge, this study is the first to exploit the PPP technique for the collection of QDs from living animals and PTFE tubing as a SPE adsorbent for the online extraction of QDs and the removal of biological matrix prior to ICPMS analysis of cadmium-containing inorganic nanocrystal. We confirmed the analytical reliability of this method from measurements of the spike recoveries of saline samples; in addition, we demonstrated the systems' applicability through in vivo monitoring of the time-dependent concentration profile of liver extracellular QDs in living rats after intravenous administration.

  1. TiO₂/SiO₂ core-shell composite-based sample preparation method for selective extraction of phospholipids from shrimp waste followed by hydrophilic interaction chromatography coupled with quadrupole time-of-flight/mass spectrometry analysis.

    Science.gov (United States)

    Shen, Qing; Cheung, Hon-Yeung

    2014-09-10

    A solid-phase extraction (SPE) procedure, using titania-coated silica (TiO2/SiO2) core-shell composites as the sorbent, combined with a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for extraction, visualization, and quantification of phospholipids in shrimp waste (Litopenaeus vannamei). The SPE protocol was optimized, and the best conditions were pH 5 of the loading solvent, 10% aqueous methanol as the washing solvent, and 1.0 mL of chloroform/methanol (1:2, v/v) as eluting solvents. Afterward, the eluate was separated on a diol hydrophilic interaction chromatography (HILIC) column. A total of 69 phospholipid species were identified and determined. The results indicated that, in comparison to previously published methods, this strategy was cost-effective and efficient in extraction, characterization, and determination of phospholipids. Meanwhile, phospholipids were abundant in shrimp waste, most of which contained unsaturated fatty acyl chains, such as 18:3 [α-linolenic acid (ALA)], 20:5 [eicosapentaenoic acid (EPA)], and 22:6 [docosahexaenoic acid (DHA)]. The successful application of this strategy paves the way for full use of traditionally discarded shrimp wastes.

  2. Determination of type A trichothecenes in coix seed by magnetic solid-phase extraction based on magnetic multi-walled carbon nanotubes coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dong, Maofeng; Si, Wenshuai; Wang, Weimin; Bai, Bing; Nie, Dongxia; Song, Weiguo; Zhao, Zhihui; Guo, Yirong; Han, Zheng

    2016-09-01

    Magnetic solid-phase extraction (m-SPE) is a promising sample preparation approach due to its convenience, speed, and simplicity. For the first time, a rapid and reliable m-SPE approach using magnetic multi-walled carbon nanotubes (m-MWCNTs) as the adsorbent was proposed for purification of type A trichothecenes including T-2 toxins (T2), HT-2 toxins (HT-2), diacetoxyscirpenol (DAS), and neosolaniol (NEO) in coix seed. The m-MWCNTs were synthesized by assembling the magnetic nanoparticles (Fe3O4) with MWCNTs by sonication through an aggregation wrap mechanism, and characterized by transmission electron microscope. Several key parameters affecting the performance of the procedure were extensively investigated including extraction solutions, desorption solvents, and m-MWCNT amounts. Under the optimal sample preparation conditions followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), high sensitivity (limit of quantification in the range of 0.3-1.5 μg kg(-1)), good linearity (R (2) > 0.99), satisfactory recovery (73.6-90.6 %), and acceptable precision (≤2.5 %) were obtained. The analytical performance of the developed method has also been successfully evaluated in real coix seed samples. Graphical Abstract Flow chart of determination of type A trichothecenes in coix seed by magnetic solid-phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

  3. Core-shell polydopamine magnetic nanoparticles as sorbent in micro-dispersive solid-phase extraction for the determination of estrogenic compounds in water samples prior to high-performance liquid chromatography-mass spectrometry analysis.

    Science.gov (United States)

    Socas-Rodríguez, Bárbara; Hernández-Borges, Javier; Salazar, Pedro; Martín, Miriam; Rodríguez-Delgado, Miguel Ángel

    2015-06-05

    In this work, core-shell Fe3O4@poly(dopamine) magnetic nanoparticles (m-NPs) were prepared and characterized in our laboratory and applied as sorbents for the magnetic-micro solid phase extraction (m-μSPE) of twelve estrogenic compounds of interest (i.e. 17α-estradiol, 17β-estradiol, estrone, hexestrol, 17α-ethynylestradiol, diethylstibestrol, dienestrol, zearalenone, α-zearalanol, β-zearalanol, α-zearalenol and β-zearalenol) from different water samples. Separation, determination and quantification were achieved by high-performance liquid chromatography coupled to ion trap mass spectrometry with electrospray ionization. NPs@poly(dopamine) were synthesized by a chemical coprecipitation procedure and characterized by different surface characterization techniques (X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, transmission and scanning electron microscopy, infrared and Raman spectroscopy, vibrating sample magnetometry, microelectrophoresis and adsorption/desorption isotherms). Parameters affecting the extraction efficiency of m-μSPE (i.e. polymerization time, pH of the sample, extraction and elution conditions) were studied and optimized. The methodology was validated for Milli-Q, mineral, tap and wastewater using 2-methoxyestradiol as internal standard, obtaining recoveries ranging from 70 to 119% with relative standard deviation values lower than 20% and limits of quantification in the range 0.02-1.1 μg/L. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxyethylamphetamine, and 3,4-methylenedioxymethamphetamine in urine by online solid-phase extraction and ion-pairing liquid chromatography with detection by electrospray tandem mass spectrometry.

    Science.gov (United States)

    Wu, Ti-Yu; Fuh, Ming-Ren

    2005-01-01

    A method using an online solid-phase extraction (SPE) and ion-pairing liquid chromatography with electrospray tandem mass spectrometry (LC/ES-MS/MS) was developed for determination of amphetamine (Amp), methamphetamine (mAmp), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxyethylamphetamine (MDEA), and 3,4-methylenedioxymethamphetamine (MDMA) in urine samples. A SPE cartridge column with both hydrophilic and lipophilic functions was utilized for online extraction. A reversed-phase C18 LC column was employed for LC separation and MS/MS was used for detection. Trifluoroacetic acid was added to the mobile phase as an ion-pairing reagent. This method was fully automated and the extraction and analysis procedures were controlled by a six-port switch valve. Recoveries ranging from 85-101% were measured. Good linear ranges (10-500 ng/mL) for Amp and mAmp were determined. For MDA, MDMA and MDEA, dual linear ranges were obtained from 5-100 and 100-500 ng/mL, respectively. The detection limit of each analytical compound, based on a signal-to-noise ratio of 3, ranged from 1-3 ng/mL. The applicability of this newly developed method was examined by analyzing several urine samples from drug users. Good agreement was obtained between the results from this method and a literature GC/MS method.

  5. New method to discriminate between cathepsin B and cathepsin L in crude extracts from fish muscle based on a simple acidification procedure

    DEFF Research Database (Denmark)

    Godiksen, Helene; Nielsen, Henrik Hauch

    2007-01-01

    A new and simple method to distinguish between cathepsin B and cathepsin L in crude extracts of herring (Clupea harengus) muscle has been established. An acid treatment of crude extracts (exposed to pH 3 for 5 min) activated a latent form of cathepsin L and inactivated cathepsin B. Furthermore......). Cathepsin B activity is measured in neutral extract using the specific cathepsin B substrate Z-Arg-Arg-MCA and cathepsin L activity is measured in acid-treated extract with Z-Phe-Arg-MCA as substrate. The specific cathepsin B inhibitor, CA-074, did not inhibit the Z-Arg-Arg-MCA significantly without...

  6. 运用SPE-GC/MS技术分析马克思克鲁维酵母对发酵乳中游离脂肪酸的影响%SPE-GC/MS analysis on effect of Kluyveromyces marxianus on free fatty acids in the fermented milk

    Institute of Scientific and Technical Information of China (English)

    李路; 刘敬兰; 姜铁民; 闵伟红; 刘继超; 陈历俊

    2015-01-01

    利用固相萃取及气相色谱质谱联用仪(solid-phase extraction-gas chromatography mass spectrometry,SPE-GC/MS)技术,分析以马克思克鲁维酵母菌(Kluyveromyces marxianus)和乳酸菌(Streptococcus thermophilus,ST;Lactobacillus bulgaricus,LB)为混合发酵剂的发酵乳中游离脂肪酸含量变化,并对整个发酵过程进行跟踪监测.结果发现:使用SPE-GC/MS共检测出12种游离脂肪酸,其中短链及中链脂肪酸(C4-C12)有5种,长链饱和脂肪酸(C14-C18)7种,不饱和脂肪酸2种.2种发酵乳中主要的游离脂肪酸为棕榈酸、硬脂酸、肉豆蔻酸、油酸,且随着发酵时间的延长,混菌发酵乳中的含量显著高于双菌发酵乳(P <0.001).在发酵l~6h范围内,马克思克鲁维酵母菌的添加显著增加了双菌发酵乳中游离脂肪酸的含量(P <0.001).%Mixed bacteria fermented milk was fermented from mixed culture of Kluyveromyces marxianus and lactic acid bacteria and was analyzed by the solid phase extraction and gas chromatography mass spectrometry.The whole fermentation process was monitored.The results showed that the total 12 kinds of free fatty acids were detected using SPE-GC/MS,including 5 kinds of short-chain and medium-chain fatty acids (C4-C12),7 kinds of long chain saturated fatty acids (C14-C18),2 kinds of unsaturated fatty acids.The main free fatty acids in the two kinds of fermented milk were palmitic acid,stearic acid,myristic acid,oleic acid,and with the extension of fermentation time,their contents in the mixed bacteria fermented milk were significantly higher than those in the double bacteria fermented milk (P <0.001).Within 1 ~ 6h of fermentation,Kluyveromyces marxianus significantly increased the contents of free fatty acids in double bacteria fermented milk (P <0.001).

  7. Fully automated determination of 74 pharmaceuticals in environmental and waste waters by online solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry.

    Science.gov (United States)

    López-Serna, Rebeca; Pérez, Sandra; Ginebreda, Antoni; Petrović, Mira; Barceló, Damià

    2010-12-15

    The present work describes the development of a fully automated method, based on on-line solid-phase extraction (SPE)-liquid chromatography-electrospray-tandem mass spectrometry (LC-MS-MS), for the determination of 74 pharmaceuticals in environmental waters (superficial water and groundwater) as well as sewage waters. On-line SPE is performed by passing 2.5 mL of the water sample through a HySphere Resin GP cartridge. For unequivocal identification and confirmation two selected reaction monitoring (SRM) transitions are monitored per compound, thus four identification points are achieved. Quantification is performed by the internal standard approach, indispensable to correct the losses during the solid phase extraction, as well as the matrix effects. The main advantages of the method developed are high sensitivity (limits of detection in the low ng L(-1) range), selectivity due the use of tandem mass spectrometry and reliability due the use of 51 surrogates and minimum sample manipulation. As a part of the validation procedure, the method developed has been applied to the analysis of various environmental and sewage samples from a Spanish river and a sewage treatment plant. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Vortex-Assisted Dispersive Micro-Solid Phase Extraction Using CTAB-Modified Zeolite NaY Sorbent Coupled with HPLC for the Determination of Carbamate Insecticides.

    Science.gov (United States)

    Salisaeng, Pawina; Arnnok, Prapha; Patdhanagul, Nopbhasinthu; Burakham, Rodjana

    2016-03-16

    A vortex-assisted dispersive micro-solid phase extraction (VA-D-μ-SPE) based on cetyltrimethylammonium bromide (CTAB)-modified zeolite NaY was developed for preconcentration of carbamate pesticides in fruits, vegetables, and natural surface water prior to analysis by high performance liquid chromatography with photodiode array detection. The small amounts of solid sorbent were dispersed in a sample solution, and extraction occurred by adsorption in a short time, which was accelerated by vortex agitation. Finally, the sorbents were filtered from the solution, and the analytes were subsequently desorbed using an appropriate solvent. Parameters affecting the VA-D-μ-SPE performance including sorbent amount, sample volume, desorption solvent ,and vortex time were optimized. Under the optimum condition, linear dynamic ranges were achieved between 0.004-24.000 mg kg(-1) (R(2) > 0.9946). The limits of detection (LODs) ranged from 0.004-4.000 mg kg(-1). The applicability of the developed procedure was successfully evaluated by the determination of the carbamate residues in fruits (dragon fruit, rambutan, and watermelon), vegetables (cabbage, cauliflower, and cucumber), and natural surface water.

  9. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R.; Garcia-Lopez, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I., E-mail: isaac.rodriguez@usc.es [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2010-07-12

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL{sup -1} and linear responses for concentrations up to 2.5 {mu}g mL{sup -1}, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL{sup -1}. Cis-resveratrol was also found in all samples. In