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).

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...

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.

Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

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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.

Combining cationic and anionic mixed-mode sorbents in a single cartridge to extract basic and acidic pharmaceuticals simultaneously from environmental waters.

Science.gov (United States)

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

2018-01-01

The aim of the present study is to broaden the applications of mixed-mode ion-exchange solid-phase extraction sorbents to extract both basic and acidic compounds simultaneously by combining the sorbents in a single cartridge and developing a simplified extraction procedure. Four different cartridges containing negative and positive charges in the same configuration were evaluated and compared to extract a group of basic, neutral, and acidic pharmaceuticals selected as model compounds. After a thorough optimization of the extraction conditions, the four different cartridges showed to be capable of retaining basic and acidic pharmaceuticals simultaneously through ionic interactions, allowing the introduction of a washing step with 15 mL methanol to eliminate interferences retained by hydrophobic interactions. Using the best combined cartridge, a method was developed, validated, and further applied to environmental waters to demonstrate that the method is promising for the extraction of basic and acidic compounds from very complex samples.

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......, is described and the code included as Supplementary Information. Two mixtures of natural products was used to test the approach; one extract of Carthamus oxyacantha (wild safflower) containing an array of spiro compounds and one extract of the endophytic fungus Penicillum namyslowski containing griseofulvin...

Determination of 90Sr from aqueous solutions using SPE extraction

International Nuclear Information System (INIS)

Dulanska, S.; Rajec, P.; Matel, L.

2008-01-01

Solid Phase Extraction (SPE) is widely used technique for the isolation and concentration of analytes from liquid samples to achieve increased sensitivity in the analytical process. Three commercial sorbents produced by three different manufacturers were tested. 3M Empore TM Strontium Rad Disks, Sr resin and AnaLig Sr-01 were used to efficiently isolate strontium from aqueous samples. (authors)

Sistema limpo em linha para extração em fase sólida de contaminantes emergentes em águas naturais An in-line clean system for the solid-phase extraction of emerging contaminants in natural waters

Directory of Open Access Journals (Sweden)

Fernando F. Sodré

2010-01-01

Full Text Available A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L using commercial solid-phase extraction (SPE cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus is robust and less expensive than the typical available system. Its also provides less experimental handling, avoiding cross contamination and sample losses.

Development of SPE for recovery of polysaccharides and its application to the determination of monosaccharides composition of the polysaccharide sample of a lactobacillus KLB 58.

Science.gov (United States)

Baik, Yoon Suk; Cheong, Won Jo

2007-07-01

A new SPE cartridge has been prepared in this study to purify polysaccharides of high molecular weights. A porous nonpolar styrene-divinylbenzene copolymer phase (Hamilton PRP-1) was used to make the new cartridge. The cartridge was conditioned with methanol, water, and ACN in sequence, and the sample dissolved in a small amount of water was loaded. Impurities of low molecular weights were removed first by elution of 80:20 or 90:10 v/v% ACN/water, and polysaccharides were quantitatively recovered by elution of 50:50 v/v% ACN/water or pure water. The recovery of pure dextran 10000 was 90-95%. The SPE method was applied to purification of the polysaccharide sample of KLB58, a new lactobacillus discovered in Korea. The purified KLB 58 sample (weight recovery after SPE purification; 60%) was hydrolyzed for analysis of composition of monosaccharides. The hydrolysate was found to be composed primarily of fructose, glucose, galactose, rhamnose, mannose with small amounts of fucose and ribose.

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

Science.gov (United States)

Pavlović, Dragana Mutavdžić; Ašperger, Danijela; Tolić, Dijana; Babić, Sandra

2013-09-01

This paper describes the development, optimization, and validation of a method for the determination of five pharmaceuticals from different therapeutic classes (antibiotics, anthelmintics, glucocorticoides) in water samples. Water samples were prepared using SPE and extracts were analyzed by HPLC with diode-array detection. The efficiency of 11 different SPE cartridges to extract the investigated compounds from water was tested in preliminary experiments. Then, the pH of the water sample, elution solvent, and sorbent mass were optimized. Except for optimization of the SPE procedure, selection of the optimal HPLC column with different stationary phases from different manufacturers has been performed. The developed method was validated using spring water samples spiked with appropriate concentrations of pharmaceuticals. Good linearity was obtained in the range of 2.4-200 μg/L, depending on the pharmaceutical with the correlation coefficients >0.9930 in all cases, except for ciprofloxacin (0.9866). Also, the method has revealed that low LODs (0.7-3.9 μg/L), good precision (intra- and interday) with RSD below 17% and recoveries above 98% for all pharmaceuticals. The method has been successfully applied to the analysis of production wastewater samples from the pharmaceutical industry. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

Science.gov (United States)

This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

Automated sample preparation using membrane microtiter extraction for bioanalytical mass spectrometry.

Science.gov (United States)

Janiszewski, J; Schneider, P; Hoffmaster, K; Swyden, M; Wells, D; Fouda, H

1997-01-01

The development and application of membrane solid phase extraction (SPE) in 96-well microtiter plate format is described for the automated analysis of drugs in biological fluids. The small bed volume of the membrane allows elution of the analyte in a very small solvent volume, permitting direct HPLC injection and negating the need for the time consuming solvent evaporation step. A programmable liquid handling station (Quadra 96) was modified to automate all SPE steps. To avoid drying of the SPE bed and to enhance the analytical precision a novel protocol for performing the condition, load and wash steps in rapid succession was utilized. A block of 96 samples can now be extracted in 10 min., about 30 times faster than manual solvent extraction or single cartridge SPE methods. This processing speed complements the high-throughput speed of contemporary high performance liquid chromatography mass spectrometry (HPLC/MS) analysis. The quantitative analysis of a test analyte (Ziprasidone) in plasma demonstrates the utility and throughput of membrane SPE in combination with HPLC/MS. The results obtained with the current automated procedure compare favorably with those obtained using solvent and traditional solid phase extraction methods. The method has been used for the analysis of numerous drug prototypes in biological fluids to support drug discovery efforts.

SPE HG-AAS method for the determination of inorganic arsenic in rice—results from method validation studies and a survey on rice products

DEFF Research Database (Denmark)

Rasmussen, Rie Romme; Qian, Yiting; Sloth, Jens Jørgen

2013-01-01

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 (AsV). 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...

Determination of nanomolar chromate in drinking water with solid phase extraction and a portable spectrophotometer.

Science.gov (United States)

Ma, Jian; Yang, Bo; Byrne, Robert H

2012-06-15

Determination of chromate at low concentration levels in drinking water is an important analytical objective for both human health and environmental science. Here we report the use of solid phase extraction (SPE) in combination with a custom-made portable light-emitting diode (LED) spectrophotometer to achieve detection of chromate in the field at nanomolar levels. The measurement chemistry is based on a highly selective reaction between 1,5-diphenylcarbazide (DPC) and chromate under acidic conditions. The Cr-DPC complex formed in the reaction can be extracted on a commercial C18 SPE cartridge. Concentrated Cr-DPC is subsequently eluted with methanol and detected by spectrophotometry. Optimization of analytical conditions involved investigation of reagent compositions and concentrations, eluent type, flow rate (sample loading), sample volume, and stability of the SPE cartridge. Under optimized conditions, detection limits are on the order of 3 nM. Only 50 mL of sample is required for an analysis, and total analysis time is around 10 min. The targeted analytical range of 0-500 nM can be easily extended by changing the sample volume. Compared to previous SPE-based spectrophotometric methods, this analytical procedure offers the benefits of improved sensitivity, reduced sample consumption, shorter analysis time, greater operational convenience, and lower cost. Copyright © 2012 Elsevier B.V. All rights reserved.

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.)

Development of a rapid LC-DAD/FLD method for the simultaneous determination of auxins and abscisic acid in plant extracts.

Science.gov (United States)

Bosco, Renato; Caser, Matteo; Vanara, Francesca; Scariot, Valentina

2013-11-20

Plant hormones play a crucial role in controlling plant growth and development. These groups of naturally occurring substances trigger physiological processes at very low concentrations, which mandate sensitive techniques for their quantitation. This paper describes a method to quantify endogenous (±)-2-cis-4-trans-abscisic acid, indole-3-acetic acid, indole-3-propionic acid, and indole-3-butyric acid. The method combines high-performance liquid chromatography (HPLC) with diode array and fluorescence detection in a single run. Hybrid tea rose 'Monferrato' matrices (leaves, petals, roots, seeds, androecium, gynoecium, and pollen) were used as references. Rose samples were separated and suspended in extracting methanol, after which (±)-2-cis-4-trans-abscisic acid and auxins were extracted by solvent extraction. Sample solutions were added first to cation solid phase extraction (SPE) cartridges and the eluates to anion SPE cartridges. The acidic hormones were bound to the last column and eluted with 5% phosphoric acid in methanol. Experimental results showed that this approach can be successfully applied to real samples and that sample preparation and total time for routine analysis can be greatly reduced.

Dual solid-phase and stir bar sorptive extraction combined with gas chromatography-mass spectrometry analysis provides a suitable tool for assaying limonene-derived mint aroma compounds in red wine.

Science.gov (United States)

Picard, Magali; Franc, Céline; de Revel, Gilles; Marchand, Stéphanie

2018-02-25

A novel analytical method was developed for quantitative determination of eight limonene-derived monoterpenes responsible for the mint aroma in red wine. As these aromatic compounds are present at trace levels, a new dual extraction approach was proposed, combining solid-phase extraction (SPE) and stir bar sorptive extraction (SBSE), followed by gas chromatography-mass spectrometry analysis. The various parameters affecting the efficiency of extracting the analytes from wine samples in both the SPE and SBSE steps were first investigated, to determine the best compromise for the simultaneous analysis of the compounds studied. Following preliminary optimization of the dilution factor, phase ratio, and methanol content in the SBSE sample, cartridge sorbent mass, type of solvent, elution volume, and wine sample volume in the pre-concentration SPE step were studied. Highest response values were obtained when a 90 mL wine sample was extracted on a 500 mg SPE C18 cartridge and eluted with 1.5 mL methanol. The wine extract was then diluted in 10 mL water to obtain a final methanol content of 15% before the SBSE step. Good linearity, repeatability, reproducibility, accuracy and the required low detection and quantification limits were obtained under the conditions described, making this SPE-SBSE combination a suitable, powerful tool for routine analysis of the selected limonene-derived mint aroma compounds in large series of wine samples. Finally, the validated method was applied to 15 commercial red Bordeaux wines, aged from 3 to 23 years. Most of the compounds studied, present within the ng.L -1 range, were easily quantified for the first time in wine. Copyright © 2017 Elsevier B.V. All rights reserved.

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...

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.

Monitoring of chloropesticide methoxychlor preconcentration from waste water using hplc - solid phase extraction (abstract)

International Nuclear Information System (INIS)

Butt, S.B.; Saqlin, M.; Riaz, M.

2011-01-01

The method involves preconcentration of methoxychlor by solid phase extraction (SPE) with 1 mL silica based C-18 and 3 mL polymer based C-18 cartridge and then quantification by high performance liquid chromatography with UV detector (HPLC-UV). Optimization of HPLC parameters was done by determining max of methoxychlor on a double beam UV/Visible spectrophotometer, flow rate of mobile phase on reversed phase columns. Lowest detection limit for methoxychlor dissolved in water and methanol was 0.2ppm and 0.1ppm respectively. For solid phase extraction recovery studies and effect of different parameters such as initial concentration of analyte 0.01 to 0.05 ppm, loading rate 1 and 2mL/min, nature of desorbing solvent (methanol, ethyl acetate and acetonitrile) were investigated. Periodic self degradation of methoxychlor, and reusing potential of both SPE materials was also explored. Lower initial concentrations and slower loading rate of methoxychlor solutions gave improved recoveries. Recoveries were in the range of 80 to 90% for new SPE cartridge and reduced to 35 to 57% for once used silica based C-18 tubes. It was around 73 % for HLB C18 on their second use, and decreased on their repeated reuse. Lastly recoveries for stimulant and real waste water samples were determined to be 77 and 60% respectively. (author)

Speciation analysis of tellurium by solid-phase extraction in the presence of ammonium pyrrolidine dithiocarbamate and inductively coupled plasma mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Yu, Chunhai; Cai, Qiantao; Guo, Zhong-Xian; Yang, Zhaoguang [Centre for Advanced Water Technology, Innovation Centre (NTU), Singapore (Singapore); Khoo, Soo Beng [Department of Chemistry, National University of Singapore (Singapore)

2003-05-01

Under acidic conditions tellurium(IV) formed a complex with ammonium pyrrolidine dithiocarbamate (APDC). The tellurium(IV) complex was completely retained on a non-polar Isolute silica-based octadecyl (C{sub 18}) sorbent-containing solid-phase extraction (SPE) cartridge, while the uncomplexed Te(VI) passed through the cartridge and remained as a free species in the solution. Only partial Te(IV) was retained on the SPE cartridge for samples without addition of APDC. On the basis of different retention behaviours of the complexed Te(IV) and uncomplexed Te(VI), a simple and highly sensitive method is proposed for the determination of total tellurium and Te(VI) by SPE separation and inductively coupled plasma mass spectrometry (ICP-MS) detection. The Te(IV) concentration was calculated as the difference between total tellurium and Te(VI) concentrations. The detection limit (3{sigma}) is 3 ng L{sup -1} tellurium. Factors affecting the separation and detection of tellurium species were investigated. Coexisting ions did not show significant interferences with the Te(IV)-APDC complex retention and the subsequent ICP-MS detection of Te. The method has been successfully applied to the tellurium speciation analysis in waters with spiked recoveries for Te(IV) and Te(VI) of 86.0-108% and 87.1-97.4%, respectively. (orig.)

Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

Science.gov (United States)

Meyer, M.T.; Mills, M.S.; Thurman, E.M.

1993-01-01

An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.

Extraction tools for identification of chemical contaminants in estuarine and coastal waters to determine toxic pressure on primary producers.

Science.gov (United States)

Booij, Petra; Sjollema, Sascha B; Leonards, Pim E G; de Voogt, Pim; Stroomberg, Gerard J; Vethaak, A Dick; Lamoree, Marja H

2013-09-01

The extent to which chemical stressors affect primary producers in estuarine and coastal waters is largely unknown. However, given the large number of legacy pollutants and chemicals of emerging concern present in the environment, this is an important and relevant issue that requires further study. The purpose of our study was to extract and identify compounds which are inhibitors of photosystem II activity in microalgae from estuarine and coastal waters. Field sampling was conducted in the Western Scheldt estuary (Hansweert, The Netherlands). We compared four different commonly used extraction methods: passive sampling with silicone rubber sheets, polar organic integrative samplers (POCIS) and spot water sampling using two different solid phase extraction (SPE) cartridges. Toxic effects of extracts prepared from spot water samples and passive samplers were determined in the Pulse Amplitude Modulation (PAM) fluorometry bioassay. With target chemical analysis using LC-MS and GC-MS, a set of PAHs, PCBs and pesticides was determined in field samples. These compound classes are listed as priority substances for the marine environment by the OSPAR convention. In addition, recovery experiments with both SPE cartridges were performed to evaluate the extraction suitability of these methods. Passive sampling using silicone rubber sheets and POCIS can be applied to determine compounds with different structures and polarities for further identification and determination of toxic pressure on primary producers. The added value of SPE lies in its suitability for quantitative analysis; calibration of passive samplers still needs further investigation for quantification of field concentrations of contaminants. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison between Different Extraction Methods for Determination of Primary Aromatic Amines in Food Simulant

Directory of Open Access Journals (Sweden)

Morteza Shahrestani

2018-01-01

Full Text Available The primary aromatic amines (PAAs are food contaminants which may exist in packaged food. Polyurethane (PU adhesives which are used in flexible packaging are the main source of PAAs. It is the unreacted diisocyanates which in fact migrate to foodstuff and then hydrolyze to PAAs. These PAAs include toluenediamines (TDAs and methylenedianilines (MDAs, and the selected PAAs were 2,4-TDA, 2,6-TDA, 4,4′-MDA, 2,4′-MDA, and 2,2′-MDA. PAAs have genotoxic, carcinogenic, and allergenic effects. In this study, extraction methods were applied on a 3% acetic acid as food simulant which was spiked with the PAAs under study. Extraction methods were liquid-liquid extraction (LLE, dispersive liquid-liquid microextraction (DLLME, and solid-phase extraction (SPE with C18 ec (octadecyl, HR-P (styrene/divinylbenzene, and SCX (strong cationic exchange cartridges. Extracted samples were detected and analyzed by HPLC-UV. In comparison between methods, recovery rate of SCX cartridge showed the best adsorption, up to 91% for polar PAAs (TDAs and MDAs. The interested PAAs are polar and relatively soluble in water, so a cartridge with cationic exchange properties has the best absorption and consequently the best recoveries.

Determination of quaternary ammonium compounds in seawater samples by solid-phase extraction and liquid chromatography-mass spectrometry.

Science.gov (United States)

Bassarab, P; Williams, D; Dean, J R; Ludkin, E; Perry, J J

2011-02-04

A method for the simultaneous determination of two biocidal quaternary ammonium compounds; didecyldimethylammonium chloride (didecyldimethyl quat) and dodecylbenzyldimethylammonium chloride (benzyl quat), in seawater by solid phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS) was developed. The optimised procedure utilised off-line extraction of the analytes from seawater using polymeric (Strata-X) SPE cartridges. Recoveries ranged from 80 to 105%, with detection limits at the low parts-per-trillion (ng/l) level for both analytes. To demonstrate sensitivity, environmental concentrations were measured at three different locations along the North East coast of England with measured values in the range 120-270ng/l. Copyright © 2010 Elsevier B.V. All rights reserved.

Study of alkylphenols, indol and pyridinic nucleus of HPAN compounds by SPE/SI and SPE/C{sub 18}/NEC: application of SPE/Si phase to oils from the Alagoas sub-basin

Energy Technology Data Exchange (ETDEWEB)

Reboucas, L.M.C.; Nogueira, F.A.R.; Sabino, A.R.; Araujo, O.R.P.; Sant' Ana, A.E.G. [Universidade Federal de Alagoas (LABIS/UFAL), Maceio, AL (Brazil). Inst. de Quimica e Biotecnologia. Lab. de Analise de Biomarcadores e Semioquimicos], E-mail: lmcr@qui.ufal.br

2008-10-15

Alkylphenols (AP) and hydrocarbon polycyclic aromatic nitrogen (HPAN) compounds are important to study secondary migrations of petroleum. The behavior of AP and HPAN standards was investigated by solid phase extraction (SPE) on silica gel (SPE/Si) and C{sub 18}/NEC (SPE/C{sub 18}) stationary phases. The AP standards were eluted with dichloromethane (DCM) in the F2 fraction, on both SPE/Si and SPE/C{sub 18} phases. The basic and neutral HPAN compounds were eluted together with DCM, in F2 fraction, when a SPE/C18 column was used. However in the SPE/Si column the HPAN compounds were separated by their basic and neutral character in two different fractions. The neutral HPAN compounds were eluted with DCM, F2 fraction, and the HPAN basic compounds were eluted with the mixture DCM:isopropanol 5%, F3 fraction. In general, the quantity of recovered AP and HPAN compounds was higher with SPE/Si than SPE/C{sub 18}. The nine oil samples were analyzed by SPE/Si and the saturated and aromatic hydrocarbon were separated from the polar AP and HPAN. (author)

Disposable cartridge extraction of retinol and alpha-tocopherol from fatty samples.

Science.gov (United States)

Bourgeois, C F; Ciba, N

1988-01-01

A new approach is proposed for liquid/solid extraction of retinol and alpha-tocopherol from samples, using a disposable kieselguhr cartridge. The substitution of the mixture methanol-ethanol-n-butanol (4 + 3 + 1) for methanol in the alkaline hydrolysis solution makes it now possible to process fatty samples. Methanol is necessary to solubilize the antioxidant ascorbic acid, and a linear chain alcohol such as n-butanol is necessary to reduce the size of soap micelles so that they can penetrate into the kieselguhr pores. In comparisons of the proposed method with conventional methods on mineral premixes and fatty feedstuffs, recovery and accuracy are at least as good by the proposed method. Advantages are increased rate of determinations and the ability to hydrolyze and extract retinol and alpha-tocopherol together from the same sample.

Optimization of hydrophilic interaction liquid chromatography/mass spectrometry and development of solid-phase extraction for the determination of paralytic shellfish poisoning toxins.

Science.gov (United States)

Turrell, Elizabeth; Stobo, Lesley; Lacaze, Jean-Pierre; Piletsky, Sergey; Piletska, Elena

2008-01-01

The combination of hydrophilic interaction liquid chromatography (HILIC) and liquid chromatography/mass spectrometry (LC/MS) for the determination of paralytic shellfish poisoning (PSP) toxins has been proposed for use in routine monitoring of shellfish. In this study, methods for the detection of multiple PSP toxins [saxitoxin (STX), neosaxitoxin (NEO), decarbamoyl saxitoxin (dcSTX), decarbamoyl neosaxitoxin (dcNEO), gonyautoxins 1-5 (GTX1, GTX2, GTX3, GTX4, GTX5), decarbamoyl gonyautoxins (dcGTX2 and dcGTX3), and the N-sulfocarbamoyl C toxins (C1 and C2)] were optimized using single (MS) and triple quadrupole (MS/MS) instruments. Chromatographic separation of the toxins was achieved by using a TSK-gel Amide-80 analytical column, although superior chromatography was observed through application of a ZIC-HILIC column. Preparative procedures used to clean up shellfish extracts and concentrate PSP toxins prior to analysis were investigated. The capacity of computationally designed polymeric (CDP) materials and HILIC solid-phase extraction (SPE) cartridges to retain highly polar PSP toxins was explored. Three CDP materials and 2 HILIC cartridges were assessed for the extraction of PSP toxins from aqueous solution. Screening of the CDPs showed that all tested polymers adsorbed PSP toxins. A variety of elution procedures were examined, with dilute 0.01% acetic acid providing optimum recovery from a CDP based on 2-(trifluoromethyl)acrylic acid as the monomer. ZIC-HILIC SPE cartridges were superior to the PolyLC equivalent, with recoveries ranging from 70 to 112% (ZIC-HILIC) and 0 to 90% (PolyLC) depending on the PSP toxin. It is proposed that optimized SPE and HILIC-MS methods can be applied for the quantitative determination of PSP toxins in shellfish.

Sistema limpo em linha para extração em fase sólida de contaminantes emergentes em águas naturais

OpenAIRE

Sodré,Fernando F.; Locatelli,Marco Antonio F.; Jardim,Wilson F.

2010-01-01

A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus i...

Bioanalysis of tobramycin for therapeutic drug monitoring by solid-phase extraction and capillary zone electrophoresis.

Science.gov (United States)

Fonge, Humphrey; Kaale, Eliangiringa; Govaerts, Cindy; Desmet, Koenraad; Van Schepdael, Ann; Hoogmartens, Jos

2004-10-25

A method based on solid-phase extraction (SPE) and capillary zone electrophoresis (CZE) for the analysis of tobramycin in human serum is presented. An off-line SPE employing a carboxypropyl bonded phase (CBA) cartridge was used for the extraction of tobramycin from human serum. Adsorbed tobramycin was eluted from the CBA cartridge using a mixture of NH(3) (25%, w/v)-methanol (30:70, v/v). After evaporation, the analyte was reconstituted and derivatized with o-phthaldialdehyde (OPA)/3-mercaptopropionic acid (MPA). The resulting tobramycin-OPA/MPA derivative was purified, and then identified by mass spectrometry. The tobramycin-OPA/MPA derivative was then analysed by CZE with a background electrolyte (BGE) comprising of 30 mM sodium tetraborate pH 10.0-acetonitrile (ACN) (80:20, v/v) with ultraviolet detection at 230 nm. A linear response was observed in the range of 0.3-30 microg/ml with r(2) = 0.992. The sensitivity of the method was determined by its limit of quantitation (LOQ) and limit of detection (LOD) of 0.3 microg/ml and 0.1 microg/ml, respectively. SPE recovery ranged from 68 to 79% at the trough levels to 98% at the peak levels found in serum. Furosemide has been added as internal standard (IS) to improve precision. For the therapeutic range of tobramycin in serum (2-10 microg/ml) the relative standard deviation (R.S.D.) was less than 11% for the entire SPE/CE process. The method demonstrated excellent selectivity as shown by the lack of interference from a total of 20 drugs investigated. The method was then used in therapeutic drug monitoring of patients receiving the drug.

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.

Forensic analysis of high explosives residues in post-blast water samples employing solid phase extraction for analyte pro-concentration

International Nuclear Information System (INIS)

Umi Kalsom Ahmad; Rajendran, Sumathy; Ling, Lee Woan

2008-01-01

Nitro aromatic, nitramine and nitrate ester compounds are a major group of high order explosive or better known as military explosives. Octahydro-1,3,5,7-tetrazocine (HMX), 1,3,5-hexahydro-1,3,5-trinitro triazine (RDX), 2,4,6-trinitro-toluene (TNT), pentaerythritol tetranitrate (PETN) and 2,4-dinitrotoluene (2,4-DNT) are secondary high explosives classified as most commonly used explosives components. There is an increasing demand for pre-concentration of these compounds in water samples as the sensitivity achieved by instrumental analytical methods for these high explosives residues are the main drawback in the application at trace levels for forensic analysis. Hence, a simple cartridge solid phase extraction (SPE) procedure was optimized as the off-line extraction and pre-concentration method to enhance the detection limit of high explosive residues using micellar electrokinetic chromatography (MEKC) and gas chromatography with electron-capture detection (GC-ECD) methods. The SPE cartridges utilized LiChrolut EN as the SPE adsorbent. By emplying pre-concentration using SPE, the detection limits of the target analytes in water sample were lowered by more than 1000 times with good percentage recovery (>87%) for MEKC method and lowered by 120 times with more than 2 % percentage recovery for GC-ECD methods. In order to test the feasibility of the developed method to real cases, post-blast water samples were analyzed. The post-blast water samples which were collected from Baling Bom training range, Ulu Kinta, Perak contained RDX and PETN in the range of 0.05 - 0.17 ppm and 0.0124 - 0.0390 ppm respectively. (author)

A New Solid Phase Extraction for the Determination of Anthocyanins in Grapes

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Marta Ferreiro-González

2014-12-01

Full Text Available A method for the concentration and cleaning of red grape extracts prior to the determination of anthocyanins by UPLC-DAD has been developed. This method is of special interest in the determination of phenolic maturity as it allows the analysis of the anthocyanins present in grapes. Several different SPE cartridges were assessed, including both C-18- and vinylbenzene-based cartridges. C-18-based cartridges presented a very low retention for the glucosylated anthocyanidins while vinylbenzene-based cartridges showed excellent retention for these compounds. The optimized method involves the initial conditioning of the cartridge using 10 mL of methanol and 10 mL of water, followed by loading of up to 100 mL of red grape extract. Ten mL of water was used in the washing step and anthocyanins were subsequently eluted using 1.5 mL of acidified methanol at pH 2. This method simplifies the determination of individual anthocyanins as, on the one hand, it cleans the sample of interference and, on the other hand, it increases the concentration to up to 25:1.5. The developed method has been validated with a range of different grapes and it has also been tested as a means of determining the different anthocyanins in grapes with different levels of maturity.

Determination of Wastewater Compounds in Sediment and Soil by Pressurized Solvent Extraction, Solid-Phase Extraction, and Capillary-Column Gas Chromatography/Mass Spectrometry

Science.gov (United States)

Burkhardt, Mark R.; Zaugg, Steven D.; Smith, Steven G.; ReVello, Rhiannon C.

2006-01-01

A method for the determination of 61 compounds in environmental sediment and soil samples is described. The method was developed in response to increasing concern over the effects of endocrine-disrupting chemicals in wastewater and wastewater-impacted sediment on aquatic organisms. This method also may be used to evaluate the effects of combined sanitary and storm-sewer overflow on the water and sediment quality of urban streams. Method development focused on the determination of compounds that were chosen on the basis of their endocrine-disrupting potential or toxicity. These compounds include the alkylphenol ethoxylate nonionic surfactants and their degradates, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Sediment and soil samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from interfering matrix components by high-pressure water/isopropyl alcohol extraction. The compounds were isolated using disposable solid-phase extraction (SPE) cartridges containing chemically modified polystyrene-divinylbenzene resin. The cartridges were dried with nitrogen gas, and then sorbed compounds were eluted with methylene chloride (80 percent)-diethyl ether (20 percent) through Florisil/sodium sulfate SPE cartridge, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-sand samples fortified at 4 to 72 micrograms averaged 76 percent ?13 percent relative standard deviation for all method compounds. Initial method reporting levels for single-component compounds ranged from 50 to 500 micrograms per kilogram. The concentrations of 20 out of 61 compounds initially will be reported as estimated with the 'E' remark code for one of three reasons: (1) unacceptably low-biased recovery (less than 60 percent) or highly variable method performance

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

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......The high peptide sequencing speed provided by modern hybrid tandem mass spectrometers enables the utilization of fast liquid chromatographic (LC) separation techniques. We present a robust solid-phase extraction/capillary LC system (speLC) for 5-10 min separation of semicomplex peptide mixtures...

Coupling HPLC-SPE-NMR with a microplate-based high-resolution antioxidant assay for efficient analysis of antioxidants in food--validation and proof-of-concept study with caper buds.

Science.gov (United States)

Wiese, Stefanie; Wubshet, Sileshi G; Nielsen, John; Staerk, Dan

2013-12-15

This work describes the coupling of a microplate-based antioxidant assay with a hyphenated system consisting of high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy, i.e., HPLC-SPE-NMR/high-resolution antioxidant assay, for the analysis of complex food extracts. The applicability of the microplate-based antioxidant assay for high-resolution screening of common food phenolics as well as parameters related to their trapping efficiency, elution behavior, and recovery on/from SPE cartridges are described. It was found that the microplate-based high-resolution antioxidant assay is an attractive and easy implementable alternative to direct on-line screening methods. Furthermore, it was shown that Resin SH and Resin GP SPE material are superior to RP C18HD for trapping of phenolic compounds. Proof-of-concept study was performed with caper bud extract, revealing the most important antioxidants to be quercetin, kaempferol, rutin, kaempferol-3-O-β-rutinoside and N(1),N(5),N(10)-triphenylpropenoyl spermidine amides. Targeted isolation of the latter, and comprehensive NMR experiments showed them to be N(1),N(10)-di-(E)-caffeoyl-N(5)-p-(E)-coumaroyl spermidine, N(1)-(E)-caffeoyl-N(5),N(10)-di-p-(E)-coumaroyl spermidine, N(10)-(E)-caffeoyl-N(1),N(5)-di-p-(E)-coumaroyl spermidine, and N(1),N(5),N(10)-tri-p-(E)-coumaroyl spermidine amides. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preliminary results for the detection method of perfluoroalkyl substances (PFASs residues in pork

Directory of Open Access Journals (Sweden)

Shih-kuo Lin

2017-05-01

Full Text Available The perfluoroalkyl substances (PFASs residues, which come from environmental pollution, tend to accumulate in the food chain (EFSA, 2008; Guerranti et al., 2013. 17 chemicals of PFASs family were selected for this study. Fresh pork samples were extracted by Waters® WAX SPE (solid phase extraction cartridges. All extracted samples were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS. The results of calibration curves of each PFAS were good, the R2 values ranging from 0.9901 to 0.9993. The Recoveries were in the range 80%-119%. The protocol of extraction by Waters® WAX SPE cartridge will be applied in future studies.

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.

Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Chen, Y C; Tsai, M F

2000-01-01

Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution. Copyright 2000 John Wiley & Sons, Ltd.

Characterization of the metabolic transformation of thiamethoxam to clothianidin in Helicoverpa armigera larvae by SPE combined UPLC-MS/MS and its relationship with the toxicity of thiamethoxam to Helicoverpa armigera larvae.

Science.gov (United States)

Fan, Yinjun; Shi, Xueyan

2017-09-01

In order to characterize the metabolic transformation of thiamethoxam (TMX) to clothianidin (CLO) in Helicoverpa armigera larvae and clarify its relationship with the insecticidal toxicity of TMX, method for determination of TMX and its metabolite clothianidin (CLO) residues in H. armigera larvae by solid phase extraction (SPE) combined UPLC-MS/MS was established. Following acetonitrile extraction and purification by SPE on florisil cartridge and C 18 cartridge sequently, and cleanup by PSA adsorption, TMX and CLO residues in H. armigera larvae were successfully determined by UPLC-MS/MS. By using the established method, the concentration-time curves of TMX and its metabolite CLO in H. armigera larvae in vivo and metabolism of TMX by microsome of H. armigera larvae midguts in vitro were studied. TMX was quickly eliminated from H. armigera larvae with the elimination half-life as 4.2h. Meanwhile, only a small amount of CLO was formed from TMX metabolism, with the maximum CLO level in H. armigera larvae only accounts for the metabolic transformation of 7.99% of TMX, at 10h after intravenous TMX administration. Our results suggested that the low insecticidal efficacy of TMX against H. armigera larvae was related with the rapidly elimination of TMX from H. armigera larvae, meanwhile, CLO as TMX metabolite at a very low level in vivo didn't contribute to TMX toxicity to H. armigera larvae. In H. armigera larvae, TMX didn't act as proinsecticide for CLO in insecticidal efficacy of TMX. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantification of isoflavones in coffee by using solid phase extraction (SPE) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

Science.gov (United States)

Caprioli, Giovanni; Navarini, Luciano; Cortese, Manuela; Ricciutelli, Massimo; Torregiani, Elisabetta; Vittori, Sauro; Sagratini, Gianni

2016-09-01

A new method for extracting isoflavones from espresso coffee (EC) was coupled with high-performance liquid chromatography-tandem mass spectrometry (MS/MS) for the first time to analyse five isoflavones, which included both a glycosilated form, genistin and the aglycons daidzein, genistein, formononetin and biochanin A. Isoflavones were extracted from coffee samples using methanol, stored in a freezer overnight to precipitate proteic or lipidic residues and purified on SPE C18 cartridges before high-performance liquid chromatography-MS/MS analysis. The recovery percentages obtained by spiking the matrix at concentrations of 10 and 100 µg l(-1) with a standard mixture of isoflavones were in the range of 70 to 104%. The limits of detection and limits of quantification were in the range of 0.015-0.3 µg l(-1) and 0.05-1 µg l(-1) , respectively. Once validated, the method was used to analyze the concentrations of isoflavones in six ECs and ten ground coffee samples. Only formononetin and biochanin A were found, and their respective concentrations ranged from 0.36 to 0.41 µg l(-1) and from 0.58 to 3.26 µg l(-1) in ECs and from 0.36 to 4.27 µg kg(-1) and from 0.71 to 3.95 µg kg(-1) in ground coffees. This method confirms the high specificity and selectivity of MS/MS systems for detecting bioactives in complex matrices such as coffee.Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

[Determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection].

Science.gov (United States)

Luo, Xiao-Fei; Yang, Yuan; Sun, Cheng-Jun

2012-01-01

To develop a method for the simultaneous determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection. Organophosphorus pesticides in food were extracted ultrasonically with water. Then the extract was cleaned-up with SPE disk and eluted with ethyl acetate. Finally the eluent was condensed to 1mL under N2 at 55 degrees C. Gas chromatography was applied for quantitative detection of the organophosphorus pesticides in the sample. The linear range of the method for all the pesticides were in the range of 0.01-0.5 mg/kg with correlation coefficients of 0.992-1.000. The detection limits of the method were in the range of 0.0005-0.01 mg/kg. The recoveries for most pesticides were 60%-120% with relative standard deviations of less than 15%. The method is simple, sensitive, environmentally friendly and suitable for the determination of organophosphorous pesticides in food.

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.

A solid-phase extraction method for rapidly determining the adsorption coefficient of pharmaceuticals in sewage sludge

Science.gov (United States)

Berthod, Laurence; Roberts, Gary; Whitley, David C.; Sharpe, Alan; Mills, Graham A.

2014-01-01

The partitioning of pharmaceuticals in the environment can be assessed by measuring their adsorption coefficients (Kd) between aqueous and solid phases. Measuring this coefficient in sewage sludge gives an indication of their partitioning behaviour in a wastewater treatment plant and hence contributes to an understanding of their subsequent fate. The regulatory approved method for measuring Kd in sewage sludge is the US Environmental Protection Agency's Office of Prevention, Pesticides and Toxic Substances (OPPTS) guideline 835.1110, which is labour intensive and time consuming. We describe an alternative method for measuring the Kd of pharmaceuticals in sewage sludge using a modified solid-phase extraction (SPE) technique. SPE cartridges were packed at different sludge/PTFE ratios (0.4, 6.0, 24.0 and 40.0% w/w sludge) and eluted with phosphate buffer at pH 7.4. The approach was tested initially using three pharmaceuticals (clofibric acid, diclofenac and oxytetracycline) that covered a range of Kd values. Subsequently, the sorption behaviour of ten further pharmaceuticals with varying physico-chemical properties was evaluated. Results from the SPE method were comparable to those of the OPPTS test, with a correlation coefficient of 0.93 between the two approaches. SPE cartridges packed with sludge and PTFE were stable for up to one year; use within one month reduced variability in measurements (to a maximum of 0.6 log units). The SPE method is low-cost, easy to use and enables the rapid measurement of Kd values for a large number of chemicals. It can be used as an alternative to the more laborious full OPPTS test in environmental fate studies and risk assessments. PMID:25299795

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.

Automated Solid Phase Extraction (SPE) LC/NMR Applied to the Structural Analysis of Extractable Compounds from a Pharmaceutical Packaging Material of Construction.

Science.gov (United States)

Norwood, Daniel L; Mullis, James O; Davis, Mark; Pennino, Scott; Egert, Thomas; Gonnella, Nina C

2013-01-01

The structural analysis (i.e., identification) of organic chemical entities leached into drug product formulations has traditionally been accomplished with techniques involving the combination of chromatography with mass spectrometry. These include gas chromatography/mass spectrometry (GC/MS) for volatile and semi-volatile compounds, and various forms of liquid chromatography/mass spectrometry (LC/MS or HPLC/MS) for semi-volatile and relatively non-volatile compounds. GC/MS and LC/MS techniques are complementary for structural analysis of leachables and potentially leachable organic compounds produced via laboratory extraction of pharmaceutical container closure/delivery system components and corresponding materials of construction. Both hyphenated analytical techniques possess the separating capability, compound specific detection attributes, and sensitivity required to effectively analyze complex mixtures of trace level organic compounds. However, hyphenated techniques based on mass spectrometry are limited by the inability to determine complete bond connectivity, the inability to distinguish between many types of structural isomers, and the inability to unambiguously determine aromatic substitution patterns. Nuclear magnetic resonance spectroscopy (NMR) does not have these limitations; hence it can serve as a complement to mass spectrometry. However, NMR technology is inherently insensitive and its ability to interface with chromatography has been historically challenging. This article describes the application of NMR coupled with liquid chromatography and automated solid phase extraction (SPE-LC/NMR) to the structural analysis of extractable organic compounds from a pharmaceutical packaging material of construction. The SPE-LC/NMR technology combined with micro-cryoprobe technology afforded the sensitivity and sample mass required for full structure elucidation. Optimization of the SPE-LC/NMR analytical method was achieved using a series of model compounds

Time since discharge of 9mm cartridges by headspace analysis, part 1: Comprehensive optimisation and validation of a headspace sorptive extraction (HSSE) method.

Science.gov (United States)

Gallidabino, M; Romolo, F S; Weyermann, C

2017-03-01

Estimating the time since discharge of spent cartridges can be a valuable tool in the forensic investigation of firearm-related crimes. To reach this aim, it was previously proposed that the decrease of volatile organic compounds released during discharge is monitored over time using non-destructive headspace extraction techniques. While promising results were obtained for large-calibre cartridges (e.g., shotgun shells), handgun calibres yielded unsatisfying results. In addition to the natural complexity of the specimen itself, these can also be attributed to some selective choices in the methods development. Thus, the present series of paper aimed to more systematically evaluate the potential of headspace analysis to estimate the time since discharge of cartridges through the use of more comprehensive analytical and interpretative techniques. Specifically, in this first part, a method based on headspace sorptive extraction (HSSE) was comprehensively optimised and validated, as the latter recently proved to be a more efficient alternative than previous approaches. For this purpose, 29 volatile organic compounds were preliminary selected on the basis of previous works. A multivariate statistical approach based on design of experiments (DOE) was used to optimise variables potentially involved in interaction effects. Introduction of deuterated analogues in sampling vials was also investigated as strategy to account for analytical variations. Analysis was carried out by selected ion mode, gas chromatography coupled to mass spectrometry (GC-MS). Results showed good chromatographic resolution as well as detection limits and peak area repeatability. Application to 9mm spent cartridges confirmed that the use of co-extracted internal standards allowed for improved reproducibility of the measured signals. The validated method will be applied in the second part of this work to estimate the time since discharge of 9mm spent cartridges using multivariate models. Copyright �

Preconcentration of trace uranium from seawater with solid phase extraction followed by differential pulse polarographic determination in chloroform eluate

International Nuclear Information System (INIS)

Dojozan, Dj.; Pournaghi-Azar, M.H.; Toutounchi-Asr, J.

1998-01-01

In the present study, an effective method is presented for the separation and preconcentration of uranium (VI) by solid phase extraction (SPE). For this purpose, U(VI) oxinate is formed by the reaction of U(VI) with 8-hydroxyquinoline and adsorbed onto the octylsilane (C-8) SPE cartridge. The analyte is completely eluted with chloroform and determined by differential pulse polarography. The SPE conditions were optimized by evaluating the effective factors such as pH, oxine concentration, type and concentration of buffer and masking agent. By the proposed method a preconcentration factor of more than 100 was achieved. The average recovery of uranium (VI) oxinate (0.1 mg l -1 ) was 99.8%. The relative standard deviation was 1.6% for seven replicate determinations of uranyl ion in the solution with a concentration 20 μg l -1 . Some concomitant ions such as Ca +2 , Mg +2 and Fe +3 which interfere in extraction or determination process of uranium were masked with EDTA in aqueous phase during the extraction process. The proposed method was successfully used for the determination of uranium in Caspian Sea and Persian Gulf water samples

Determination of acetanilide herbicides in cereal crops using accelerated solvent extraction, solid-phase extraction and gas chromatography-electron capture detector.

Science.gov (United States)

Zhang, Yaping; Yang, Jun; Shi, Ronghua; Su, Qingde; Yao, Li; Li, Panpan

2011-07-01

A method was developed to determine eight acetanilide herbicides from cereal crops based on accelerated solvent extraction (ASE) and solid-phase extraction (SPE) followed by gas chromatography-electron capture detector (GC-ECD) analysis. During the ASE process, the effect of four parameters (temperature, static time, static cycles and solvent) on the extraction efficiency was considered and compared with shake-flask extraction method. After extraction with ASE, four SPE tubes (graphitic carbon black/primary secondary amine (GCB/PSA), GCB, Florisil and alumina-N) were assayed for comparison to obtain the best clean-up efficiency. The results show that GCB/PSA cartridge gave the best recoveries and cleanest chromatograms. The analytical process was validated by the analysis of spiked blank samples. Performance characteristics such as linearity, limit of detection (LOD), limit of quantitation (LOQ), precision and recovery were studied. At 0.05 mg/kg spiked level, recoveries and precision values for rice, wheat and maize were 82.3-115.8 and 1.1-13.6%, respectively. For all the herbicides, LOD and LOQ ranged from 0.8 to 1.7 μg/kg and from 2.4 to 5.3 μg/kg, respectively. The proposed analytical methodology was applied for the analysis of the targets in samples; only three herbicides, propyzamid, metolachlor and diflufenican, were detected in two samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of Nanofiber-packed SPE for Determination of Urinary 1-Hydroxypyrene Level Using HPLC.

Science.gov (United States)

Ifegwu, Okechukwu Clinton; Anyakora, Chimezie; Chigome, Samuel; Torto, Nelson

2014-01-01

It is always desirable to achieve maximum sample clean-up, extraction, and pre-concentration with the minimum possible organic solvent. The miniaturization of sample preparation devices was successfully demonstrated by packing 10 mg of 11 electrospun polymer nanofibers into pipette tip micro column and mini disc cartridges for efficient pre-concentration of 1-hydroxypyrene in urine samples. 1-hydroxypyrene is an extensively studied biomarker of the largest class of chemical carcinogens. Excretory 1-hydroxypyrene was monitored with HPLC/fluorescence detector. Important parameters influencing the percentage recovery such as fiber diameter, fiber packing amount, eluent, fiber packing format, eluent volume, surface area, porosity, and breakthrough parameters were thoroughly studied and optimized. Under optimized condition, there was a near perfect linearity of response in the range of 1-1000 μg/L with a coefficient of determination (r (2)) between 0.9992 and 0.9999 and precision (% RSD) ≤7.64% (n = 6) for all the analysis (10, 25, and 50 μg/L). The Limit of detection (LOD) was between 0.022 and 0.15 μg/L. When compared to the batch studies, both disc packed nanofiber sorbents and pipette tip packed sorbents exhibited evident dominance based on their efficiencies. The experimental results showed comparable absolute recoveries for the mini disc packed fibers (84% for Nylon 6) and micro columns (80% for Nylon 6), although the disc displayed slightly higher recoveries possibly due to the exposure of the analyte to a larger reacting surface. The results also showed highly comparative extraction efficiencies between the nanofibers and conventional C-18 SPE sorbent. Nevertheless, miniaturized SPE devices simplified sample preparation, reducing back pressure, time of the analysis with acceptable reliability, selectivity, detection levels, and environmental friendliness, hence promoting green chemistry.

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.

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

Rapid and sensitive determination of phenylurea herbicides in water in the presence of their anilines by extraction with a Carbopack cartridge followed by liquid chromatography.

Science.gov (United States)

Di Corcia, A; Marchetti, M

1991-03-22

A rapid and sensitive method for determining phenylurea herbicides in environmental aqueous samples in the presence of their anilines is described. The water sample is preconcentrated by passage at a flow-rate of ca. 150 ml/min through a 250-mg graphitized carbon black (Carbopack B) cartridge. After washing with 0.6 ml of methanol, the Carbopack B trap is connected with a cartridge containing a strong cation exchanger. Organics trapped by the Carbopack cartridge are eluted by passage of 6 ml of methylene chloride-methanol (95:5, v/v). Anilines and other basic compounds are quantitatively subtracted from the solvent system while flowing through the cation-exchange cartridge. After evaporation and redissolution, the sample is subjected to reversed-phase gradient elution high-performance liquid chromatography with UV detection at 250 nm. Recoveries of phenylureas added to water at levels between 30 and 3000 ng/l were higher than 92%. The limit of detection was about 1 ng/l, for a 2-1 sample. With respect to an octadecyl (C18)-bonded silica cartridge, the Carbopack B cartridge had a far better extraction efficiency for polar phenylureas.

Are Extracted Materials Truly Representative of Original Samples? Impact of C18 Extraction on CDOM Optical and Chemical Properties.

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Andrew, Andrea A; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil V

2016-01-01

Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction (SPE) is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission, and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

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.

Simultaneous Analysis of Simple Coumarins and Furocoumarines in Cigarettes by Solid-Phase Extraction with Gas Chromatography-Mass Spectrometry.

Science.gov (United States)

Zheng, Yang; Xu, Xiuli; Yuan, Fei; Yao, Meiyi; Ji, Shunli; Huang, Zhiqiang; Zhang, Feng

2017-09-01

A sensitive, high-throughput analytical method based on a GC-MS method was established for the simultaneous quantitative determination of two categories of harmful coumarins: simple coumarins (coumarin, 6-methylcoumarin, 7-methoxycoumarin, 3,4-dihydrocoumarin, and 7-ethoxy-4-methylcoumarin) and furocoumarines (psoralen, 8-methoxypsoralen, 5-methoxypsoralen, and trioxysalen). The nine analytes were extracted with ethyl acetate, purified with Oasis HLB solid-phase extraction (SPE) cartridges, and identified and quantitatively determined by GC-MS in selected-ion monitoring mode. The LODs and LOQs of these compounds were in the ranges of 12.5-21.2 and 41.6-70.0 μg/kg, respectively. Average recoveries for the nine analytes ranged from 72.7 to 86.6% at LOQ, 1.5× LOQ, and 2× LOQ spike levels, with RSDs that were typically lower than 5.1%. The SPE-GC-MS method developed in this study was initially applied to research coumarins in cigarette samples; it proved to be accurate, sensitive, convenient, and practical.

Novel chromatographic separation and carbon solid-phase extraction of acetanilide herbicide degradation products.

Science.gov (United States)

Shoemaker, Jody A

2002-01-01

One acetamide and 5 acetanilide herbicides are currently registered for use in the United States. Over the past several years, ethanesulfonic acid (ESA) and oxanilic acid (OA) degradation products of these acetanilide/acetamide herbicides have been found in U.S. ground waters and surface waters. Alachlor ESA and other acetanilide degradation products are listed on the U.S. Environmental Protection Agency's (EPA) 1998 Drinking Water Contaminant Candidate List. Consequently, EPA is interested in obtaining national occurrence data for these contaminants in drinking water. EPA currently does not have a method for determining these acetanilide degradation products in drinking water; therefore, a research method is being developed using liquid chromatography/negative ion electrospray/mass spectrometry with solid-phase extraction (SPE). A novel chromatographic separation of the acetochlor/alachlor ESA and OA structural isomers was developed which uses an ammonium acetate-methanol gradient combined with heating the analytical column to 70 degrees C. Twelve acetanilide degradates were extracted by SPE from 100 mL water samples using carbon cartridges with mean recoveries >90% and relative standard deviations < or =16%.

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. Copyright �

A simplified radiometabolite analysis procedure for PET radioligands using a solid phase extraction with micellar medium

International Nuclear Information System (INIS)

Nakao, Ryuji; Halldin, Christer

2013-01-01

A solid phase extraction method has been developed for simple and high-speed direct determination of PET radioligands in plasma. Methods: This methodology makes use of a micellar medium and a solid-phase extraction cartridge for displacement of plasma protein bound radioligand and separation of PET radioligands from their radiometabolites without significant preparation. The plasma samples taken from monkey or human during PET measurements were mixed with a micellar eluent containing an anionic surfactant sodium dodecyl sulphate and loaded onto SPE cartridges. The amount of radioactivity corresponding to parent radioligand (retained on the cartridge) and its radioactive metabolites (eluted with micellar eluent) was measured. Results: Under the optimized conditions, excellent separation of target PET radioligands from their radiometabolites was achieved with a single elution and short run-time of 1 min. This method was successfully applied to study the metabolism for 11 C-labelled radioligands in human or monkey plasma. The amount of parent PET radioligands estimated by micellar solid phase extraction strongly corresponded with that determined by radio-LC. The improved throughput permitted the analysis of a large number of plasma samples (up to 13 samples per one PET study) for accurate estimation of metabolite-corrected input function during quantitative PET imaging studies. Conclusion: Solid phase extraction together with micellar medium is fast, sensitive and easy to use, and therefore it is an attractive alternative method to determine relative composition of PET radioligands in plasma

Microfluidic cartridges for DNA purification and genotyping processed in standard laboratory instruments

Science.gov (United States)

Focke, Maximilian; Mark, Daniel; Stumpf, Fabian; Müller, Martina; Roth, Günter; Zengerle, Roland; von Stetten, Felix

2011-06-01

Two microfluidic cartridges intended for upgrading standard laboratory instruments with automated liquid handling capability by use of centrifugal forces are presented. The first microfluidic cartridge enables purification of DNA from human whole blood and is operated in a standard laboratory centrifuge. The second microfluidic catridge enables genotyping of pathogens by geometrically multiplexed real-time PCR. It is operated in a slightly modified off-the-shelf thermal cycler. Both solutions aim at smart and cost-efficient ways to automate work flows in laboratories. The DNA purification cartridge automates all liquid handling steps starting from a lysed blood sample to PCR ready DNA. The cartridge contains two manually crushable glass ampoules with liquid reagents. The DNA yield extracted from a 32 μl blood sample is 192 +/- 30 ng which corresponds to 53 +/- 8% of a reference extraction. The genotyping cartridge is applied to analyse isolates of the multi-resistant Staphyloccus aureus (MRSA) by real-time PCR. The wells contain pre-stored dry reagents such as primers and probes. Evaluation of the system with 44 genotyping assays showed a 100% specificity and agreement with the reference assays in standard tubes. The lower limit of detection was well below 10 copies of DNA per reaction.

A self-contained fully-enclosed microfluidic cartridge for lab on a chip.

Science.gov (United States)

Yobas, Levent; Cheow, Lih Feng; Tang, Kum-Cheong; Yong, Shien-Eit; Ong, Eleana Kye-Zheng; Wong, Lionel; Teo, William Cheng-Yong; Ji, Hongmiao; Rafeah, Siti; Yu, Chen

2009-12-01

We describe a self-contained fully-enclosed cartridge for lab-on-a-chip applications where sample and reagents can be applied sequentially as is performed in a heterogeneous immunoassay, or nucleic acid extraction. Both the self-contained and fully-enclosed features of the cartridge are sought to ensure its safe use in the field by unskilled staff. Simplicity in cartridge design and operation is obtained via adopting a valveless concept whereby reagents are stored and used in the form of liquid plugs isolated by air spacers around a fluidic loop. Functional components integrated in the loop include a microfluidic chip specific to the target application, a novel peristaltic pump to displace the liquid plugs, and a pair of removable tubing segments where one is used to introduce biological sample and while the other is to collect eluant. The novel pump is fabricated through soft-lithography technique and works by pinching a planar channel under stainless-steel ball bearings that have been magnetically loaded. The utility of the cartridge is demonstrated for automated extraction and purification of nucleic acids (DNA) from a cell lysate on a battery-operated portable system. The cartridge shown here can be further extended to sample-in-answer-out diagnostic tests.

Fully automated synthesis of ¹¹C-acetate as tumor PET tracer by simple modified solid-phase extraction purification.

Science.gov (United States)

Tang, Xiaolan; Tang, Ganghua; Nie, Dahong

2013-12-01

Automated synthesis of (11)C-acetate ((11)C-AC) as the most commonly used radioactive fatty acid tracer is performed by a simple, rapid, and modified solid-phase extraction (SPE) purification. Automated synthesis of (11)C-AC was implemented by carboxylation reaction of MeMgBr on a polyethylene Teflon loop ring with (11)C-CO2, followed by acidic hydrolysis with acid and SCX cartridge, and purification on SCX, AG11A8 and C18 SPE cartridges using a commercially available (11)C-tracer synthesizer. Quality control test and animals positron emission tomography (PET) imaging were also carried out. A high and reproducible decay-uncorrected radiochemical yield of (41.0 ± 4.6)% (n=10) was obtained from (11)C-CO2 within the whole synthesis time about 8 min. The radiochemical purity of (11)C-AC was over 95% by high-performance liquid chromatography (HPLC) analysis. Quality control test and PET imaging showed that (11)C-AC injection produced by the simple SPE procedure was safe and efficient, and was in agreement with the current Chinese radiopharmaceutical quality control guidelines. The novel, simple, and rapid method is readily adapted to the fully automated synthesis of (11)C-AC on several existing commercial synthesis module. The method can be used routinely to produce (11)C-AC for preclinical and clinical studies with PET imaging. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determination of antibiotic compounds in water by on-line SPE-LC/MSD.

Science.gov (United States)

Choi, Keun-Joo; Kim, Sang-Goo; Kim, Chang-won; Kim, Seung-Hyun

2007-01-01

This study attempts to provide an improved approach for the analysis of antibiotics, which normally exist at low concentration in complex matrices such as receiving streams of wastewater treatment plant discharge. The analytical method developed in this study combines an existing pretreatment technique of solid-phase extraction (SPE) with liquid chromatography mass spectrometry (LC/MSD) through on-line connection. The on-line connection suppressed the target loss by keeping the cartridge from drying, which resulted in improvement of the recovery and saving of the analytical time. For the on-line solid-phase extraction of 10 ml water samples, recoveries were between 74.3% and 116.5% and average LOQ was 0.11 microg l(-1) for the sulfonamide antibiotics (SA) and 0.09 microg l(-1) for the tetracycline antibiotics (TA). Application of the developed method for the analysis of fourteen antibiotics revealed that several antibiotics were detected at concentrations above the LOQ in ARW. Treated and untreated sewage and agricultural wastewater were mostly responsible for the antibiotics contamination of the river. Antibiotics were detected at much higher concentrations in the agricultural wastewater sample than in the sewage sample, implying substantial use of antibiotics in the agricultural industry. Wastewater treatment was generally effective in separation of the antibiotics tested in this study. The extent of the treatment depended on the type of antibiotics. Hydrophobic antibiotics were more effectively separated from the solution than hydrophilic antibiotics.

Fully automated synthesis of 11C-acetate as tumor PET tracer by simple modified solid-phase extraction purification

International Nuclear Information System (INIS)

Tang, Xiaolan; Tang, Ganghua; Nie, Dahong

2013-01-01

Introduction: Automated synthesis of 11 C-acetate ( 11 C-AC) as the most commonly used radioactive fatty acid tracer is performed by a simple, rapid, and modified solid-phase extraction (SPE) purification. Methods: Automated synthesis of 11 C-AC was implemented by carboxylation reaction of MeMgBr on a polyethylene Teflon loop ring with 11 C-CO 2 , followed by acidic hydrolysis with acid and SCX cartridge, and purification on SCX, AG11A8 and C18 SPE cartridges using a commercially available 11 C-tracer synthesizer. Quality control test and animals positron emission tomography (PET) imaging were also carried out. Results: A high and reproducible decay-uncorrected radiochemical yield of (41.0±4.6)% (n=10) was obtained from 11 C-CO 2 within the whole synthesis time about 8 min. The radiochemical purity of 11 C-AC was over 95% by high-performance liquid chromatography (HPLC) analysis. Quality control test and PET imaging showed that 11 C-AC injection produced by the simple SPE procedure was safe and efficient, and was in agreement with the current Chinese radiopharmaceutical quality control guidelines. Conclusion: The novel, simple, and rapid method is readily adapted to the fully automated synthesis of 11 C-AC on several existing commercial synthesis module. The method can be used routinely to produce 11 C-AC for preclinical and clinical studies with PET imaging. - Highlights: • A fully automated synthesis of 11 C-acetate by simple modified solid-phase extraction purification has been developed. • Typical non-decay-corrected yields were (41.0±4.6)% (n=10) • Radiochemical purity was determined by radio-HPLC analysis on a C18 column using the gradient program, instead of expensive organic acid column or anion column. • QC testing (RCP>99%)

Direct preparation of a graphene oxide modified monolith in a glass syringe as a solid-phase extraction cartridge for the extraction of quaternary ammonium alkaloids from Chinese patent medicine.

Science.gov (United States)

Liang, Xiaojing; Wang, Licheng; Wang, Shuai; Li, Yijing; Guo, Yong

2017-11-01

Packed cartridges have been widely used in solid-phase extraction. However, there are still some drawbacks, such as they are blocked easily and the method is time-consuming. In view of the advantages of monoliths, a monolithic extraction material has been directly synthesized in a glass syringe without any gap between the monolith and syringe inner wall. The monolithic syringe was modified with graphene oxide by loading graphene oxide dispersion onto it. The content of graphene oxide and the surface topography of the monolith have been evaluated by elemental analysis and scanning electron microscopy, respectively, which confirmed the successful modification. This prepared graphene oxide-modified monolithic syringe was directly used as a traditional solid-phase extraction cartridge. As expected, it shows good permeability and excellent capability for the extraction of quaternary ammonium alkaloids. The sample loading velocity (1-6 mL/min) does not affect the recovery. Under the optimal conditions, good linearities (R = 0.9992-0.9998) were obtained for five quaternary ammonium alkaloids, and the limits of detection and quantification were 0.5-1 and 1-2 μg/L, respectively. The proposed method was successfully applied for the analysis of quaternary ammonium alkaloids in Chinese patent medicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of six polyether antibiotic residues in foods of animal origin by solid phase extraction combined with liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Ha, Jing; Song, Ge; Ai, Lian-Feng; Li, Jian-Chen

2016-04-01

A new method using solid phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of six polyether antibiotics, including lasalocid, salinomycin, monensin, narasin, madubamycin and nigericin residues, in foods of animal origin. The samples were extracted with acetonitrile and purified by ENVI-Carb SPE columns after comparing the impurity effect and maneuverability of several SPE cartridges. Subsequently, the analytes were separated on a Hypersil Gold column (2.1×150mm, 5μm) and analyzed by MS/MS detection. The limit of quantization (LOQ) for milk and chicken was 0.4μg/kg, and for chicken livers and eggs, it was 1μg/kg. The linearity was satisfactory with a correlation coefficient of >0.9995 at concentrations ranging from 2 to 100μg/L. The average recoveries of the analytes fortified at three levels ranged from 68.2 to 114.3%, and the relative standard deviations ranged from 4.5 to 12.1%. The method was suitable for quantitative analysis and confirmation of polyether antibiotic residues in foods of animal origin. Copyright © 2016 Elsevier B.V. All rights reserved.

Simultaneous detection of nine cyanotoxins in drinking water using dual solid-phase extraction and liquid chromatography-mass spectrometry.

Science.gov (United States)

Yen, Hung-Kai; Lin, Tsair-Fuh; Liao, Pao-Chi

2011-08-01

A solid-phase extraction (SPE)-liquid chromatography (LC)-mass spectrometry (MS) method was developed to concentrate and detect nine cyanotoxins simultaneously, including six microcystins (MCs) congeners, nodularin (NOD), anatoxin-a (ATX) and cylindrospermopsin (CYN), in pure and natural waters. A dual cartridge SPE assembly was tested for the operating parameters of cyanotoxin extraction. A surrogate standard (SS), 1,9-diaminononane, was spiked in all the samples before the SPE extraction, and an internal standard (IS), 2,3,5-trimethylphenyl methyl carbamate, was spiked before LC/MS analysis. The method detection limit (MDL) was 2-100 ng/L for nine cyanotoxins in pure water and was increased by a factor of three to ten in a more complicated water matrix. The recoveries based on SS were between 83 and 104%, while those based on IS were 80-120%. The developed method was successfully employed in analyzing 33 water samples collected from eutrophic lakes, water treatment plants and distribution taps. MCs, NOD, and CYN were detected in the reservoir water, with concentrations as high as 36 μg/L. In addition, for the first time in Taiwan's tap water, CYN was detected at concentrations as high as 8.6 μg/L. Quality control data for the field samples shows that the analytical scheme developed is appropriate for monitoring cyanotoxins. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development, validation and clinical application of an online-SPE-LC-HRMS/MS for simultaneous quantification of phenobarbital, phenytoin, carbamazepine, and its active metabolite carbamazepine 10,11-epoxide.

Science.gov (United States)

Qu, Lihua; Fan, Yuanjie; Wang, Wenjun; Ma, Kai; Yin, Zheng

2016-09-01

A simple and efficient bioanalytical method for simultaneous determination of phenobarbital (PB), phenytoin (PHT), carbamazepine (CBZ), and its active metabolite carbamazepine 10,11-epoxide (CBZE) in human plasma using online solid phase extraction (SPE)-liquid chromatography (LC) coupled with high resolution mass spectrum (HRMS) under targeted MS/MS (t-MS(2)) analysis mode has been developed. The procedure integrated an automated sample clean-up of human plasma by Oasis®HLB SPE cartridge, a separation by ZORBAX SB-C18 analysis column, and a quantification by Q-Exactive Hybrid Quadrupole-Orbitrap. The total running time was 13min. The lower limit of quantification (LLOQ) of PB, PHT, CBZ, and CBZE were 0.008, 0.008, 0.0016 and 0.0016μgmL(-1) respectively and the linearities were in the range of 0.008-2.500, 0.008-2.500, 0.0016-0.500 and 0.0016-0.500μgmL(-1) respectively. The mean recovery was between 91.82% and 108.27% and the matrix effect was between 93.29% and 102.09%. The relative standard deviations of interday and intraday were less than 6.41%. The method has been successfully applied in therapeutic drug monitoring (TDM) of four Chinese epilepsy patients. This fully automated, simple, sensitive and reliable online-SPE-LC-HRMS/MS method serves well for TDM of PB, PHT, CBZ and CBZE at clinics for either single or combination treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Hyphenation of solid-phase extraction with liquid chromatography and nuclear magnetic resonance: application of HPLC-DAD-SPE-NMR to identification of constituents of Kanahia laniflora.

Science.gov (United States)

Clarkson, Cailean; Staerk, Dan; Hansen, Steen Honoré; Jaroszewski, Jerzy W

2005-06-01

The introduction of on-line solid-phase extraction (SPE) in HPLC-NMR has dramatically enhanced the sensitivity of this technique by concentration of the analytes in a small-volume NMR flow cell and by increasing the amount of the analyte by multiple peak trapping. In this study, the potential of HPLC-DAD-SPE-NMR hyphenation was demonstrated by structure determination of complex constituents of flower, leaf, root, and stem extracts of an African medicinal plant Kanahia laniflora. The technique was shown to allow acquisition of high-quality homo- and heteronuclear 2D NMR data following analytical-scale HPLC separation of extract constituents. Four flavonol glycosides [kaempferol 3-O-(6-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside; kaempferol 3-O-(2,6-di-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside; quercetin 3-O-(2,6-di-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside (rutin); and isorhamnetin, 3-O-(6-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside] and three 5alpha-cardenolides [coroglaucigenin 3-O-6-deoxy-beta-d-allopyranoside; coroglaucigenin 3-O-(4-O-beta-d-glucopyranosyl)-6-deoxy-beta-d-glucopyranoside; 3'-O-acetyl-3'-epiafroside] were identified, with complete assignments of 1H and 13C resonances based on HSQC and HMBC spectra whenever required. Confirmation of the structures was provided by HPLC-MS data. The HPLC-DAD-SPE-NMR technique therefore speeds up the dereplication of complex mixtures of natural origin significantly, by characterization of individual extract components prior to preparative isolation work.

A rapid assay for the simultaneous determination of nicotine, cocaine and metabolites in meconium using disposable pipette extraction and gas chromatography-mass spectrometry (GC-MS).

Science.gov (United States)

Mozaner Bordin, Dayanne C; Alves, Marcela N R; Cabrices, Oscar G; de Campos, Eduardo G; De Martinis, Bruno Spinosa

2014-01-01

Drug abuse by pregnant women is considered a serious public health problem worldwide. Meconium is the first excretion in newborns and has been used as an alternative matrix to evaluate in utero drug exposure. Solid phase extraction (SPE) is widely employed to prepare and clean up samples in the field of forensic analysis. Most SPE products require large volumes of solvent, which culminates in longer sample processing times and increased cost per sample. Disposable pipette extraction (DPX) tips have been used as an alternative to traditional SPE cartridges. They combine efficient and rapid extraction with reduced solvent consumption. The purpose of this study was to develop and validate a method to determine nicotine, cotinine, cocaine, benzoylecgonine, cocaethylene and methyl ester anhydroecgonine in meconium using DPX and gas chromatography-mass spectrometry (GC-MS). Validation results indicated that extraction efficiency ranged 50-98%, accuracy 92-106%, intra-assay precision 4-12% and inter-assay precision 6-12%. Linear calibration curves resulted in R(2) values >0.99, limits of detection ranged from 2.5 to 15 ng/g and the limit of quantitation from 10 to 20 ng/g. The DPX-GC-MS method was shown to selectively analyze trace concentrations of drugs in meconium samples. Finally, the developed and validated method was applied to 50 meconium samples.

Electronic publishing of SPE papers

International Nuclear Information System (INIS)

Perdue, J.M.

1992-01-01

This paper reports that the SPE is creating an electronic index to over 25,000 technical papers and will produce a CD-ROM as an initial product. This SPE CD-ROM Masterdisc will be available at the SPE Annual Meeting in Washington, D.C. on October 4-7, 1992. The SPE Board has appointed an Ad Hoc Committee on Electronic Publishing to coordinate and oversee this project and to recommend authoring standards for submitting SPE papers electronically in the future

Rapid extraction and quantitative detection of the herbicide diuron in surface water by a hapten-functionalized carbon nanotubes based electrochemical analyzer.

Science.gov (United States)

Sharma, Priyanka; Bhalla, Vijayender; Tuteja, Satish; Kukkar, Manil; Suri, C Raman

2012-05-21

A solid phase extraction micro-cartridge containing a non-polar polystyrene absorbent matrix was coupled with an electrochemical immunoassay analyzer (EIA) and used for the ultra-sensitive detection of the phenyl urea herbicide diuron in real samples. The EIA was fabricated by using carboxylated carbon nanotubes (CNTs) functionalized with a hapten molecule (an amine functionalized diuron derivative). Screen printed electrodes (SPE) were modified with these haptenized CNTs and specific in-house generated anti diuron antibodies were used for bio-interface development. The immunodetection was realized in a competitive electrochemical immunoassay format using alkaline phosphatase labeled secondary anti-IgG antibody. The addition of 1-naphthyl phosphate substrate resulted in the production of an electrochemically active product, 1-naphthol, which was monitored by using differential pulse voltammetry (DPV). The assay exhibited excellent sensitivity and specificity having a dynamic response range of 0.01 pg mL(-1) to 10 μg mL(-1) for diuron with a limit of detection of around 0.1 pg mL(-1) (n = 3) in standard water samples. The micro-cartridge coupled hapten-CNTs modified SPE provided an effective and efficient electrochemical immunoassay for the real-time monitoring of pesticides samples with a very high degree of sensitivity.

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

The Indicating FTA Elute Cartridge

Science.gov (United States)

de Bie, Roosmarie P.; Schmeink, Channa E.; Bakkers, Judith M.J.E.; Snijders, Peter J.F.; Quint, Wim G.V.; Massuger, Leon F.A.G.; Bekkers, Ruud L.M.; Melchers, Willem J.G.

2011-01-01

The clinically validated high-risk human papillomavirus (hrHPV) Hybrid Capture 2 (HC2) and GP5+/6+-PCR assays were analyzed on an Indicating FTA Elute cartridge (FTA cartridge). The FTA cartridge is a solid dry carrier that allows safe transport of cervical samples. FTA cartridge samples were compared with liquid-based samples for hrHPV and high-grade cervical intraepithelial neoplasia (CIN) detection. One cervical sample was collected in a liquid-based medium, and one was applied to the FTA cartridge. DNA was eluted directly from the FTA cartridge by a simple elution step. HC2 and GP5+/6+-PCR assays were performed on both the liquid-based and the FTA-eluted DNA of 88 women. Overall agreement between FTA and liquid-based samples for the presence of hrHPV was 90.9% with GP5+/6+-PCR and 77.3% with HC2. The sensitivity for high-grade CIN of hrHPV testing on the FTA cartridges was 84.6% with GP5+/6+-PCR and only 53.8% with HC2. By comparison, these sensitivities on liquid-based samples were 92.3% and 100% for GP5+/6+-PCR and HC2, respectively. Therefore, the FTA cartridge shows reasonably good overall agreement for hrHPV detection with liquid-based media when using GP5+/6+-PCR but not HC2 testing. Even with GP5+/6+-PCR, the FTA cartridge is not yet capable of detecting all high-grade CIN lesions. PMID:21704269

Preparation and use of maize tassels' activated carbon for the adsorption of phenolic compounds in environmental waste water samples.

Science.gov (United States)

Olorundare, O F; Msagati, T A M; Krause, R W M; Okonkwo, J O; Mamba, B B

2015-04-01

The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84-98.49%, 80.75-97.11%, and 78.27-97.08% for BPA, o-NTP, and PCP, respectively). The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes.

Comparison between a commercial solid-phase extraction cartridge and a home-made silver containing charcoal column: purification of Mo-99 from I-131 and Te-121

International Nuclear Information System (INIS)

Dias, Carla Roberta; Teodoro, Rodrigo; Osso Junior, Joao

2011-01-01

Among the radioisotopes used for medical application in Nuclear Medicine, 99m Tc, readily available from the elution of 99 Mo/ 99m Tc generators, is the most used, responsible for more than eighty percent of the total applications. These generators use the 99 Mo radioisotope that is produced in nuclear reactors and IPEN imports all the 99 Mo used in Brazil, mainly from Canada (Nordion). Due to the increasing needs of the Nuclear Medicine in Brazil and the world shortage of 99 Mo observed since 2008, IPEN decided to construct a new research reactor named Brazilian Multipurpose Reactor (BMR) as well as to develop the production of 99 Mo through the route of 235 U fission using a CINTICHEM modified separation process. The 99 Mo obtained from this process contains some contaminants and need to be purified. The aim of this work is to compare the preliminary results of the purification step of the solution containing 99 Mo and the contaminants, 131 I and 121 Te in the silver containing charcoal column and a solid-phase extraction cartridge. The purification process of 99 Mo coming from fission LEU foils was performed by adsorption chromatography using a home-made activated charcoal containing silver column (AC-Ag) and a commercial solid-phase extraction cartridge (OnGuard II Ag). High yields of 99 Mo elution and high retention of 131 I were achieved in the AC-Ag column and silver cartridge but 121 Te was more retained in the cartridge than in the AC-Ag column. (author)

Comparison of extraction techniques and mass spectrometric ionization modes in the analysis of wine volatile carbonyls

International Nuclear Information System (INIS)

Zapata, Julian; Mateo-Vivaracho, Laura; Cacho, Juan; Ferreira, Vicente

2010-01-01

This work presents a comparative study of the analytical characteristics of two methods for the analysis of carbonyl compounds in wine, both based on the derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). In the first method derivatives are formed in the solid phase extraction (SPE) cartridge in which the analytes have been previously isolated, while in the second method derivatives are formed in a solid phase microextraction (SPME) fibre saturated with vapors of the reagent and exposed to the sample headspace. In both cases detection has been carried out by electron impact (EI) or negative chemical ionization (NCI) mass spectrometry. The possibility of determining haloanisols simultaneously has been also considered. The method based on SPE presents, in general, better analytical properties than the SPME one. Although linearity was satisfactory for both methods (R 2 > 0.99), repeatability of the SPE method (RSD < 10%) was better than that obtained with SPME (9% < RSD < 20%). Detection limits obtained with EI are better for the SPE method except for trihaloanisols, while with NCI detection limits for both strategies are comparable, although the SPME strategy presents worse results for ketones and methional. Detection limits are always lower with NCI, being the improvement most notable for SPME. Recovery experiments show that in the case of SPE, uncertainties are lower than 12% in all cases, while with the SPME method the imprecision plus the existence of matrix effects make the global uncertainty to be higher than 15%.

Comparison of extraction techniques and mass spectrometric ionization modes in the analysis of wine volatile carbonyls

Energy Technology Data Exchange (ETDEWEB)

Zapata, Julian; Mateo-Vivaracho, Laura; Cacho, Juan [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain); Ferreira, Vicente, E-mail: vferre@unizar.es [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain)

2010-02-15

This work presents a comparative study of the analytical characteristics of two methods for the analysis of carbonyl compounds in wine, both based on the derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). In the first method derivatives are formed in the solid phase extraction (SPE) cartridge in which the analytes have been previously isolated, while in the second method derivatives are formed in a solid phase microextraction (SPME) fibre saturated with vapors of the reagent and exposed to the sample headspace. In both cases detection has been carried out by electron impact (EI) or negative chemical ionization (NCI) mass spectrometry. The possibility of determining haloanisols simultaneously has been also considered. The method based on SPE presents, in general, better analytical properties than the SPME one. Although linearity was satisfactory for both methods (R{sup 2} > 0.99), repeatability of the SPE method (RSD < 10%) was better than that obtained with SPME (9% < RSD < 20%). Detection limits obtained with EI are better for the SPE method except for trihaloanisols, while with NCI detection limits for both strategies are comparable, although the SPME strategy presents worse results for ketones and methional. Detection limits are always lower with NCI, being the improvement most notable for SPME. Recovery experiments show that in the case of SPE, uncertainties are lower than 12% in all cases, while with the SPME method the imprecision plus the existence of matrix effects make the global uncertainty to be higher than 15%.

Accurate determination of 3-alkyl-2-methoxypyrazines in wines by gas chromatography quadrupole time-of-flight tandem mass spectrometry following solid-phase extraction and dispersive liquid-liquid microextraction.

Science.gov (United States)

Fontana, Ariel; Rodríguez, Isaac; Cela, Rafael

2017-09-15

A new reliable method for the determination 3-alkyl-2-methoxypyrazines (MPs) in wine samples based on the sequential combination of solid-phase extraction (SPE), dispersive liquid-liquid microextraction (DLLME) and gas chromatography (GC) quadrupole time-of-flight accurate tandem mass spectrometry (QTOF-MS/MS) is presented. Primary extraction of target analytes was carried out by using a reversed-phase Oasis HLB (200mg) SPE cartridge combined with acetonitrile as elution solvent. Afterwards, the SPE extract was submitted to DLLME concentration using 0.06mL carbon tetrachloride (CCl 4 ) as extractant. Under final working conditions, sample concentration factors above 379 times and limits of quantification (LOQs) between 0.3 and 2.1ngL -1 were achieved. Moreover, the overall extraction efficiency of the method was unaffected by the particular characteristics of each wine; thus, accurate results (relative recoveries from 84 to 108% for samples spiked at concentrations from 5 to 25ngL -1 ) were obtained using matrix-matched standards, without using standard additions over every sample. Highly selective chromatographic records were achieved considering a mass window of 5mDa, centered in the quantification product ion corresponding to each compound. Twelve commercial wines, elaborated with grapes from different varieties and geographical origins, were processed with the optimized method. The 2-isobutyl-3-methoxypyrazine (IBMP) was determined at levels above the LOQs of the method in half of the samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Profiling of tryptophan-related plasma indoles in patients with carcinoid tumors by automated, on-line, solid-phase extraction and HPLC with fluorescence detection.

Science.gov (United States)

Kema, I P; Meijer, W G; Meiborg, G; Ooms, B; Willemse, P H; de Vries, E G

2001-10-01

Profiling of the plasma indoles tryptophan, 5-hydroxytryptophan (5-HTP), serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) is useful in the diagnosis and follow-up of patients with carcinoid tumors. We describe an automated method for the profiling of these indoles in protein-containing matrices as well as the plasma indole concentrations in healthy controls and patients with carcinoid tumors. Plasma, cerebrospinal fluid, and tissue homogenates were prepurified by automated on-line solid-phase extraction (SPE) in Hysphere Resin SH SPE cartridges containing strong hydrophobic polystyrene resin. Analytes were eluted from the SPE cartridge by column switching. Subsequent separation and detection were performed by reversed-phase HPLC combined with fluorometric detection in a total cycle time of 20 min. We obtained samples from 14 healthy controls and 17 patients with metastasized midgut carcinoid tumors for plasma indole analysis. In the patient group, urinary excretion of 5-HIAA and serotonin was compared with concentrations of plasma indoles. Within- and between-series CVs for indoles in platelet-rich plasma were 0.6-6.2% and 3.7-12%, respectively. Results for platelet-rich plasma serotonin compared favorably with those obtained by single-component analysis. Plasma 5-HIAA, but not 5-HTP was detectable in 8 of 17 patients with carcinoid tumors. In the patient group, platelet-rich plasma total tryptophan correlated negatively with platelet-rich plasma serotonin (P = 0.021; r = -0.56), urinary 5-HIAA (P = 0.003; r = -0.68), and urinary serotonin (P manual, single-component analyses.

Glufosinate ammonium clean-up procedure from water samples using SPE

Science.gov (United States)

Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

2015-09-01

For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at λ ex = 260 nm and λ em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

Determination of DDT and metabolites in surface water and sediment using LLE, SPE, ACE and SE.

Science.gov (United States)

Sibali, Linda L; Okonkwo, Jonathan O; Zvinowanda, Caliphs

2009-12-01

Surface water and sediment samples collected from Jukskei River in South Africa, were subjected to different extraction techniques, liquid-liquid (LLE), solid-phase extraction (SPE), activated carbon extraction (ACE) and soxhlet extraction (SE) for sediment. The samples were extracted with dichloromethane, cleaned in a silica gel column and the extracts quantified using a Varian 3800 GC-ECD. The percentage recovery test for 2,4'DDT, DDE and DDD and 4,4'DDT, DDE and DDD in water ranged from 80%-96% and 76%-95% (LLE); 56%-76% and 56%-70% (SPE) and 75%-84% (ACE), respectively; while that recoveries for sediment samples varied from 65%-95% for 2,4'DDT, DDE and DDD and 80%-91% for 4,4'DDT, DDE and DDD. The high recoveries exhibited by ACE compared very well with LLE and SE. This was not the case with SPE which exhibited the lowest value of recoveries for both 2,4 and 4,4'DDD, DDE and DDT standard samples. The mean concentrations of DDT and metabolites ranged from nd-1.10 μg/L, nd-0.80 μg/L, nd-1.21 μg/L and 1.92 μg/L for LLE, SPE, ACE and SE, respectively. The total DDT (2,4' and 4,4'-DDT) in water and sediment samples ranged from 1.20-3.25 μg/L and 1.82-5.24 μg/L, respectively. The low concentrations of the DDT metabolites obtained in the present study may suggest a recent contamination of the river by DDT.

Low-cost humic acid-bonded silica as an effective solid-phase extraction sorbent for convenient determination of aflatoxins in edible oils

Energy Technology Data Exchange (ETDEWEB)

Zhou, Neng-Zhi [Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, Guangxi 530028 (China); Liu, Ping [School of Pharmaceutical Science, Guangxi Medical University, Nanning, Guangxi 530021 (China); Su, Xiao-Chuan; Liao, Yan-Hua; Lei, Ning-Sheng [Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, Guangxi 530028 (China); Liang, Yong-Hong [School of Pharmaceutical Science, Guangxi Medical University, Nanning, Guangxi 530021 (China); Zhou, Shao-Huan; Lin, Wen-Si; Chen, Jie [Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, Guangxi 530028 (China); Feng, Yu-Qi [Key Laboratory of Analytical Chemistry for Biology and Medicine, Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072 (China); Tang, Yang, E-mail: tycarson2@163.com [Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, Guangxi 530028 (China)

2017-06-01

Aflatoxins (AFs) are highly toxic, mutagenic, carcinogenic, and teratogenic secondary metabolites produced by the toxigenic fungi Aspergillus flavus and Aspergillus parasiticus. AFs tend to contaminate a wide range of foods which is a serious and recurring food safety problem worldwide. Currently, immunoaffinity chromatography (IAC) has become the most conventional sample clean-up method for determining AFs in foodstuffs. However, IAC method is limited in the large-scale food analysis because it requires the use of expensive disposable cartridges and the IA procedure is time-consuming. Herein, to achieve the cost-effective determination of AFs in edible oils, we developed a promising solid-phase extraction (SPE) method based on commercially available humic acid-bonded silica (HAS) sorbent, followed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) analysis. In HAS-SPE, AFs can be captured by the HAS sorbent with both hydrophobic and hydrophilic interactions, whereas the oil matrix was captured only with the hydrophobic interactions. The oil matrix can be sufficiently washed off with isopropanol, while the AFs were still retained on the SPE packing, thus achieving selective extraction of AFs and clean-up of oil matrices. Under the optimal conditions of HAS-SPE, satisfactory recoveries ranging from 82% to 106% for four AFs (B{sub 1}, B{sub 2}, G{sub 1}, and G{sub 2}) were achieved in various oil matrices, containing blended oil, tea oil, rapeseed oil, peanut oil, sunflower seed oil, corn oil, blended olive oil, rice oil, soybean oil, and sesame oil. Only minor matrix effects ranging from 99% to 105% for four AFs were observed. Moreover, the LODs of AFs between 0.012 and 0.035 μg/kg completely meet the regulatory levels fixed by the EU, China or other countries. The methodology was further validated for assaying the naturally contaminated peanut oils, and consistent results between the HAS-SPE and the referenced IAC were

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).

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

International Nuclear Information System (INIS)

Wang Ziming; Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi; Ma Qiang; Lu Chunmei; Dong Deming

2013-01-01

Highlights: ► An absorbing microwave μ-SPE device packed with activated carbon was used. ► Absorbing microwave μ-SPE device was made and used to enrich the analytes. ► Absorbing microwave μ-SPE device was made and used to heat samples directly. ► MAE-μ-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 (μ-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 μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-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 μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-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%.

Validation of an automated solid-phase extraction method for the analysis of 23 opioids, cocaine, and metabolites in urine with ultra-performance liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Ramírez Fernández, María del Mar; Van Durme, Filip; Wille, Sarah M R; di Fazio, Vincent; Kummer, Natalie; Samyn, Nele

2014-06-01

The aim of this work was to automate a sample preparation procedure extracting morphine, hydromorphone, oxymorphone, norcodeine, codeine, dihydrocodeine, oxycodone, 6-monoacetyl-morphine, hydrocodone, ethylmorphine, benzoylecgonine, cocaine, cocaethylene, tramadol, meperidine, pentazocine, fentanyl, norfentanyl, buprenorphine, norbuprenorphine, propoxyphene, methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine from urine samples. Samples were extracted by solid-phase extraction (SPE) with cation exchange cartridges using a TECAN Freedom Evo 100 base robotic system, including a hydrolysis step previous extraction when required. Block modules were carefully selected in order to use the same consumable material as in manual procedures to reduce cost and/or manual sample transfers. Moreover, the present configuration included pressure monitoring pipetting increasing pipetting accuracy and detecting sampling errors. The compounds were then separated in a chromatographic run of 9 min using a BEH Phenyl analytical column on a ultra-performance liquid chromatography-tandem mass spectrometry system. Optimization of the SPE was performed with different wash conditions and elution solvents. Intra- and inter-day relative standard deviations (RSDs) were within ±15% and bias was within ±15% for most of the compounds. Recovery was >69% (RSD automated SPE system was observed. The extracted samples were stable for 72 h in the autosampler (4°C). This method was applied to authentic samples (from forensic and toxicology cases) and to proficiency testing schemes containing cocaine, heroin, buprenorphine and methadone, offering fast and reliable results. Automation resulted in improved precision and accuracy, and a minimum operator intervention, leading to safer sample handling and less time-consuming procedures.

Determination of urinary aromatic amines in smokers and nonsmokers using a MIPs-SPE coupled with LC-MS/MS method.

Science.gov (United States)

Yu, Jingjing; Wang, Sheng; Zhao, Ge; Wang, Bing; Ding, Li; Zhang, Xiaobing; Xie, Jianping; Xie, Fuwei

2014-05-01

Urinary aromatic amines (AAs) could be used as biomarkers for human exposure to AAs in cigarette smoke. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of urinary AAs (i.e. 1-naphthylamine (1-NA), 2-naphthylamine (2-NA), 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP)) in smokers and nonsmokers. A molecularly imprinted polymers (MIPs) solid phase extraction (SPE) cartridge was applied to purify urine samples and no derivatization reaction was involved. Each analytes used respective stable isotope internal standards, which could well compensate matrix effect. Lower limit of detections (LODs) for four AAs were obtained and in the range of 1.5-5ngL(-1). Recovery ranged from 87.7±4.5% to 111.3±6.4% and precision were less than 9.9%. The method was applied to analyze urine samples of 40 smokers and 10 nonsmokers. The 24h urinary excretion amounts of total AAs were higher for smokers compared with nonsmokers. What's more, 1-NA, 3-ABP and 4-ABP excretion amounts showed significant differences (p<0.05) between smokers and nonsmokers. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

Sprogøe, Kennett; Staerk, Dan; Jäger, Anna K; Adsersen, Anne; Hansen, Steen Honoré; Witt, Matthias; Landbo, Anne-Katrine R; Meyer, Anne S; Jaroszewski, Jerzy W

2007-09-01

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 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. Using homo- and heteronuclear 2D NMR data acquired in the HPLC-SPE-NMR mode, complete structure determination of three new natural products, i.e., 3,5-di-O-caffeoyl-4-O-[(1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl]quinic acid (1), its 2-hydroxy derivative (2), and 3,5-di-O-caffeoyl-4-O-[(4-hydroxyphenyl)acetyl]quinic acid (3), was performed. Finally, targeted isolation of 1 was achieved by SPE fractionation and preparative HPLC, followed by evaluation of its antioxidant and antimicrobial activity. In contrast to chlorogenic acid and 3,5-di-O-caffeoylquinic acid, which act as antioxidants, compound 1 proved at the same conditions to possess prooxidant activity in an assay evaluating the oxidation of human low-density lipoprotein induced by Cu(2+).

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%.

Multi-layer solid-phase extraction and evaporation-enrichment methods for polar organic chemicals from aqueous matrices.

Science.gov (United States)

Köke, Niklas; Zahn, Daniel; Knepper, Thomas P; Frömel, Tobias

2018-03-01

Analysis of polar organic chemicals in the aquatic environment is exacerbated by the lack of suitable and widely applicable enrichment methods. In this work, we assessed the suitability of a novel combination of well-known solid-phase extraction (SPE) materials in one cartridge as well as an evaporation method and for the enrichment of 26 polar model substances (predominantly log D evaporation method were investigated for the recovery and matrix effects of the model substances and analyzed with hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). In total, 65% of the model substances were amenable (> 10% recovery) to the mlSPE method with a mean recovery of 76% while 73% of the model substances were enriched with the evaporation method achieving a mean recovery of 78%. Target and non-target screening comparison of both methods with a frequently used reversed-phase SPE method utilizing "hydrophilic and lipophilic balanced" (HLB) material was performed. Target analysis showed that the mlSPE and evaporation method have pronounced advantages over the HLB method since the HLB material retained only 30% of the model substances. Non-target screening of a ground water sample with the investigated enrichment methods showed that the median retention time of all detected features on a HILIC system decreased in the order mlSPE (3641 features, median t R 9.7 min), evaporation (1391, 9.3 min), HLB (4414, 7.2 min), indicating a higher potential of the described methods to enrich polar analytes from water compared with HLB-SPE. Graphical abstract Schematic of the method evaluation (recovery and matrix effects) and method comparison (target and non-target analysis) of the two investigated enrichment methods for very polar chemicals in aqueousmatrices.

Investigation of solid phase sorbents for the pre- concentration of pads from aqueous medium and their quantitation by high performance liquid chromatography-UV detection

International Nuclear Information System (INIS)

Waqar, F.; Jan, S.; Muhammad, B.; Ahmad, S.; Riaz, M.; Akram, N.

2005-01-01

A solid phase extraction method was optimized for the pre-concentration of polyaromatic hydrocarbons (PAHs) in water samples. Graphite powder and Lab scale locally synthesized styrene divinylbenzene (SDVB) Copolymer were used as sorbents for the extraction of PAHs and compared with commercially used C18 solid phase extraction cartridge (SPE). Various parameters were optimized to evaluate the extraction efficiencies, the best results were obtained by proper conditioning of extraction cartridges and desorption with suitable solvent. Percentage recoveries were enhanced by rinsing the sample bottles with acetonitrile and combining the rinse with the sample extract. Quantitative analysis was performed by High performance Liquid chromatography (HPLC) with UV detection. Many other parameters, including optimization of mobile phase, selection of HPLC Columns, sample-loading flow rate on extraction cartridge and weight of sorbent were performed to get optimal results. Percent recoveries obtained with synthesized copolymer were comparable with commercial cartridge, while graphite powder showed excellent retention but very poor recoveries. Obtained recoveries of selected PAHs were ranged from 80-87% with relative standard deviation <6%. Developed method was applied for the analysis of drinking water samples(author)

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...

Consolidation and Disclosure of SPE

OpenAIRE

中野, 貴之

2011-01-01

The purpose of this study is to discuss what kinds of information are demanded by the users of financial statements and what kinds of problems plague the companies using SPE (special purpose equity), while considering the actual situations of the consolidation and disclosure of SPE in Japan. At present, there is the trend of consolidating a broad range of SPE in Japan, etc., but some users of financial statements point out that it became difficult to understand consolidated financial stat...

Simultaneous quantification of dissolved organic carbon fractions and copper complexation using solid-phase extraction

International Nuclear Information System (INIS)

McElmurry, Shawn P.; Long, David T.; Voice, Thomas C.

2010-01-01

Trace metal cycling in natural waters is highly influenced by the amount and type of dissolved organic C (DOC). Although determining individual species of DOC is unrealistic, there has been success in classifying DOC by determining operationally defined fractions. However, current fractionation schemes do not allow for the simultaneous quantification of associated trace metals. Using operational classifications, a scheme was developed to fractionate DOC based on a set of seven solid-phase extraction (SPE) cartridges. The cartridges isolated fractions based on a range of specific mechanisms thought to be responsible for DOC aggregation in solution, as well as molecular weight. The method was evaluated to determine if it can identify differences in DOC characteristics, including differences in Cu-DOC complexation. Results are that: (1) cartridge blanks were low for both DOC and Cu, (2) differences are observed in the distribution of DOC amongst the fractions from various sources that are consistent with what is known about the DOC materials and the mechanisms operative for each cartridge, (3) when present as a free cation, Cu was not retained by non-cationic cartridges allowing the method to be used to assess Cu binding, (4) the capability of the method to provide quantitative assessment of Cu-DOC complexation was demonstrated for a variety of DOC standards, (5) Cu was found to preferentially bind with high molecular weight fractions of DOC, and (6) estimated partitioning coefficients and conditional binding constants for Cu were similar to those reported elsewhere. The method developed describes DOC characteristics based on specific bonding mechanisms (hydrogen, donor-acceptor, London dispersion, and ionic bonding) while simultaneously quantifying Cu-DOC complexation. The method provides researchers a means of describing not only the extent of DOC complexation but also how that complex will be behave in natural waters.

Low-cost humic acid-bonded silica as an effective solid-phase extraction sorbent for convenient determination of aflatoxins in edible oils.

Science.gov (United States)

Zhou, Neng-Zhi; Liu, Ping; Su, Xiao-Chuan; Liao, Yan-Hua; Lei, Ning-Sheng; Liang, Yong-Hong; Zhou, Shao-Huan; Lin, Wen-Si; Chen, Jie; Feng, Yu-Qi; Tang, Yang

2017-06-01

Aflatoxins (AFs) are highly toxic, mutagenic, carcinogenic, and teratogenic secondary metabolites produced by the toxigenic fungi Aspergillus flavus and Aspergillus parasiticus. AFs tend to contaminate a wide range of foods which is a serious and recurring food safety problem worldwide. Currently, immunoaffinity chromatography (IAC) has become the most conventional sample clean-up method for determining AFs in foodstuffs. However, IAC method is limited in the large-scale food analysis because it requires the use of expensive disposable cartridges and the IA procedure is time-consuming. Herein, to achieve the cost-effective determination of AFs in edible oils, we developed a promising solid-phase extraction (SPE) method based on commercially available humic acid-bonded silica (HAS) sorbent, followed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) analysis. In HAS-SPE, AFs can be captured by the HAS sorbent with both hydrophobic and hydrophilic interactions, whereas the oil matrix was captured only with the hydrophobic interactions. The oil matrix can be sufficiently washed off with isopropanol, while the AFs were still retained on the SPE packing, thus achieving selective extraction of AFs and clean-up of oil matrices. Under the optimal conditions of HAS-SPE, satisfactory recoveries ranging from 82% to 106% for four AFs (B 1 , B 2 , G 1 , and G 2 ) were achieved in various oil matrices, containing blended oil, tea oil, rapeseed oil, peanut oil, sunflower seed oil, corn oil, blended olive oil, rice oil, soybean oil, and sesame oil. Only minor matrix effects ranging from 99% to 105% for four AFs were observed. Moreover, the LODs of AFs between 0.012 and 0.035 μg/kg completely meet the regulatory levels fixed by the EU, China or other countries. The methodology was further validated for assaying the naturally contaminated peanut oils, and consistent results between the HAS-SPE and the referenced IAC were obtained. In

Determination of Human-Health Pharmaceuticals in Filtered Water by Chemically Modified Styrene-Divinylbenzene Resin-Based Solid-Phase Extraction and High-Performance Liquid Chromatography/Mass Spectrometry

Science.gov (United States)

Furlong, Edward T.; Werner, Stephen L.; Anderson, Bruce D.; Cahill, Jeffery D.

2008-01-01

In 1999, the Methods Research and Development Program of the U.S. Geological Survey National Water Quality Laboratory began the process of developing a method designed to identify and quantify human-health pharmaceuticals in four filtered water-sample types: reagent water, ground water, surface water minimally affected by human contributions, and surface water that contains a substantial fraction of treated wastewater. Compounds derived from human pharmaceutical and personal-care product use, which enter the environment through wastewater discharge, are a newly emerging area of concern; this method was intended to fulfill the need for a highly sensitive and highly selective means to identify and quantify 14 commonly used human pharmaceuticals in filtered-water samples. The concentrations of 12 pharmaceuticals are reported without qualification; the concentrations of two pharmaceuticals are reported as estimates because long-term reagent-spike sample recoveries fall below acceptance criteria for reporting concentrations without qualification. The method uses a chemically modified styrene-divinylbenzene resin-based solid-phase extraction (SPE) cartridge for analyte isolation and concentration. For analyte detection and quantitation, an instrumental method was developed that used a high-performance liquid chromatography/mass spectrometry (HPLC/MS) system to separate the pharmaceuticals of interest from each other and coextracted material. Immediately following separation, the pharmaceuticals are ionized by electrospray ionization operated in the positive mode, and the positive ions produced are detected, identified, and quantified using a quadrupole mass spectrometer. In this method, 1-liter water samples are first filtered, either in the field or in the laboratory, using a 0.7-micrometer (um) nominal pore size glass-fiber filter to remove suspended solids. The filtered samples then are passed through cleaned and conditioned SPE cartridges at a rate of about 15

Simultaneous analysis of nine aromatic amines in mainstream cigarette smoke using online solid-phase extraction combined with liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Zhang, Jie; Bai, Ruoshi; Zhou, Zhaojuan; Liu, Xingyu; Zhou, Jun

2017-04-01

A fully automated analytical method was developed and validated by this present study. The method was based on two-dimensional (2D) online solid-phase extraction liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) to determine nine aromatic amines (AAs) in mainstream smoke (MSS) simultaneously. As a part of validation process, AAs yields for 16 top-selling commercial cigarettes from China market were evaluated by the developed method under both Health Canada Intensive (HCI) and ISO machine smoking regimes. The gas phase of MSS was trapped by 25 mL 0.6 M hydrochloric acid solution, while the particulate phase was collected on a glass fiber filter. Then, the glass fiber pad was extracted with hydrochloric acid solution in an ultrasonic bath. The extract was analyzed with 2D online SPE-LC-MS/MS. In order to minimize the matrix effects of sample on each analyte, two cartridges with different extraction mechanisms were utilized to cleanup disturbances of different polarity, which were performed by the 2D SPE. A phenyl-hexyl analytical column was used to achieve a chromatographic separation. Under the optimized conditions, the isomers of p-toluidine, m-toluidine and o-toluidine, 3-aminobiphenyl and 4-aminobiphenyl, and 1-naphthylamine and 2-naphthylamine were baseline separated with good peak shapes for the first time. The limits of detection for nine AAs ranged from 0.03 to 0.24 ng cig -1 . The recovery of the measurement of nine AAs was from 84.82 to 118.47%. The intra-day and inter-day precisions of nine AAs were less than 10 and 16%, respectively. Compared with ISO machine smoking regime, the AAs yields in MSS were 1.17 to 3.41 times higher under HCI machine smoking regime. Graphical abstract New method using online SPE-LC/MS/MS for analysis of aromatic amines in mainstream cigarette smoke.

Cathare2 V1.3E post-test computations of SPE-1 and SPE-2 experiments at PMK-NVH facility

International Nuclear Information System (INIS)

Belliard, M.; Laugier, E.

1994-01-01

This paper presents the first CATHARE2 V1.3E simulations of the SPE-2 transients at PMK-NVH loop. Concerning the SPE-1 and the SPE-2 experimentations at PMK-NVH, it contains a description of the facilities and the transient, as well as different conditions of use. The paper includes also a presentation of the CATHARE2 model and different type of computation, such as the steady state computation or SPE-1 and SPE-2 transient (TEC). 4 refs., 12 figs., 4 tabs

Analysis of nitrosamines in water by automated SPE and isotope dilution GC/HRMS Occurrence in the different steps of a drinking water treatment plant, and in chlorinated samples from a reservoir and a sewage treatment plant effluent.

Science.gov (United States)

Planas, Carles; Palacios, Oscar; Ventura, Francesc; Rivera, Josep; Caixach, Josep

2008-08-15

A method based on automated solid-phase extraction (SPE) and isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS) has been developed for the analysis of nine nitrosamines in water samples. The combination of automated SPE and GC/HRMS for the analysis of nitrosamines has not been reported previously. The method shows as advantages the selectivity and sensitivity of GC/HRMS analysis and the high efficiency of automated SPE with coconut charcoal EPA 521 cartridges. Low method detection limits (MDLs) were achieved, along with a greater facility of the procedure and less dependence on the operator with regard to the methods based on manual SPE. Quality requirements for isotope dilution-based methods were accomplished for most analysed nitrosamines, regarding to trueness (80-120%), method precision (water samples (16 samples from a drinking water treatment plant {DWTP}, 2 chlorinated samples from a sewage treatment plant {STP} effluent, and 1 chlorinated sample from a reservoir) were analysed. Concentrations of nitrosamines in the STP effluent were 309.4 and 730.2 ng/L, being higher when higher doses of chlorine were applied. N-Nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were the main compounds identified in the STP effluent, and NDEA was detected above 200 ng/L, regulatory level for NDMA in effluents stated in Ontario (Canada). Lower concentrations of nitrosamines were found in the reservoir (20.3 ng/L) and in the DWTP samples (n.d. -28.6 ng/L). NDMA and NDEA were respectively found in the reservoir and in treated and highly chlorinated DWTP samples at concentrations above 10 ng/L (guide value established in different countries). The highest concentrations of nitrosamines were found after chlorination and ozonation processes (ozonated, treated and highly chlorinated water) in DWTP samples.

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.

MCX based solid phase extraction combined with liquid chromatography tandem mass spectrometry for the simultaneous determination of 31 endocrine-disrupting compounds in surface water of Shanghai.

Science.gov (United States)

Zhang, Hong-Chang; Yu, Xue-jun; Yang, Wen-chao; Peng, Jin-feng; Xu, Ting; Yin, Da-Qiang; Hu, Xia-lin

2011-10-15

A novel analytical method employing MCX (mixed-mode cationic exchange) based solid phase extraction (SPE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed to detect 31 endocrine-disrupting compounds (EDCs) in surface water samples simultaneously. The target EDCs belong to five classes, including seven estrogens, eight androgens, six progesterones, five adrenocortical hormones and five industrial compounds. In order to simultaneously concentrate the target EDCs and eliminate matrix interferences in the water samples, MCX SPE cartridges were employed for SPE, and then followed by a simple and highly efficient three-step sequential elution procedure. Two electrospray ionization (ESI) detection modes, positive (ESI+) and (ESI-), were optimized for HPLC-MS/MS analysis to obtain the highest sensitivity for all the EDCs. The limits of detection (LODs) were 0.02-1.9 ng L(-1), which are lower than or comparable to these reported in references. Wide linear ranges (LOD-100 ng L(-1) for ESI+ mode, and LOD-200 ng L(-1) for ESI- mode) were obtained with determination coefficients (R(2)) higher than 0.99 for all the compounds. With five internal standards, good recoveries (84.4-103.0%) of all the target compounds were obtained in selected surface water samples. The developed method was successfully applied to investigate the EDCs occurrence in the surface water of Shanghai by analyzing surface water samples from 11 sites. The results showed that nearly all the target compounds (30 in 31) were present in the surface water samples of Shanghai, of which three industrial compounds (4-t-OP, BPA, and BPF) showed the highest concentrations (median concentrations were 11.88-23.50 ng L(-1)), suggesting that industrial compounds were the dominating EDCs in the surface water of Shanghai, and much more attention should be paid on these compounds. Our present research demonstrated that SPE with MCX cartridges combined with HPLC-MS/MS was convenient

Quick-change filter cartridge

Science.gov (United States)

Rodgers, John C.; McFarland, Andrew R.; Ortiz, Carlos A.

1995-01-01

A quick-change filter cartridge. In sampling systems for measurement of airborne materials, a filter element is introduced into the sampled airstream such that the aerosol constituents are removed and deposited on the filter. Fragile sampling media often require support in order to prevent rupture during sampling, and careful mounting and sealing to prevent misalignment, tearing, or creasing which would allow the sampled air to bypass the filter. Additionally, handling of filter elements may introduce cross-contamination or exposure of operators to toxic materials. Moreover, it is desirable to enable the preloading of filter media into quick-change cartridges in clean laboratory environments, thereby simplifying and expediting the filter-changing process in the field. The quick-change filter cartridge of the present invention permits the application of a variety of filter media in many types of instruments and may also be used in automated systems. The cartridge includes a base through which a vacuum can be applied to draw air through the filter medium which is located on a porous filter support and held there by means of a cap which forms an airtight seal with the base. The base is also adapted for receiving absorbing media so that both particulates and gas-phase samples may be trapped for investigation, the latter downstream of the aerosol filter.

Determination of radiation-induced hydrocarbons in processed food and complex lipid matrices. A new solid phase extraction (SPE) method for detection of irradiated components in food

International Nuclear Information System (INIS)

Hartmann, M.; Ammon, J.; Berg, H.

1997-01-01

Detection of irradiated components in processed food with complex lipid matrices can be affected by two problems. First, the processed food may contain only a small amount of the irradiated component, and the radiation-induced hydrocarbons may be diluted throughout the lipid matrix of the whole food. Second, in complex lipid matrices, the detection of prior irradiation is often disturbed by fat-associated compounds. In these cases, common solid phase extraction (SPE) Florisil clean-up alone is inadequate in the detection of prior irradiation. Subsequent SPE argentation chromatography of the Florisil eluate allows the measurement of small amounts of irradiated lipid-containing ingredients in processed food as well as the detection of prior irradiation in complex lipid matrices such as paprika and chilli. SPE argetation chromatography is the first method available for the selective enrichment of radiation-specific hydrocarbons from even complex lipid matrices, thus enabling the detection of irradiation does as low as 0.025 kGy. Furthermore, by using radiation-induced hydrocarbons in the detection of prior irradiation of paprika and chilli powder, a second independent method, the first being measurement of thermoluminescence, is available for the analysis of these matrices. Such analysis could be achieved by using this highly sensitive, cheap and easy to perform combined SPE Florisil/argentation chromatography method, without the need for sophisticated techniques like SFE-GC/MS or LC-GC/MS, so that highly sensitive detection of prior irradiation colud be performed in almost every laboratory

Extraction optimization and pixel-based chemometric analysis of semi-volatile organic compounds in groundwater

DEFF Research Database (Denmark)

Christensen, Peter; Tomasi, Giorgio; Kristensen, Mette

2017-01-01

. In this study, we tested the combination of solid phase extraction (SPE) with dispersive liquid-liquid micro extraction (DLLME), or with stir bar sorptive extraction (SBSE), as an extraction method for semi-VOCs in groundwater. Combining SPE with DLLME or SBSE resulted in better separation of peaks...... in an unresolved complex mixture. SPE-DLLME was chosen as the preferred extraction method. SPE-DLLME covered a larger polarity range (logKo/w 2.0-11.2), had higher extraction efficiency at logKo/w 2.0-3.8 and 5.8-11.2, and was faster compared to SPE-SBSE. SPE-DLLME extraction combined with chemical analysis by gas...... chromatography-mass spectrometry (GC-MS) and pixel-based data analysis of summed extraction ion chromatograms (sEICs) was tested as a new method for chemical fingerprinting of semi-VOCs in 15 groundwater samples. The results demonstrate that SPE-DLLME-GC-MS provides an excellent compromise between compound...

Development of a solid-phase extraction method with simple MEKC-UV analysis for simultaneous detection of indole metabolites in human urine after administration of indole dietary supplement.

Science.gov (United States)

Phonchai, Apichai; Wilairat, Prapin; Chantiwas, Rattikan

2017-11-01

This work presents the development of a solid phase extraction method with simple MEKC-UV analysis for the simultaneous determination of indole-3-carbinol (I3C) and its metabolites (3, 3'-diindolylmethane (DIM), indole-3-carboxaldehyde (I3CAL), indole-3-acetonitrile (I3A)) in human urine after oral administration of an indole dietary supplement. Solid phase extraction (SPE) method was applied for the first time for simultaneous analysis of these indole metabolites. The MEKC separation method was developed in a previous work. Three commercial SPE cartridges, each with different sorbent materials, were investigated: Sep-Pak ® C18, Oasis ® HLB and Oasis ® WCX. The Sep-Pak ® C18 material provided the highest extraction recovery of 88-113% (n = 9), for the four target indole metabolites (I3C, DIM, I3CAL and I3A). The optimal washing and elution solutions were 40% methanol/water (v/v) and 100% methanol, respectively, and optimal elution volume was 2.0mL. The specificity of the proposed SPE method was evaluated with negative control urine samples (n = 10) from healthy volunteers who had not taken the dietary supplement or vegetables known to contain indole compounds. Linear calibration curves were in the range of 0.2-25μgmL -1 (r 2 > 0.998) using diphenylamine (DPA) as the internal standard. Intra-day and inter-day precisions were 3.5-12.3%RSD and 2.7-14.1%RSD, respectively. Limits of detection and quantification were 0.05-0.10μgmL -1 and 0.10-0.50μgmL -1 , respectively. The four target indole compounds were separated within only 5min by MEKC-UV analysis. Urine from 5 subjects who had taken a dietary supplement containing I3C and DIM were found to contain only the DIM metabolite at concentrations ranging from 0.10 to 0.35µgmL -1 . Accuracy of the proposed method based on the percentage recovery of spiked urine samples were 70-108%, 82-116%, 82-132% and 80-100% for I3C, I3CAL, I3A and DIM, respectively. The Sep-Pak ® C18 cartridge was highly effective in

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

Science.gov (United States)

Wang, Ziming; Zhao, Xin; Xu, Xu; Wu, Lijie; Su, Rui; Zhao, Yajing; Jiang, Chengfei; Zhang, Hanqi; Ma, Qiang; Lu, Chunmei; Dong, Deming

2013-01-14

A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-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 μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-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 μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60°C for 10 min. The extracts obtained by MAE-μ-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%. Copyright © 2012 Elsevier B.V. All rights reserved.

A rapid solid-phase extraction method for measurement of non-metabolised peripheral benzodiazepine receptor ligands, [18F]PBR102 and [18F]PBR111, in rat and primate plasma

International Nuclear Information System (INIS)

Katsifis, Andrew; Loc'h, Christian; Henderson, David; Bourdier, Thomas; Pham, Tien; Greguric, Ivan; Lam, Peter; Callaghan, Paul; Mattner, Filomena; Eberl, Stefan; Fulham, Michael

2011-01-01

Objectives: To develop a rapid and reliable method for estimating non-metabolised PBR ligands fluoroethoxy ([ 18 F]PBR102)- and fluoropropoxy ([ 18 F]PBR111)-substituted 2-(6-chloro-2-phenyl)imidazo[1,2-a]pyridine-3-yl)-N,N-diethylacetamides in plasma. Methods: Rats and baboons were imaged with PET up to 2 h postinjection of [ 18 F]PBR102 and [ 18 F]PBR111 under baseline conditions, after pre-blocking or displacement with PK11195. Arterial plasma samples were directly analysed by reverse-phase solid-phase extraction (RP-SPE) and RP-HPLC and by normal-phase TLC. SPE cartridges were successively washed with acetonitrile/water mixtures. SPE eluant radioactivity was measured in a γ-counter to determine the parent compound fraction and then analysed by HPLC and TLC for validation. Results: In SPE, hydrophilic and lipophilic radiolabelled metabolites were eluted in water and 20% acetonitrile/water. All non-metabolised [ 18 F]PBR102 and [ 18 F]PBR111 were in SPE acetonitrile fraction as confirmed by HPLC and TLC analysis. Unchanged (%) [ 18 F]PBR102 and [ 18 F]PBR111 from SPE analysis in rat and baboon plasma agreed with those from HPLC and TLC analysis. In rats and baboons, the fraction of unchanged tracer followed a bi-exponential decrease, with half-lives of 7 to 10 min for the fast component and >80 min for the slow component for both tracers. Conclusions: Direct plasma SPE analysis of [ 18 F]PBR102 and [ 18 F]PBR111 can reliably estimate parent compound fraction. SPE was superior to HPLC for samples with low activity; it allows rapid and accurate metabolite analysis of a large number of plasma samples for improved estimation of metabolite-corrected input function during quantitative PET imaging studies.

StorageTek T10000 Data Cartridge

CERN Multimedia

This data cartridge works on several StorageTek systems. The goal is to provide cartridge compatibility across several system. It has been designed for space saving and ultra-high capacity tape. It permit to fulfill high-volume backup, archiving, and disaster recovery.

Detection and genotyping of human papillomavirus in self-obtained cervicovaginal samples by using the FTA cartridge: new possibilities for cervical cancer screening.

Science.gov (United States)

Lenselink, Charlotte H; de Bie, Roosmarie P; van Hamont, Dennis; Bakkers, Judith M J E; Quint, Wim G V; Massuger, Leon F A G; Bekkers, Ruud L M; Melchers, Willem J G

2009-08-01

This study assesses human papillomavirus (HPV) detection and genotyping in self-sampled genital smears applied to an indicating FTA elute cartridge (FTA cartridge). The study group consisted of 96 women, divided into two sample sets. All samples were analyzed by the HPV SPF(10)-Line Blot 25. Set 1 consisted of 45 women attending the gynecologist; all obtained a self-sampled cervicovaginal smear, which was applied to an FTA cartridge. HPV results were compared to a cervical smear (liquid based) taken by a trained physician. Set 2 consisted of 51 women who obtained a self-sampled cervicovaginal smear at home, which was applied to an FTA cartridge and to a liquid-based medium. DNA was obtained from the FTA cartridges by simple elution as well as extraction. Of all self-obtained samples of set 1, 62.2% tested HPV positive. The overall agreement between self- and physician-obtained samples was 93.3%, in favor of the self-obtained samples. In sample set 2, 25.5% tested HPV positive. The overall agreement for high-risk HPV presence between the FTA cartridge and liquid-based medium and between DNA elution and extraction was 100%. This study shows that HPV detection and genotyping in self-obtained cervicovaginal samples applied to an FTA cartridge is highly reliable. It shows a high level of overall agreement with HPV detection and genotyping in physician-obtained cervical smears and liquid-based self-samples. DNA can be obtained by simple elution and is therefore easy, cheap, and fast. Furthermore, the FTA cartridge is a convenient medium for collection and safe transport at ambient temperatures. Therefore, this method may contribute to a new way of cervical cancer screening.

IBM 3480 tape cartridge

CERN Multimedia

1984-01-01

The 3480 tape format is a magnetic tape data storage format developed by IBM. The cartridge contains a single reel. IBM’s 3480 cartridge tape system sought to replace the traditional reels of magnetic tape in the computer center. Because of their speed, reliability, durability and low media cost, these tapes and tape drives are still in high demand. A hallmark of the genre is transferability. Tapes recorded with one tape drive are generally readable on another drive, even if the tape drives were built by different manufacturers.

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-02-28

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

Analysis of {sup 210}Pb in water samples with plastic scintillation resins

Energy Technology Data Exchange (ETDEWEB)

Lluch, E.; Barrera, J. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Tarancón, A., E-mail: alex.tarancon@ub.edu [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Bagán, H. [Department of Pure and Applied Biochemistry, Lund University, Getingevägen 60, Hus II, 22100 SE, Lund (Sweden); García, J.F. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain)

2016-10-12

{sup 210}Pb is a radioactive lead isotope present in the environment as member of the {sup 238}U decay chain. Since it is a relatively long-lived radionuclide (T{sub 1/2} = 22.2 years), its analysis is of interest in radiation protection and the geochronology of sediments and artwork. Here, we present a method for analysing {sup 210}Pb using plastic scintillation resins (PSresins) packaged in solid-phase extraction columns (SPE cartridge). The advantages of this method are its selectivity, the low limit of detection, as well as reductions in the amount of time and reagents required for analysis and the quantity of waste generated. The PSresins used in this study were composed of a selective extractant (4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 in 1-octanol) covering the surface of plastic scintillation microspheres. Once the amount of extractant (1:1/4) and medium of separation (2 M HNO{sub 3}) were optimised, PSresins in SPE cartridges were calibrated with a standard solution of {sup 210}Pb. {sup 210}Pb could be fully separated from its daughters, {sup 210}Bi and {sup 210}Po, with a recovery value of 91(3)% and detection efficiency of 44(3)%. Three spiked water samples (one underground and two river water samples) were analysed in triplicates with deviations lower than 10%, demonstrating the validity of the PS resin method for {sup 210}Pb analysis. - Highlights: • A plastic scintillation resin for selective analysis of {sup 210}Pb has been developed. • A commercial SPE cartridge has been use for separation and scintillation counting. • {sup 210}Pb separation from {sup 210}Bi and {sup 210}Po is achieved with a 91(3)% of recovery. • The method is valid for analysis of {sup 210}Pb in river water samples.

Novel approach to microwave-assisted extraction and micro-solid-phase extraction from soil using graphite fibers as sorbent.

Science.gov (United States)

Xu, Li; Lee, Hian Kee

2008-05-30

A single-step extraction-cleanup procedure involving microwave-assisted extraction (MAE) and micro-solid-phase extraction (micro-SPE) has been developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) from soil samples. Micro-SPE is a relatively new extraction procedure that makes use of a sorbent enclosed within a sealed polypropylene membrane envelope. In the present work, for the first time, graphite fiber was used as a sorbent material for extraction. MAE-micro-SPE was used to cleanup sediment samples and to extract and preconcentrate five PAHs in sediment samples prepared as slurries with addition of water. The best extraction conditions comprised of microwave heating at 50 degrees C for a duration of 20 min, and an elution (desorption) time of 5 min using acetonitrile with sonication. Using gas chromatography (GC)-flame ionization detection (FID), the limits of detection (LODs) of the PAHs ranged between 2.2 and 3.6 ng/g. With GC-mass spectrometry (MS), LODs were between 0.0017 and 0.0057 ng/g. The linear ranges were between 0.1 and 50 or 100 microg/g for GC-FID analysis, and 1 and 500 or 1000 ng/g for GC-MS analysis. Granular activated carbon was also used for the micro-SPE device but was found to be not as efficient in the PAH extraction. The MAE-micro-SPE method was successfully used for the extraction of PAHs in river and marine sediments, demonstrating its applicability to real environmental solid matrixes.

[18F]Fallypride: Metabolism studies and quantification of the radiotracer and its radiometabolites in plasma using a simple and rapid solid-phase extraction method

International Nuclear Information System (INIS)

Peyronneau, Marie-Anne; Saba, Wadad; Goutal, Sébastien; Kuhnast, Bertrand; Dollé, Frédéric; Bottlaender, Michel; Valette, Héric

2013-01-01

Introduction: [ 18 F]Fallypride, a fluorinated and substituted benzamide with high affinity for D 2 /D 3 receptors, is a useful PET radioligand for the study of striatal/extrastriatal areas. Since [ 18 F]fallypride is extensively metabolized in vivo and since PET examinations are long lasting in humans, the rapid measurement of the unchanged radiotracer in plasma is essential for the quantification of images. The present study aims: i) to evaluate if the radiometabolites of [ 18 F]fallypride cross the blood–brain barrier in rodents, ii) to identify these radiometabolites in baboon plasma and iii) to develop a rapid solid phase extraction method (SPE) suitable for human applications to quantify both [ 18 F]fallypride and its radiometabolites in plasma. Methods: The metabolites P450-dependant in rat and human liver microsomes were characterized by LC–MS–MS and compared to those detected in vivo. Sequential solvent elution on Oasis®-MCX-SPE cartridges was used to quantify [ 18 F]fallypride and its radiometabolites. Result: In rat microsomal incubations, five metabolites generated upon N/O-dealkylation or hydroxylation at the pyrrolidine and/or at the benzamide moiety were identified. No radiometabolite was detected in the rat brain. N-dealkylated and hydroxylated derivatives were detected in human microsomal incubations as well as in baboon plasma. The use of SPE (total recovery 100.2% ± 2.8%, extraction yield 95.5% ± 0.3%) allowed a complete separation of [ 18 F]fallypride from its radiometabolites in plasma and evaluate [ 18 F]fallypride at 150 min pi to be 22% ± 5% of plasma radioactivity. Conclusions: The major in vivo radiometabolites of [ 18 F]fallypride were produced by N-dealkylation and hydroxylation. Allowing the rapid analysis of multiple plasma samples, SPE is a method of choice for the determination of [ 18 F]fallypride until late images required for quantitative PET imaging in humans

Polymeric Sorbent with Controlled Surface Polarity: An Alternate for Solid-Phase Extraction of Nerve Agents and Their Markers from Organic Matrix.

Science.gov (United States)

Roy, Kanchan Sinha; Purohit, Ajay Kumar; Chandra, Buddhadeb; Goud, D Raghavender; Pardasani, Deepak; Dubey, Devendra Kumar

2018-06-05

Extraction and identification of lethal nerve agents and their markers in complex organic background have a prime importance from the forensic and verification viewpoint of the Chemical Weapons Convention (CWC). Liquid-liquid extraction with acetonitrile and commercially available solid phase silica cartridges are extensively used for this purpose. Silica cartridges exhibit limited applicability for relatively polar analytes, and acetonitrile extraction shows limited efficacy toward relatively nonpolar analytes. The present study describes the synthesis of polymeric sorbents with tunable surface polarity, their application as a solid-phase extraction (SPE) material against nerve agents and their polar as well as nonpolar markers from nonpolar organic matrices. In comparison with the acetonitrile extraction and commercial silica cartridges, the new sorbent showed better extraction efficiency toward analytes of varying polarity. The extraction parameters were optimized for the proposed method, which included ethyl acetate as an extraction solvent and n-hexane as a washing solvent. Under optimized conditions, method linearity ranged from 0.10 to 10 μg mL -1 ( r 2 = 0.9327-0.9988) for organophosphorus esters and 0.05-20 μg mL -1 ( r 2 = 0.9976-0.9991) for nerve agents. Limits of detection (S:N = 3:1) in the SIM mode were found in the range of 0.03-0.075 μg mL -1 for organophosphorus esters and 0.015-0.025 μg mL -1 for nerve agents. Limits of quantification (S:N = 10:1) were found in the range of 0.100-0.25 μg mL -1 for organophosphorus esters and 0.05-0.100 μg mL -1 for nerve agents in the SIM mode. The recoveries of the nerve agents and their markers ranged from 90.0 to 98.0% and 75.0 to 95.0% respectively. The repeatability and reproducibility (with relative standard deviations (RSDs) %) for organophosphorus esters were found in the range of 1.35-8.61% and 2.30-9.25% respectively. For nerve agents, the repeatability range from 1.00 to 7.75% and reproducibility

Rapid, efficient and selective preconcentration of benzo[a]pyrene (BaP) by molecularly imprinted composite cartridge and HPLC

Energy Technology Data Exchange (ETDEWEB)

Çorman, Mehmet Emin, E-mail: mecorman@sinop.edu.tr [Hacettepe University, Department of Chemistry, Ankara (Turkey); Sinop University, Department of Bioengineering, Sinop (Turkey); Armutcu, Canan [Hacettepe University, Department of Chemistry, Ankara (Turkey); Uzun, Lokman, E-mail: lokman@hacettepe.edu.tr [Hacettepe University, Department of Chemistry, Ankara (Turkey); Denizli, Adil [Hacettepe University, Department of Chemistry, Ankara (Turkey)

2017-01-01

In this study, cryogel-based molecularly imprinted composite cartridges were designed for the rapid, efficient, and selective preconcentration of benzo[a]pyrene (BaP) from water samples. First, a BaP-imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-phenylalanine) composite cartridge was synthesized under semi-frozen conditions and characterized by scanning electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, and swelling tests. After the optimization of preconcentration parameters, i.e., pH and initial BaP concentration, the selectivity and preconcentration efficiency, and reusability of these cartridges were also evaluated. In selectivity experiments, BaP imprinted composite cartridge exhibited binding capacities 3.09, 9.52, 8.87, and 8.77-fold higher than that of the non-imprinted composite cartridge in the presence of competitors, such as benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), indeno[1,2,3-cd]pyrene (IcdP), and 1-naphthol, respectively. The method detection limit (MDL), relative standard deviation (RSD) and preconcentration efficiency (PE) of the synthesized composite cartridge were calculated as 24.86 μg/L, 1.60%, and 349.6%, respectively. - Highlights: • Cryogel based molecularly imprinted composite cartridges as solid-phase extraction sorbents • Combination unique structural features of cryogels with MIP • An excellent ability to recognize the BaP molecule even if single-run contact • Rapid, efficient, selective and cost-friendly PAH preconcentration • Hydrophobic interactions via N-methacryloyl-(L)-phenylalanine.

Analytical method for the determination of atrazine and its dealkylated chlorotriazine metabolites in water using SPE sample preparation and GC-MSD analysis.

Science.gov (United States)

Huang, Sung-Ben; Stanton, Jeffrey S; Lin, Yi; Yokley, Robert A

2003-12-03

A method is reported for the determination of atrazine and its dealkylated chlorotriazine metabolites in ground, surface, and deionized water. Water samples are adjusted to pH 3-4 prior to loading onto two SPE cartridges in series: C-18 and C-18/cation exchange mixed-mode polymeric phases. The analytes are eluted from each of the two cartridges separately, and the pooled and concentrated fraction is analyzed using gas chromatography-mass selective detection in the selected ion monitoring mode. The lower limit of method validation is 0.10 micrograms/L (ppb) for 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine), 2-amino-4-chloro-6-(isopropylamino)-s-triazine (G-30033, deethylatrazine), 2-amino-4-chloro-6-(ethylamino)-s-triazine (G-28279, deisopropylatrazine), and 2,4-diamino-6-chloro-s-triazine (G-28273, didealkyatrazine). The overall mean procedural recoveries (and standard deviations) are 96 (6.9), 96 (5.5), 95 (6.8), and 100% (10%) for atrazine, G-30033, G-28279, and G-28273, respectively (n = 49). The method validation study was conducted under U.S. EPA FIFRA Good Laboratory Practice Guidelines 40 CFR 160. The reported procedure accounts for residues of G-28273 in water.

Targeted isolation and identification of bioactive compounds lowering cholesterol in the crude extracts of crabapples using UPLC-DAD-MS-SPE/NMR based on pharmacology-guided PLS-DA.

Science.gov (United States)

Wen, Chao; Wang, Dongshan; Li, Xing; Huang, Tao; Huang, Cheng; Hu, Kaifeng

2018-02-20

The anti-hyperlipidemic effects of crude crabapple extracts derived from Malus 'Red jade', Malus hupehensis (Pamp.) Rehd. and Malus prunifolia (Willd.) Borkh. were evaluated on high-fat diet induced obese (HF DIO) mice. The results revealed that some of these extracts could lower serum cholesterol levels in HF DIO mice. The same extracts were also parallelly analyzed by LC-MS in both positive and negative ionization modes. Based on the pharmacological results, 22 LC-MS variables were identified to be correlated with the anti-hyperlipidemic effects using partial least square discriminant analysis (PLS-DA) and independent samples t-test. Further, under the guidance of the bioactivity-correlated LC-MS signals, 10 compounds were targetedly isolated and enriched using UPLC-DAD-MS-SPE and identified/elucidated by NMR together with MS/MS as citric acid(1), p-coumaric acid(2), hyperoside(3), myricetin(4), naringenin(5), quercetin(6), kaempferol(7), gentiopicroside(8), ursolic acid(9) and 8-epiloganic acid(10). Among these 10 compounds, 6 compounds, hyperoside(3), myricetin(4), naringenin(5), quercetin(6), kaempferol(7) and ursolic acid(9), were individually studied and reported to indeed have effects on lowering the serum lipid levels. These results demonstrated the efficiency of this strategy for drug discovery. In contrast to traditional routes to discover bioactive compounds in the plant extracts, targeted isolation and identification of bioactive compounds in the crude plant extracts using UPLC-DAD-MS-SPE/NMR based on pharmacology-guided PLS-DA of LC-MS data brings forward a new efficient dereplicated approach to natural products research for drug discovery. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection and Genotyping of Human Papillomavirus in Self-Obtained Cervicovaginal Samples by Using the FTA Cartridge: New Possibilities for Cervical Cancer Screening ▿

Science.gov (United States)

Lenselink, Charlotte H.; de Bie, Roosmarie P.; van Hamont, Dennis; Bakkers, Judith M. J. E.; Quint, Wim G. V.; Massuger, Leon F. A. G.; Bekkers, Ruud L. M.; Melchers, Willem J. G.

2009-01-01

This study assesses human papillomavirus (HPV) detection and genotyping in self-sampled genital smears applied to an indicating FTA elute cartridge (FTA cartridge). The study group consisted of 96 women, divided into two sample sets. All samples were analyzed by the HPV SPF10-Line Blot 25. Set 1 consisted of 45 women attending the gynecologist; all obtained a self-sampled cervicovaginal smear, which was applied to an FTA cartridge. HPV results were compared to a cervical smear (liquid based) taken by a trained physician. Set 2 consisted of 51 women who obtained a self-sampled cervicovaginal smear at home, which was applied to an FTA cartridge and to a liquid-based medium. DNA was obtained from the FTA cartridges by simple elution as well as extraction. Of all self-obtained samples of set 1, 62.2% tested HPV positive. The overall agreement between self- and physician-obtained samples was 93.3%, in favor of the self-obtained samples. In sample set 2, 25.5% tested HPV positive. The overall agreement for high-risk HPV presence between the FTA cartridge and liquid-based medium and between DNA elution and extraction was 100%. This study shows that HPV detection and genotyping in self-obtained cervicovaginal samples applied to an FTA cartridge is highly reliable. It shows a high level of overall agreement with HPV detection and genotyping in physician-obtained cervical smears and liquid-based self-samples. DNA can be obtained by simple elution and is therefore easy, cheap, and fast. Furthermore, the FTA cartridge is a convenient medium for collection and safe transport at ambient temperatures. Therefore, this method may contribute to a new way of cervical cancer screening. PMID:19553570

Humic acid-bonded silica as a novel sorbent for solid-phase extraction of benzo[a]pyrene in edible oils

International Nuclear Information System (INIS)

Luo Dan; Yu Qiongwei; Yin Hongrui; Feng Yuqi

2007-01-01

A novel solid-phase extraction (SPE) sorbent, humic acid-bonded silica (HAS), was prepared. Humic acids (HAs) were grafted onto silica matrices via an amide linkage between humyl chloride and the amido terminus of 3-aminopropyltrimethoxysilane (APTS)-silica gel. The resulting material was characterized by Fourier transform infrared spectrometer, elemental analysis, and nitrogen adsorption analysis. This sorbent exhibits an excellent adsorption capacity for some electron-abundant analytes owing to its peculiar structure. In this paper, we choose benzo[a]pyrene (BaP) in oil as a probe to validate the adsorption capacity of the material. Thus a fast, cheap and simple SPE method with humic acid-bonded silica cartridge for edible oil clean-up, followed by high-performance liquid chromatography (HPLC) with fluorescence detection was established. The effects of experimental variables, such as washing and elution solvents, and the amount of sorbents have been studied. The recoveries of BaP in edible oils spiked at 0.2-100 μg kg -1 were in the range of 78.8-102.7% with relative standard deviations ranging between 1.3 and 9.3%; the limit of detection was -0.06 μg kg -1

Rapid solid-phase extraction method to quantify [11C]-verapamil, and its [11C]-metabolites, in human and macaque plasma

International Nuclear Information System (INIS)

Unadkat, Jashvant D.; Chung, Francisco; Sasongko, Lucy; Whittington, Dale; Eyal, Sara; Mankoff, David; Collier, Ann C.; Muzi, Mark; Link, Jeanne

2008-01-01

Introduction: P-glycoprotein (P-gp), an efflux transporter, is a significant barrier to drug entry into the brain and the fetus. The positron emission tomography (PET) ligand, [ 11 C]-verapamil, has been used to measure in vivo P-gp activity at various tissue-blood barriers of humans and animals. Since verapamil is extensively metabolized in vivo, it is important to quantify the extent of verapamil metabolism in order to interpret such P-gp activity. Therefore, we developed a rapid solid-phase extraction (SPE) method to separate, and then quantify, verapamil and its radiolabeled metabolites in plasma. Methods: Using high-performance liquid chromatography (HPLC), we established that the major identifiable circulating radioactive metabolite of [ 11 C]-verapamil in plasma of humans and the nonhuman primate, Macaca nemestrina, was [ 11 C]-D-617/717. Using sequential and differential pH elution on C 8 SPE cartridges, we developed a rapid method to separate [ 11 C]-verapamil and [ 11 C]-D-617/717. Recovery was measured by spiking the samples with the corresponding nonradioactive compounds and assaying these compounds by HPLC. Results: Verapamil and D-617/717 recovery with the SPE method was >85%. When the method was applied to PET studies in humans and nonhuman primates, significant plasma concentration of D-617/717 and unknown polar metabolite(s) were observed. The SPE and the HPLC methods were not significantly different in the quantification of verapamil and D-617/717. Conclusions: The SPE method simultaneously processes multiple samples in less than 5 min. Given the short half-life of [ 11 C], this method provides a valuable tool to rapidly determine the concentration of [ 11 C]-verapamil and its [ 11 C]-metabolites in human and nonhuman primate plasma

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.

Silica Modified with Polyaniline as a Potential Sorbent for Matrix Solid Phase Dispersion (MSPD) and Dispersive Solid Phase Extraction (d-SPE) of Plant Samples

Science.gov (United States)

Sowa, Ireneusz; Wójciak-Kosior, Magdalena; Strzemski, Maciej; Sawicki, Jan; Staniak, Michał; Dresler, Sławomir; Szwerc, Wojciech; Mołdoch, Jarosław; Latalski, Michał

2018-01-01

Polyaniline (PANI) is one of the best known conductive polymers with multiple applications. Recently, it was also used in separation techniques, mostly as a component of composites for solid-phase microextraction (SPME). In the present paper, sorbent obtained by in situ polymerization of aniline directly on silica gel particles (Si-PANI) was used for dispersive solid phase extraction (d-SPE) and matrix solid–phase extraction (MSPD). The efficiency of both techniques was evaluated with the use of high performance liquid chromatography with diode array detection (HPLC-DAD) quantitative analysis. The quality of the sorbent was verified by Raman spectroscopy and microscopy combined with automated procedure using computer image analysis. For extraction experiments, triterpenes were chosen as model compounds. The optimal conditions were as follows: protonated Si-PANI impregnated with water, 160/1 sorbent/analyte ratio, 3 min of extraction time, 4 min of desorption time and methanolic solution of ammonia for elution of analytes. The proposed procedure was successfully used for pretreatment of plant samples. PMID:29565297

An on-line coupling of nanofibrous extraction with column-switching high performance liquid chromatography - A case study on the determination of bisphenol A in environmental water samples.

Science.gov (United States)

Háková, Martina; Chocholoušová Havlíková, Lucie; Chvojka, Jiří; Solich, Petr; Šatínský, Dalibor

2018-02-01

Polyamide 6 nanofiber polymers were used as modern sorbents for on-line solid phase extraction (SPE) coupled with liquid chromatography. The on-line SPE system was tested for the determination of bisphenol A in river water samples. Polyamide nanofibers were prepared using needleless electrospinning, inserted into a mini-column cartridge (5 × 4.6mm) and coupled with HPLC. The effect of column packing and the amount of polyamide 6 on extraction efficiency was tested and the packing process was optimized. The proposed method was performed using a 50-µL sample injection followed by an on-line nanofibrous extraction procedure. The influence of the washing mobile phase on the retention of bisphenol A during the extraction procedure was evaluated. Ascentis ® Express C18 (10cm × 4.6mm) core-shell column was used as an analytical column. Fluorescence detection wavelengths (λ ex = 225nm and λ em = 320nm) were used for identification and quantification of Bisphenol A in river waters. The linearity was tested in the range from 2 to 500µgL -1 (using nine calibration points). The limits of detection and quantification were 0.6 and 2µgL -1 , respectively. The developed method was successfully used for the determination of bisphenol A in various samples of river waters in the Czech Republic (The Ohře, Labe, Nisa, Úpa, and Opava Rivers). Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid solid-phase extraction method to quantify [{sup 11}C]-verapamil, and its [{sup 11}C]-metabolites, in human and macaque plasma

Energy Technology Data Exchange (ETDEWEB)

Unadkat, Jashvant D. [Department of Pharmaceutics, University of Washington, Box 357610, Seattle, WA 98195 (United States)], E-mail: jash@u.washington.edu; Chung, Francisco; Sasongko, Lucy; Whittington, Dale; Eyal, Sara [Department of Pharmaceutics, University of Washington, Box 357610, Seattle, WA 98195 (United States); Mankoff, David [Department of Radiology, University of Washington, Box 356004, Seattle, WA 98195 (United States); Collier, Ann C. [Department of Medicine, University of Washington, Box 359929, Seattle, WA 98195 (United States); Muzi, Mark; Link, Jeanne [Department of Radiology, University of Washington, Box 356004, Seattle, WA 98195 (United States)

2008-11-15

Introduction: P-glycoprotein (P-gp), an efflux transporter, is a significant barrier to drug entry into the brain and the fetus. The positron emission tomography (PET) ligand, [{sup 11}C]-verapamil, has been used to measure in vivo P-gp activity at various tissue-blood barriers of humans and animals. Since verapamil is extensively metabolized in vivo, it is important to quantify the extent of verapamil metabolism in order to interpret such P-gp activity. Therefore, we developed a rapid solid-phase extraction (SPE) method to separate, and then quantify, verapamil and its radiolabeled metabolites in plasma. Methods: Using high-performance liquid chromatography (HPLC), we established that the major identifiable circulating radioactive metabolite of [{sup 11}C]-verapamil in plasma of humans and the nonhuman primate, Macaca nemestrina, was [{sup 11}C]-D-617/717. Using sequential and differential pH elution on C{sub 8} SPE cartridges, we developed a rapid method to separate [{sup 11}C]-verapamil and [{sup 11}C]-D-617/717. Recovery was measured by spiking the samples with the corresponding nonradioactive compounds and assaying these compounds by HPLC. Results: Verapamil and D-617/717 recovery with the SPE method was >85%. When the method was applied to PET studies in humans and nonhuman primates, significant plasma concentration of D-617/717 and unknown polar metabolite(s) were observed. The SPE and the HPLC methods were not significantly different in the quantification of verapamil and D-617/717. Conclusions: The SPE method simultaneously processes multiple samples in less than 5 min. Given the short half-life of [{sup 11}C], this method provides a valuable tool to rapidly determine the concentration of [{sup 11}C]-verapamil and its [{sup 11}C]-metabolites in human and nonhuman primate plasma.

New Insights into the Explosion Source from SPE

Science.gov (United States)

Patton, H. J.

2015-12-01

Phase I of the Source Physics Experiments (SPE) is a series of chemical explosions at varying depths and yields detonated in the same emplacement hole on Climax stock, a granitic pluton located on the Nevada National Security Site. To date, four of the seven planned tests have been conducted, the last in May 2015, called SPE-4P, with a scaled depth of burial of 1549 m/kt1/3 in order to localize the source in time and space. Surface ground motions validated that the source medium did not undergo spallation, and a key experimental objective was achieved where SPE-4P is the closest of all tests in the series to a pure monopole source and will serve as an empirical Green's function for analysis against other SPE tests. A scientific objective of SPE is to understand mechanisms of rock damage for generating seismic waves, particularly surface and S waves, including prompt damage under compressive stresses and "late-time" damage under tensile stresses. Studies have shown that prompt damage can explain ~75% of the seismic moment for some SPE tests. Spallation is a form of late-time damage and a facilitator of damage mechanisms under tensile stresses including inelastic brittle deformation and shear dilatancy on pre-existing faults or joints. As an empirical Green's function, SPE-4P allows the study of late-time damage mechanisms on other SPE tests that induce spallation and late-time damage, and I'll discuss these studies. The importance for nuclear monitoring cannot be overstated because new research shows that damage mechanisms can affect surface wave magnitude Ms more than tectonic release, and are a likely factor related to anomalous mb-Ms behavior for North Korean tests.

Optimization of the Determination Method for Dissolved Cyanobacterial Toxin BMAA in Natural Water.

Science.gov (United States)

Yan, Boyin; Liu, Zhiquan; Huang, Rui; Xu, Yongpeng; Liu, Dongmei; Lin, Tsair-Fuh; Cui, Fuyi

2017-10-17

There is a serious dispute on the existence of β-N-methylamino-l-alanine (BMAA) in water, which is a neurotoxin that may cause amyotrophic lateral sclerosis/Parkinson's disease (ALS/PDC) and Alzheimer' disease. It is believed that a reliable and sensitive analytical method for the determination of BMAA is urgently required to resolve this dispute. In the present study, the solid phase extraction (SPE) procedure and the analytical method for dissolved BMAA in water were investigated and optimized. The results showed both derivatized and underivatized methods were qualified for the measurement of BMAA and its isomer in natural water, and the limit of detection and the precision of the two methods were comparable. Cartridge characteristics and SPE conditions could greatly affect the SPE performance, and the competition of natural organic matter is the primary factor causing the low recovery of BMAA, which was reduced from approximately 90% in pure water to 38.11% in natural water. The optimized SPE method for BMAA was a combination of rinsed SPE cartridges, controlled loading/elution rates and elution solution, evaporation at 55 °C, reconstitution of a solution mixture, and filtration by polyvinylidene fluoride membrane. This optimized method achieved > 88% recovery of BMAA in both algal solution and river water. The developed method can provide an efficient way to evaluate the actual concentration levels of BMAA in actual water environments and drinking water systems.

Multiwalled carbon nanotubes as solid-phase extraction materials for the gas chromatographic determination of organophosphorus pesticides in waters.

Science.gov (United States)

Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Angel Rodríguez-Delgado, Miguel

2008-10-01

In the present work, a GC method with nitrogen-phosphorus detection (NPD) was developed for the simultaneous determination of eight organophosphorus pesticide (OPP) residues (i.e., ethoprofos, diazinon, chlorpyrifos-methyl, fenitrothion, malathion, chlorpyrifos, fenamiphos, and buprofezin) in water samples. Preconcentration of the water samples was carried out using an SPE procedure with multiwalled carbon nanotubes (MWCNTs) of 10-15 nm od, 2-6 nm id, and 0.1-10 microm length as stationary phase. Extraction parameters, such as the amount of MWCNTs, sample volume, pH, and type and amount of the eluent were optimized. The most favorable conditions were as follows: 40 mg MWCNTs, 800 mL water, pH 6.0, and 20 mL dichloromethane, respectively. The MWCNTs-SPE-GC-NPD method was applied to the determination of these pesticides in real water samples: mineral and ground water as well as run-off water from an agricultural area collected shortly before opening out onto the sea. A recovery study was developed with five consecutive extractions of the three types of water spiked at three concentration levels (n = 15). Mean recovery values were in the range of 75-116% for mineral water (RSD water (RSD waters (RSDs waters, RSDs waters). The proposed method was also applied to the analysis of six water samples (two of each type: mineral, ground, and run-off waters) in which no residues of the selected pesticides were found. Results show that the MWCNTs used in this work have a high adsorbability of the pesticides under study. The main advantage of the use of these MWCNTs is their low cost when compared with those MWCNTs previously used in the literature and with conventional SPE cartridges.

Synthesis of O-(2-[18F]fluoroethyl)-L-tyrosine based on a cartridge purification method

International Nuclear Information System (INIS)

Mueller, Dirk; Klette, Ingo; Kalb, Fabrizia; Baum, Richard P.

2011-01-01

Introduction: O-(2-[ 18 F]fluoroethyl)-L-tyrosine (FET) is widely used as a positron emission tomography tracer for brain tumors. Usually, a high-performance liquid chromatography (HPLC) purification at the end of the two-step synthesis is applied. In this work, we report an automatic radiosynthesis of FET with a purification procedure based on standard cartridges. Methods: O-(2-[ 18 F]fluoroethyl)-L-tyrosine was prepared by [ 18 F]fluoroethylation of L-tyrosine by a two-step synthesis using a modified [ 11 C]methionine module (Nuclear Interface). In the first reaction step, we synthesized [ 18 F]fluoroethyltosylate starting from [ 18 F]fluoride. After a purification step, L-tyrosine was [ 18 F]fluoroethylated with [ 18 F]fluoroethyltosylate. The final reaction mixture was purified by means of solid phase extraction. The FET was trapped on an SCX cartridge, eluted with saline solution and trapped again on an HRX cartridge. For a second purification step, the FET was eluted from the HRX cartridge with ammonium acetate buffer and collected on two SCX cartridges followed by a washing step with water. The final product was eluted with saline solution and neutralised with 450 μl NaHCO 3 solution (8.4%). Results: The synthesis was finished after 50 min and delivered the FET in a range of 3-16 GBq. The synthesis typically yielded 41% (21 experiments) of FET (d.c.) without an HPLC purification step. The radiochemical purity ranged between 97% and 100%. Conclusion: We present a radiosynthesis of FET where the usually used HPLC purification procedure has been substituted by a purification step based on standard cartridges. This method is useful for automatic modules without an expensive HPLC purification unit and for the routine production of FET.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

A sensitive analytical procedure for monitoring acrylamide in environmental water samples by offline SPE-UPLC/MS/MS.

Science.gov (United States)

Togola, Anne; Coureau, Charlotte; Guezennec, Anne-Gwenaëlle; Touzé, Solène

2015-05-01

The presence of acrylamide in natural systems is of concern from both environmental and health points of view. We developed an accurate and robust analytical procedure (offline solid phase extraction combined with UPLC/MS/MS) with a limit of quantification (20 ng L(-1)) compatible with toxicity threshold values. The optimized (considering the nature of extraction phases, sampling volumes, and solvent of elution) solid phase extraction (SPE) was validated according to ISO Standard ISO/IEC 17025 on groundwater, surface water, and industrial process water samples. Acrylamide is highly polar, which induces a high variability during the SPE step, therefore requiring the use of C(13)-labeled acrylamide as an internal standard to guarantee the accuracy and robustness of the method (uncertainty about 25 % (k = 2) at limit of quantification level). The specificity of the method and the stability of acrylamide were studied for these environmental media, and it was shown that the method is suitable for measuring acrylamide in environmental studies.

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

Simultaneous determination of UV-filters and estrogens in aquatic invertebrates by modified quick, easy, cheap, effective, rugged, and safe extraction and liquid chromatography tandem mass spectrometry.

Science.gov (United States)

He, Ke; Timm, Anne; Blaney, Lee

2017-08-04

Ultraviolet-filters (UV-filters) and estrogens have attracted increased attention as contaminants of emerging concern (CECs) due to their widespread occurrence in the environment. Most of these CECs are hydrophobic and have the potential to accumulate in aquatic organisms. To date, co-analysis of UV-filters and estrogens has not been reported due, in part, to the complex environmental matrices. Here, a multi-residue method has been developed for simultaneous determination of five UV-filters and three estrogens in tissue from aquatic and marine organisms. The procedure involved a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction with a novel reverse-solid-phase extraction (reverse-SPE) cleanup in place of dispersive-SPE, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The tissue mass, acetonitrile content, and salt conditions for QuEChERS extraction, along with the reverse-SPE cartridge material and elution conditions, were thoroughly investigated and optimized. Five UV-filters (i.e., 3-(4-methylbenzylidene) camphor, benzophenone-3, ethylhexylmethoxycinnamate, homosalate, and octocrylene) and three estrogens (i.e., estrone, 17β-estradiol, and 17α-ethinylestradiol) were simultaneously analyzed by taking advantage of wrong-way-round ionization in LC-MS/MS. The optimized analytical protocol exhibited good recoveries (>80%) for target compounds and enabled their detection at concentrations as low as 0.2ng/g in 50mg tissue samples. The method was applied to determine concentrations of target analytes in four invertebrates (i.e., Orconectes virilis, Procambarus clarkii, Crassostrea virginica, and Ischadium recurvum). All eight target analytes were detected at least once in the tissue samples, with the highest concentration being 399ng/g of homosalate in O. virilis. These results highlight the ubiquitous bioaccumulation of CECs in aquatic and marine invertebrates. Copyright © 2017 Elsevier B.V. All rights

Hexagonal boron nitride nanosheets as adsorbents for solid-phase extraction of polychlorinated biphenyls from water samples

Energy Technology Data Exchange (ETDEWEB)

Jia, Shiliang; Wang, Zhenhua; Ding, Ning [Key Laboratory for Applied Technology of Sophisticated Analytical Instruments, Shandong Academy of Sciences, Jinan, Shandong (China); Elaine Wong, Y.-L. [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Chen, Xiangfeng, E-mail: xiangfchensdas@163.com [Key Laboratory for Applied Technology of Sophisticated Analytical Instruments, Shandong Academy of Sciences, Jinan, Shandong (China); Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Qiu, Guangyu [Department of Physics and Materials Science, City University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Dominic Chan, T.-W., E-mail: twdchan@cuhk.edu.hk [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong)

2016-09-14

The adsorptive potential of hexagonal boron nitride nanosheets (h-BNNSs) for solid-phase extraction (SPE) of pollutants was investigated for the first time. Seven indicators of polychlorinated biphenyls (PCBs) were selected as target analytes. The adsorption of PCBs on the surface of the h-BNNSs in water was simulated by the density functional theory and molecular dynamics. The simulation results indicated that the PCBs are adsorbed on the surface by π–π, hydrophobic, and electrostatic interactions. The PCBs were extracted with an h-BNNS-packed SPE cartridge, and eluted by dichloromethane. Gas chromatography–tandem mass spectrometry working in the multiple reaction monitor mode was used for the sample quantification. The effect of extraction parameters, including the flow rate, pH value, breakthrough volume, and the ionic strength, were investigated. Under the optimal working conditions, the developed method showed low limits of detection (0.24–0.50 ng L{sup −1}; signal-to-noise ratio = 3:1), low limits of quantification (0.79–1.56 ng L{sup −1}; signal-to-noise ratio = 10:1), satisfactory linearity (r > 0.99) within the concentration range of 2–1000 ng L{sup −1}, and good precision (relative standard deviation < 12%). The PCBs concentration in environmental water samples was determined by the developed method. This results demonstrate that h-BNNSs have high analytical potential in the enrichment of pollutants. - Highlights: • The hexagonal boron nitride nanosheets were synthesized. • The nanosheets were used as adsorbent for solid-phase extraction. • The h-BN demonstrates remarkable adsorption of PCBs from water samples. • The method was successfully applied in determination of PCBs in water samples.

Electrospun UiO-66/polyacrylonitrile nanofibers as efficient sorbent for pipette tip solid phase extraction of phytohormones in vegetable samples.

Science.gov (United States)

Yan, Zhiming; Wu, Mei; Hu, Biqing; Yao, Minna; Zhang, Lan; Lu, Qiaomei; Pang, Jie

2018-03-23

In this work, metal-organic framework particles incorporated fibers (UiO-66/PAN nanofibers) were used as adsorbent in pipette tip solid phase extraction (PT-SPE) for the first time. The UiO-66/PAN nanofibers were fabricated by a facile electrospinning method and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption experiments. The UiO-66/PAN nanofibers were applied to assemble a novel PT-SPE cartridge for determination of four phytohormones followed by high performance liquid chromatography (HPLC). Several experimental parameters such as kinds of UiO-66/PAN nanofibers, the amount of UiO-66/PAN nanofibers, the effect of solution pH, ionic strength and desorption conditions were intensively investigated. Under the optimal conditions, the linear ranges of the phytohormones were in the range of 0.06-60 ng/mL with correlation coefficients above 0.992. The limits of detection were between 0.01 ng/mL to 0.02 ng/mL. The interday and intraday precision (RSD) for three replicate extractions of the four phytohormones (15 ng/mL for each) was in the range of 1.5-5.6%. The established method was successfully applied for the determination of phytohormones in watermelon and mung bean sprouts samples. The results showed that the electrostatic interaction between the positively charged UiO-66 and anionic forms of phytohormones played an important role in the extraction of the phytohormones. Copyright © 2018 Elsevier B.V. All rights reserved.

Silica Modified with Polyaniline as a Potential Sorbent for Matrix Solid Phase Dispersion (MSPD and Dispersive Solid Phase Extraction (d-SPE of Plant Samples

Directory of Open Access Journals (Sweden)

Ireneusz Sowa

2018-03-01

Full Text Available Polyaniline (PANI is one of the best known conductive polymers with multiple applications. Recently, it was also used in separation techniques, mostly as a component of composites for solid-phase microextraction (SPME. In the present paper, sorbent obtained by in situ polymerization of aniline directly on silica gel particles (Si-PANI was used for dispersive solid phase extraction (d-SPE and matrix solid–phase extraction (MSPD. The efficiency of both techniques was evaluated with the use of high performance liquid chromatography with diode array detection (HPLC-DAD quantitative analysis. The quality of the sorbent was verified by Raman spectroscopy and microscopy combined with automated procedure using computer image analysis. For extraction experiments, triterpenes were chosen as model compounds. The optimal conditions were as follows: protonated Si-PANI impregnated with water, 160/1 sorbent/analyte ratio, 3 min of extraction time, 4 min of desorption time and methanolic solution of ammonia for elution of analytes. The proposed procedure was successfully used for pretreatment of plant samples.

Rapid monitoring particulate radiocesium with nonwoven fabric cartridge filter and application to field monitoring

International Nuclear Information System (INIS)

Tsuji, Hideki; Yasutaka, Tetsuo; Kondo, Yoshihiko; Kawashima, Shoji

2013-01-01

A method for rapid monitoring particulate radiocesium using a nonwoven fabric cartridge filter was developed, which needs no further preprocessing before served to a detector. By a performance test, more than 98% of suspended solid (SS) was collected. This method showed the same radioactivity measurement accuracy as filtration by membrane filter and more rapid extraction capability of SS. (author)

Chapter 3. Determination of semivolatile organic compounds and polycyclic aromatic hydrocarbons in solids by gas chromatography/mass spectrometry

Science.gov (United States)

Zaugg, Steven D.; Burkhardt, Mark R.; Burbank, Teresa L.; Olson, Mary C.; Iverson, Jana L.; Schroeder, Michael P.

2006-01-01

A method for the determination of 38 polycyclic aromatic hydrocarbons (PAHs) and semivolatile organic compounds in solid samples is described. Samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from the solid sample twice at 13,800 kilopascals; first at 120 degrees Celsius using a water/isopropyl alcohol mixture (50:50, volume-to-volume ratio), and then the sample is extracted at 200 degrees Celsius using a water/isopropyl alcohol mixture (80:20, volume-to-volume ratio). The compounds are isolated using disposable solid-phase extraction (SPE) cartridges containing divinylbenzene-vinylpyrrolidone copolymer resin. The cartridges are dried with nitrogen gas, and then sorbed compounds are eluted from the SPE material using a dichloromethane/diethyl ether mixture (80:20, volume-to-volume ratio) and passed through a sodium sulfate/Florisil SPE cartridge to remove residual water and to further clean up the extract. The concentrated extract is solvent exchanged into ethyl acetate and the solvent volume reduced to 0.5 milliliter. Internal standard compounds are added prior to analysis by capillary-column gas chromatography/mass spectrometry. Comparisons of PAH data for 28 sediment samples extracted by Soxhlet and the accelerated solvent extraction (ASE) method described in this report produced similar results. Extraction of PAH compounds from standard reference material using this method also compared favorably with Soxhlet extraction. The recoveries of PAHs less than molecular weight 202 (pyrene or fluoranthene) are higher by up to 20 percent using this ASE method, whereas the recoveries of PAHs greater than or equal to molecular weight 202 are equivalent. This ASE method of sample extraction of solids has advantages over conventional Soxhlet extraction by increasing automation of the extraction process, reducing extraction time, and using less solvent. Extract cleanup also is greatly simplified because SPE replaces

Highly selective solid-phase extraction and large volume injection for the robust gas chromatography-mass spectrometric analysis of TCA and TBA in wines.

Science.gov (United States)

Insa, S; Anticó, E; Ferreira, V

2005-09-30

A reliable solid-phase extraction (SPE) method for the simultaneous determination of 2,4,6-trichloroanisole (TCA) and 2,4,6-tribromoanisole (TBA) in wines has been developed. In the proposed procedure 50 mL of wine are extracted in a 1 mL cartridge filled with 50 mg of LiChrolut EN resins. Most wine volatiles are washed up with 12.5 mL of a water:methanol solution (70%, v/v) containing 1% of NaHCO3. Analytes are further eluted with 0.6 mL of dichloromethane. A 40 microL aliquot of this extract is directly injected into a PTV injector operated in the solvent split mode, and analysed by gas chromatography (GC)-ion trap mass spectrometry using the selected ion storage mode. The solid-phase extraction, including sample volume and rinsing and elution solvents, and the large volume GC injection have been carefully evaluated and optimized. The resulting method is precise (RSD (%) TBA, respectively), robust (the absolute recoveries of both analytes are higher than 80% and consistent wine to wine) and friendly to the GC-MS system (the extract is clean, simple and free from non-volatiles).

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)

International Nuclear Information System (INIS)

Koivunen, Marja E.; Dettmer, Katja; Vermeulen, Roel; Bakke, Berit; Gee, Shirley J.; Hammock, Bruce D.

2006-01-01

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 -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 -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 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 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

Adsorbent cartridge for the exhaust of diazo process machines

International Nuclear Information System (INIS)

Michlin, N.; Thies, E.J.

1982-01-01

A disposable cartridge filled with a chemical composition that acts as an adsorbent for ammonia vapor is adapted to be used in connection with a diazo process printing machine having a vacuum exhausted chamber. Exhaust from the chamber is passed through the cartridge to remove the noxious ammonia vapors and then is vented into the atmosphere. The cartridge is housed in an elongated rectangular cardboard box having three end flaps formed at each of its opposed open ends. Two opposed flaps of each set are formed with central holes and a plastic screen section adhered between these flaps to retain and allow access to the center section of the box which contains the adsorbent chemical. The center end flaps have knock-outs or tear strips that allow holes to be formed in their centers. These center end flaps cover the screens during shipment and when the cartridge is ready for use the center sections of these end flaps are knocked-out to allow the machine exhaust to be vented into and out of the cartridge

Combined solid-phase extraction and gas chromatography-mass spectrometry used for determination of chloropropanols in water.

Science.gov (United States)

González, Paula; Racamonde, Inés; Carro, Antonia M; Lorenzo, Rosa A

2011-10-01

A sensitive and rapid derivatization method for the simultaneous determination of 1,3-dichloro-2-propanol (1,3-DCP) and 3-chloropropane-1,2-diol (3-MCPD) in water samples has been developed. The aim was to research the optimal conditions of the derivatization process for two selected reagents. A central composite design was used to determine the influence of derivatization time, derivatization temperature and reagent volume. A global desirability function was applied for multi-response optimization. The analysis was performed by gas chromatography-mass spectrometry. During the optimization of the extraction procedure, four different types of solid-phase extraction (SPE) columns were tested. It was demonstrated that the Oasis HLB cartridge produced the best recoveries of the target analytes. The pH value and the salinity were investigated using a Doehlert design. The best results for the SPE of both analytes were obtained with 1.5 g of NaCl and pH 6. The proposed method provides high sensitivity, good linearity (R(2)≥0.999) and repeatability (relative standard deviations % between 2.9 and 3.4%). Limits of detection and quantification were in the range of 1.4-11.2 ng/mL and 4.8-34.5 ng/mL, respectively. Recoveries obtained for water samples were ca. 100% for 1,3-DCP and 3-MCPD. The method has been successfully applied to the analysis of different samples including commercially bottled water, an influent and effluent sewage. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of inorganic arsenic in algae using bromine halogenation and on-line nonpolar solid phase extraction followed by hydride generation atomic fluorescence spectrometry.

Science.gov (United States)

Zhang, Weihong; Qi, Yuehan; Qin, Deyuan; Liu, Jixin; Mao, Xuefei; Chen, Guoying; Wei, Chao; Qian, Yongzhong

2017-08-01

Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydride generation atomic fluorescence spectrometry (HG-AFS). The separation of iAs from algae was first performed by nonpolar SPE sorbent using Br - for arsenic halogenation. Algae samples were extracted with 1% perchloric acid. Then, 1.5mL extract was reduced by 1% thiourea, and simultaneously reacted (for 30min) with 50μL of 10% KBr for converting iAs to AsBr 3 after adding 3.5mL of 70% HCl to 5mL. A polystyrene (PS) resin cartridge was employed to retain arsenicals, which were hydrolyzed, eluted from the PS resin with H 2 O, and categorized as iAs. The total iAs was quantified by HG-AFS. Under optimum conditions, the spiked recoveries of iAs in real algae samples were in the 82-96% range, and the method achieved a desirable limit of detection of 3μgkg -1 . The inter-day relative standard deviations were 4.5% and 4.1% for spiked 100 and 500μgkg -1 respectively, which proved acceptable for this method. For real algae samples analysis, the highest presence of iAs was found in sargassum fusiforme, followed by kelp, seaweed and laver. Copyright © 2017 Elsevier B.V. All rights reserved.

Criticality safety evaluation report for K Basin filter cartridges

International Nuclear Information System (INIS)

Schwinkendorf, K.N.

1995-01-01

A criticality safety evaluation of the K Basin filter cartridge assemblies has been completed to support operations without a criticality alarm system. The results show that for normal operation, the filter cartridge assembly is far below the safety limit of k eff = 0.95, which is applied to plutonium systems at the Hanford Site. During normal operating conditions, uranium, plutonium, and fission and corrosion products in solution are continually accumulating in the available void spaces inside the filter cartridge medium. Currently, filter cartridge assemblies are scheduled to be replaced at six month intervals in KE Basin, and at one year intervals in KW Basin. According to available plutonium concentration data for KE Basin and data for the U/Pu ratio, it will take many times the six-month replacement time for sufficient fissionable material accumulation to take place to exceed the safety limit of k eff = 0.95, especially given the conservative assumption that the presence of fission and corrosion products is ignored. Accumulation of sludge with a composition typical of that measured in the sand filter backwash pit will not lead to a k eff = 0.95 value. For off-normal scenarios, it would require at least two unlikely, independent, and concurrent events to take place before the k eff = 0.95 limit was exceeded. Contingencies considered include failure to replace the filter cartridge assemblies at the scheduled time resulting in additional buildup of fissionable material, the loss of geometry control from the filter cartridge assembly breaking apart and releasing the individual filter cartridges into an optimal configuration, and concentrations of plutonium at U/Pu ratios less than measured data for KE Basin, typically close to 400 according to extensive measurements in the sand filter backwash pit and plutonium production information

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.

Solid-phase extraction combined with high-performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry analysis of pesticides in water: method performance and application in a reconnaissance survey of residues in drinking water in Greater Cairo, Egypt.

Science.gov (United States)

Potter, Thomas L; Mohamed, Mahmoud A; Ali, Hannah

2007-01-24

Monitoring of water resources for pesticide residues is often needed to ensure that pesticide use does not adversely impact the quality of public water supplies or the environment. In many rural areas and throughout much of the developing world, monitoring is often constrained by lack of testing facilities; thus, collection of samples and shipment to centralized laboratories for analysis is required. The portability, ease of use, and potential to enhance analyte stability make solid-phase extraction (SPE) an attractive technique for handling water samples prior to their shipment. We describe performance of an SPE method targeting a structurally diverse mixture of 25 current-use pesticides and two common degradates in samples of raw and filtered drinking water collected in Greater Cairo, Egypt. SPE was completed in a field laboratory in Egypt, and cartridges were shipped to the United States for elution and high-performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry analysis. Quantitative and reproducible recovery of 23 of 27 compounds (average = 96%; percent relative standard deviation = 21%) from matrix spikes (1 microg L-1 per component) prepared in the field and from deionized water fortified similarly in the analytical laboratory was obtained. Concurrent analysis of unspiked samples identified four parent compounds and one degradate in drinking water samples. No significant differences were observed between raw and filtered samples. Residue levels in all cases were below drinking water and "harm to aquatic-life" thresholds, indicating that human and ecological risks of pesticide contamination were relatively small; however, the study was limited in scale and scope. Further monitoring is needed to define spatial and temporal variation in residue concentrations. The study has demonstrated the feasibility of performing studies of this type using SPE to extract and preserve samples in the field. The approach should be broadly

Sensitive determination of polycyclic aromatic hydrocarbons in water samples by HPLC coupled with SPE based on graphene functionalized with triethoxysilane.

Science.gov (United States)

Huang, Ke-Jing; Li, Jing; Liu, Yan-Ming; Wang, Lan

2013-02-01

The graphene functionalized with (3-aminopropyl) triethoxysilane was synthesized by a simple hydrothermal reaction and applied as SPE sorbents to extract trace polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. These sorbents possess high adsorption capacity and extraction efficiency due to strong adsorption ability of carbon materials and large specific surface area of nanoparticles, and only 10 mg of sorbents are required to extract PAHs from 100 mL water samples. Several condition parameters, such as eluent and its volume, adsorbent amount, sample volume, sample pH, and sample flow rate, were optimized to achieve good sensitivity and precision. Under the optimized extraction conditions, the method showed good linearity in the range of 1-100 μg/L, repeatability of the extraction (the RSDs were between 1.8 and 2.9%, n = 6), and satisfactory detection limits of 0.029-0.1 μg/L. The recoveries of PAHs spiked in environmental water samples ranged from 84.6 to 109.5%. All these results demonstrated that this new SPE technique was a viable alternative to conventional enrichment techniques for the extraction and analysis of PAHs in complex samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pre-concentration of pesticide residues in environmental water samples using Silica nanoparticles and identification of residues By GC-MS method

OpenAIRE

Tentu. Nageswara Rao; A. Muralidhar Reddy; SNVS. Murthy; Prathipati Revathi; K. Suneel Kumar

2016-01-01

The silica nanoparticles prepared by stober’s mechanism by reaction of tetraethylorthosilicate (TEOS) with ammonia was tested for their adsorption capacity in the pre-concentration of residues of pesticides in water. The synthesized nanoparticles were characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD). The size of the silica nanoparticles were 50 to 250 nm. The solid phase extraction (SPE) cartridges were prepared by filling...

StorageTek T10000 Tape Cartridge

CERN Multimedia

1985-01-01

Oracle StorageTek T10000T2 cartridge has total capacity of 5 TB. It is actually manufactured by Fuji Film, uses Barium Ferrite (BaFe) particles technology data store, but is also equipped with RFID chip. There is over 1 km of tape inside of the cartridge with 3584 data tracks and it supports over 25000 load/unload cycles. The archival life is estimated to be around 30 years and uncorrected bit error rate is 10-19. CERN however usually migrates data to newer technologies roughly every 5 years in order to keep the footprint under control.

Determination of biocides as well as some biocide metabolites from facade run-off waters by solid phase extraction and high performance liquid chromatographic separation and tandem mass spectrometry detection.

Science.gov (United States)

Bester, K; Lamani, X

2010-08-06

Biocides are used to protect buildings, boats, and other materials from microbial infestations. A huge variety of compounds are being used: isothiazolinones, e.g., to prevent bacterial growth in paints, triazines and phenylureas against algal growth on water exposed materials while carbamates are used against fungal investations. However these biocides can be leached from the respective materials. As these are very effective compounds it is important to know the concentrations of these biocides in the leachates as well as their leaching behaviour to assess their risk to the environment. In this study, a method for the determination of biocides from facade material run-off water by means of high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was developed. Due to the amphiphilic character and the expected varying pH-values in the samples, the extractions as well as the HPLC-method development proved to be demanding. The water samples (leachates) were buffered with a phosphate buffer to pH 7. As some of the biocides are very hydrophilic, different SPE cartridges were tested to identify the SPE material with the highest recovery rates for all compounds. For gaining a good separation, analyte trapping was performed on the HPLC column. Quantification was performed using a mass spectrometer in multi-reaction monitoring with two transitions per compound. The final recovery rates were conducted using a cartridge with a divenylbenzyl polymer sorbent. A combination of methanol and acetonitrile as eluents was used to reach recovery rates in the range of 70-100%. The limit of quantification for the compounds of interest ranged from 0.01 to 0.1 microg/L. Copyright 2010 Elsevier B.V. All rights reserved.

Performance and stability of low-cost dye-sensitized solar cell based crude and pre-concentrated anthocyanins: Combined experimental and DFT/TDDFT study

Science.gov (United States)

Chaiamornnugool, Phrompak; Tontapha, Sarawut; Phatchana, Ratchanee; Ratchapolthavisin, Nattawat; Kanokmedhakul, Somdej; Sang-aroon, Wichien; Amornkitbamrung, Vittaya

2017-01-01

The low cost DSSCs utilized by crude and pre-concentrated anthocyanins extracted from six anthocyanin-rich samples including mangosteen pericarp, roselle, red cabbage, Thai berry, black rice and blue pea were fabricated. Their photo-to-current conversion efficiencies and stability were examined. Pre-concentrated extracts were obtained by solid phase extraction (SPE) using C18 cartridge. The results obviously showed that all pre-concentrated extracts performed on photovoltaic performances in DSSCs better than crude extracts except for mangosteen pericarp. The DSSC sensitized by pre-concentrated anthocyanin from roselle and red cabbage showed maximum current efficiency η = 0.71% while DSSC sensitized by crude anthocyanin from mangosteen pericarp reached maximum efficiency η = 0.97%. In addition, pre-concentrated extract based cells possess more stability than those of crude extract based cells. This indicates that pre-concentration of anthocyanin via SPE method is very effective for DSSCs based on good photovoltaic performance and stability. The DFT/TDDFT calculations of electronic and photoelectrochemical properties of the major anthocyanins found in the samples are employed to support the experimental results.

Determination of organophosphorus pesticides using molecularly imprinted polymer solid phase extraction

International Nuclear Information System (INIS)

Mohd Marsin Sanagi; Syairah Salleh; Wan Aini Wan Ibrahim

2011-01-01

Molecularly imprinted polymer solid phase extraction (MIP-SPE) method has been developed for the determination of organophosphorus pesticides (OPPs) in water samples. The MIP was prepared by thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, acetonitrile as porogenic solvent and quinalphos as the template molecule. The three OPPs (diazinon, quinalphos and chloropyrifos) were selected as target analytes as they are widely used in agriculture sector. Various parameters affecting the extraction efficiency of the imprinted polymers have been evaluated to optimize the selective preconcentration of OPPs from aqueous samples. The characteristics of the MIP-SPE method were validated by high performance liquid chromatography (HPLC). The accuracy and selectivity of the MIP-SPE process developed were verified using non-imprinted polymer solid phase extraction (NIP-SPE) and a commercial C 18 -SPE was used for comparison. The recoveries of the target analytes obtained using the MIPs as the solid phase sorbent ranged from 83% to 98% (RSDs 1.05 - 1.98 %; n=3) for water sample. The developed MIP-SPE method demonstrates that it could be applied for the determination of OPPs in water samples. (author)

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

-hydroxyphenyl)acetyl]quinic acid (3), was performed. Finally, targeted isolation of 1 was achieved by SPE fractionation and preparative HPLC, followed by evaluation of its antioxidant and antimicrobial activity. In contrast to chlorogenic acid and 3,5-di-O-caffeoylquinic acid, which act as antioxidants...... 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....... Using homo- and heteronuclear 2D NMR data acquired in the HPLC-SPE-NMR mode, complete structure determination of three new natural products, i.e., 3,5-di-O-caffeoyl-4-O-[(1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl]quini c acid (1), its 2-hydroxy derivative (2), and 3,5-di-O-caffeoyl-4-O-[(4...

Alterations in a Unique Class of Cortical Chandelier Cell Axon Cartridges in Schizophrenia.

Science.gov (United States)

Rocco, Brad R; DeDionisio, Adam M; Lewis, David A; Fish, Kenneth N

2017-07-01

The axons of chandelier cells (ChCs) target the axon initial segment of pyramidal neurons, forming an array of boutons termed a cartridge. In schizophrenia, the density of cartridges detectable by gamma-aminobutyric acid (GABA) membrane transporter 1 immunoreactivity is lower, whereas the density of axon initial segments detectable by immunoreactivity for the α2 subunit of the GABA A receptor is higher in layers 2/superficial 3 of the prefrontal cortex. These findings were interpreted as compensatory responses to lower GABA levels in ChCs. However, we recently found that in schizophrenia, ChC cartridge boutons contain normal levels of the 67 kDa isoform of glutamic acid decarboxylase (GAD67) protein, the enzyme responsible for GABA synthesis in these boutons. To understand these findings we quantified the densities of ChC cartridges immunoreactive for vesicular GABA transporter (vGAT+), which is present in all cartridge boutons, and the subset of cartridges that contain calbindin (CB+). Prefrontal cortex tissue sections from 20 matched pairs of schizophrenia and unaffected comparison subjects were immunolabeled for vGAT, GAD67, and CB. The mean density of vGAT+/CB+ cartridges was 2.7-fold higher, exclusively in layer 2 of schizophrenia subjects, whereas the density of vGAT+/CB- cartridges did not differ between subject groups. Neither vGAT, CB, or GAD67 protein levels per ChC bouton nor the number of boutons per cartridge differed between subject groups. Our findings of a greater density of CB+ ChC cartridges in prefrontal cortex layer 2 from schizophrenia subjects suggests that the normal developmental pruning of these cartridges is blunted in the illness. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Molecularly imprinted solid-phase extraction in the analysis of agrochemicals.

Science.gov (United States)

Yi, Ling-Xiao; Fang, Rou; Chen, Guan-Hua

2013-08-01

The molecular imprinting technique is a highly predeterminative recognition technology. Molecularly imprinted polymers (MIPs) can be applied to the cleanup and preconcentration of analytes as the selective adsorbent of solid-phase extraction (SPE). In recent years, a new type of SPE has formed, molecularly imprinted polymer solid-phase extraction (MISPE), and has been widely applied to the extraction of agrochemicals. In this review, the mechanism of the molecular imprinting technique and the methodology of MIP preparations are explained. The extraction modes of MISPE, including offline and online, are discussed, and the applications of MISPE in the analysis of agrochemicals such as herbicides, fungicides and insecticides are summarized. It is concluded that MISPE is a powerful tool to selectively isolate agrochemicals from real samples with higher extraction and cleanup efficiency than commercial SPE and that it has great potential for broad applications.

Thermal analysis with expendable cartridge

International Nuclear Information System (INIS)

Susaki, K.; Landgraf, F.J.G.

1981-01-01

The pratical method of thermal analysis with expendable cartridge and some aspects of its use are presented. The results of the method applied to the system Nb-Mn are presented together with data from microprobe. (Author) [pt

Fluorous Parallel Synthesis of A Hydantoin/Thiohydantoin Library

Science.gov (United States)

Lu, Yimin; Zhang, Wei

2007-01-01

Fluorous tagging strategy is applied to solution-phase parallel synthesis of a library containing hydantoin and thiohydantoin analogs. Two perfluoroalkyl (Rf)-tagged α-amino esters each react with 6 aromatic aldehydes under reductive amination conditions. Twelve amino esters then each react with 10 isocyanates and isothiocyanates in parallel. The resulting 120 ureas and thioureas undergo spontaneous cyclization to form the corresponding hydantoins and thiohydantoins. The intermediate and final product purifications are performed with solid-phase extraction (SPE) over FluoroFlash™ cartridges, no chromatography is required. Using standard instruments and straightforward SPE technique, one chemist accomplished the 120-member library synthesis in less than 5 working days, including starting material synthesis and product analysis. PMID:15789556

[Corrected Title: Solid-Phase Extraction of Polar Compounds from Water] Automated Electrostatics Environmental Chamber

Science.gov (United States)

Sauer, Richard; Rutz, Jeffrey; Schultz, John

2005-01-01

A solid-phase extraction (SPE) process has been developed for removing alcohols, carboxylic acids, aldehydes, ketones, amines, and other polar organic compounds from water. This process can be either a subprocess of a water-reclamation process or a means of extracting organic compounds from water samples for gas-chromatographic analysis. This SPE process is an attractive alternative to an Environmental Protection Administration liquid-liquid extraction process that generates some pollution and does not work in a microgravitational environment. In this SPE process, one forces a water sample through a resin bed by use of positive pressure on the upstream side and/or suction on the downstream side, thereby causing organic compounds from the water to be adsorbed onto the resin. If gas-chromatographic analysis is to be done, the resin is dried by use of a suitable gas, then the adsorbed compounds are extracted from the resin by use of a solvent. Unlike the liquid-liquid process, the SPE process works in both microgravity and Earth gravity. In comparison with the liquid-liquid process, the SPE process is more efficient, extracts a wider range of organic compounds, generates less pollution, and costs less.

Development of andrographolide molecularly imprinted polymer for solid-phase extraction

Science.gov (United States)

Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

2011-06-01

A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

Retention of Halogenated Solutes on Stationary Phases Containing Heavy Atoms

Directory of Open Access Journals (Sweden)

Toshio Miwa

2013-05-01

Full Text Available To examine the effects of weak intermolecular interactions on solid-phase extraction (SPE and chromatographic separation, we synthesized some novel stationary phases with a heavy atom effect layer by immobilizing halogenated aromatic rings and hydroxyl groups onto the surface of a hydrophilic base polymer. Using SPE cartridges packed with the functionalized materials, we found that the heavy atom stationary phases could selectively retain halophenols in organic solvents, such as 1-propanol which blocks the hydrogen bonding, or acetonitrile which blocks the p-p interaction. The extraction efficiency of the materials toward the halophenols depended on the dipole moments of phenoxy groups present as functional groups. On the other hand, the extraction efficiency of solutes toward the functional group depended on their molar refractions, i.e., induced dipole moments. The retention of the solutes to the stationary phase ultimately depended on not only strong intermolecular interactions, but also the effects of weak interactions such as the dispersion force.

Organic compounds in hot-water-soluble fractions from water repellent soils

Science.gov (United States)

Atanassova, Irena; Doerr, Stefan

2014-05-01

Water repellency (WR) is a soil property providing hydrophobic protection and preventing rapid microbial decomposition of organic matter entering the soil with litter or plant residues. Global warming can cause changes in WR, thus influencing water storage and plant productivity. Here we assess two different approaches for analysis of organic compounds composition in hot water extracts from accelerated solvent extraction (ASE) of water repellent soils. Extracts were lyophilized, fractionated on SiO2 (sand) and SPE cartridge, and measured by GC/MS. Dominant compounds were aromatic acids, short chain dicarboxylic acids (C4-C9), sugars, short chain fatty acids (C8-C18), and esters of stearic and palmitic acids. Polar compounds (mainly sugars) were adsorbed on applying SPE clean-up procedure, while esters were highly abundant. In addition to the removal of polar compounds, hydrophobic esters and hydrocarbons (alkanes and alkenes particle wettability and C dynamics in soils. Key words: soil water repellency, hot water soluble carbon (HWSC), GC/MS, hydrophobic compounds

DNA purification using dynamic solid-phase extraction on a rotationally-driven polyethylene-terephthalate microdevice

Energy Technology Data Exchange (ETDEWEB)

Jackson, K.R. [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Borba, J.C. [Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos-SP (Brazil); Meija, M. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Mills, D.L. [TeGrex Technologies, Sperryville, VA 22740 (United States); Haverstick, D.M. [Department of Pathology, University of Virginia, Charlottesville, VA 22904 (United States); Olson, K.E.; Aranda, R. [Office of the Chief Scientist, Defense Forensic Science Center, N 31st Street, Atlanta, GA 30297 (United States); Garner, G.T. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Carrilho, E. [Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos-SP (Brazil); Landers, J.P., E-mail: landers@virginia.edu [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Department of Pathology, University of Virginia, Charlottesville, VA 22904 (United States)

2016-09-21

We report the development of a disposable polyester toner centrifugal device for semi-automated, dynamic solid phase DNA extraction (dSPE) from whole blood samples. The integration of a novel adhesive and hydrophobic valving with a simple and low cost microfabrication method allowed for sequential addition of reagents without the need for external equipment for fluid flow control. The spin-dSPE method yielded an average extraction efficiency of ∼45% from 0.6 μL of whole blood. The device performed single sample extractions or accommodate up to four samples for simultaneous DNA extraction, with PCR-readiness DNA confirmed by effective amplification of a β-globin gene. The purity of the DNA was challenged by a multiplex amplification with 16 targeted amplification sites. Successful multiplexed amplification could routinely be obtained using the purified DNA collected post an on-chip extraction, with the results comparable to those obtained with commercial DNA extraction methods. This proof-of-principle work represents a significant step towards a fully-automated low cost DNA extraction device. - Highlights: • dSPE design on centrifugal PeT device with a unique mixing strategy was proposed. • Increased fluidic control with novel adhesive tape valves on a PeT device. • Multiplexed spin-dSPE device to run up to 4 samples simultaneously. • Demonstrated strong singleplexed and multiplexed amplification following chip dSPE.

Solid-phase extraction based on hydrophilic interaction liquid chromatography with acetone as eluent for eliminating matrix effects in the analysis of biological fluids by LC-MS.

Science.gov (United States)

Van Damme, T; Lachová, M; Lynen, F; Szucs, R; Sandra, P

2014-01-01

Analysis of drugs and metabolites in biological matrices such as blood or plasma by LC-MS is routinely challenged by the presence of large quantities of competing molecules for ionization in soft ionization sources, such as proteins and phospholipids. While the former can easily be removed by protein precipitation, pre-analytical extraction of the latter is necessary because they show very high retention in reversed-phase LC resulting in long analysis times or in ion suppression effects when not eluted before the next runs. A novel HILIC-based SPE approach, making use of silica cartridges and of acetone as organic solvent, is introduced as a potent alternative to current commercial methods for phospholipid removal. The methodology was developed and tested for a broad polarity range of pharmaceutical solutes (log P from 0 to 6.6) and broad applicability can therefore be envisaged.

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.

Evaluation and comparison of a national made dental cartridge with two foreign made

Directory of Open Access Journals (Sweden)

Mahmood Hashemi H

2006-06-01

Full Text Available Background and Aim: Several factories produce dental cartridge in the world. In Iran, Daroupakhsh company is responsible for this task. The aim of this study was evaluate some properties of daroupakhsh cartridge and compare them with two imported ones: Ecocaine (made in Italy and Septodont (made in France. Materials and Methods: In this experimental study, 70 healthy patients from maxillofacial clinic of Shariaty hospital were selected. After obtaining informed consent, 0.1 cc of each carpule was injected to the patients' frontal region and the extent of anesthesia was measured at different time intervals. Also the quality of injections was evaluated by 11 surgeons. The dimensions of the three cartridges were also measured and compared together. Data were analyzed by repeated measure ANOVA and Friedman with p<0.05 as the limit of significance. Results: There was no significant difference in extent and duration of anesthesia among the studied cartridges. Surgeons were equally satisfied of all three kinds of cartridges. All of the cartridges were aspirable. Conclusion: Based on the results of this study, the three studied cartridges had similar properties.

Rapid and automated on-line solid phase extraction HPLC-MS/MS with peak focusing for the determination of ochratoxin A in wine samples.

Science.gov (United States)

Campone, Luca; Piccinelli, Anna Lisa; Celano, Rita; Pagano, Imma; Russo, Mariateresa; Rastrelli, Luca

2018-04-01

This study reports a fast and automated analytical procedure based on an on-line SPE-HPLC-MS/MS method for the automatic pre-concentration, clean up and sensitive determination of OTA in wine. The amount of OTA contained in 100μL of sample (pH≅5.5) was retained and concentrated on an Oasis MAX SPE cartridge. After a washing step to remove matrix interferents, the analyte was eluted in back-flush mode and the eluent from the SPE column was diluted through a mixing Tee, using an aqueous solution before the chromatographic separation achieved on a monolithic column. The developed method has been validated according to EU regulation N. 519/2014 and applied for the analysis of 41 red and 17 white wines. The developed method features minimal sample handling, low solvent consumption, high sample throughput, low analysis cost and provides an accurate and highly selective results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic Ligand Fishing as a Targeting Tool for HPLC-HRMS-SPE-NMR: α-Glucosidase Inhibitory Ligands and Alkylresorcinol Glycosides from Eugenia catharinae.

Science.gov (United States)

Wubshet, Sileshi G; Brighente, Inês M C; Moaddel, Ruin; Staerk, Dan

2015-11-25

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 were synthesized and characterized for their inherent catalytic activity. Ligand fishing with the immobilized enzyme was optimized using an artificial test mixture consisting of caffeine, ferulic acid, and luteolin before proof-of-concept with the crude extract of Eugenia catharinae. The combination of ligand fishing and HPLC-HRMS-SPE-NMR identified myricetin 3-O-α-L-rhamnopyranoside, myricetin, quercetin, and kaempferol as α-glucosidase inhibitory ligands in E. catharinae. Furthermore, HPLC-HRMS-SPE-NMR analysis led to identification of six new alkylresorcinol glycosides, i.e., 5-(2-oxopentyl)resorcinol 4-O-β-D-glucopyranoside, 5-propylresorcinol 4-O-β-D-glucopyranoside, 5-pentylresorcinol 4-O-[α-D-apiofuranosyl-(1→6)]-β-D-glucopyranoside, 5-pentylresorcinol 4-O-β-D-glucopyranoside, 4-hydroxy-3-O-methyl-5-pentylresorcinol 1-O-β-D-glucopyranoside, and 3-O-methyl-5-pentylresorcinol 1-O-[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside.

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

Solid-phase extraction of polar pesticides from environmental water samples on graphitized carbon and Empore-activated carbon disks and on-line coupling to octadecyl-bonded silica analytical columns.

Science.gov (United States)

Slobodník, J; Oztezkizan, O; Lingeman, H; Brinkman, U A

1996-10-25

The suitability of Empore-activated carbon disks (EACD), Envi-Carb graphitized carbon black (GCB) and CPP-50 graphitized carbon for the trace enrichment of polar pesticides from water samples was studied by means of off-line and on-line solid-phase extraction (SPE). In the off-line procedure, 0.5-2 l samples spiked with a test mixture of oxamyl, methomyl and aldicarb sulfoxide were enriched on EnviCarb SPE cartridges or 47 mm diameter EACD and eluted with dichloromethane-methanol. After evaporation, a sample was injected onto a C18-bonded silica column and analysed by liquid chromatography with ultraviolet (LC-UV) detection. EACD performed better than EnviCarb cartridges in terms of breakthrough volumes (> 2 l for all test analytes), reproducibility (R.S.D. of recoveries, 4-8%, n = 3) and sampling speed (100 ml/min); detection limits in drinking water were 0.05-0.16 microgram/l. In the on-line experiments, 4.6 mm diameter pieces cut from original EACD and stacked onto each other in a 9 mm long precolumn, and EnviCarb and CPP-50 packed in 10 x 2.0 mm I.D. precolumn, were tested, and 50-200 ml spiked water samples were preconcentrated. Because of the peak broadening caused by the strong sorption of the analytes on carbon, the carbon-packed precolumns were eluted by a separate stream of 0.1 ml/min acetonitrile which was mixed with the gradient LC eluent in front of the C18 analytical column. The final on-line procedure was also applied for the less polar propoxur, carbaryl and methiocarb. EnviCarb could not be used due to its poor pressure resistance. CPP-50 provided less peak broadening than EACD: peak widths were 0.1-0.3 min and R.S.D. of peak heights 4-14% (n = 3). In terms of analyte trapping efficiency on-line SPE-LC-UV with a CPP-50 precolumn also showed better performance than when Bondesil C18/OH or polymeric PLRP-S was used, but chromatographic resolution was similar. With the CPP-50-based system, detection limits of the test compounds were 0.05-1 microgram

42 CFR 84.194 - Filters used with chemical cartridges; location; replacement.

Science.gov (United States)

2010-10-01

...; replacement. 84.194 Section 84.194 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN...; replacement. (a) Particulate matter filters used in conjunction with a chemical cartridge shall be located on... replacement on the cartridge. ...

Hazard classification test of the cartridge, 120-mm, APFSDS-T, XM829

Energy Technology Data Exchange (ETDEWEB)

Hooker, C.D.; Hadlock, D.E.; Mishima, J.; Gilchrist, R.L.

1983-11-01

Research was conducted to determine the behavior of the ammunition XM829 when subjected to detonation of an adjacent XM829 cartridge, and a sustained hot fire. It was concluded that the functioning of an XM829 cartridge, in one shipping container, will not cause immediate functioning of XM829 cartridges in adjacent containers. However, if a fire results and is sustained, adjacent cartridges may ignite, resulting in some scattering of debris within a maximum radius of 40 feet. Further, the XM829 cartridge can be expected to remain in a kinetic controlled regime with vigorous oxidation occurring early in such a fire but dropping off as the temperature cools toward ambient. Mass balance analyses data indicated a recovery of at least 80% in the 1982 external heat; in the 1983 test, the recovery percentage was improved to approximately 100% of the original depleted uranium weight volume. Therefore, it may be concluded that a significant airborne release of the depleted uranium material did not occur.

Principles and applications of colorimetric solid-phase extraction with negligible depletion

International Nuclear Information System (INIS)

Dias, Neil C.; Porter, Marc D.; Fritz, James S.

2006-01-01

Colorimetric solid-phase extraction (C-SPE) is an integrated technique in which an analyte is selectively concentrated onto a disk and then quantitated by diffuse reflectance spectroscopy. This paper describes the results of an investigation that applies the concept of negligible depletion (ND) to C-SPE, representing the first application of ND concepts to solid-phase extractions. The approach relies on passing the minimal volume of sample through the disk required to reach an equilibrium in which the concentration of analyte in the sample entering and exiting the disk are equal. At this point, the amount of analyte extracted by the disk is proportional to the sample concentration but is independent of the sample volume passed through the disk. With this new method, called C-SPE/ND, the precise measurement of sample volume is no longer necessary. The work herein details the general principles of this new methodology, and validates its basic tenets in an investigation of the extraction of the organic dye methyl violet. The analytical capabilities of C-SPE/ND are then demonstrated by its application to measurements of iodine. Iodine is a biocide increasingly used as a simple and effective disinfectant for water in locations where municipal water treatment systems are potentially compromised. Thus, the ability to operate C-SPE in an ND mode notably enhances the broad-based utility of this methodology as a reliable and an easy-to-use analysis tool for water quality assessments. Since iodine is also the biocide used on NASAs Space Shuttle, C-SPE/ND has the potential to overcome problems associated with the removal of air bubbles entrapped in a water sample in the microgravity environment encountered in space exploration. Extensions of C-SPE/ND to facile determinations of other water quality parameters with respect to both earth- and space-based needs are briefly discussed

Rapid determination of six carcinogenic primary aromatic amines in mainstream cigarette smoke by two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry.

Science.gov (United States)

Bie, Zhenying; Lu, Wei; Zhu, You; Chen, Yusong; Ren, Hubo; Ji, Lishun

2017-01-27

A fully automated, rapid, and reliable method for simultaneous determination of six carcinogenic primary aromatic amines (AAs), including o-toluidine (o-TOL), 2, 6-dimethylaniline (2, 6-DMA), o-anisidine (o-ASD), 1-naphthylamine (1-ANP), 2-naphthylamine (2-ANP), and 4-aminobiphenyl (4-ABP), in mainstream cigarette smoke was established. The proposed method was based on two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry (SPE/LC-MS/MS). The particulate phase of the mainstream cigarette smoke was collected on a Cambridge filter pad and pretreated via ultrasonic extraction with 2% formic acid (FA), while the gas phase was trapped by 2% FA without pretreatment for determination. The two-dimensional online SPE comprised of two cartridges with different absorption characteristics was applied for sample pretreatment. Analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) under multiple reaction monitoring mode. Each sample required about 0.5h for solid phase extraction and analysis. The limit of detections (LODs) for six AAs ranged from 0.04 to 0.58ng/cig and recoveries were within 84.5%-122.9%. The relative standard deviations of intra- and inter-day tests for 3R4F reference cigarette were less than 6% and 7%, respectively, while no more than 7% and 8% separately for a type of Virginia cigarette. The proposed method enabled minimum sample pretreatment, full automation, and high throughput with high selectivity, sensitivity, and accuracy. As a part of the validation procedure, fifteen brands of cigarettes were tested by the designed method. Copyright © 2016 Elsevier B.V. All rights reserved.

Aroma composition of red wines by different extraction methods and Gas Chromatography-SIM/MASS spectrometry analysis.

Science.gov (United States)

Genovese, Alessandro; Dimaggio, Rosa; Lisanti, Maria Tiziana; Piombino, Paola; Moio, Luigi

2005-06-01

One hundred and one volatile compounds, reported in literature as powerful odorants of wine, were quantified by Gas Chromatography-Selective Ion Monitoring/Mass Spectrometry (GC-SIM/MS) in Primitivo, Aglianico, Merlot and Cabernet Sauvignon red wines. Wine samples were extracted by 3 different extraction methods: 1) separation of the alcoholic fraction from the aqueous phase by salting-out and subsequent extraction by liquid-liquid micro-extraction with 1,1,2-trichlorotrifluoroethane (Freon 113); 2) extraction by liquid-liquid micro-extraction with dichloromethane; 3) solid phase extraction (SPE cartridge: 800 mg of LiChrolut EN resin) with pentane-dichloromethane (20:1) and dichloromethane. The selection of the ion fragments used for quantification was directly performed on a red wine sample. For each compound the area of the corresponding peak was normalized respect to the peak of the internal standard and then interpolated in a calibration curve obtained analysing a model wine solution (water, ethanol, tartaric acid and known amounts of analytes and of internal standard). The methods showed a good linearity: r2>0.990, except for farnesol (isomer a and c), octanal, decanal, furaneol and phenylacetic acid with 0.966 furaneol and sotolon. The Aglianico wines were characterised by the major fermentation compounds (esters, fatty acids and 2-phenylethanol), beta-damascenone, beta-ionone and linalool. The Primitivo wines were characterized by furaneol, methoxypyrazine, gamma-nonalactone and acetaldehyde, while Cabernet Sauvignon and Merlot wines principally by cask derivates (vanillin, (Z) 3-methyl-gamma-octalactone [(Z) wiskylactone], maltol and eugenol), some aldehydes and 3-isopropyl-2-methoxypyrazine.

Steroid hormones in environmental matrices: extraction method comparison.

Science.gov (United States)

Andaluri, Gangadhar; Suri, Rominder P S; Graham, Kendon

2017-11-09

The U.S. Environmental Protection Agency (EPA) has developed methods for the analysis of steroid hormones in water, soil, sediment, and municipal biosolids by HRGC/HRMS (EPA Method 1698). Following the guidelines provided in US-EPA Method 1698, the extraction methods were validated with reagent water and applied to municipal wastewater, surface water, and municipal biosolids using GC/MS/MS for the analysis of nine most commonly detected steroid hormones. This is the first reported comparison of the separatory funnel extraction (SFE), continuous liquid-liquid extraction (CLLE), and Soxhlet extraction methods developed by the U.S. EPA. Furthermore, a solid phase extraction (SPE) method was also developed in-house for the extraction of steroid hormones from aquatic environmental samples. This study provides valuable information regarding the robustness of the different extraction methods. Statistical analysis of the data showed that SPE-based methods provided better recovery efficiencies and lower variability of the steroid hormones followed by SFE. The analytical methods developed in-house for extraction of biosolids showed a wide recovery range; however, the variability was low (≤ 7% RSD). Soxhlet extraction and CLLE are lengthy procedures and have been shown to provide highly variably recovery efficiencies. The results of this study are guidance for better sample preparation strategies in analytical methods for steroid hormone analysis, and SPE adds to the choice in environmental sample analysis.

Tandem solid-phase extraction followed by HPLC-ESI/QTOF/MS/MS for rapid screening and structural identification of trace diterpenoids in flowers of Rhododendron molle.

Science.gov (United States)

Zou, Hong-Yan; Luo, Jun; Xu, De-Ran; Kong, Ling-Yi

2014-01-01

'Naoyanghua', composed of the flowers of Rhododendron molle G. Don, is a traditional Chinese medicine that is widely known for its toxicity. Grayanane-type diterpenoids are the main active ingredients in R. molle, as well as possibly their toxicity: they are, however, difficult to isolate and analyse using common chromatographic methods, due to their small amounts and absence of conjugated groups, such as phenyl and α, β-unsaturated ketone. To establish a highly sensitive, selective and reliable method for the qualitative evaluation of trace diterpenoids in the flowers of R. molle by using tandem solid-phase extraction followed by high-performance liquid chromatography with electrospray ionisation quadrupole-time-of-flight mass spectrometry (HPLC-ESI/QTOF/MS/MS). Tandem solid phase extraction (SPE) was undertaken using a polyamide cartridge and a C18E cartridge in succession to enrich the trace diterpenoids. HPLC-ESI/QTOF/MS/MS was used to determine the fragmentation patterns of diterpenoids and to tentatively characterise their fragmentation pathways. HPLC-ESI/QTOF/MS/MS detected a total of 14 diterpenoids, eight of which were identified by comparison with literature sources and six based on fragmentation analysis. Among the latter six, rhodojaponin VI-3-glucoside was tentatively identified as a new diterpenoid glycoside and rhodojaponin VII, rhodojaponin IV and rhodojaponin I were reported from R. molle for the first time. By qualitative research of diterpenoids in this plant by HPLC-ESI/QTOF/MS/MS, a reliable methodology for the analysis of these active constituents of R. molle was established for the first time. Copyright © 2014 John Wiley & Sons, Ltd.

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.

A reliable method for the quality control of 99mTc-MIBI prepared using fractionated cardiolite kits

International Nuclear Information System (INIS)

Poot, M.T.; Varelis, P.

1998-01-01

Full text: The reconstitution of fractionated Cardiolite kits with Na[ 99m Tc]TcO 4 eluted from a wet-column generator results in a preparation that contains elevated amounts of a polar radiochemical impurity, which is normally present in only trace amounts when such kits are reconstituted with eluate from a dry-column generator. We demonstrate, using HPLC, that this impurity causes a positive bias in several reported quality control methods (TLC, ITLC and SPE) for 99m Tc-MIBI, including that recommended by the manufacturer (TLC). A rapid procedure, based on a C18 solid phase extraction (SPE) cartridge, for measuring the radiochemical purity (RCP) of 99m Tc-MIBI samples was developed and compared with three other methods including HPLC. Over a RCP range of 49-98%, the values obtained using our SPE method deviated from those obtained using HPLC by 1.1+1.395 (n=26). In conclusion our SPE method is a rapid and reliable means of quality controlling 99m Tc-MIBI

A reliable method for the quality control of 99mTc-MIBI prepared using fractionated cardiolite kits

Energy Technology Data Exchange (ETDEWEB)

Poot, M.T.; Varelis, P. [St George Hospital, Sydney, NSW (Australia). Department of Nuclear Medicine

1998-06-01

Full text: The reconstitution of fractionated Cardiolite kits with Na[{sup 99m}Tc]TcO{sub 4} eluted from a wet-column generator results in a preparation that contains elevated amounts of a polar radiochemical impurity, which is normally present in only trace amounts when such kits are reconstituted with eluate from a dry-column generator. We demonstrate, using HPLC, that this impurity causes a positive bias in several reported quality control methods (TLC, ITLC and SPE) for {sup 99m}Tc-MIBI, including that recommended by the manufacturer (TLC). A rapid procedure, based on a C18 solid phase extraction (SPE) cartridge, for measuring the radiochemical purity (RCP) of {sup 99m}Tc-MIBI samples was developed and compared with three other methods including HPLC. Over a RCP range of 49-98%, the values obtained using our SPE method deviated from those obtained using HPLC by 1.1+1.395 (n=26). In conclusion our SPE method is a rapid and reliable means of quality controlling {sup 99m}Tc-MIBI

Liquid chromatography-tandem mass spectrometry determination of synthetic cathinones and phenethylamines in influent wastewater of eight European cities

DEFF Research Database (Denmark)

Bade, Richard; Bijlsma, Lubertus; Sancho, Juan V.

2017-01-01

(SPE) with Oasis MCX cartridges. Isotopically labelled internal standards were used to correct for matrix effects and potential SPE losses. Following chromatographic separation on a C18 column within 6 min, the compounds were measured by tandem mass spectrometry in positive ionization mode. The method...

Possible prebiotics and gallic acid separations from jackfruit seed extract

Directory of Open Access Journals (Sweden)

Kulchanat Prasertsit

2015-06-01

Full Text Available A large amount of jackfruit seeds can be extracted for possible prebiotics and phenolics (gallic acid and purified by crystallization and solid phase extraction (SPE, respectively. The studied parameters for crystallization were mixing speed, crystallizing temperature and cooling rate while the studied parameters for SPE were feed concentration, feed flow rate and length to diameter ratio (L/D of the extraction column. The optimal condition for the crystallization provided the crystal yield of 0.028 g crystal /g dry extract at 100 rpm mixing speed, 58°C crystallizing temperature and 1°C /min cooling rate. Molecular weight analysis of the crystals indicated that the crystals can be fructo-oligosaccharide or raffinose. The optimal condition for SPE obtaining gallic acid 92 percent yield was at 4% w/v feed concentration with 3 mL/min flow rate and L/D of 15.3. Finally a high temperature can degrade both possible prebiotic and gallic acid.

Solid-phase extraction of the alcohol abuse biomarker phosphatidylethanol using newly synthesized polymeric sorbent materials containing quaternary heterocyclic groups.

Science.gov (United States)

Duarte, Mariana; Jagadeesan, Kishore Kumar; Billing, Johan; Yilmaz, Ecevit; Laurell, Thomas; Ekström, Simon

2017-10-13

Phosphatidylethanol (PEth) is an interesting biomarker finding increased use for detecting long term alcohol abuse with high specificity and sensitivity. Prior to detection, sample preparation is an unavoidable step in the work-flow of PEth analysis and new protocols may facilitate it. Solid-phase extraction (SPE) is a versatile sample preparation method widely spread in biomedical laboratories due to its simplicity of use and the possibility of automation. In this work, SPE was used for the first time to directly extract PEth from spiked human plasma and spiked human blood. A library of polymeric SPE materials with different surface functionalities was screened for PEth extraction in order to identify the surface characteristics that control PEth retention and recovery. The plasma samples were diluted 1:10 (v/v) in water and spiked at different concentrations ranging from 0.3 to 5μM. The library of SPE materials was then evaluated using the proposed SPE method and detection was done by LC-MS/MS. One SPE material efficiently retained and recovered PEth from spiked human plasma. With this insight, four new SPE materials were formulated and synthesized based on the surface characteristics of the best SPE material found in the first screening. These new materials were tested with spiked human blood, to better mimic a real clinical sample. All the newly synthetized materials outperformed the pre-existing commercially available materials. Recovery values for the new SPE materials were found between 29.5% and 48.6% for the extraction of PEth in spiked blood. A material based on quaternized 1-vinylimidazole with a poly(trimethylolpropane trimethacrylate) backbone was found suitable for PEth extraction in spiked blood showing the highest analyte recovery in this experiment, 48.6%±6.4%. Copyright © 2017 Elsevier B.V. All rights reserved.

The Imation 9840 Tape Cartridge

CERN Multimedia

It’s a 20 GB uncompressed center-load cartridge used in StorageTek T9840 tape drives. The tape is a Metal Particle (MP) tape suitable for use on all Oracle/Sun/StorageTek 9840 A, B, C and D drives. The 9840 tape has an archival life of 15-30 years.

Nanoparticle separation with a miniaturized asymmetrical flow field-flow fractionation cartridge

Science.gov (United States)

Müller, David; Cattaneo, Stefano; Meier, Florian; Welz, Roland; deMello, Andrew

2015-07-01

Asymmetrical Flow Field-Flow Fractionation (AF4) is a separation technique applicable to particles over a wide size range. Despite the many advantages of AF4, its adoption in routine particle analysis is somewhat limited by the large footprint of currently available separation cartridges, extended analysis times and significant solvent consumption. To address these issues, we describe the fabrication and characterization of miniaturized AF4 cartridges. Key features of the scale-down platform include simplified cartridge and reagent handling, reduced analysis costs and higher throughput capacities. The separation performance of the miniaturized cartridge is assessed using certified gold and silver nanoparticle standards. Analysis of gold nanoparticle populations indicates shorter analysis times and increased sensitivity compared to conventional AF4 separation schemes. Moreover, nanoparticulate titanium dioxide populations exhibiting broad size distributions are analyzed in a rapid and efficient manner. Finally, the repeatability and reproducibility of the miniaturized platform are investigated with respect to analysis time and separation efficiency.

Pharmacological effects of saw palmetto extract in the lower urinary tract.

Science.gov (United States)

Suzuki, Mayumi; Ito, Yoshihiko; Fujino, Tomomi; Abe, Masayuki; Umegaki, Keizo; Onoue, Satomi; Noguchi, Hiroshi; Yamada, Shizuo

2009-03-01

Saw palmetto extract (SPE), an extract from the ripe berries of the American dwarf palm, has been widely used as a therapeutic 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 5alpha-reductase. Today, alpha(1)-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 relevant receptors in the lower urinary tract, such as alpha(1)-adrenoceptors, muscarinic cholinoceptors, 1,4-dihyropyridine receptors and vanilloid receptors. Furthermore, oral administration of SPE has been shown to attenuate the up-regulation of alpha(1)-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 understanding of the pharmacological effects of SPE in the treatment of patients with BPH and associated lower urinary tract symptoms (LUTS).

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

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

Science.gov (United States)

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

2017-10-15

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

Investigation of effective forensic cleaning methods for bullet and cartridge case samples

Science.gov (United States)

Shuherk, Cassie Marie

Bullet and cartridge case evidence may potentially link weapons and crimes through the comparison of toolmark patterns. This analysis relies on the clarity of the toolmarks and the ability of the examiner to identify patterns on the evidence. These patterns may be distorted by debris such as soil, blood, cyanoacrylate, and construction materials. Despite the potential importance of bullet and cartridge case evidence, few investigations of proper cleaning methods have been conducted. The present study was designed to examine the effects of various cleaning solutions and application methods on copper and brass bullets and cartridge cases. Additionally, this research investigated the efficacy of these cleaning protocols on the common evidence contaminants blood and cyanoacrylate. No cleaning method was found to be universally effective on both contaminant types and nondestructive to the metal surface. Ultrasonication was the most efficient application method employed when used in conjunction with an appropriate cleaning solution. Acetone proved to be safe and successful at removing heavy cyanoacrylate deposits from brass cartridge cases without damaging the metal. Although sulfuric acid removed most of the cyanoacrylate from the brass cartridge case, ultrasonication of the fumed cartridge cases in sulfuric acid caused the nickel-plated primer caps to turn black. Additionally, etching occurred when sulfuric acid was allowed to dry on the cartridge case surface. Citric acid, salt-flour-vinegar paste, TergazymeRTM, and water did not effectively remove the cyanoacrylate from the cartridge cases, but the solutions were safe to use on the brass and sometimes resulted in a shinier surface. Regardless of the cleaning method employed, the bloodstained bullets retained most or all of the underlying brown tarnish. Ultrasonication with sulfuric acid was successful at removing some blood-initiated tarnishing; however, the removal of residues was not complete, making it difficult

Simultaneous determination of mushroom toxins α-amanitin, β-amanitin and muscarine in human urine by solid-phase extraction and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry.

Science.gov (United States)

Tomková, Jana; Ondra, Peter; Válka, Ivo

2015-06-01

This paper presents a method for the simultaneous determination of α-amanitin, β-amanitin and muscarine in human urine by solid-phase extraction (SPE) and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. The method can be used for a diagnostics of mushroom poisonings. Different SPE cartridges were tested for sample preparation, namely hydrophilic modified reversed-phase (Oasis HLB) and polymeric weak cation phase (Strata X-CW). The latter gave better results and therefore it was chosen for the subsequent method optimization and partial validation. In the course of validation, limits of detection, linearity, intraday and interday precisions and recoveries were evaluated. The obtained LOD values of α-amanitin and β-amanitin were 1ng/mL and of muscarine 0.09ng/mL. The intraday and interday precisions of human urine spiked with α-amanitin (10ng/mL), β-amanitin (10ng/mL) and muscarine (1ng/mL) ranged from 6% to 10% and from 7% to 13%, respectively. The developed method was proved to be a relevant tool for the simultaneous determination of the studied mushroom toxins in human urine after mushroom poisoning. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Comparison of extraction and clean-up techniques for the ...

African Journals Online (AJOL)

user

ultrasonication and mechanical shaking used in the extraction of a low-level PAH soil certified ... hydrocarbons (PAHs), soil, solid phase extraction (SPE), soxhlet extraction, ultrasonication. ... soxhlet) (Lopez-Avila et al., 1993) supercritical fluid.

[Optimization of solid-phase extraction for enrichment of toxic organic compounds in water samples].

Science.gov (United States)

Zhang, Ming-quan; Li, Feng-min; Wu, Qian-yuan; Hu, Hong-ying

2013-05-01

A concentration method for enrichment of toxic organic compounds in water samples has been developed based on combined solid-phase extraction (SPE) to reduce impurities and improve recoveries of target compounds. This SPE method was evaluated in every stage to identify the source of impurities. Based on the analysis of Waters Oasis HLB without water samples, the eluent of SPE sorbent after dichloromethane and acetone contributed 85% of impurities during SPE process. In order to reduce the impurities from SPE sorbent, soxhlet extraction of dichloromethane followed by acetone and lastly methanol was applied to the sorbents for 24 hours and the results had proven that impurities were reduced significantly. In addition to soxhlet extraction, six types of prevalent SPE sorbents were used to absorb 40 target compounds, the lgK(ow) values of which were within the range of 1.46 and 8.1, and recovery rates were compared. It was noticed and confirmed that Waters Oasis HLB had shown the best recovery results for most of the common testing samples among all three styrenedivinylbenzene (SDB) polymer sorbents, which were 77% on average. Furthermore, Waters SepPak AC-2 provided good recovery results for pesticides among three types of activated carbon sorbents and the average recovery rates reached 74%. Therefore, Waters Oasis HLB and Waters SepPak AC-2 were combined to obtain a better recovery and the average recovery rate for the tested 40 compounds of this new SPE method was 87%.

Identification of irradiation treatment in processed food. Pt. 2. Evaluation of a SPE-method for analyzing irradiation induced hydrocarbons

International Nuclear Information System (INIS)

Hartmann, M.; Ammon, J.; Berg, H.

1996-01-01

This paper deals with a solid phase extraction (SPE) method for the isolation of irradiation induced hydrocarbons which can replace the column chromatography described in the paragraph 35 LMBG (German Food Law) procedure L06.00-37. Using this new method, only a tenth of solvents and column material is necessary. The SPE method was a good as LC-LC-GC/FID or LC-LC-GC/MS in analyzing new or complex matrices like paprika or salmon. Additionally, it is fast, cheap and easy to perform. As far as we know, the detection of irradiation traetment in paprika powder by analyzing irradiation induced hydrocarbons has not been described before. The new method is a good alternative for the commonly used thermoluminescence procedure. (orig.) [de

RPA using a multiplexed cartridge for low cost point of care diagnostics in the field.

Science.gov (United States)

Ereku, Luck Tosan; Mackay, Ruth E; Craw, Pascal; Naveenathayalan, Angel; Stead, Thomas; Branavan, Manorharanehru; Balachandran, Wamadeva

2018-04-15

A point of care device utilising Lab-on-a-Chip technologies that is applicable for biological pathogens was designed, fabricated and tested showing sample in to answer out capabilities. The purpose of the design was to develop a cartridge with the capability to perform nucleic acid extraction and purification from a sample using a chitosan membrane at an acidic pH. Waste was stored within the cartridge with the use of sodium polyacrylate to solidify or gelate the sample in a single chamber. Nucleic acid elution was conducted using the RPA amplification reagents (alkaline pH). Passive valves were used to regulate the fluid flow and a multiplexer was designed to distribute the fluid into six microchambers for amplification reactions. Cartridges were produced using soft lithography of silicone from 3D printed moulds, bonded to glass substrates. The isothermal technique, RPA is employed for amplification. This paper shows the results from two separate experiments: the first using the RPA control nucleic acid, the second showing successful amplification from Chlamydia Trachomatis. Endpoint analysis conducted for the RPA analysis was gel electrophoresis that showed 143 base pair DNA was amplified successfully for positive samples whilst negative samples did not show amplification. End point analysis for Chlamydia Trachomatis samples was fluorescence detection that showed successful detection of 1 copy/μL and 10 copies/μL spiked in a MES buffer. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Development and Preliminary Assessment of Hemoperfusion Cartridge with Tannic Acid for Toxic Proteins' Precipitation: An In Vitro Model

Directory of Open Access Journals (Sweden)

Valquíria Miwa Hanai Yoshida

2016-09-01

Full Text Available Charcoal hemoperfusion (CHP is one of the extracorporeal removal techniques that are used to remove toxins from the body. CHP generally is considered the preferred method for extracorporeal extraction of several toxins—toxins that are adsorbed by activated charcoal. Assessments of the tannic acid's protective effects on ophidian poisoning are associated with the toxic proteins' precipitation by tannic acid. The challenge in treating a snakebite lies in removing the injected poison with minimal damage to blood constituent proteins. An alternative is CHP, and this investigation proposed to develop a column for hemoperfuser cartridge, combining charcoal granules trapped between layers of polymeric material conjugated to tannic acid, using an in vitro model scaled to the Wistar rat, which can be tested in an animal model. The cartridge was evaluated using the 22 full factorial design, in duplicate, as a method to study the effects of granulated-charcoal size and tannic acid concentration on the hematologic profile (platelet and leukocyte counts and biochemical profile (total serum protein and albumin dosages of sheep blood. The results demonstrate that charcoal in hemoperfuser cartridge: (1 decreases the serum in sheep blood volume, as consequence, (2 increases the serum proteins' concentration, and (iii exerts slight influence on albumin. The inclusion of tannic acid in hemoperfuser column precipitates some of serum proteins and albumin, decreasing their concentrations in the plasma serum. In conclusion, based on these effects we can suggest the use of 0.02 g tannic acid concentration and 8–20 mesh granulated charcoal in hemoperfuser cartridge for precipitating toxic proteins from snake venoms.

Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

Energy Technology Data Exchange (ETDEWEB)

Esteve-Turrillas, Francesc A. [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain); Pastor, Agustin [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)]. E-mail: agustin.pastor@uv.es; Guardia, Miguel de la [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)

2006-02-23

A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C{sub 18}. Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, {lambda}-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 {+-} 8 to 103 {+-} 7% for microwave-assisted extraction, versus 54 {+-} 4 to 104 {+-} 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 {mu}g/SPMD, were found in indoor air after 2 h of a standard application.

A solid-phase extraction method for analyzing trace amounts of polychlorinated dibenzo-p-dioxins and dibenzofurans in waste water

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Hye-Sung Cho

2011-03-01

Full Text Available The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fsin waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to bereinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in wastewater. Liquid-liquid extraction (LLE is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes itinadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE method for the analysisof dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompressionpump, which enables continuous semi-automated extraction. Small (0.5 L and large (7 L samples were extracted using LLE andSPE methods, respectively. The method detection limits (MDLs were 0.001−0.25 and 0.015−4.1 pg I-TEQ/L for the SPE andLLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrationsof several congeners that were not detected with the LLE method were quantified using the SPE method

Symbiotics and Aloe vera and Symphytum officinale extracts in broiler feed

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Paula Rodrigues Oliveira

2016-09-01

Full Text Available This study aimed to test the effects of dietary Aloe vera and Symphytum officinale extracts added separately or in combination with symbiotics on the performance, nutrient utilization, serum biochemical parameters, biometrics, and intestinal histomorfometry of broilers. The experiment had a randomized block design with five treatments and six replicates of ten broilers each. Treatments were as follows: negative control and positive control (diet without and with antibiotic, respectively; 0.2% Aloe vera (AV; 0.2% Symphytum officinale (S; 0.2% functional supplement, composed of symbiotics fermented in Aloe vera and comfrey plant extracts (S+PE. At seven days of age, FI of birds fed the Aloe vera extracts diets were lower than that observed for birds consuming the diet with Symphytum officinale extract and S+PE. Broiler performance remained unaffected by treatments at others ages evaluated. At 10 to 14 days of age the lowest ADCDM ADCCP was shown in group feed NC. The highest ADCCP was observed in PC control group and in diets supplemented with Aloe vera and S+PE. Serum levels of cholesterol, triglycerides, and phosphorus were affected by addition of extracts at seven, 21, and 35 days of age. The longest duodenal villi were observed in broilers fed S+PE diets at seven days of age. Aloe vera and Symphytum officinale extracts and symbiotics can be used in broiler diets as an alternative to growth-promoting antibiotics.

Liquid chromatography mass spectrometry determination of perfluoroalkyl acids in environmental solid extracts after phospholipid removal and on-line turbulent flow chromatography purification.

Science.gov (United States)

Mazzoni, M; Polesello, S; Rusconi, M; Valsecchi, S

2016-07-01

An on-line TFC (Turbulent Flow Chromatography) clean up procedures coupled with UHPLC-MS/MS (Ultra High Performance Liquid Chromatography Mass Spectrometry) multi-residue method was developed for the simultaneous determination of 8 perfluroalkyl carboxylic acids (PFCA, from 5 to 12 carbon atoms) and 3 perfluoroalkyl sulfonic acids (PFSA, from 4 to 8 carbon atoms) in environmental solid matrices. Fast sample preparation procedure was based on a sonication-assisted extraction with acetonitrile. Phospholipids in biological samples were fully removed by an off-line SPE purification before injection, using HybridSPE(®) Phospholipid Ultra cartridges. The development of the on-line TFC clean-up procedure regarded the choice of the stationary phase, the optimization of the mobile phase composition, flow rate and injected volume. The validation of the optimized method included the evaluation of matrix effects, accuracy and reproducibility. Signal suppression in the analysis of fortified extracts ranged from 1 to 60%, and this problem was overcome by using isotopic dilution. Since no certified reference materials were available for PFAS in these matrices, accuracy was evaluated by recoveries on spiked clam samples which were 98-133% for PFCAs and 40-60% for PFSAs. MLDs and MLQs ranged from 0.03 to 0.3ngg(-1) wet weight and from 0.1 to 0.9ngg(-1) wet weight respectively. Repeatability (intra-day precision) and reproducibility (inter-day precision) showed RSD from 3 to 13% and from 4 to 27% respectively. Validated on-line TFC/UHPLC-MS/MS method has been applied for the determination of perfluoroalkyl acids in different solid matrices (sediment, fish, bivalves and bird yolk). Copyright © 2016 Elsevier B.V. All rights reserved.

Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe3O4 nanoparticles

Science.gov (United States)

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

2015-07-01

The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100 mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL-1 with low detection limit of 0.03 ng mL-1 were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method.

42 CFR 84.1155 - Filters used with canisters and cartridges; location; replacement.

Science.gov (United States)

2010-10-01

...; location; replacement. 84.1155 Section 84.1155 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... Efficiency Respirators and Combination Gas Masks § 84.1155 Filters used with canisters and cartridges; location; replacement. (a) Particulate matter filters used in conjunction with a canister or cartridge...

Extraction and characterization of radish seed oils using different ...

African Journals Online (AJOL)

Purpose: To evaluate the impact of three different extraction methods on oil yield, physicochemical properties and bioactive ingredients of radish seeds. Methods: Radish seed oil was prepared by traditional solvent extraction (SE), supercritical carbon dioxide extraction (SCE) and sub-critical propane extraction (SPE).

C18, C8, and perfluoro reversed phases on diamond for solid-phase extraction.

Science.gov (United States)

Saini, Gaurav; Wiest, Landon A; Herbert, David; Biggs, Katherine N; Dadson, Andrew; Vail, Michael A; Linford, Matthew R

2009-04-17

In spite of advances in solid-phase extraction (SPE) technology there are certain disadvantages to current SPE silica-based, column packings. The pH range over which extraction can occur is limited and each column is generally only used once. New diamond-based reversed SPE phases (C(18), C(8), and perfluorinated) were developed in our laboratories. Studies were done which show that these phases do not have the same limitations as traditional silica-based stationary phases. The synthesis and properties of these diamond-based phases are presented, and the stability, percent recovery, and column capacity are given for the C(18) phase.

Extraction and characterization of Raphanus Sativus seed oil ...

African Journals Online (AJOL)

properties and bioactive ingredients of Raphanus sativus seed oil. Methods: Raphanus sativus seed oil was prepared by traditional solvent extraction (SE), super-critical carbon dioxide extraction (SCE) and sub-critical propane extraction (SPE). The yield, physicochemical properties, fatty acid composition and oxidative ...

Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of dextromethorphan in human plasma samples.

Science.gov (United States)

Moein, Mohammad Mahdi; Javanbakht, Mehran; Akbari-Adergani, Behrouz

2011-04-01

In this paper, a novel method is described for automated determination of dextromethorphan in biological fluids using molecularly imprinted solid-phase extraction (MISPE) as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker, chloroform as porogen and dextromethorphan as template molecule. These imprinted polymers were used as solid-phase extraction sorbent for the extraction of dextromethorphan from human plasma samples. Various parameters affecting the extraction efficiency of the MIP cartridges were evaluated. The high selectivity of the sorbent coupled to the high performance liquid chromatographic system permitted a simple and rapid analysis of this drug in plasma samples with limits of detection (LOD) and quantification (LOQ) of 0.12 ng/mL and 0.35 ng/mL, respectively. The MIP selectivity was evaluated by analyzing of the dextromethorphan in presence of several substances with similar molecular structures and properties. Results from the HPLC analyses showed that the recoveries of dextromethorphan using MIP cartridges from human plasma samples in the range of 1-50 ng/mL were higher than 87%. Copyright © 2011 Elsevier B.V. All rights reserved.

Development and validation of an automated unit for the extraction of radiocaesium from seawater

International Nuclear Information System (INIS)

Bokor, Ilonka; Sdraulig, Sandra; Jenkinson, Peter; Madamperuma, Janaka; Martin, Paul

2016-01-01

An automated unit was developed for the in-situ extraction of radiocaesium ( 137 Cs and 134 Cs) from large volumes of seawater to achieve very low detection limits. The unit was designed for monitoring of Australian ocean and coastal waters, including at ports visited by nuclear-powered warships. The unit is housed within a robust case, and is easily transported and operated. It contains four filter cartridges connected in series. The first two cartridges are used to remove any suspended material that may be present in the seawater, while the last two cartridges are coated with potassium copper hexacyanoferrate for caesium extraction. Once the extraction is completed the coated cartridges are ashed. The ash is transferred to a small petri dish for counting of 137 Cs and 134 Cs by high resolution gamma spectrometry for a minimum of 24 h. The extraction method was validated for the following criteria: selectivity, trueness, precision, linearity, limit of detection and traceability. The validation showed the unit to be fit for purpose with the method capable of achieving low detection limits required for environmental samples. The results for the environmental measurements in Australian seawater correlate well with those reported in the Worldwide Marine Radioactivity Study (WOMARS). The cost of preparation and running the system is low and waste generation is minimal. - Highlights: • Automated unit for in-situ extraction of 137 Cs and 134 Cs from 1000 L of seawater. • Unit is robust, and easily transported and operated. • Cs extraction uses cartridges coated with potassium copper hexacyanoferrate. • Validated for selectivity, trueness, precision, linearity, LOD and traceability. • System fit for purpose for monitoring of Australian coastal and ocean waters.

Isolation and pharmacological characterization of fatty acids from saw palmetto extract.

Science.gov (United States)

Abe, Masayuki; Ito, Yoshihiko; Suzuki, Asahi; Onoue, Satomi; Noguchi, Hiroshi; Yamada, Shizuo

2009-04-01

Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary-tract symptoms secondary to benign prostatic hyperplasia. The mechanisms of pharmacological effects of SPE include the inhibition of 5alpha-reductase, anti-androgenic effects, anti-proliferative effects, and anti-inflammatory effects. Previously, we showed that SPE bound actively to alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine calcium channel (1,4-DHP) receptors in the prostate and bladder of rats, whereas its active constituents have not been fully clarified. The present investigation is aimed to identify the main active components contained in hexane and diethyl ether extracts of SPE with the use of column chromatography and preparative HPLC. Based on the binding activity with alpha(1)-adrenergic, muscarinic, and 1,4-DHP receptors, both isolated oleic and lauric acids were deduced to be active components. Authentic samples of oleic and lauric acids also exhibited similar binding activities to these receptors as the fatty acids isolated from SPE, consistent with our findings. In addition, oleic and lauric acids inhibited 5alpha-reductase, possibly leading to therapeutic effects against benign prostatic hyperplasia and related lower urinary-tract symptoms.

Vps33b pathogenic mutations preferentially affect VIPAS39/SPE-39-positive endosomes.

Science.gov (United States)

Tornieri, Karine; Zlatic, Stephanie A; Mullin, Ariana P; Werner, Erica; Harrison, Robert; L'hernault, Steven W; Faundez, Victor

2013-12-20

Mutations in Vps33 isoforms cause pigment dilution in mice (Vps33a, buff) and Drosophila (car) and the neurogenic arthrogryposis, renal dysfunction and cholestasis syndrome in humans (ARC1, VPS33B). The later disease is also caused by mutations in VIPAS39, (Vps33b interacting protein, apical-basolateral polarity regulator, SPE-39 homolog; ARC2), a protein that interacts with the HOmotypic fusion and Protein Sorting (HOPS) complex, a tether necessary for endosome-lysosome traffic. These syndromes offer insight into fundamental endosome traffic processes unique to metazoans. However, the molecular and cellular mechanisms underlying these mutant phenotypes remain poorly understood. Here we investigate interactions of wild-type and disease-causing mutations in VIPAS39/SPE-39 and Vps33b by yeast two hybrid, immunoprecipitation and quantitative fluorescent microscopy. We find that although few mutations prevent interaction between VIPAS39/SPE-39 and Vps33b, some mutants fragment VIPAS39/SPE-39-positive endosomes, but all mutants alter the subcellular localization of Vps33b to VIPAS39/SPE-39-positive endosomes. Our data suggest that the ARC syndrome may result through impaired VIPAS39/SPE-39 and Vps33b-dependent endosomal maturation or fusion.

Simple and quick determination of analgesics and other contaminants of emerging concern in environmental waters by on-line solid phase extraction coupled to liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Ferrer-Aguirre, Alejandra; Romero-González, Roberto; Vidal, J L Martínez; Frenich, Antonia Garrido

2016-05-13

A simple and quick analytical method has been developed for the determination of pharmaceutical compounds in water. An on-line solid-phase extraction (SPE) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been optimized to determine 7 contaminants of emerging concern in environmental waters at ngL(-1) levels. This procedure requires minimal sample handling and small sample volume (900μL) with a total running time of 18min. Several SPE parameters were evaluated and optimized in order to achieve a high sample throughput. Therefore sample volume, carryover and reusability of the cartridges were evaluated. Performance characteristics were evaluated and good linearity was obtained (R(2)>0.98). Recoveries were evaluated in spiked samples at three concentrations and the values ranged from 71 to 104%. Intra and inter-day precision was lower than 10 and 13% respectively. Limits of quantification were equal to or lower than 10ngL(-1), except for 1,7-dimethylxanthine (20ngL(-1)) and ibuprofen (50ngL(-1)). The method was applied to 20 environmental water samples, and ibuprofen was the compound most widely detected at concentrations up to 42.06μgL(-1), whereas the other compounds were detected in fewer samples at lower concentrations (up to 15.99μgL(-1)). Copyright © 2016 Elsevier B.V. All rights reserved.

Substrate-Induced Allosteric Change in the Quaternary Structure of the Spermidine N-Acetyltransferase SpeG

OpenAIRE

Filippova, Ekaterina V.; Weigand, Steven; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Anderson, Wayne F.

2015-01-01

The spermidine N-acetyltransferase SpeG is a dodecameric enzyme that catalyzes the transfer of an acetyl group from acetyl-coenzyme A to polyamines such as spermidine and spermine. SpeG has an allosteric polyamine-binding site and acetylating polyamines regulates their intracellular concentrations. The structures of SpeG from Vibrio cholerae in complexes with polyamines and cofactor have been characterized earlier. Here, we present the dodecameric structure of SpeG from V. cholerae in a ligan...

A new screening method for amphetamine and methamphetamine using dansyl chloride derivatization and cartridge fluorescence.

Science.gov (United States)

Yamada, H; Ikeda-Wada, S; Oguri, K

1998-07-01

A new screening method for amphetamines was developed. It consists of derivatization with dansyl chloride, extraction of the derivative using a Sep-Pak C18 or a Bond Elut C18, solid phase extraction columns, and visualization of the fluorescence of the cartridge. A control test using drug-free urine showed no fluorescence. Amphetamine, methamphetamine and the methylenedioxy derivatives exhibited strong fluorescence, while related compounds, such as N-ethylamphetamine and fenetylline, were negative or weakly positive. The disadvantage of the present method is that it is a multi-step procedure and 20-30 min is required for screening. However, since it has a different specificity from the widely used immunochemical technique, it is suggested to be a useful screen for amphetamines.

Molecularly imprinted solid-phase extraction for selective extraction of bisphenol analogues in beverages and canned food.

Science.gov (United States)

Yang, Yunjia; Yu, Jianlong; Yin, Jie; Shao, Bing; Zhang, Jing

2014-11-19

This study aimed to develop a selective analytical method for the simultaneous determination of seven bisphenol analogues in beverage and canned food samples by using a new molecularly imprinted polymer (MIP) as a sorbent for solid-phase extraction (SPE). Liquid chromatography coupled to triple-quadruple tandem mass spectrometry (LC-MS/MS) was used to identify and quantify the target analytes. The MIP-SPE method exhibited a higher level of selectivity and purification than the traditional SPE method. The developed procedures were further validated in terms of accuracy, precision, and sensitivity. The obtained recoveries varied from 50% to 103% at three fortification levels and yielded a relative standard deviation (RSD, %) of less than 15% for all of the analytes. The limits of quantification (LOQ) for the seven analytes varied from 0.002 to 0.15 ng/mL for beverage samples and from 0.03 to 1.5 ng/g for canned food samples. This method was used to analyze real samples that were collected from a supermarket in Beijing. Overall, the results revealed that bisphenol A and bisphenol F were the most frequently detected bisphenols in the beverage and canned food samples and that their concentrations were closely associated with the type of packaging material. This study provides an alternative method of traditional SPE extraction for screening bisphenol analogues in food matrices.

Characterization of plasma protein binding dissociation with online SPE-HPLC

OpenAIRE

Li, Ping; Fan, Yiran; Wang, Yunlong; Lu, Yaxin; Yin, Zheng

2015-01-01

A novel parameter of relative recovery (Rre) was defined and determined by online SPE-HPLC to characterize plasma protein binding (PPB) kinetics of highly plasma binding drugs. The proportional relationship of Rre with koff of PPB has been established with a new SPE model. A rapid, easy to use method could potentially be used to categorize PK properties of the drug candidates in the decision process of drug discovery and development.

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...

Determination of synthetic colorants and natural carmine in wines

Directory of Open Access Journals (Sweden)

S. Virtanen

1999-09-01

Full Text Available Methods were developed for the determination of synthetic colorants and natural carmine (E120 in wines. The synthetic colorants studied were tartrazine (E102, quinoline yellow (E104, sunset yellow (E110, azo ruby (E122, amaranth (E123, ponceau 4R (E124, and erythrosine (E127. The colorants were extracted using solid-phase extraction (SPE with NH2 cartridges. The extracted colorants were then analysed by high-performance liquid chromatography (HPLC. The compounds were identified by comparing the spectrum of extract with spectra in a UV-vis spectral library of known food colorants. The detection limits in red wine ranged from 0.1 mg/l to 0.2 mg/l. Diode array detection and library search makes the method very effective in identifying forbidden colorants in wines. SPE is sufficiently effective in separating and concentrating colorants from wine. The effect of added colorants, e.g. azo ruby (E122, amaranth (E123 and tartrazine (E102 on the UV-vis spectra of red and white wines were studied. The added colorants could be identified in this way but not as accurately as by the HPLC method.

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.

A novel optimised and validated method for analysis of multi-residues of pesticides in fruits and vegetables by microwave-assisted extraction (MAE)-dispersive solid-phase extraction (d-SPE)-retention time locked (RTL)-gas chromatography-mass spectrometry with Deconvolution reporting software (DRS).

Science.gov (United States)

Satpathy, Gouri; Tyagi, Yogesh Kumar; Gupta, Rajinder Kumar

2011-08-01

A rapid, effective and ecofriendly method for sensitive screening and quantification of 72 pesticides residue in fruits and vegetables, by microwave-assisted extraction (MAE) followed by dispersive solid-phase extraction (d-SPE), retention time locked (RTL) capillary gas-chromatographic separation in trace ion mode mass spectrometric determination has been validated as per ISO/IEC: 17025:2005. Identification and reporting with total and extracted ion chromatograms were facilitated to a great extent by Deconvolution reporting software (DRS). For all compounds LOD were 0.002-0.02mg/kg and LOQ were 0.025-0.100mg/kg. Correlation coefficients of the calibration curves in the range of 0.025-0.50mg/kg were >0.993. To validate matrix effects repeatability, reproducibility, recovery and overall uncertainty were calculated for the 35 matrices at 0.025, 0.050 and 0.100mg/kg. Recovery ranged between 72% and 114% with RSD of <20% for repeatability and intermediate precision. The reproducibility of the method was evaluated by an inter laboratory participation and Z score obtained within ±2. Copyright © 2011 Elsevier Ltd. All rights reserved.

Determination of glyphosate and aminomethylphosphonic acid for assessing the quality tap water using SPE and HPLC

Directory of Open Access Journals (Sweden)

Eduardo Luiz Delmonico

2014-02-01

Full Text Available The use of pesticides in agriculture is one of the current problems that may result in contamination of both ground and surface water and groundwater. Considering the environmental importance and the increasing use of herbicides in Maringá region, in the present work methods for extraction and determination of glyphosate (GLYP and aminomethylphosphonic acid (AMPA using solid phase extraction (SPE and high performance liquid chromatography (HPLC were developed. For SPE, anion exchange resin was used and elution was done with hydrochloric acid 50.0 mmol L-1, achieving recovery rates of 82.5-116.2% and 67.1-104.0% for AMPA and GLYP, respectively. For HPLC determination the analytes were derivatized and injected in the HPLC with a C18 column and using mobile phase consisting of phosphate buffer 0.20 mol L-1 at pH 3.0 and acetonitrile (85:15; the monitoring was done at 240 nm. The analysis was performed in 8 min with the same limit of detection and limit of quantification for AMPA and GLYP of 0.09 and 0.20 mg L-1, respectively. The methods were applied to analysis of public water supply samples and concentrations from 2.1 up to 2.9 µg L-1 for AMPA and from 2.3 up to 3.3 µg L-1 for glyphosate were found.

[Application of saw palmetto fruit extract in the treatment of prostate diseases].

Science.gov (United States)

Zhan, Xu-xin; Shang, Xue-jun; Huang, Yu-feng

2015-09-01

Saw palmetto fruit extract (SPE), as a herbal product, is widely used for the treatment of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Recent studies show that SPE also has some therapeutic effects on chronic prostatitis, prostate cancer, sexual dysfunction, and so on. This article presents an overview on the application of SPE in the treatment of BPH, prostate cancer, and chronic prostatitis/chronic pelvic pain syndrome, with a discussion on its action mechanisms.

Application of solid-phase extraction coupled with freezing-lipid filtration clean-up for the determination of endocrine-disrupting phenols in fish

International Nuclear Information System (INIS)

Ahn, Yun Gyong; Shin, Jeoung Hwa; Kim, Hye-Young; Khim, Jeehyeong; Lee, Mi-Kyoung; Hong, Jongki

2007-01-01

An analytical method has been developed for the determination of endocrine-disrupting phenols (eight alkylphenols and bisphenol A) in fish samples. The extraction of nine phenols from fish samples was carried out by ultrasonification. After the extraction, high levels of lipids were removed by freezing-lipid filtration instead of the traditional methods of column chromatography or saponification. During freezing-lipid filtration, about 90% of the lipids were eliminated without any significant loss of phenolic compounds. For further purification, hydrophilic-lipophilic balanced copolymer (HLB) sorbent with a poly(divinylbenzene-co-N-vinylpyrrolidone) phase and Florisil-solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. Silyl-derivatization, with N,N'-methyl-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA), was applied to enhance the sensitivity of detection of phenolic compounds. Quantification was performed by gas chromatography/mass spectrometry (GC/MS)-selected ion monitoring (SIM) mode, using deuterium-labeled internal standards. Spiking experiments were carried out to determine the recovery, precision and detection limit of the method. The overall recoveries ranged between 70 and 120%, with relative standard deviations of 3-17% for the entire procedure. The detection limits of the method for the nine phenols ranged from 0.02 to 0.41 ng g -1 . The method provided simultaneous screening and accurate confirmation of each phenol when applied to biological samples

Application of solid-phase extraction coupled with freezing-lipid filtration clean-up for the determination of endocrine-disrupting phenols in fish

Energy Technology Data Exchange (ETDEWEB)

Ahn, Yun Gyong [Hazardous Substance Research Team, Korea Basic Science Institute, Seoul 136-701 (Korea, Republic of); Department of Civil Environment Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Shin, Jeoung Hwa; Kim, Hye-Young [Hazardous Substance Research Team, Korea Basic Science Institute, Seoul 136-701 (Korea, Republic of); Khim, Jeehyeong [Department of Civil Environment Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Mi-Kyoung [College of Pharmacy, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Hong, Jongki [College of Pharmacy, Kyung Hee University, Seoul 130-701 (Korea, Republic of)], E-mail: jhong@khu.ac.kr

2007-11-05

An analytical method has been developed for the determination of endocrine-disrupting phenols (eight alkylphenols and bisphenol A) in fish samples. The extraction of nine phenols from fish samples was carried out by ultrasonification. After the extraction, high levels of lipids were removed by freezing-lipid filtration instead of the traditional methods of column chromatography or saponification. During freezing-lipid filtration, about 90% of the lipids were eliminated without any significant loss of phenolic compounds. For further purification, hydrophilic-lipophilic balanced copolymer (HLB) sorbent with a poly(divinylbenzene-co-N-vinylpyrrolidone) phase and Florisil-solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. Silyl-derivatization, with N,N'-methyl-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA), was applied to enhance the sensitivity of detection of phenolic compounds. Quantification was performed by gas chromatography/mass spectrometry (GC/MS)-selected ion monitoring (SIM) mode, using deuterium-labeled internal standards. Spiking experiments were carried out to determine the recovery, precision and detection limit of the method. The overall recoveries ranged between 70 and 120%, with relative standard deviations of 3-17% for the entire procedure. The detection limits of the method for the nine phenols ranged from 0.02 to 0.41 ng g{sup -1}. The method provided simultaneous screening and accurate confirmation of each phenol when applied to biological samples.

Basic hydrolysis of 1, 3, 4, 6-tetra-O-acetyl-2-[18F] fluoro-D-glucose on solid phase extraction

International Nuclear Information System (INIS)

Zhang Jinming; Tian Jiahe; He Yijie; Huan Dingcai; Liu Boli

2003-01-01

A new base hydrolysis method are used for 1, 3, 4, 6-tetra-O-acetyl-2-[ 18 F] fluoro-D-glucose on solid phase extraction. The labeled intermediate is trapped on an active C-18 solid phase extraction cartridge, and hydrolyzed in cartridge with 1 mL 2 mol/L NaOH at room temperature. The results show that there are over 99% of the labeled intermediate being turned into 18 F-FDG within 2 min. It is easy to get 18 F-FDG after neutralized with phosphate buffer, purified by C-18 and Alumina cartridge. The basic hydrolysis on solid extraction is a simple method for preparation of 18 F-FDG

Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

International Nuclear Information System (INIS)

Esteve-Turrillas, Francesc A.; Pastor, Agustin; Guardia, Miguel de la

2006-01-01

A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C 18 . Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, λ-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 ± 8 to 103 ± 7% for microwave-assisted extraction, versus 54 ± 4 to 104 ± 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 μg/SPMD, were found in indoor air after 2 h of a standard application

The determination of organochlorine pesticides based on dynamic microwave-assisted extraction coupled with on-line solid-phase extraction of high-performance liquid chromatography

International Nuclear Information System (INIS)

Chen Ligang; Ding Lan; Jin Haiyan; Song Daqian; Zhang Huarong; Li Jiantao; Zhang Kun; Wang Yutang; Zhang Hanqi

2007-01-01

A rapid technique based on dynamic microwave-assisted extraction coupled with on-line solid-phase extraction of high-performance liquid chromatography (DMAE-SPE-HPLC) has been developed. A TM 010 microwave resonance cavity built in the laboratory was applied to concentrate the microwave energy. The sample placed in the zone of microwave irradiation was extracted with 95% acetonitrile (ACN) aqueous solution which was driven by a peristaltic pump at a flow rate of 1.0 mL min -1 . The extraction can be completed in a recirculating system in 10 min. When a number of extraction cycles were completed, the extract (1 mL) was diluted on-line with water. Then the extract was loaded into an SPE column where the analytes were retained while the unretained matrix components were washed away. Subsequently, the analytes were automatically transferred from the SPE column to the analytical column and determined by UV detector at 238 nm. The technique was used for determination of organochlorine pesticides (OCPs) in grains, including wheat, rice, corn and bean. The limits of detection of OCPs are in the range of 19-37 ng g -1 . The recoveries obtained by analyzing the four spiked grain samples are in the range of 86-105%, whereas the relative standard deviation (R.S.D.) values are <8.7% ranging from 1.2 to 8.7%. Our method was demonstrated to be fast, accurate, and precise. In addition, only small quantities of solvent and sample were required

Extraction and Ozonation of organic pollutants in drinking waters

International Nuclear Information System (INIS)

Kenawi, I.M.; Barsoum, B.N.; Abdelhaflz, M.M.

2006-01-01

The continuous liquid-liquid, CLLE, and solid-phase, SPE. extraction techniques were used to study a problem of international relevance. The work was incident on the evaluation of the efficiency and optimisation of extruding techniques, CLLE. SPE and CLLEt-SPE, towards chlorinated pesticides and phenolic compounds from the Giza treatment plant station (Egypt), where the degree of pollution of such substances in drinking waters must be reduced. The total recoveries, rs, using SPE ranged between I).74 -0.87, whereas, the values were much less using the other two methods (0.158 - 0.1961; indicating the preferability of the SF'E technique. Analytical results were obtained through the various chromatographic techniques, liquid or gas. with adequately chosen detectors. A simple mathematical algorithm has been empirically developed allowing the assessment and comparison of the efficiencies of the three extracting procedures. Further treatment with ozone resulted in the oxidation and elimination of organic pollutants, with consequent improvement of water quality (total pesticide content 0.332-0.19μgL -1 ). A useful ozone treatment unit, capable of dealing with the emanation of contaminants in tap water, was built

Membrane solid-phase extraction: Field application for isolation of polycyclic aromatic hydrocarbons from water samples

International Nuclear Information System (INIS)

Furlong, E.T.; Koleis, J.C.; Gates, P.M.

1995-01-01

Solid-phase extraction (SPE) membranes (M-SPE) were used to isolate microgram-per-liter to nanogram-per-liter quantities of polycyclic aromatic hydrocarbons (PAH) in 4- to 8-liter ground-water samples from a crude-oil-contaminated ground-water site near Bemidji, Minnesota. The M-SPE method was evaluated (1) under laboratory conditions using reagent water fortified with individual PAH at 1.23 micrograms per liter, and (2) at the Bemidji site. At the site, ground-water samples were processed and PAH isolated using a M-SPE system connected directly to the well pump. Following sample isolation, all M-SPE samples were extracted using dichloromethane and analyzed by gas chromatography-mass spectrometry with selected-ion monitoring. Operationally, the M-SPE method provided a simple means to isolate PAH on site at the wellhead, particularly for anoxic water samples. Acceptable recoveries, ranging from 56 to over 100 percent, were observed for lower molecular weight PAH (naphthalene to pyrene) using the M-SPE method. Recoveries using M-SPE were somewhat lower, but reproducible, for higher molecular weight PAH (chrysene to benzo[ghi]perylene), ranging from 18 to 56 percent. M-SPE provides the capability to collect and field isolate PAH from a sufficiently large number of samples to identify environmental chemical processes occurring at individual compound concentrations of 50 to 1,200 nanograms per liter. Using M-SPE, the potential for facilitated transport of PAH by in situ-derived dissolved organic carbon (DOC) was evaluated at the site. Plots comparing DOC and PAH concentrations indicate that PAH concentrations increase exponentially with linear increases in DOC concentrations

The reactor Phenix - cartridge rupture detection

International Nuclear Information System (INIS)

Graftieaux, J.

1967-01-01

This report defines the role of cartridge rupture detection in the reactor Phenix. It gives the possible methods, their probable performances, their advantages and disadvantages. The final form of the installation will be determined mainly by the degree of safety required, by the technical possibilities of the reactor design and by the operational flexibility wanted. (author) [fr

Study of methodologies for quality control of 99Mo used in 99Mo/99mTc generators

International Nuclear Information System (INIS)

Said, Daphne de Souza

2016-01-01

99m Tc is the most used radionuclide in nuclear medicine. In Brazil, the 99 Mo/ 99m Tc generators are exclusively produced by Radiopharmacy Center at IPEN-CNEN/ SP, by importing 99 Mo from different suppliers. 99 Mo (t 1/2 = 66 h) is a fission product of 235 U and it can have radionuclidic impurities that are prejudicial for human health. For safe use of generators, it is necessary to perform the evaluation of 99 Mo by quality control tests in order to assess if 99 Mo complies with the specifications. The European Pharmacopoeia (EP) presents a monograph for evaluation of the quality of the [ 99 Mo] solution as sodium molybdate,that is used as raw material for 99 Mo/ 99m Tc generators production, including specification parameters (identification, radiochemical purity and radionuclidic purity), analysis methods and limits. However, it has been observed difficulties on the execution and implementation of these methods by the generators producers, with a few literature about this subject, probably due to complexity of the proposed methods. In this work, many quality control parameters of 99 Mo described in the EP monograph were evaluated. Separation methods for 99M o from its radionuclidic impurities by solid phase extraction (SPE) and TLC were studied. After SPE separation, the quantification of metals by ICP-OES to evaluate the percentage of retention of Mo and the percentage of recovery of Ru, Te and Sr using different types of cartridges were proposed, replacing radiotracers use. It was observed that the specific type of SPE cartridge recommended by the EP for separation of 99 Mo presented low recoveries for Ru, compared to other available anion exchange SPE cartridges. 99 Mo samples from different worldwide suppliers were analyzed. It was observed that quantification of 103 Ru in 99 Mo samples with decay time higher than 4 weeks is possible. An alternative method for separation of 131 I from 99 Mo showed promising results by TLC. The quantification of beta and

The indicating FTA elute cartridge a solid sample carrier to detect high-risk HPV and high-grade cervical lesions

NARCIS (Netherlands)

Bie, R.P. de; Schmeink, C.E.; Bakkers, J.M.J.E.; Snijders, P.J.L.M.; Quint, W.G.V.; Massuger, L.F.A.G.; Bekkers, R.L.M.; Melchers, W.J.G.

2011-01-01

The clinically validated high-risk human papillomavirus (hrHPV) Hybrid Capture 2 (HC2) and GP5+/6+-PCR assays were analyzed on an Indicating FTA Elute cartridge (FTA cartridge). The FTA cartridge is a solid dry carrier that allows safe transport of cervical samples. FTA cartridge samples were

[Monitoring of the residue of fosthiazate in water samples using solid-phase extraction coupled with gas chromatography/mass spectrometry].

Science.gov (United States)

Zhu, Jing; Zhou, Xin; Fu, Chunmei; Liu, Sankang; Li, Zhangwan

2004-11-01

Solid-phase extraction (SPE) coupled with gas chromatography/mass spectrometry (GC/MS) was used to determine the fosthiazate residue in water samples. The water samples were first filtered through cellulose filters (0.45 microm pore size). A 100 mL volume of filtered water, in which 1 mL of methanol has been added, was then passed through a pre-conditioned 3 cm C18 cartridge at a flow-rate of 1.5 mL/min. Elution was performed by 1 mL of methanol. The eluant was finally dried under reduced pressure for solvent evaporation. The volume was quantitatively adjusted to 0.5 mL with methanol. The analysis was carried out on GC/MS. The mass spectrometer was operated in selected ion monitoring (SIM) mode. According to mass spectrum of fosthiazate, three selected ions at m/z of 126, 195, 283, respectively, were monitored for identification and quantification. High sensitivity and selectivity were achieved by using this method. The limit of detection for fosthiazate in water samples was determined to be 56.4 ng/L. The linearity was demonstrated over a wide range of concentrations covering from 0.282 to 141 microg/L. The recoveries were more than 85.5% and the relative standard deviations for the overall procedure were less than 4.42%. The fosthiazate residue was detected in the water samples from a pool near cropland where fosthiazate was used. The results demonstrate the suitability of the SPE-GC/MS approach for the analysis of fosthiazate in water.

State-of-the-art in solid-phase extraction of biofluids (M10)

International Nuclear Information System (INIS)

Boos, K.-S.; Fleischer, C.T.

2002-01-01

Full text: A major drawback of many SPE protocols in bioanalytical LC is a rather unselective and/or time consuming clean-up procedure. In order to optimize SPE based sample processing with regard to selectivity and speed we investigated tailor-made SPE adorbents, distinct SPE column hardware as well as a novel software (ChromSword ADS, Merck KGaA) for LC(MS)-integrated SPE using column-switching. Restricted Access Materials (RAM) are one family of such special SPE column packing. RAMs are characterized in that they have a defined size-selective exclusion barrier and a non-adsorptive outer particle surface towards macromolecular matrix components (e.g. proteins, nucleic acids, polysaccharides). Low-molecular compounds (e.g. drugs) have free access to the binding centers and thus can be extracted and enriched prior to their analytical separation and MS detection. A RAM-SPE column (e.g. LiChrospher ADS, Merck KGaA, Germany) allows the direct, multiple injection and fractionation of crude, complex samples such as hemolyzed blood, plasma, serum, milk, saliva, urine, fermentation broth and cell-culture or tissue homogenate supernatant. In order to improve the selectivity, we extended this on-line sample clean-up protocol by coupling a reversed-phase modified RAM-SPE column with a second short column packed with a Molecularly Imprinted Polymeric (MIP) adsorbent. MIP-SPE adsorbents can be compared with immunoaffinity adsorbents. Besides selective/specific molecular recognition properties, these artificial antibodies exhibit a high stability with respect to pressure, pH, temperature as well as organic solvents. These innovative adsorbents are also attractive because of the ease, low-cost and high reproducibility of preparation. Using MIPS in combination with RAMs we developed a generic SPE platform and protocol, respectively, for highly selective clean-up of complex (bio)fluids. Finally, we succeeded in speeding up the RAM fractionation step (e.g. extraction of 50 pl of

Determining Service Life of Respirator Cartridges Using a Simple and Practical Method: Case Study in a Car Manufacturing Industry

Directory of Open Access Journals (Sweden)

A.M Rashidi

2012-01-01

Full Text Available Background and aims: For ensuring about proper performance of air-purifying respirators in providing protection against workplace contaminants, it is necessary to change the respirator cartridges before the end of their service life. The aim of this study was determination of service life of organic vapor cartridges using a simple and practical method in a spray painting booth of a car manufacturing industry.   Methods: NIOSH MultiVapor software was used for estimating service life of respirator cartridges based on workplace conditions and cartridge specifications. Efficiency of determined service life was investigated using an apparatus for field testing of cartridges in the workplace.   Results: The results showed that existing schedule for changing the respirator cartridges is not effective and no longer provide adequate protection for sprayers against organic contaminants while working in a painting booth. It is necessary to change the cartridges before their estimated service life (every 4 hours.   Conclusion: NIOSH MultiVapor has acceptable efficiency for determining respirator cartridges service life and could be used as a simple and practical method in the workplace. Moreover, Service life estimated by this software was confirmed by cartridge field test apparatus.

Muscarinic and alpha 1-adrenergic receptor binding characteristics of saw palmetto extract in rat lower urinary tract.

Science.gov (United States)

Suzuki, Mayumi; Oki, Tomomi; Sugiyama, Tomomi; Umegaki, Keizo; Uchida, Shinya; Yamada, Shizuo

2007-06-01

To elucidate the in vitro and ex vivo effects of saw palmetto extract (SPE) on autonomic receptors in the rat lower urinary tract. The in vitro binding affinities for alpha 1-adrenergic, muscarinic, and purinergic receptors in the rat prostate and bladder were measured by radioligand binding assays. Rats received vehicle or SPE (0.6 to 60 mg/kg/day) orally for 4 weeks, and alpha 1-adrenergic and muscarinic receptor binding in tissues of these rats were measured. Saw palmetto extract inhibited specific binding of [3H]prazosin and [N-methyl-3H]scopolamine methyl chloride (NMS) but not alpha, beta-methylene adenosine triphosphate [2,8-(3)H]tetrasodium salt in the rat prostate and bladder. The binding activity of SPE for muscarinic receptors was four times greater than that for alpha 1-adrenergic receptors. Scatchard analysis revealed that SPE significantly reduced the maximal number of binding sites (Bmax) for each radioligand in the prostate and bladder under in vitro condition. Repeated oral administration of SPE to rats brought about significant alteration in Bmax for prostatic [3H]prazosin binding and for bladder [3H]NMS binding. Such alteration by SPE was selective to the receptors in the lower urinary tract. Saw palmetto extract exerts significant binding activity on autonomic receptors in the lower urinary tract under in vitro and in vivo conditions.

Screening and dereplication of microbial natural products extracts

DEFF Research Database (Denmark)

Månsson, Maria; Vynne, Nikolaj Grønnegaard; Wietz, Matthias

expedition,1 we use a combination of chemical profiling2 and explorative solid-phase extraction (E-SPE)3 to assess the bacteria’s potential to produce new and interesting molecules. We found the use of chemical profiling by LC-UV/MS very useful for marine bacteria such as Vibrio4 and Pseudoalteromonas.5....... The chemical profile could be linked to a bioactivity profile using E-SPE,3 which through the use of three different ion-exchangers and a size-exclusion column gives information about the charge, size, and polarity of active components in an extract. This can be used to discriminate between possible candidates...

CONSTRUCTION AND OPTIMISATION OF A CARTRIDGE FILTER ...

African Journals Online (AJOL)

a

1Department of Chemistry, Egerton University, P.O. Box 356, Njoro, Kenya .... the resident time in the filter, thus there is not enough time for F- to interact with the ... associated with creation of too much backpressure in the cartridge as well as ...

Development of an interface for directly coupled solid-phase extraction and GC-MS analysis

NARCIS (Netherlands)

Öllers, M.J.H.; van Lieshout, H.P.M.; Janssen, J.G.M.; Cramers, C.A.M.G.

Solid-phase extraction (SPE) is widely used as a sample preparation technique in numerous application areas of chromatography. Large-volume injection is an attractive technique for coupling SPE to gas chromatography (GC) because it provides improved detection limits and circumvents the need for

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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Highly sensitive determination of polycyclic aromatic hydrocarbons in ambient air dust by gas chromatography-mass spectrometry after molecularly imprinted polymer extraction

Energy Technology Data Exchange (ETDEWEB)

Krupadam, Reddithota J.; Bhagat, Bhagyashree; Khan, Muntazir S. [National Environmental Engineering Research Institute, Nagpur (India)

2010-08-15

A method based on solid-phase extraction with a molecularly imprinted polymer (MIP) has been developed to determine five probable human carcinogenic polycyclic aromatic hydrocarbons (PAHs) in ambient air dust by gas chromatography-mass spectrometry (GC-MS). Molecularly imprinted poly(vinylpyridine-co-ethylene glycol dimethacrylate) was chosen as solid-phase extraction (SPE) material for PAHs. The conditions affecting extraction efficiency, for example surface properties, concentration of PAHs, and equilibration times were evaluated and optimized. Under optimum conditions, pre-concentration factors for MIP-SPE ranged between 80 and 93 for 10 mL ambient air dust leachate. PAHs recoveries from MIP-SPE after extraction from air dust were between 85% and 97% and calibration graphs of the PAHs showed a good linearity between 10 and 1000 ng L{sup -1} (r=0.99). The extraction efficiency of MIP for PAHs was compared with that of commercially available SPE materials - powdered activated carbon (PAC) and polystyrene-divinylbenzene resin (XAD) - and it was shown that the extraction capacity of the MIP was better than that of the other two SPE materials. Organic matter in air dust had no effect on MIP extraction, which produced a clean extract for GC-MS analysis. The detection limit of the method proposed in this article is 0.15 ng L{sup -1} for benzo[a]pyrene, which is a marker molecule of air pollution. The method has been applied to the determination of probable carcinogenic PAHs in air dust of industrial zones and satisfactory results were obtained. (orig.)

Highly sensitive determination of polycyclic aromatic hydrocarbons in ambient air dust by gas chromatography-mass spectrometry after molecularly imprinted polymer extraction.

Science.gov (United States)

Krupadam, Reddithota J; Bhagat, Bhagyashree; Khan, Muntazir S

2010-08-01

A method based on solid--phase extraction with a molecularly imprinted polymer (MIP) has been developed to determine five probable human carcinogenic polycyclic aromatic hydrocarbons (PAHs) in ambient air dust by gas chromatography-mass spectrometry (GC-MS). Molecularly imprinted poly(vinylpyridine-co-ethylene glycol dimethacrylate) was chosen as solid-phase extraction (SPE) material for PAHs. The conditions affecting extraction efficiency, for example surface properties, concentration of PAHs, and equilibration times were evaluated and optimized. Under optimum conditions, pre-concentration factors for MIP-SPE ranged between 80 and 93 for 10 mL ambient air dust leachate. PAHs recoveries from MIP-SPE after extraction from air dust were between 85% and 97% and calibration graphs of the PAHs showed a good linearity between 10 and 1000 ng L(-1) (r = 0.99). The extraction efficiency of MIP for PAHs was compared with that of commercially available SPE materials--powdered activated carbon (PAC) and polystyrene-divinylbenzene resin (XAD)--and it was shown that the extraction capacity of the MIP was better than that of the other two SPE materials. Organic matter in air dust had no effect on MIP extraction, which produced a clean extract for GC-MS analysis. The detection limit of the method proposed in this article is 0.15 ng L(-1) for benzo[a]pyrene, which is a marker molecule of air pollution. The method has been applied to the determination of probable carcinogenic PAHs in air dust of industrial zones and satisfactory results were obtained.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Batch fabrication of polymer microfluidic cartridges for QCM sensor packaging by direct bonding

Science.gov (United States)

Sandström, Niklas; Zandi Shafagh, Reza; Gylfason, Kristinn B.; Haraldsson, Tommy; van der Wijngaart, Wouter

2017-12-01

Quartz crystal microbalance (QCM) sensing is an established technique commonly used in laboratory based life-science applications. However, the relatively complex, multi-part design and multi-step fabrication and assembly of state-of-the-art QCM cartridges make them unsuited for disposable applications such as point-of-care (PoC) diagnostics. In this work, we present the uncomplicated manufacturing of QCMs in polymer microfluidic cartridges. Our novel approach comprises two key innovations: the batch reaction injection molding of microfluidic parts; and the integration of the cartridge components by direct, unassisted bonding. We demonstrate molding of batches of 12 off-stoichiometry thiol-ene epoxy polymer (OSTE+) polymer parts in a single molding cycle using an adapted reaction injection molding process; and the direct bonding of the OSTE+  parts to other OSTE+  substrates, to printed circuit boards, and to QCMs. The microfluidic QCM OSTE+  cartridges were successfully evaluated in terms of liquid sealing as well as electrical properties, and the sensor performance characteristics are on par with those of a commercially available QCM biosensor cartridge. The simplified manufacturing of QCM sensors with maintained performance potentializes novel application areas, e.g. as disposable devices in a point of care setting. Moreover, our results can be extended to simplifying the fabrication of other microfluidic devices with multiple heterogeneously integrated components.

A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

Energy Technology Data Exchange (ETDEWEB)

Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

2003-02-01

Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

Determination of free fatty acids in beer.

Science.gov (United States)

Bravi, Elisabetta; Marconi, Ombretta; Sileoni, Valeria; Perretti, Giuseppe

2017-01-15

Free fatty acids (FFA) content of beer affects the ability to form a stable head of foam and plays an important role in beer staling. Moreover, the presence of saturated FAs is related sometimes to gushing problems in beer. The aim of this research was to validate an analytical method for the determination of FFAs in beer. The extraction of FFAs in beer was achieved via Liquid-Liquid Cartridge Extraction (LLCE), the FFAs extract was purified by Solid Phase Extraction (SPE), methylated by boron trifluoride in methanol, and injected into GC-FID system. The performance criteria demonstrate that this method is suitable for the analysis of medium and long chain FFAs in beer. The proposed method was tested on four experimental beers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preliminary X-ray crystallographic studies of Bacillus subtilis SpeA protein

International Nuclear Information System (INIS)

Liu, Xiao-Yan; Lei, Jian; Liu, Xiang; Su, Xiao-Dong; Li, Lanfen

2009-01-01

In order to further illustrate the catalytic mechanism of arginine decarboxylase by determining the three-dimensional structure of the enzyme the speA gene was amplified from B. subtilis genomic DNA and cloned. The enzyme was expressed in Escherichia coli and purified to homogeneity by nickel-chelation chromatography followed by size-exclusion chromatography. High-quality crystals were obtained using the hanging-drop vapour-diffusion method at 298 K. The speA gene in Bacillus subtilis encodes arginine decarboxylase, which catalyzes the conversion of arginine to agmatine. Arginine decarboxylase is an important enzyme in polyamine metabolism in B. subtilis. In order to further illustrate the catalytic mechanism of arginine decarboxylase by determining the three-dimensional structure of the enzyme, the speA gene was amplified from B. subtilis genomic DNA and cloned into the expression vector pET-28a(+). SpeA was expressed in Escherichia coli and purified to homogeneity by nickel-chelation chromatography followed by size-exclusion chromatography. High-quality crystals were obtained using the hanging-drop vapour-diffusion method at 289 K. The best crystal diffracted to 2.0 Å resolution and belonged to space group P2 1 , with unit-cell parameters a = 86.4, b = 63.3 c = 103.3 Å, β = 113.9°

Stir-bar supported micro-solid-phase extraction for the determination of polychlorinated biphenyl congeners in serum samples.

Science.gov (United States)

Sajid, Muhammad; Basheer, Chanbasha

2016-07-15

In present work, a new configuration of micro-solid phase extraction was introduced and termed as stir-bar supported micro-solid-phase extraction (SB-μ-SPE). A tiny stir-bar was packed inside the porous polypropylene membrane along with sorbent material and the edges of membrane sheet were heat sealed to secure the contents. The packing of stir-bar inside the μ-SPE device does not allow the device to stick with the wall or any corner of the sample vial during extraction, which is, however, a frequent observation in routine μ-SPE. Moreover, it enhances effective surface area of the sorbent exposed to sample solution through continuous agitation (motion and rotation). It also completely immerses the SB-μ-SPE device in the sample solution even for non-polar sorbents. Polychlorinated biphenyls (PCBs) were selected as model compounds and the method performance was evaluated in human serum samples. After extraction, samples were analyzed by gas chromatography mass spectrometry (GC-MS). The factors that affect extraction efficiency of SB-μ-SPE were optimized. Under optimum conditions, a good linearity (0.1-100ngmL(-1)) with coefficients of determinations ranging from 0.9868 to 0.9992 was obtained. Limits of detections were ranged between 0.003 and 0.047ngmL(-1). Acceptable values for inter-day (3.2-9.1%) and intra-day (3.1-7.2%) relative standard deviations were obtained. The optimized method was successfully applied to determine the concentration of PCB congeners in human serum samples. Copyright © 2016 Elsevier B.V. All rights reserved.

The isolation of water-soluble radionuclides from deteriorating spent nuclear fuel in zeolite cartridge

International Nuclear Information System (INIS)

Hassan, N.M.; Thompson, M.C.

1996-01-01

A method of isolating water-soluble radionuclides leaching from deteriorating spent nuclear fuel by ion-exchange in zeolite cartridges has been studied. Design calculations of two zeolite cartridges to be incorporated in typical spent fuel storage bundle have been provided. Equilibrium exchange data obtained at several temperatures have shown that the maximum exchange capacity of total cesium in sodium titanium aluminosilicate was 114 mg/g zeolite and the capacity at 95% exchange for radioactive isotope Cs-137 was calculated as 55.2 mg/g zeolite. The kinetic data suggest that the rate of exchange of Cs + in sodium titanium aluminosilicate zeolite takes place by a fast initial exchange step followed by slow diffusion of cesium cations. Design calculations based on the equilibrium exchange data show that water-soluble radionuclides leaching from Mk 31 slugs can be isolated using two zeolite cartridges, each 3.7 inches in inside diameter and 2.5 inches in length. The cartridges are designed to isolate 95% of the Cs + leaching from the spent fuel storage bundle. The results from the thermal induced convective flow tests indicate that the system will provide necessary cooling to the spent fuel by convective currents while isolating the Cs + leaching from spent fuel storage bundle in the cartridges

Determination of tylosin residues in pig tissues using high-performance liquid chromatography.

Science.gov (United States)

De Liguoro, M; Anfossi, P; Angeletti, R; Montesissa, C

1998-06-01

In accordance with the maximum residue limit of 100 micrograms kg-1 established by EU legislation, a simple and sensitive high-performance liquid chromatographic (HPLC) method was developed for the measurement of tylosin residues in pig tissues (fat, kidney, liver and muscle). Tylosin, a macrolide antibiotic, is extracted with water-methanol and cleaned-up by solid-phase extraction (SPE) on cation-exchange cartridges using methanol elution. Tylosin was determined by reversed-phase HPLC with UV detection at 280 nm and the mean recovery from pig tissues fortified in the range 50-200 micrograms kg-1 was 70-85%, with intra- and inter-day RSDs in the ranges 3.4-9.1 and 3.9-10.1% respectively.

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.

Simple synthesis of carbon-11-labeled chromen-4-one derivatives as new potential PET agents for imaging of DNA-dependent protein kinase (DNA-PK) in cancer

International Nuclear Information System (INIS)

Gao, Mingzhang; Wang, Min; Miller, Kathy D.; Zheng, Qi-Huang

2012-01-01

Carbon-11-labeled chromen-4-one derivatives were synthesized as new potential PET agents for imaging of DNA repair enzyme DNA-dependent protein kinase (DNA-PK) in cancer. The target tracers, X-[ 11 C]methoxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; [ 11 C]4a–d), were prepared from their corresponding precursors, X-hydroxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; 5a–d), with [ 11 C]CH 3 OTf through O-[ 11 C]methylation and isolated by a simplified solid-phase extraction (SPE) method using a C-18 Sep-Pak Plus cartridge. The radiochemical yields decay corrected to end of bombardment (EOB), from [ 11 C]CO 2 , were 40–60%. The specific activity at end of synthesis (EOS) was 185–370 GBq/μmol. - Highlights: ► New chromen-4-one derivatives were synthesized. ► New carbon-11-labeled chromen-4-one derivatives were synthesized. ► Simple solid-phase extraction (SPE) method was employed in radiosynthesis.

Determination of volatile compounds in grape distillates by solid-phase extraction and gas chromatography.

Science.gov (United States)

Lukić, Igor; Banović, Mara; Persurić, Dordano; Radeka, Sanja; Sladonja, Barbara

2006-01-06

Solid-phase extraction (SPE) procedure on octadecylsilica (C18) was developed for accumulation of volatile compounds from grape distillates. The procedure was optimised for final analysis by capillary gas chromatography. At mass concentrations in model solutions ranging from 0.1 to 50 mg/l solid-phase extraction recoveries of all analytes ranged from 69% for 2-phenylethanol to 102% for capric acid, with RSD values from 2 to 9%. SPE recoveries of internal standards to be added in the sample solution prior to extraction, higher alcohols 2-ethyl-1-hexanol and 1-undecanol, were 97 and 93%, respectively, with RSD values of 3%. Detection limits of analyzed compounds in model solutions ranged from 0.011 mg/l for isoamyl acetate to 0.037 mg/l for caproic acid. Method efficiency was tested in relation to acetic acid content, volume fraction of ethanol and possible matrix effects. A significant influence of matrix on SPE efficiency for geraniol, cis-2-hexen-1-ol and cis-3-hexen-1-ol was detected. For the same reason, 2-phenylethanol could not be determined by developed SPE method in samples of grape distillates. The developed solid-phase extraction method was successfully applied to determine the differences in volatile compound content in different grape distillates produced by the distillation of crushed, pressed and fermented grapes.

Fifty years of solid-phase extraction in water analysis--historical development and overview.

Science.gov (United States)

Liska, I

2000-07-14

The use of an appropriate sample handling technique is a must in an analysis of organic micropollutants in water. The efforts to use a solid phase for the recovery of analytes from a water matrix prior to their detection have a long history. Since the first experimental trials using activated carbon filters that were performed 50 years ago, solid-phase extraction (SPE) has become an established sample preparation technique. The initial experimental applications of SPE resulted in widespread use of this technique in current water analysis and also to adoption of SPE into standardized analytical methods. During the decades of its evolution, chromatographers became aware of the advantages of SPE and, despite many innovations that appeared in the last decade, new SPE developments are still expected in the future. A brief overview of 50 years of the history of the use of SPE in organic trace analysis of water is given in presented paper.

Simplified quality control of radioactive seeds in sterile cartridge for prostate brachytherapy using an imaging plate and a collimator

International Nuclear Information System (INIS)

Saze, T.; Miyoshi, H.; Maezawa, H.; Kubota, M.; Furutani, S.; Nishitani, H.; Kawaguchi, Y.; Nakayama, S.; Ito, S.; Nishizawa, K.

2008-01-01

Image analyzer system and collimator has been successfully applied to calibrate simultaneously multiple 125 I seeds in a sterile cartridge. Seeds within the cartridge were placed on an imaging plate, and the imaging plate irradiated. To remove scatter radiation, and improve spatial resolution of seed images, this study used a specially designed collimator. The irradiated imaging plate was scanned using an image analyzer system, and radioactivity intensities of seed images were given in counts. Counts could be translated to profiles, and each seed within the cartridge was analyzed. It is observed that a good correlation between counts and total radioactivity of the seeds within the cartridge. Thus, using a least-squares line, it was possible to calibrate a seed with unknown apparent activity. By analyzing the profiles, it was possible not only to detect a mis calibrated seed in the cartridge from its relative difference in counts, but also to identify its position in the cartridge. Using an imaging analyzer system, all seeds in a cartridge could be calibrated in a sterile environment. (author)

Influence of Salvadora persica (miswak) extract on physical and antimicrobial properties of glass ionomer cement

NARCIS (Netherlands)

El-Tatari, A.; de Soet, J.J.; de Gee, A.J.; Abou Shelib, M.; van Amerongen, W.E.

2011-01-01

AIM: To investigate physical and antimicrobial properties of Glass Ionomer Cement (GIC) combined with Salvadora Persica Extract (SPE). METHODS: SPE was added to GIC (Fuji IX) in concentrations of 1%, 2% and 4% w/w. The compressive strength and diametral tensile strength were measured at 1 h, 24 h

Clinical Effects of Formulated Food of Peucedanum japonicum Extract and Saw Palmetto Extract in Male Patients with Lower Urinary Tract Symptoms.

Science.gov (United States)

Kageyama, Shinji; Beppu, Masanori; Ohnogi, Hiromu; Miyazaki, Sayaka; Haruno, Akihiro; Ito, Yoshihiko; Yamada, Shizuo

2018-05-01

To evaluate changes over time in subjective symptom scores and urination parameters before and after oral administration of formulated food containing a combination of Peucedanum japonicum (P. japonicum) extract and saw palmetto extract (SPE) in male patients with lower urinary tract symptoms (LUTS). This study was conducted in an open label manner on male patients with untreated LUTS. The urination state of patients was evaluated before and after administration of food formulated with P. japonicum extract and SPE for 4 weeks, based on urodynamic parameters and subjective symptom scores (International Prostate Symptom Score [IPSS and IPSS-QOL], Overactive Bladder Symptom Score [OABSS], Overactive Bladder Questionnaire [OAB-q], and International Index of Erectile Function [IIEF]). After the administration of food formulated with these extracts, the following results were obtained: (i) Subjective findings: The IPSS-QOL score improved significantly; both parameters related to nocturia, i.e., frequency of nighttime urination and OABSS-2, improved significantly; other ratings for subjective symptoms slightly improved. (ii) Objective findings: Residual urine volume decreased significantly, and blood prostate specific antigen (PSA) and urinary 8-OHdG levels decreased slightly after the treatment. (iii) Other findings: Blood pressure decreased slightly. No adverse drug reactions were reported. (iv) Patient impressions: 75% of patients gave a rating of "Good" or higher, with 15 out of 20 patients wanting to continue treatment after the end of 4-week administration period. Food formulated with P. japonicum extract and SPE may be useful to decrease frequency of nighttime urination and residual urine volume in male patients with LUTS. © 2017 John Wiley & Sons Australia, Ltd.

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

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...

Substrate-Induced Allosteric Change in the Quaternary Structure of the Spermidine N-Acetyltransferase SpeG.

Science.gov (United States)

Filippova, Ekaterina V; Weigand, Steven; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Anderson, Wayne F

2015-11-06

The spermidine N-acetyltransferase SpeG is a dodecameric enzyme that catalyzes the transfer of an acetyl group from acetyl coenzyme A to polyamines such as spermidine and spermine. SpeG has an allosteric polyamine-binding site and acetylating polyamines regulate their intracellular concentrations. The structures of SpeG from Vibrio cholerae in complexes with polyamines and cofactor have been characterized earlier. Here, we present the dodecameric structure of SpeG from V. cholerae in a ligand-free form in three different conformational states: open, intermediate and closed. All structures were crystallized in C2 space group symmetry and contain six monomers in the asymmetric unit cell. Two hexamers related by crystallographic 2-fold symmetry form the SpeG dodecamer. The open and intermediate states have a unique open dodecameric ring. This SpeG dodecamer is asymmetric except for the one 2-fold axis and is unlike any known dodecameric structure. Using a fluorescence thermal shift assay, size-exclusion chromatography with multi-angle light scattering, small-angle X-ray scattering analysis, negative-stain electron microscopy and structural analysis, we demonstrate that this unique open dodecameric state exists in solution. Our combined results indicate that polyamines trigger conformational changes and induce the symmetric closed dodecameric state of the protein when they bind to their allosteric sites. Copyright © 2015. Published by Elsevier Ltd.

Comparative antioxidant effect of BHT and water extracts of banana and sapodilla peels in raw poultry meat.

Science.gov (United States)

Devatkal, Suresh K; Kumboj, Ritu; Paul, Devosmita

2014-02-01

Antioxidant properties of banana (Musa paradisiaca) and Sapodilla/Chikoo (Manilkara zapota) peel extracts in chicken patties were evaluated. Four treatments viz., I. Control (meat + 2% salt), II.BHT (meat + 2% salt + 0.1% BHT), III. BPE (meat + 2% salt + 2% banana peel extract) and IV. SPE (meat + 2% salt + 2% sapodilla/chikoo peel extract) were compared for changes in colour and lipid oxidation during 8 days refrigerated storage (4 ± °C). The average phenolic content was 550.2 and 550.8 mg gallic acid equivalent per 10 g peel in BPE and SPE respectively. Free radical scavenging activity was 66.9 and 67.8% in BPE and SPE respectively. Banana peel extract had significantly (P peel extract (0.91). During refrigerated storage period, all color parameters decreased significantly in all treatments. Observation on lipid oxidation showed a significantly (P banana and sapodilla peels could be explored as natural antioxidants in poultry meat and meat products.

Validation of a cartridge method for the quality control determination of 99Tcm-HMPAO

International Nuclear Information System (INIS)

Pandos, G.; Penglis, S.; Tsopelas, C.; Royal Adelaide Hospital, Adelaide, SA

1999-01-01

Full text: The manufacturer's method for assessing the radiochemical purity (RCP) of ±-HMPAO requires the use of three solvent types on two different stationary phases, and is time-consuming (∼ 15 min) in consideration of the short shelf-life (30 min). An impetus to develop a rapid quality control procedure for this product has led to the use of a single strip Whatman 17 chromatography system using ethyl acetate as the developing solvent. This popular Whatman paper system was previously validates against the manufacturer's method. We have developed a new method to successfully determine the % RCP of ±-HMPAO, which employs a disposable, inexpensive and reusable Amprep C-18 cartridge with normal saline as a non-organic mobile phase. The Whatman paper system separates the primary lipophilic 99 Tc m -HMPAO complex from 99 Tc m O-2, 99 Tc m O 4 and secondary 99 Tc m -HMPAO complex at the origin. By comparison, the lipophilic portion was retained on the cartridge and the hydrophilic impurities were found in saline eluent with the cartridge method. Whatman 17 paper system results showed 95.1 ± I.7% 99 Tc m -HMPAO after 5 min and the cartridge method gave 95.5 ± 1.5% 99 Tc m -HMPAO (n = 8) after 3 min. The % 99 Tc m O 2 levels in 99 Tc m -HMPAO were insignificant. When a failed kit was assessed for RCP at 2.5 h post-reconstitution, the Whatman paper system and the cartridge method correlated well, resulting in 63.1 ± 2.7% and 62.9±2.1% 99 Tc m -HMPAO (n=3) respectively. Although the cartridge method may slightly overestimate the % RCP of 99 Tc m -HMPAO, it was found to be simple, rapid and reliable for the quality control analysis of routine 99 Tc m -HMPAO preparations

Sensitivity analysis overlaps of friction elements in cartridge seals

Directory of Open Access Journals (Sweden)

Žmindák Milan

2018-01-01

Full Text Available Cartridge seals are self-contained units consisting of a shaft sleeve, seals, and gland plate. The applications of mechanical seals are numerous. The most common example of application is in bearing production for automobile industry. This paper deals with the sensitivity analysis of overlaps friction elements in cartridge seal and their influence on the friction torque sealing and compressive force. Furthermore, it describes materials for the manufacture of sealings, approaches usually used to solution of hyperelastic materials by FEM and short introduction into the topic wheel bearings. The practical part contains one of the approach for measurement friction torque, which results were used to specifying the methodology and precision of FEM calculation realized by software ANSYS WORKBENCH. This part also contains the sensitivity analysis of overlaps friction elements.

Sorptive capacities of lipids determined by passive dosing of non-polar organic chemicals

DEFF Research Database (Denmark)

Jahnke, Annika; Kierkegaard, Amelie; Bolinius, Damien

VMS), chlorobenzenes and polychlorinated biphenyls via a common headspace over an olive oil donor phase to transfer the same chemical activity into the samples; iii) sampling of EOM and olive oil controls at different time points; iv) purge-and-trap extraction of the model chemicals onto ENV+ SPE cartridges, elution...... and GC/MS analysis; v) characterization of the lipid composition in all samples via NMR. Our experiments demonstrate that the sorptive capacities of the EOM samples do not differ significantly from the olive oil controls if the EOM consists of neutral lipids only. However, the EOM samples show small...

Optimal stapler cartridge selection according to the thickness of the pancreas in distal pancreatectomy.

Science.gov (United States)

Kim, Hongbeom; Jang, Jin-Young; Son, Donghee; Lee, Seungyeoun; Han, Youngmin; Shin, Yong Chan; Kim, Jae Ri; Kwon, Wooil; Kim, Sun-Whe

2016-08-01

Stapling is a popular method for stump closure in distal pancreatectomy (DP). However, research on which cartridges are suitable for different pancreatic thickness is lacking. To identify the optimal stapler cartridge choice in DP according to pancreatic thickness.From November 2011 to April 2015, data were prospectively collected from 217 consecutive patients who underwent DP with 3-layer endoscopic staple closure in Seoul National University Hospital, Korea. Postoperative pancreatic fistula (POPF) was graded according to International Study Group on Pancreatic Fistula definitions. Staplers were grouped based on closed length (CL) (Group I: CL ≤ 1.5 mm, II: 1.5 mm 17 mm. With pancreatic thickness <12 mm, the POPF rate was lowest with Group II (I: 50%, II: 27.6%, III: 69.2%, P = 0.035).The optimal stapler cartridges with pancreatic thickness <12 mm were those in Group II (Gold, CL: 1.8 mm). There was no suitable cartridge for thicker pancreases. Further studies are necessary to reduce POPF in thick pancreases.

Preparation of magnetic graphene/mesoporous silica composites with phenyl-functionalized pore-walls as the restricted access matrix solid phase extraction adsorbent for the rapid extraction of parabens from water-based skin toners.

Science.gov (United States)

Feng, Jianan; He, Xinying; Liu, Xiaodan; Sun, Xueni; Li, Yan

2016-09-23

In this work, phenyl-functionalized magnetic graphene/mesoporous silica composites (MG-mSiO2-Ph) were prepared and applied as restricted access matrix solid phase extraction (RAM-SPE) adsorbents to determine the parabens in commercially available retail cosmetics. MG-mSiO2-Ph composites were synthesized by a surfactant-mediated co-condensation reaction in which mesoporous silica with phenyl-functionalized pore-walls was coated on a magnetic graphene sheet. The obtained nano-composites were proven to be of sufficient quality for an ideal RAM-SPE adsorbent with a large specific surface area of 369m(2)g(-1), uniform mesopores of 2.8nm, and special phenyl-functionalized pore-walls. Parabens, such as methyl paraben, ethyl paraben and propyl paraben, were extracted from water-based skin toners using one step of the RAM-SPE and were then analysed by a HPLC-DAD system. The SPE conditions were optimized by studying the parameters, such as the adsorbent amount, elution solvent type, adsorption time and desorption time, that influence the extraction efficiency. For each analyte, there were good linearities of approximately 0.10-120μgmL(-1) with determination coefficients (R(2))>0.995. The sensitivity was as low as 0.01-0.025μgmL(-1) for the LOD, and the percent recoveries were 98.37-105.84%. The intra-day and inter-day RSDs were 1.44-6.11% (n=6) and 3.12-11.70% (n=6), respectively. The results indicated that this method with novel RAM-SPE adsorbents is sensitive and convenient. The results also offered an attractive alternative for the extraction and determination of paraben preservatives in a complex matrix, such as cosmetics. Copyright © 2016 Elsevier B.V. All rights reserved.

Solid Phase Extraction and Spectrophotometric Determination of ...

African Journals Online (AJOL)

NJD

2005-04-15

Apr 15, 2005 ... to the economy and has significant industrial applications. The development of a ... Waters Solid Phase Extraction (SPE) device (the device can carry out twenty ... HPLC grade dimethyl formamide (DMF) (Fisher. Corporation ...

Magazine Influence on Cartridge Case Ejection Patterns with Glock Pistols.

Science.gov (United States)

Kerkhoff, Wim; Alberink, Ivo; Mattijssen, Erwin J A T

2018-01-01

In this study, the cartridge case ejection patterns of six different Glock model pistols (one specimen per model) were compared under three conditions: firing with a loaded magazine, an empty magazine, and without magazine. The distances, covered by the ejected cartridge cases given these three conditions, were compared for each of the six models. A significant difference was found between the groups of data for each of the tested specimens. This indicates that it is important that, to reconstruct a shooting scene incident based on the ejection patterns of a pistol, test shots are fired with the same pistol type and under the correct magazine condition. © 2017 American Academy of Forensic Sciences.

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.

The indicating FTA elute cartridge a solid sample carrier to detect high-risk HPV and high-grade cervical lesions.

Science.gov (United States)

de Bie, Roosmarie P; Schmeink, Channa E; Bakkers, Judith M J E; Snijders, Peter J F; Quint, Wim G V; Massuger, Leon F A G; Bekkers, Ruud L M; Melchers, Willem J G

2011-07-01

The clinically validated high-risk human papillomavirus (hrHPV) Hybrid Capture 2 (HC2) and GP5+/6+-PCR assays were analyzed on an Indicating FTA Elute cartridge (FTA cartridge). The FTA cartridge is a solid dry carrier that allows safe transport of cervical samples. FTA cartridge samples were compared with liquid-based samples for hrHPV and high-grade cervical intraepithelial neoplasia (CIN) detection. One cervical sample was collected in a liquid-based medium, and one was applied to the FTA cartridge. DNA was eluted directly from the FTA cartridge by a simple elution step. HC2 and GP5+/6+-PCR assays were performed on both the liquid-based and the FTA-eluted DNA of 88 women. Overall agreement between FTA and liquid-based samples for the presence of hrHPV was 90.9% with GP5+/6+-PCR and 77.3% with HC2. The sensitivity for high-grade CIN of hrHPV testing on the FTA cartridges was 84.6% with GP5+/6+-PCR and only 53.8% with HC2. By comparison, these sensitivities on liquid-based samples were 92.3% and 100% for GP5+/6+-PCR and HC2, respectively. Therefore, the FTA cartridge shows reasonably good overall agreement for hrHPV detection with liquid-based media when using GP5+/6+-PCR but not HC2 testing. Even with GP5+/6+-PCR, the FTA cartridge is not yet capable of detecting all high-grade CIN lesions. Copyright © 2011 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Graphene oxide for solid-phase extraction of bioactive phenolic acids.

Science.gov (United States)

Hou, Xiudan; Wang, Xusheng; Sun, Yingxin; Wang, Licheng; Guo, Yong

2017-05-01

A solid-phase extraction (SPE) method for the efficient analysis of trace phenolic acids (PAs, caffeic acid, ferulic acid, protocatechuic acid, cinnamic acid) in urine was established. In this work, a graphene oxide (GO) coating was grafted onto pure silica to be investigated as SPE material. The prepared GO surface had a layered and wrinkled structure that was rough and well organized, which could provide more open adsorption sites. Owing to its hydrophilicity and polarity, GO showed higher extraction efficiency toward PAs than reduced GO did, in agreement with the theoretical calculation results performed by Gaussian 09 software. The adsorption mechanism of PAs on GO@Sil was also investigated through static state and kinetic state adsorption experiments, which showed a monolayer surface adsorption. Extraction capacity of the as-prepared material was optimized using the response surface methodology. Under the optimized conditions, the as-established method provided wide linearity range (2-50 μg L -1 for protocatechuic acid and 1-50 μg L -1 for caffeic acid, ferulic acid, and cinnamic acid) and low limits of detection (0.25-1 μg L -1 ). Finally, the established method was applied for the analysis of urine from two healthy volunteers. The results indicate that the prepared material is a practical, cost-effective medium for the extraction and determination of phenolic acids in complex matrices. Graphical Abstract A graphene oxide coating was grafted onto pure silica as the SPE material for the extraction of phenolic acids in urines and the extraction mechanism was also mainly investigated.

A Rapid LC-HRMS Method for the Determination of Domoic Acid in Urine Using a Self-Assembly Pipette Tip Solid-Phase Extraction

Science.gov (United States)

Zhang, Yiping; Chen, Dawei; Hong, Zhuan

2015-01-01

In this study, we developed a self-assembly pipette tip solid-phase extraction (PTSPE) method using a high molecular weight polymer material (PAX) as the adsorbent for the determination of domoic acid (DA) in human urine samples by liquid chromatography high-resolution mass spectrometry (LC-HRMS) analysis. The PTSPE cartridge, assembled by packing 9.1 mg of PAX as sorbent into a 200 μL pipette tip, showed high adsorption capacity for DA owing to the strong cationic properties of PAX. Compared with conventional SPE, the PTSPE is simple and fast, and shows some advantages in the aspects of less solvent consumption, low cost, the absence of the evaporation step, and short time requirement. All the parameters influencing the extraction efficiency such as pH, the amount of sorbent, the number of aspirating/dispensing cycles, and the type and volume of eluent in PTSPE were carefully investigated and optimized. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of DA were 0.12 μg/L and 0.37 μg/L respectively. The extraction recoveries of DA from the urine samples spiked at four different concentrations were in a range from 88.4% to 102.5%. The intra- and inter-day precisions varied from 2.1% to 7.6% and from 2.6% to 12.7%, respectively. The accuracy ranged from −1.9% to −7.4%. PMID:26729165

A Rapid LC-HRMS Method for the Determination of Domoic Acid in Urine Using a Self-Assembly Pipette Tip Solid-Phase Extraction

Directory of Open Access Journals (Sweden)

Yiping Zhang

2015-12-01

Full Text Available In this study, we developed a self-assembly pipette tip solid-phase extraction (PTSPE method using a high molecular weight polymer material (PAX as the adsorbent for the determination of domoic acid (DA in human urine samples by liquid chromatography high-resolution mass spectrometry (LC-HRMS analysis. The PTSPE cartridge, assembled by packing 9.1 mg of PAX as sorbent into a 200 μL pipette tip, showed high adsorption capacity for DA owing to the strong cationic properties of PAX. Compared with conventional SPE, the PTSPE is simple and fast, and shows some advantages in the aspects of less solvent consumption, low cost, the absence of the evaporation step, and short time requirement. All the parameters influencing the extraction efficiency such as pH, the amount of sorbent, the number of aspirating/dispensing cycles, and the type and volume of eluent in PTSPE were carefully investigated and optimized. Under the optimized conditions, the limit of detection (LOD and limit of quantification (LOQ values of DA were 0.12 μg/L and 0.37 μg/L respectively. The extraction recoveries of DA from the urine samples spiked at four different concentrations were in a range from 88.4% to 102.5%. The intra- and inter-day precisions varied from 2.1% to 7.6% and from 2.6% to 12.7%, respectively. The accuracy ranged from −1.9% to −7.4%.

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.

Optimization of cloud point extraction and solid phase extraction methods for speciation of arsenic in natural water using multivariate technique.

Science.gov (United States)

Baig, Jameel A; Kazi, Tasneem G; Shah, Abdul Q; Arain, Mohammad B; Afridi, Hassan I; Kandhro, Ghulam A; Khan, Sumaira

2009-09-28

The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As(3+) and total inorganic arsenic (iAs) in surface and ground water samples. The As(3+) was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1 mol L(-1) HNO(3) in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO(2)); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As(3+) and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As(3+) and iAs (>98.0%). The concentration factor in both cases was found to be 40.

DNA extraction on bio-chip: history and preeminence over conventional and solid-phase extraction methods.

Science.gov (United States)

Ayoib, Adilah; Hashim, Uda; Gopinath, Subash C B; Md Arshad, M K

2017-11-01

This review covers a developmental progression on early to modern taxonomy at cellular level following the advent of electron microscopy and the advancement in deoxyribonucleic acid (DNA) extraction for expatiation of biological classification at DNA level. Here, we discuss the fundamental values of conventional chemical methods of DNA extraction using liquid/liquid extraction (LLE) followed by development of solid-phase extraction (SPE) methods, as well as recent advances in microfluidics device-based system for DNA extraction on-chip. We also discuss the importance of DNA extraction as well as the advantages over conventional chemical methods, and how Lab-on-a-Chip (LOC) system plays a crucial role for the future achievements.

Change in muzzle velocity due to freezing and water immersion of .22, long rifle, K.F. cartridges.

Science.gov (United States)

Jauhari, M; Chatterjee, S M; Ghosh, P K

1975-01-01

A study of change in muzzle velocity due to freezing and water immersion of .22, long rifle, K. F. cartridges has been presented. A statistical criterion has been formulated to ascertain whether or not a cartridge undergoes a change in muzzle velocity due to a particular treatment. The muzzle velocity data of .22, long rifle, K. F. cartridges, obtained by an electronic timer before and after the various treatments, have been analyzed in the light of this criterion. These cartridges have generally been found to suffer considerable loss in muzzle velocity when immersed in water for three weeks and also when immersed in water for three days and simultaneously cooled to 0 degrees C. The forensic significance of this loss in muzzle velocity has been discussed.

Rapid determination of trace nitrophenolic organics in water by combining solid-phase extraction with surface-assisted laser desorption/ionization time-of-flight mass spectrometry.

Science.gov (United States)

Chen, Y C; Shiea, J; Sunner, J

2000-01-01

A rapid technique for the screening of trace compounds in water by combining solid-phase extraction (SPE) with activated carbon surface-assisted laser desorption/ionization (SALDI) time-of-flight mass spectrometry is demonstrated. Activated carbon is used both as the sorbent in SPE and as the solid in the SALDI matrix system. This eliminates the need for an SPE elution process. After the analytes have been adsorbed on the surfaces of the activated carbon during SPE extraction, the activated carbon is directly mixed with the SALDI liquid and mass spectrometric analysis is performed. Trace phenolic compounds in water were used to demonstrate the effectiveness of the method. The detection limit for these compounds is in the ppb to ppt range. Copyright 2000 John Wiley & Sons, Ltd.

Determination of Benzo[α]pyrene in Edible Oil Using Tetraoxocalix[2]arene[2]triazine Bonded Silica SPE Sorbent.

Science.gov (United States)

Guo, Yun; Zhao, Wen-Jie; Deng, Zhi-Fen; Hongbo, Wang; Peng, Bin; Ma, Xue; Lan, Chen; Zhang, Shu-Sheng

2018-06-01

Benzo[α]pyrene (BaP) is a well-known carcinogen in edible oil. In this study, a method combined solid-phase extraction (SPE) with fluorescent detection was developed using tetraoxocalix[2]arene[2]triazine sorbent (SiO 2 -OCA) for the clean-up and enrichment of BaP. The interaction between SiO 2 -OCA and BaP involves a donor-acceptor complex mechanism. The experimental procedure was as follows: BaP was extracted from edible oil with DMF/H 2 O (9:1, v/v). Then, the ratio of DMF/H 2 O was adjusted to 1:2 prior to SPE. The final concentrate was analyzed using a fluorescence detector at excitation and emission wavelengths of 255 and 420 nm. The method was fully validated. The linearity was in the range of 0.1-100 μg kg -1 with a coefficient of 0.999. The limits of detection and quantification were 0.03 and 0.1 μg kg -1 , respectively. The average recoveries were in the range of 88.0-122.3%. The intraday and interday precisions were 6.8% and 9.2%, respectively. Compared with other methods, the method reported in this article shows a good detection limit, high reproducibility and recovery, and linearity over a broad concentration range. This established method was also applied to evaluate real samples. The concentration of six tested samples was below 5 μg kg -1 .

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.

Inhibitory effect of SPE-39 due to tyrosine phosphorylation and ubiquitination on the function of Vps33B in the EGF-stimulated cells.

Science.gov (United States)

Ishii, Ayumi; Kamimori, Kanae; Hiyoshi, Mineyoshi; Kido, Hiroshi; Ohta, Takeshi; Konishi, Hiroaki

2012-07-30

Although SPE-39 is a binding protein to Vps33B that is one of the subunit in the mammalian HOPS complex, the elements of SPE-39 function remain unknown. Here, we show that tyrosine phosphorylation of SPE-39 following EGF stimulation plays a role in the stability of SPE-39 itself. Ubiquitination of the C-terminal region of SPE-39 was also elevated in response to EGF stimulation, and this process was regulated by the phosphorylation of Tyr-11 in SPE-39. However, association of Vps33B with SPE-39 inhibited the elevation of ubiquitination of SPE-39 following EGF stimulation, which might be responsible for the stabilization of SPE-39. Furthermore, an opposing functional relationship between SPE-39 and Vps33B on the downregulation of the EGF receptor was observed in EGF-stimulated COS-7 cells. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Autonomous Monitoring of Radiation Environment and Personal Systems for Crew Enhanced SPE Protection (AMORE and PSYCHE)

Science.gov (United States)

Narici, L.; Baiocco, G.; Berrilli, F.; Giraudo, M.; Ottolenghi, A.; Rizzo, A.; Salina, G.

2018-02-01

Understand the relationship between SPE precursors, the related SPE radiation inside the Deep Space Gateway, and the associated risk levels, validating existing models, proposing countermeasures actions via a real time, autonomous intelligent system.

A novel approach to the simultaneous extraction and non-targeted analysis of the small molecules metabolome and lipidome using 96-well solid phase extraction plates with column-switching technology.

Science.gov (United States)

Li, Yubo; Zhang, Zhenzhu; Liu, Xinyu; Li, Aizhu; Hou, Zhiguo; Wang, Yuming; Zhang, Yanjun

2015-08-28

This study combines solid phase extraction (SPE) using 96-well plates with column-switching technology to construct a rapid and high-throughput method for the simultaneous extraction and non-targeted analysis of small molecules metabolome and lipidome based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry. This study first investigated the columns and analytical conditions for small molecules metabolome and lipidome, separated by an HSS T3 and BEH C18 columns, respectively. Next, the loading capacity and actuation duration of SPE were further optimized. Subsequently, SPE and column switching were used together to rapidly and comprehensively analyze the biological samples. The experimental results showed that the new analytical procedure had good precision and maintained sample stability (RSDmetabolome and lipidome to test the throughput. The resulting method represents a new analytical approach for biological samples, and a highly useful tool for researches in metabolomics and lipidomics. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of constituents in Allium by multivariate data analysis, high-resolution α-glucosidase inhibition assay and HPLC-SPE-NMR

DEFF Research Database (Denmark)

Schmidt, Jeppe Secher; Nyberg, Nils; Stærk, Dan

2014-01-01

Bulbs and leaves of 35 Allium species and cultivars bought or collected in 2010–2012 were investigated with multivariate data analysis, high-resolution α-glucosidase inhibition assays and HPLC-HRMS-SPE-NMR with the aim of exploring the potential of Allium as a future functional food for management...... of type 2 diabetes. It was found that 30 out of 106 crude extracts showed more than 80% inhibition of the α-glucosidase enzyme at a concentration of 40 mg/mL (dry sample) or 0.4 g/mL (fresh sample). High-resolution α-glucosidase biochromatograms of these extracts allowed fast identification of three...

Are extracted materials truly representative of original samples? Impact of C18 extraction on CDOM optical and chemical properties

Directory of Open Access Journals (Sweden)

Andrea A Andrew

2016-02-01

Full Text Available Some properties of dissolved organic matter (DOM and chromophoric dissolved organic matter (CDOM can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB and the Equatorial Atlantic Ocean (EAO. Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4.C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission and quantum yield of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

Are extracted materials truly representative of original samples? Impact of C18 extraction on CDOM optical and chemical properties

Science.gov (United States)

Andrew, Andrea; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil

2016-02-01

Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

Development of ion imprinted polymers for the selective extraction of lanthanides from environmental samples

International Nuclear Information System (INIS)

Moussa, Manel

2016-01-01

The analysis of the lanthanide ions present at trace level in complex environmental matrices requires often a purification and preconcentration step. The solid phase extraction (SPE) is the most used sample preparation technique. To improve the selectivity of this step, Ion Imprinted Polymers (IIPs) can be used as SPE solid supports. The aim of this work was the development of IIPs for the selective extraction of lanthanide ions from environmental samples. In a first part, IIPs were prepared according to the trapping approach using 5,7-dichloroquinoline-8-ol as non-vinylated ligand. For the first time, the loss of the trapped ligand during template ion removal and sedimentation steps was demonstrated by HPLC-UV. Moreover, this loss was not repeatable, which led to a lack of repeatability of the SPE profiles. It was then demonstrated that the trapping approach is not appropriate for the IIPs synthesis. In a second part, IIPs were synthesized by chemical immobilization of methacrylic acid as vinylated monomer. The repeatability of the synthesis and the SPE protocol were confirmed. A good selectivity of the IIPs for all the lanthanide ions was obtained. IIPs were successfully used to selectively extract lanthanide ions from tap and river water. Finally, IIPs were synthesized by chemical immobilization of methacrylic acid and 4-vinylpyridine as functional monomers and either a light (Nd 3+ ) or a heavy (Er 3+ ) lanthanide ion as template. Both kinds of IIPs led to a similar selectivity for all lanthanide ions. Nevertheless, this selectivity can be modified by changing the nature and the pH of the washing solution used in the SPE protocol. (author)

The protective role of saffron petal extracts on gentamicininduced nephrotoxicity in rats

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Arash Omidi

2016-07-01

Full Text Available Different potentially therapeutic approaches to prevent or attenuate gentamicin sulfate (GM induced nephrotoxicity have been proposed. The present study was conducted to investigate the effect of the saffron petals extracts (Crocus sativus (SPE on male Wistar rats with kidney failure. Rats (40 were randomly assigned into five groups of 8 animals each: i the control group, that received normal saline (0.5 mL/kg; ii the GM group, that received GM (80 mg/kg by intraperitoneal (i.p. injection on a daily basis; iii the GM+SPE group that received the same dose of GM and SPE (40 mg/kg by i.p. injection on a daily basis; iv the GM+2SPE group, that received the same dose of GM and twofold of SPE (80 mg/kg by i.p. injection on a daily basis; whereas v 2SPE+GM group, that received 80 mg/kg of SPE a week before initiating the treatment with GM (prevention group. Significant differences were seen in the concentration of glucose, blood urea nitrogen (BUN, and creatinine between treatment groups and control in the male Wistar rats. GM was observed to cause nephrotoxicity, which was evidenced by an elevation of serum BUN and creatinine levels. The biochemical findings of the current study are concordant with those of histopathologic findings. The results of this study indicate that SPE especially in dose of 40 mg/kg can ameliorate harmful effects of GM on the kidney. The present results may suggest that the SPE have ameliorative effects on kidney failures induced by GM.

Anesthetic success of 1.8ml lidocaine 2% for mandibular tooth extraction. A pilot study

Directory of Open Access Journals (Sweden)

Pedro Aravena

2013-04-01

Full Text Available Aim: To determine the anesthetic effect of a 1.8ml cartridge of anesthetic lidocaine 2% with epinephrine 1:100,000 in inferior alveolar nerve block (NAI for the extraction in mandibular teeth. Material and methods: A pilot study with analitic design. Participating patients of Dental Emergency Service volunteers from Valdivia-Chile for mandibular teeth extractions attending between May and July of 2010. The anesthetic technique was performed by a dentist using only one cartridge of anesthetic to the NAI. After 15 minutes, the effect was considered effective when anesthetic not require reinforcement with additional anesthesia during extraction of teeth. We analyzed the relationship between success anesthetic effect with sex, age, diagnosis of tooth and type and level of pain observed (chi-square and logistic regression, p<0.05. Results: 62 patients were selected, of which only 47(75.8% was achieved anesthetic success. There was no statistical association with sex, age, type or dental diagnosis and perceived pain. Conclusion: Using a 1.8ml cartridge of anesthesia was effective in three of four patients treated by extraction of mandibular teeth. It suggests further research in relation to the clinical effectiveness of other anesthetics with the same dose in NAI.

New Method To Estimate Total Polyphenol Excretion: Comparison of Fast Blue BB versus Folin-Ciocalteu Performance in Urine.

Science.gov (United States)

Hinojosa-Nogueira, Daniel; Muros, Joaquín; Rufián-Henares, José A; Pastoriza, Silvia

2017-05-24

Polyphenols are bioactive substances of vegetal origin with a significant impact on human health. The assessment of polyphenol intake and excretion is therefore important. The Folin-Ciocalteu (F-C) method is the reference assay to measure polyphenols in foods as well as their excretion in urine. However, many substances can influence the method, making it necessary to conduct a prior cleanup using solid-phase extraction (SPE) cartridges. In this paper, we demonstrate the use of the Fast Blue BB reagent (FBBB) as a new tool to measure the excretion of polyphenols in urine. Contrary to F-C, FBBB showed no interference in urine, negating the time-consuming and costly SPE cleanup. In addition, it showed excellent linearity (r 2 = 0.9997), with a recovery of 96.4% and a precision of 1.86-2.11%. The FBBB method was validated to measure the excretion of polyphenols in spot urine samples from Spanish children, showing a good correlation between polyphenol intake and excretion.

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.

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

Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

OpenAIRE

Afrida Kurnia Putri; Wang-Hsien Ding; Han-Wen Kuo

2012-01-01

A characterization of activated carbon (ACs) prepared from rice husks (RHs) under base treated condition as a new sorbent for solid-phase extraction (SPE) to extract 4-nonylphenol isomers (4-NPs) in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance inte...

Method of analysis and quality-assurance practices for determination of pesticides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry at the U.S. Geological Survey California District Organic Chemistry Laboratory, 1996-99

Science.gov (United States)

Crepeau, Kathryn L.; Baker, Lucian M.; Kuivila, Kathryn

2000-01-01

A method of analysis and quality-assurance practices were developed to study the fate and transport of pesticides in the San Francisco Bay-Estuary by the U.S. Geological Survey. Water samples were filtered to remove suspended-particulate matter and pumped through C-8 solid-phase extraction cartridges to extract the pesticides. The cartridges were dried with carbon dioxide and the pesticides were eluted with three cartridge volumes of hexane:diethyl ether (1:1) solution. The eluants were analyzed using capillary-column gas chromatography/mass spectrometry in full-scan mode. Method detection limits for pesticides ranged from 0.002 to 0.025 microgram per liter for 1-liter samples. Recoveries ranged from 44 to 140 percent for 25 pesticides in samples of organic-free reagent water and Sacramento-San Joaquin Delta and Suisun Bay water fortified at 0.05 and 0.50 microgram per liter. The estimated holding time for pesticides after extraction on C-8 solid-phase extraction cartridges ranged from 10 to 257 days.

A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants.

Science.gov (United States)

Heub, Sarah; Tscharner, Noe; Kehl, Florian; Dittrich, Petra S; Follonier, Stéphane; Barbe, Laurent

2016-01-01

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17β-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 µl of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.

A novel polyamine allosteric site of SpeG from Vibrio cholerae is revealed by its dodecameric structure.

Science.gov (United States)

Filippova, Ekaterina V; Kuhn, Misty L; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Ballicora, Miguel A; Anderson, Wayne F

2015-03-27

Spermidine N-acetyltransferase, encoded by the gene speG, catalyzes the initial step in the degradation of polyamines and is a critical enzyme for determining the polyamine concentrations in bacteria. In Escherichia coli, studies have shown that SpeG is the enzyme responsible for acetylating spermidine under stress conditions and for preventing spermidine toxicity. Not all bacteria contain speG, and many bacterial pathogens have developed strategies to either acquire or silence it for pathogenesis. Here, we present thorough kinetic analyses combined with structural characterization of the VCA0947 SpeG enzyme from the important human pathogen Vibrio cholerae. Our studies revealed the unexpected presence of a previously unknown allosteric site and an unusual dodecameric structure for a member of the Gcn5-related N-acetyltransferase superfamily. We show that SpeG forms dodecamers in solution and in crystals and describe its three-dimensional structure in several ligand-free and liganded structures. Importantly, these structural data define the first view of a polyamine bound in an allosteric site of an N-acetyltransferase. Kinetic characterization of SpeG from V. cholerae showed that it acetylates spermidine and spermine. The behavior of this enzyme is complex and exhibits sigmoidal curves and substrate inhibition. We performed a detailed non-linear regression kinetic analysis to simultaneously fit families of substrate saturation curves to uncover a simple kinetic mechanism that explains the apparent complexity of this enzyme. Our results provide a fundamental understanding of the bacterial SpeG enzyme, which will be key toward understanding the regulation of polyamine levels in bacteria during pathogenesis. Copyright © 2015. Published by Elsevier Ltd.

A Compact Laboratory Spectro-Goniometer (CLabSpeG) to Assess the BRDF of Materials. Presentation, Calibration and Implementation on Fagus sylvatica L. Leaves.

Science.gov (United States)

Biliouris, Dimitrios; Verstraeten, Willem W; Dutré, Phillip; Van Aardt, Jan A N; Muys, Bart; Coppin, Pol

2007-09-07

The design and calibration of a new hyperspectral Compact Laboratory Spectro-Goniometer (CLabSpeG) is presented. CLabSpeG effectively measures the bidirectionalreflectance Factor (BRF) of a sample, using a halogen light source and an AnalyticalSpectral Devices (ASD) spectroradiometer. The apparatus collects 4356 reflectance datareadings covering the spectrum from 350 nm to 2500 nm by independent positioning of thesensor, sample holder, and light source. It has an azimuth and zenith resolution of 30 and15 degrees, respectively. CLabSpeG is used to collect BRF data and extract BidirectionalReflectance Distribution Function (BRDF) data of non-isotropic vegetation elements suchas bark, soil, and leaves. Accurate calibration has ensured robust geometric accuracy of theapparatus, correction for the conicality of the light source, while sufficient radiometricstability and repeatability between measurements are obtained. The bidirectionalreflectance data collection is automated and remotely controlled and takes approximatelytwo and half hours for a BRF measurement cycle over a full hemisphere with 125 cmradius and 2.4 minutes for a single BRF acquisition. A specific protocol for vegetative leafcollection and measurement was established in order to investigate the possibility to extractBRDF values from Fagus sylvatica L. leaves under laboratory conditions. Drying leafeffects induce a reflectance change during the BRF measurements due to the laboratorySensors 2007, 7 1847 illumination source. Therefore, the full hemisphere could not be covered with one leaf. Instead 12 BRF measurements per leaf were acquired covering all azimuth positions for a single light source zenith position. Data are collected in radiance format and reflectance is calculated by dividing the leaf cycle measurement with a radiance cycle of a Spectralon reference panel, multiplied by a Spectralon reflectance correction factor and a factor to correct for the conical effect of the light source. BRF results

A Compact Laboratory Spectro-Goniometer (CLabSpeG to Assess the BRDF of Materials. Presentation, Calibration and Implementation on Fagus sylvatica L. Leaves

Directory of Open Access Journals (Sweden)

Pol Coppin

2007-09-01

Full Text Available The design and calibration of a new hyperspectral Compact Laboratory Spectro-Goniometer (CLabSpeG is presented. CLabSpeG effectively measures the bidirectionalreflectance Factor (BRF of a sample, using a halogen light source and an AnalyticalSpectral Devices (ASD spectroradiometer. The apparatus collects 4356 reflectance datareadings covering the spectrum from 350 nm to 2500 nm by independent positioning of thesensor, sample holder, and light source. It has an azimuth and zenith resolution of 30 and15 degrees, respectively. CLabSpeG is used to collect BRF data and extract BidirectionalReflectance Distribution Function (BRDF data of non-isotropic vegetation elements suchas bark, soil, and leaves. Accurate calibration has ensured robust geometric accuracy of theapparatus, correction for the conicality of the light source, while sufficient radiometricstability and repeatability between measurements are obtained. The bidirectionalreflectance data collection is automated and remotely controlled and takes approximatelytwo and half hours for a BRF measurement cycle over a full hemisphere with 125 cmradius and 2.4 minutes for a single BRF acquisition. A specific protocol for vegetative leafcollection and measurement was established in order to investigate the possibility to extractBRDF values from Fagus sylvatica L. leaves under laboratory conditions. Drying leafeffects induce a reflectance change during the BRF measurements due to the laboratorySensors 2007, 7 1847 illumination source. Therefore, the full hemisphere could not be covered with one leaf. Instead 12 BRF measurements per leaf were acquired covering all azimuth positions for a single light source zenith position. Data are collected in radiance format and reflectance is calculated by dividing the leaf cycle measurement with a radiance cycle of a Spectralon reference panel, multiplied by a Spectralon reflectance correction factor and a factor to correct for the conical effect of the light

Solid phase extraction method for determination of mitragynine in ...

African Journals Online (AJOL)

All rights reserved. ... 1Department of Pharmacology, 2Department of Applied Science, 3Police Forensic Science Center 10, Yala 95000, 4Natural ... Purpose: To develop a solid phase extraction (SPE) method that utilizes reverse-phase high.

Effects of saw palmetto extract on micturition reflex of rats and its autonomic receptor binding activity.

Science.gov (United States)

Oki, Tomomi; Suzuki, Mayumi; Nishioka, Yasuhiko; Yasuda, Akio; Umegaki, Keizo; Yamada, Shizuo

2005-04-01

We examined the effects of saw palmetto extract (SPE) on the rat micturition reflex and on autonomic receptors in the lower urinary tract. The effect of SPE was examined on cystometrograms of anesthetized rats induced by intravesical infusion of saline or 0.1% acetic acid. SHR/NDmc-cp (cp/cp) rats received repeat oral administration of SPE and nighttime urodynamic function was determined. The autonomic receptor binding activity of SPE in the rat bladder and prostate was examined by radioligand binding assay. Intraduodenal administration of SPE (60 mg/kg) in anesthetized rat cystometry caused a significant increase in the micturition interval, micturition volume and bladder capacity during intravesical saline infusion. Also, similar administration of SPE at doses of 12 and 20 mg/kg significantly reversed the shortened micturition interval as well as the decreased micturition volume and bladder capacity due to 0.1% acetic acid infusion in a dose dependent manner. In conscious SHR/NDmc-cp (cp/cp) rats repeat oral administration of SPE (6 mg/kg daily) constantly increased the micturition interval and concomitantly decreased voiding frequency. SPE inhibited specific binding of [H]NMS ([N-methyl-H]scopolamine methyl chloride) (bladder) and [H]prazosin (prostate) with IC50 values of 46.1 and 183 microg/ml, respectively. SPE significantly alleviates urodynamic symptoms in hyperactive rat bladders by increasing bladder capacity and subsequently prolonging the micturition interval. Our data may support the clinical efficacy of SPE for the treatment of lower urinary tract symptoms.

after solid phase extraction on modified sawdust s

African Journals Online (AJOL)

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extraction (SPE) techniques are widely used for the determination of trace metal ions in aqueous samples, because ... adsorption resin [16] and modified activated carbon [17]. ... washed with distilled water, and dried in oven at 40 ºC for 24 h.

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 sys...

Core-shell indium (III) sulfide@metal-organic framework nanocomposite as an adsorbent for the dispersive solid-phase extraction of nitro-polycyclic aromatic hydrocarbons.

Science.gov (United States)

Jia, Yuqian; Zhao, Yanfang; Zhao, Mei; Wang, Zhenhua; Chen, Xiangfeng; Wang, Minglin

2018-05-25

A core-shell discoid shaped indium (III) sulfide@metal-organic framework (MIL-125(Ti)) nanocomposite was synthesized by a solvothermal method and explored as an adsorbent material for dispersive solid-phase extraction (d-SPE). The as-synthesized sorbent was characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, powder X-ray diffraction, N 2 adsorption-desorption analysis, and Fourier transform infrared spectroscopy. The extraction performance was evaluated by the d-SPE of 16 nitro-polycyclic aromatic hydrocarbons (NPAHs) from water samples. The analysis was carried out by gas chromatography (GC) coupled with triple quadruple mass spectrometer in negative chemical ionization (NCI) mode. The selected ion monitoring (SIM) was used in the quantification of the target NPAHs. Extraction factors affecting the d-SPE, including the ionic strength, extraction temperature, and extraction time were optimized by the response surface methodology. The developed d-SPE method showed good linear correlations from 10 to 1000 ng L -1 (r > 0.99), low detection limits (2.9-83.0 ng L -1 ), satisfactory repeatability (relative standard deviation of <10%, n = 6), and acceptable recoveries (71.3%-112.2%) for water samples. The developed method was used for the food and environmental sample analysis. The results demonstrated that the method could be used for sample preparation of trace NPAHs in real samples. Copyright © 2018. Published by Elsevier B.V.

Microfluidic cartridges for automated, point-of-care blood cell counting

CSIR Research Space (South Africa)

Smith, Suzanne

2016-11-01

Full Text Available Disposable, low-cost microfluidic cartridges for automated blood cell counting applications are presented in this article. The need for point-of-care medical diagnostic tools is evident, particularly in low-resource and rural settings, and a full...

Rapid determination of ions by combined solid-phase extraction--diffuse reflectance spectroscopy

Science.gov (United States)

Fritz, James S.; Arena, Matteo P.; Steiner, Steven A.; Porter, Marc D.

2003-01-01

We introduce colorimetric solid-phase extraction (C-SPE) for the rapid determination of selected ions. This new technique links the exhaustive concentration of an analyte by SPE onto a membrane disk surface for quantitative measurement with a hand-held diffuse reflectance spectrometer. The concentration/measurement procedure is complete in approximately 1 min and can be performed almost anywhere. This method has been used to monitor iodine and iodide in spacecraft water in the 0.1-5.0 ppm range and silver(I) in the range of 5.0-1000 microg/l. Applications to the trace analysis of copper(II), nickel(II), iron(III) and chromium(VI) are described. Studies on the mechanism of extraction showed that impregnation of the disk with a surfactant as well as a complexing reagent results in uptake of additional water, which markedly improves the extraction efficiency.

Recent Developments in Solid-Phase Extraction for Near and Attenuated Total Reflection Infrared Spectroscopic Analysis

Directory of Open Access Journals (Sweden)

Christian W. Huck

2016-05-01

Full Text Available A review with more than 100 references on the principles and recent developments in the solid-phase extraction (SPE prior and for in situ near and attenuated total reflection (ATR infrared spectroscopic analysis is presented. New materials, chromatographic modalities, experimental setups and configurations are described. Their advantages for fast sample preparation for distinct classes of compounds containing different functional groups in order to enhance selectivity and sensitivity are discussed and compared. This is the first review highlighting both the fundamentals of SPE, near and ATR spectroscopy with a view to real sample applicability and routine analysis. Most of real sample analyses examples are found in environmental research, followed by food- and bioanalysis. In this contribution a comprehensive overview of the most potent SPE-NIR and SPE-ATR approaches is summarized and provided.

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.

Combustible Cartridge Cases: Current Status and Future Prospects

Science.gov (United States)

1992-08-01

and presents new models of combustible cartridge case burning . Following a summary of experimental data, it concludes with proposals for further...UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED SAR NSN 7540-01-280-5500 Standard Form 298 (Rev 2-89) Precribed by ANSI Std Z39-19 IWFENTIONALLY LEFT BLANK...7 3.3 In-Depth Burning Model ........................................ 7 3.3.1 M odel A ................................................ 9 3.3.2

Solid phase extraction membrane

Science.gov (United States)

Carlson, Kurt C [Nashville, TN; Langer, Roger L [Hudson, WI

2002-11-05

A wet-laid, porous solid phase extraction sheet material that contains both active particles and binder and that possesses excellent wet strength is described. The binder is present in a relatively small amount while the particles are present in a relatively large amount. The sheet material is sufficiently strong and flexible so as to be pleatable so that, for example, it can be used in a cartridge device.

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...... 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....... for the study. MVLN cells, stably transfected with an estrogen receptor (ER) luciferase reporter vector (ERE-CALUX), were exposed to the reconstituted SPE-HPLC extracts for determination of the integrated estrogenic activity. The effects of PCBs were analyzed by direct in vitro exposure of PCBs (138, 153...

[Treatment-refractory-dental-extraction-associated pyothorax involving infection by 2 species of oral originated bacteria requires surgical debridement by video assisted thoracoscopic surgery (VATS)].

Science.gov (United States)

Rai, Kammei; Matsuo, Kiyoshi; Yonei, Toshiro; Sato, Toshio

2008-09-01

Cases of septic pulmonary embolism (SPE) diagnosed clinically by CT after dental extraction rarely include verification of bacteria from the local infection site. We report the case of a 70-year-old man without background disease suffering severe pyothrax after dental extraction. We detected two species of oral bacteria from his pleural effusion. Treatment was so difficult that it required surgical debridement by video assisted thoracoscopic surgery (VATS), even after the appropriate administration of antibiotics. According to the American Heart Association (AHA) prophylaxis guidelines for preventing infective endocarditis indicate that it is uncommon to prescribe antibiotics to patients without background disease after dental extraction. No appropriate Japanese guidelines exist considering the prevention of SPE causing severe pyothorax as in our case. The hematogenous spread of bacteria such as SPE caused by sepsis after tooth extraction thus requires more attended careful consideration in clinical practice if patients are to be properly protected against potentially serious complications.

Characterization of cartridge filters from the IEA-R1 Nuclear Reactor

International Nuclear Information System (INIS)

2015-01-01

The management of radioactive waste ensures safety to human health and the environment nowadays and for the future, without overwhelming the upcoming generations. The primary characterization of radioactive waste is one of the main steps in the management of radioactive waste. This step permits to choose the best treatment for the radioactive waste before forwarding it to its final disposal. The aim of the present work is the primary characterization of cartridge filters from the IEA-R1 nuclear reactor utilizing gamma-ray spectrometry, and the method of Monte Carlo for calibration. The IEA-R1 is located in the Nuclear and Energy Research Institute (IPEN - CNEN) in the city of Sao Paulo, Brazil. Cartridge filters are used for purification of the cooling water that is pumped through the core of the pool type nuclear research reactors. Once worn out, these filters are replaced and then become radioactive waste. Determination of the radioactive inventory is of paramount importance in the management of such radioactive waste, and one of the main methods for doing so is the gamma-ray spectrometry, which can identify and quantify high energy photon emitters. The technique chosen for the characterization of radioactive waste in the present work is the gamma-ray spectrometry with High purity Germanium (HPGe) detectors. From the energy identified in the experimental spectrum, three radioisotopes were identified in the cartridge filter: 108m Ag, 110m Ag, 60 Co. For the estimated activity of the filter, the calibration in efficiency was made utilizing the MCNP4C code of the Monte Carlo method. Such method was chosen because there is no standard source available in the same geometry of the cartridge filter, therefore a simulation had to be developed in order to reach a calibration equation, necessary to estimate the activity of the radioactive waste. The results presented an activity value in the order of MBq for all radioisotopes. (authors)

Characterization of cartridge filters from the IEA-R1 Nuclear Reactor

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-07-01

The management of radioactive waste ensures safety to human health and the environment nowadays and for the future, without overwhelming the upcoming generations. The primary characterization of radioactive waste is one of the main steps in the management of radioactive waste. This step permits to choose the best treatment for the radioactive waste before forwarding it to its final disposal. The aim of the present work is the primary characterization of cartridge filters from the IEA-R1 nuclear reactor utilizing gamma-ray spectrometry, and the method of Monte Carlo for calibration. The IEA-R1 is located in the Nuclear and Energy Research Institute (IPEN - CNEN) in the city of Sao Paulo, Brazil. Cartridge filters are used for purification of the cooling water that is pumped through the core of the pool type nuclear research reactors. Once worn out, these filters are replaced and then become radioactive waste. Determination of the radioactive inventory is of paramount importance in the management of such radioactive waste, and one of the main methods for doing so is the gamma-ray spectrometry, which can identify and quantify high energy photon emitters. The technique chosen for the characterization of radioactive waste in the present work is the gamma-ray spectrometry with High purity Germanium (HPGe) detectors. From the energy identified in the experimental spectrum, three radioisotopes were identified in the cartridge filter: {sup 108m}Ag, {sup 110m}Ag, {sup 60}Co. For the estimated activity of the filter, the calibration in efficiency was made utilizing the MCNP4C code of the Monte Carlo method. Such method was chosen because there is no standard source available in the same geometry of the cartridge filter, therefore a simulation had to be developed in order to reach a calibration equation, necessary to estimate the activity of the radioactive waste. The results presented an activity value in the order of MBq for all radioisotopes. (authors)

Novel radiosynthesis of PET HSV-tk gene reporter probes [18F]FHPG and [18F]FHBG employing dual Sep-Pak SPE techniques.

Science.gov (United States)

Wang, Ji-Quan; Zheng, Qi-Huang; Fei, Xiangshu; Mock, Bruce H; Hutchins, Gary D

2003-11-17

Positron emission tomography (PET) herpes simplex virus thymidine kinase (HSV-tk) gene reporter probes 9-[(3-[(18)F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([(18)F]FHPG) and 9-(4-[(18)F]fluoro-3-hydroxymethylbutyl)guanine ([(18)F]FHBG) were prepared by nucleophilic substitution of the appropriate tosylated precursors with [(18)F]KF/Kryptofix 2.2.2 followed by a quick deprotection reaction and purification with a simplified dual Silica Sep-Pak solid-phase extraction (SPE) method in 15-30% radiochemical yield.

Use of itaconic acid-based polymers for solid-phase extraction of deoxynivalenol and application to pasta analysis.

Science.gov (United States)

Pascale, Michelangelo; De Girolamo, Annalisa; Visconti, Angelo; Magan, Naresh; Chianella, Iva; Piletska, Elena V; Piletsky, Sergey A

2008-02-25

Molecular modelling and computational design were used to identify itaconic acid (IA) as a functional monomer with high affinity towards deoxynivalenol (DON), a Fusarium-toxin frequently occurring in cereals. IA-based polymers were photochemically synthesised in dimethyl formamide (porogen) using ethylenglycol dimethacrylate as cross-linker and 1,1'-azo-bis(cyclohexane carbonitrile) as initiator, and the relevant binding interactions with DON in solvents with different polarity were investigated. The performances of the non-imprinted IA-based polymer (blank polymer, BP) and the corresponding molecularly imprinted polymer (MIP) were compared using DON as a template. Both BP and MIP were able to bind about 90% DON either in toluene, water or water containing 5% polyethylene glycol. Non-imprinted polymers with different molar ratios of IA to cross-linker were evaluated as adsorbents for solid-phase extraction (SPE) clean-up and pre-concentration of DON from wheat and pasta samples prior to HPLC analysis. Samples were extracted with PBS/0.1M EDTA solution and cleaned up through a cartridge containing blank IA-based polymer. The column was washed with PBS (pH 9.2) and the toxin was eluted with methanol and quantified by reversed-phase HPLC with UV detector (lambda=220nm), using methanol:water:acetic acid (15:85:0.1, v/v/v) as the mobile phase. Effective removal of matrix interferences was observed only for pasta with DON recoveries higher than 70% (RSD<7%, n=3) at levels close to or higher than EU regulatory limit.

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...

An Evaluation of Illicit Stimulants and Metabolites in Wastewa ter Effluent and the Wisconsin River Along the Central Wisconsin River Basin

Directory of Open Access Journals (Sweden)

Erik S. Hendrickson

2015-09-01

Full Text Available The goals of the study were to develop a method for extracting and quantifying illicit stimulants and metabolites, methamphetamine, amphetamine, cocaine, and benzoylecogonine from wastewater effluent and surface water grab samples, and evaluate Central Wisconsin wastewater treatment plant’s (WWTP removal efficiency of compounds of interest. The method created used HLB solid-phase extraction (SPE cartridges to extract substances of interest and High Performance Liquid Chromatography tandem Mass Spectrometry (HPLC/MS/MS for quantification and qualification. All four wastewater effluent samples and three Wisconsin River samples had quantifiable concentrations of at least one analyte. Conclusions derived from the study were: The method created is effective for separating, quantifying, and identifying amphetamine, cocaine, and benzoylecognine from wastewater effluent and surface water grab samples, and each illicit stimulant and metabolite analyzed in this study were all quantified in wastewater effluent, indicating these compounds have the ability to survive WWTP.

A fast, simple and green method for the extraction of carbamate pesticides from rice by microwave assisted steam extraction coupled with solid phase extraction.

Science.gov (United States)

Song, Weitao; Zhang, Yiqun; Li, Guijie; Chen, Haiyan; Wang, Hui; Zhao, Qi; He, Dong; Zhao, Chun; Ding, Lan

2014-01-15

This paper presented a fast, simple and green sample pretreatment method for the extraction of 8 carbamate pesticides in rice. The carbamate pesticides were extracted by microwave assisted water steam extraction method, and the extract obtained was immediately applied on a C18 solid phase extraction cartridge for clean-up and concentration. The eluate containing target compounds was finally analysed by high performance liquid chromatography with mass spectrometry. The parameters affecting extraction efficiency were investigated and optimised. The limits of detection ranging from 1.1 to 4.2ngg(-1) were obtained. The recoveries of 8 carbamate pesticides ranged from 66% to 117% at three spiked levels, and the inter- and intra-day relative standard deviation values were less than 9.1%. Compared with traditional methods, the proposed method cost less extraction time and organic solvent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bubble Jet agent release cartridge for chemical single cell stimulation.

Science.gov (United States)

Wangler, N; Welsche, M; Blazek, M; Blessing, M; Vervliet-Scheebaum, M; Reski, R; Müller, C; Reinecke, H; Steigert, J; Roth, G; Zengerle, R; Paust, N

2013-02-01

We present a new method for the distinct specific chemical stimulation of single cells and small cell clusters within their natural environment. By single-drop release of chemical agents with droplets in size of typical cell diameters (d agent release cartridge with integrated fluidic structures and integrated agent reservoirs are shown, tested, and compared in this publication. The single channel setup features a fluidic structure fabricated by anisotropic etching of silicon. To allow for simultaneous release of different agents even though maintaining the same device size, the second type comprises a double channel fluidic structure, fabricated by photolithographic patterning of TMMF. Dispensed droplet volumes are V = 15 pl and V = 10 pl for the silicon and the TMMF based setups, respectively. Utilizing the agent release cartridges, the application in biological assays was demonstrated by hormone-stimulated premature bud formation in Physcomitrella patens and the individual staining of one single L 929 cell within a confluent grown cell culture.

[Hemostatic system parameters of placental extracts in normal pregnancy and severe preeclampsia].

Science.gov (United States)

López-Ramírez, Ysabel; Carvajal, Zoila; Arocha-Piñango, Carmen Luisa

2006-09-01

To better understand the role of the hemostatic mechanism in preeclampsia, placental extracts obtained from 26 normal pregnant women (NP) and 12 patients with severe pre-eclampsia (SPE) were analyzed to determine thrombomodulin (TM), tissue factor (TF), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor (PAI) 1 and 2, and TF pathway inhibitor (TFPI). The results showed similar concentrations of TF, TM and PAI-2 in both groups, while tPA increased no significantly and TFPI and PAI-1 increased significantly in SPE placentas.

SPE analysis of high efficiency PMTs for the DEAP-3600 dark matter detector

International Nuclear Information System (INIS)

Olsen, Kevin; Hallin, Aksel

2011-01-01

The Dark matter Experiment using Argon Pulse-shape discrimination is a collaborative effort to develop a next-generation, tonne-scale dark matter detector at SNOLAB. The detector will feature a single-phase liquid argon (LAr) target surrounded by an array of 266 photomultiplier tubes (PMTs). A new high-efficiency Hamamatsu R877-100 PMT has been delivered to the University of Alberta for evaluation by the DEAP collaboration. The increase in efficiency could lead to a much greater light yield, but other experiments have reported a slower rise time. We have placed the PMT in a small dark box and had a base and preamplifier designed to be used with either an oscilloscope or a multi-channel analyzer. With this setup we have demonstrated the PMT's ability to distinguish single photo-electrons (SPE) and characterized the PMT by measuring the SPE pulse height spectrum, the peak-to-valley ratio, the dark pulse rate, the baseline, time resolution and SPE efficiency for varying the high voltage supplied to the PMT.

Offline solid-phase extraction for preconcentration of pharmaceuticals and personal care products in environmental water and their simultaneous determination using the reversed phase high-performance liquid chromatography method.

Science.gov (United States)

G Archana; Dhodapkar, Rita; Kumar, Anupama

2016-09-01

The present study reports a precise and simple offline solid-phase extraction (SPE) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of five representative and commonly present pharmaceuticals and personal care products (PPCPs), a new class of emerging pollutants in the aquatic environment. The target list of analytes including ciprofloxacin, acetaminophen, caffeine benzophenone and irgasan were separated by a simple HPLC method. The column used was a reversed-phase C18 column, and the mobile phase was 1 % acetic acid and methanol (20:80 v/v) under isocratic conditions, at a flow rate of 1 mL min(-1). The analytes were separated and detected within 15 min using the photodiode array detector (PDA). The linearity of the calibration curves were obtained with correlation coefficients 0.98-0.99.The limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and ruggedness demonstrated the reproducibility, specificity and sensitivity of the developed method. Prior to the analysis, the SPE was performed using a C18 cartridge to preconcentrate the targeted analytes from the environmental water samples. The developed method was applied to evaluate and fingerprint PPCPs in sewage collected from a residential engineering college campus, polluted water bodies such as Nag river and Pili river and the influent and effluent samples from a sewage treatment plant (STP) situated at Nagpur city, in the peak summer season. This method is useful for estimation of pollutants present in microquantities in the surface water bodies and treated sewage as compared to nanolevel pollutants detected by mass spectrometry (MS) detectors.

A simple solid-phase extraction method for the analysis of red cell phospholipids by liquid chromatography- tandem mass spectrometry.

Science.gov (United States)

Nguyen, Van Long

2018-02-25

There has been increasing interest in the analysis of phospholipids in red blood cells as potential long-term biomarkers of different disease states. Here, we describe a simple method for the analysis of two phospholipids: 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanol (PE 16:0/18:1) and 1-Palmitoyl-2-linoleoyl-sn-glycero-3-phosphoethanol (PE 16:/0/18:2) in erythrocytes by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Whole blood samples were removed free of plasma and washed in isotonic saline. Red cells were lysed with ultrapure water. Lysate samples were processed using a hybrid solid-phase extraction (SPE) phospholipid cartridge (1 mL, 30 mg). Both PE 16:0/18:1 and PE 16:0/18:2 and their deuterated internal standards were separated on an ACE C4 (150 mm × 2.1 mm, 2.7 μm particle size) by gradient elution at a flow rate of 0.5 mL per minute using mobile phases consisting of 0.01 mol/L ammonium acetate in: water (A), methanol (B), and isopropanol (C). The phospholipid species were quantified by the following transitions: PE 16:0/18:1: 701.5→281.3 and PE 16:0/18:2: 699.5→279.3. Both PE species displayed linearity ranging from 10 to 500 μg/L. The coefficient of variation (CV%) of PE 16:0/18:1 concerning intraday and interday precision was between 1.9%-2.6% and 3.0%-4.3%, respectively. For PE 16:0/18:2, this was between 1.8%-3.4% and 3.7%-4.1%, respectively. Both phospholipid species had accuracy (PE 16:0/18:1: 91%-98% and PE 16:0/18:2: 94%-103%) and extraction recovery (PE 16:0/18:1: 95%-106% and PE 16:0/18:2: 92%-102%) exceeding 90% over the analytical range. The limit of detection was 5 μg/L. Here we propose a simple SPE LC-MS/MS method for analyzing phospholipids in erythrocytes, which can be easily adopted. © 2018 Wiley Periodicals, Inc.

A naturally occurring mutation in ropB suppresses SpeB expression and reduces M1T1 group A streptococcal systemic virulence.

Directory of Open Access Journals (Sweden)

Andrew Hollands

Full Text Available Epidemiological studies of group A streptococcus (GAS have noted an inverse relationship between SpeB expression and invasive disease. However, the role of SpeB in the course of infection is still unclear. In this study we utilize a SpeB-negative M1T1 clinical isolate, 5628, with a naturally occurring mutation in the gene encoding the regulator RopB, to elucidate the role of RopB and SpeB in systemic virulence. Allelic exchange mutagenesis was used to replace the mutated ropB allele in 5628 with the intact allele from the well characterized isolate 5448. The inverse allelic exchange was also performed to replace the intact ropB in 5448 with the mutated allele from 5628. An intact ropB was found to be essential for SpeB expression. While the ropB mutation was shown to have no effect on hemolysis of RBC's, extracellular DNase activity or survival in the presence of neutrophils, strains with the mutated ropB allele were less virulent in murine systemic models of infection. An isogenic SpeB knockout strain containing an intact RopB showed similarly reduced virulence. Microarray analysis found genes of the SpeB operon to be the primary target of RopB regulation. These data show that an intact RopB and efficient SpeB production are necessary for systemic infection with GAS.

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.

Computer-Aided-Design of the Hydraulic System of Three-Dimensional Cartridge Valve Blocks (Selected Articles)

Science.gov (United States)

1991-03-21

sectional representation of the spatial figure can be correctly determined. 6 The AutoLisp language system in the AutoCAD software provides the most...softwares are developed on the 32-bit machines and little progress has been reported for the 16-bit machines. Even the AutoCAD is a two-ard-a-half... AutoCAD software as the basis, developed the design package of 3-D cartridge valve blocks on IM PC/AT. To realize the 3-D displaying of cartridge valves

High-Efficiency On-Line Solid-Phase Extraction Coupling to 15-150 um I.D. Column Liquid Chromatography for Proteomic Analysis

International Nuclear Information System (INIS)

Shen, Yufeng; Moore, Ronald J.; Zhao, Rui; Blonder, Josip; Auberry, Deanna L.; Masselon, Christophe D.; Pasa Tolic, Ljiljana; Hixson, Kim K.; Auberry, Kenneth J.; Smith, Richard D.

2003-01-01

Flexible manipulation of various properties of proteomic samples is important for proteomic analyses, but it has been little explored for newly developed approaches based on liquid chromatography (LC) in combination with mass spectrometry (MS). With miniaturization of the LC column inner diameter dimensions (required for improving the analysis sensitivity), this issue becomes more challenging due to the small flow rates and the increasing effects of extra column volume on the separation quality and its use for resolving complex proteomic mixtures. In this study, we used commercial switching valves (150-mm channels) to implement the on-line coupling of capillary LC columns with relatively large solid phase extraction (SPE) columns operated at 10,000 psi. With optimized column connections, switching modes, and SPE column dimensions, high-efficiency on-line SPE-capillary and nanoscale LC separations were obtained with peak capacities of ∼1000 for capillaries having inner diameters between 15 to 150 mm. The on-line coupled SPE columns increased the sample processing capabilities by ∼400-fold for sample solution volume and ∼10-fold for sample mass. The proteomic applications of this on-line SPE-capillary LC system were evaluated for analysis of both soluble and membrane protein tryptic digests. Used with an ion trap tandem MS we could typically identify 1100-1500 peptides for analyses in a single 5-hour run. Peptides extracted on the SPE column and eluted from the LC column covered a hydrophilicity/hydrophobicity range that include an estimated ∼98% of all the tryptic peptides. The present implementation also facilitates automation and enables use of both disposable SPE columns and electrospray emitters, providing a robust basis for routine proteomic analyses.

Dispersive liquid-liquid microextraction coupled with magnetic nanoparticles for extraction of zearalenone in wheat samples

Directory of Open Access Journals (Sweden)

Mitra Amoli-Diva

2017-01-01

Full Text Available A new, sensitive and fast dispersive liquid-liquid microextraction (DLLME coupled with micro-solid phase extraction (μ-SPE was developed for determination of zearalenone (ZEN in wheat samples. The DLLME was performed using acetonitrile/water (80:20 v/v as the disperser solvent and 1-octanol as the extracting solvent.  The acetonitrile/water (80:20 v/v solvent was also used to extract ZEN from solid wheat matrix, and was directly applied as the disperser solvent for DLLME process. Additionally, hydrophobic oleic-acid-modified magnetic nanoparticles were used in μ-SPE approach to retrieve the analyte from the DLLME step. So, the method uses high surface area and strong magnetism properties of these nanoparticles to avoid time-consuming column-passing processes in traditional SPE. Main parameters affecting the extraction efficiency and signal enhancement were investigated and optimized. Under the optimum conditions, the calibration curve showed a good linearity in the range of 0.1-500 μg kg−1 (R2=0.9996 with low detection limit of 83 ng g−1. The intra-day and inter-day precisions (as RSD % in the range of 2.6-4.3 % and high recoveries ranging from 91.6 to 99.1 % were obtained. The pre-concentration factor was 3. The method is simple, inexpensive, accurate and remarkably free from interference effects.

Comparison between different liquid-liquid and solid phase methods of extraction prior to the identification of the phenolic fraction present in olive oil washing wastewater from the two-phase olive oil extraction system

Directory of Open Access Journals (Sweden)

S. Jiménez-Herrera

2017-09-01

Full Text Available Phenolic compounds from olive mill wastewater (OMW, are characterized by a strong antioxidant activity. At the same time, they represent an environmental problem because they are difficult to degrade. The purpose of this work was to identify these biologically active compounds in the OMW from two-phase olive oil production in order to convert a polluting residue into a source of natural antioxidants. After optimizing the extraction process of phenolic compounds using liquid-liquid extraction (LLE and solid phase extraction (SPE methods, it was determined that the most appropriate sequence comprised a previous centrifugation to remove the lipid fraction, followed by liquid extraction with ethyl acetate or SPE. The most important compounds identified in olive oil washing wastewater (OOWW were tyrosol, hydroxytyrosol and succinic acid; whereas the ones in the wastewater derived from the washing of the olives (OWW were cresol, catechol, 4-methylcatechol, hydrocinnamic acid and p-hydroxy-hydrocinnamic acid.

Comparison between different liquid-liquid and solid phase methods of extraction prior to the identification of the phenolic fraction present in olive oil washing wastewater from the two-phase olive oil extraction system

International Nuclear Information System (INIS)

Jiménez-Herrera, S.; Ochando-Pulido, J.M.; Martínez-Ferez, A.

2017-01-01

Phenolic compounds from olive mill wastewater (OMW), are characterized by a strong antioxidant activity. At the same time, they represent an environmental problem because they are difficult to degrade. The purpose of this work was to identify these biologically active compounds in the OMW from two-phase olive oil production in order to convert a polluting residue into a source of natural antioxidants. After optimizing the extraction process of phenolic compounds using liquid-liquid extraction (LLE) and solid phase extraction (SPE) methods, it was determined that the most appropriate sequence comprised a previous centrifugation to remove the lipid fraction, followed by liquid extraction with ethyl acetate or SPE. The most important compounds identified in olive oil washing wastewater (OOWW) were tyrosol, hydroxytyrosol and succinic acid; whereas the ones in the wastewater derived from the washing of the olives (OWW) were cresol, catechol, 4-methylcatechol, hydrocinnamic acid and p-hydroxy-hydrocinnamic acid. [es

Determination of trace quaternary ammonium surfactants in water by combining solid-phase extraction with surface-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Chen, Y C; Sun, M C

2001-01-01

This study demonstrates the feasibility of combining solid-phase extraction (SPE) with surface-assisted laser desorption/ionization (SALDI) mass spectrometry to determine trace quaternary ammonium surfactants in water. The trace surfactants in water were directly concentrated on the surface of activated carbon sorbent in SPE. The activated carbon sorbent was then mixed with the SALDI liquid for SALDI analysis. No SPE elution procedure was necessary. Experimental results indicate that the surfactants with longer chain alkyl groups exhibit higher sensitivities than those with shorter chain alkyl groups in SPE-SALDI analysis. The detection limit for hexadecyltrimethylammonium bromide is around 10 ppt in SPE-SALDI analysis by sampling 100 mL of aqueous solution, while that of tetradecyltrimethylammonium bromide is about 100 ppt. The detection limit for decyltrimethylammonium bromide and dodecyltrimethylammonium bromide is in the low-ppb range. Copyright 2001 John Wiley & Sons, Ltd.

Pipette-tip selective extraction of glycoproteins with lectin modified gold nano-particles on a polymer monolithic phase

OpenAIRE

Alwael, Hassan Omar Salem; Connolly, Damian; Clarke, Paul A.; Thompson, Roisin; Twamley, Brendan; O'Connor, Brendan; Paull, Brett

2011-01-01

The selective extraction of specific proteins (non glycosylated, glycosylated or different glycoforms) from complex sample matrices utilising selective solid phase extration (SPE) is of significant interest within the fields of proteomics and glycoproteomics. Polymer monoliths have proven to be an excellent solid support for SPE applications in bio-analysis due to their excellent mass transfer characteristics for large biomolecules. Although biorecognition molecules such as lectins can be cov...

Integration of Solid-phase Extraction with Electrothermal Atomic Absorption Spectrometry for Determination of Trace Elements

OpenAIRE

NUKATSUKA, Isoshi; OHZEKI, Kunio

2006-01-01

An enrichment step in a sample treatment is essential for trace analysis to improve the sensitivity and to eliminate the matrix of the sample. Solid-phase extraction (SPE) is one of the widely used enrichment technique. Electrothermal atomic absorption spectrometry (ETAAS) is a well-established determination technique for trace elements. The integration of SPE with ETAAS leads to further improvement of sensitivity, an automation of the measurement and the economy in the sample size, amounts o...

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.

Identification of ionic chloroacetanilide-herbicide metabolites in surface water and groundwater by HPLC/MS using negative ion spray

Science.gov (United States)

Ferrer, I.; Thurman, E.M.; Barcelo, D.

1997-01-01

Solid-phase extraction (SPE) was combined with high-performance liquid chromatography/high-flow pneumatically assisted electrospray mass spectrometry (HPLC/ESP/MS) for the trace analysis of oxanilic and sulfonic acids of acetochlor, alachlor, and metolachlor. The isolation procedure separated the chloroacetanilide metabolites from the parent herbicides during the elution from C18 cartridges using ethyl acetate for parent compounds, followed by methanol for the anionic metabolites. The metabolites were separated chromatographically using reversed-phase HPLC and analyzed by negative-ion MS using electrospray ionization in selected ion mode. Quantitation limits were 0.01 ??g/L for both the oxanilic and sulfonic acids based on a 100-mL water sample. This combination of methods represents an important advance in environmental analysis of chloroacetanilide-herbicide metabolites in surface water and groundwater for two reasons. First, anionic chloroacetanilide metabolites are a major class of degradation products that are readily leached to groundwater in agricultural areas. Second, anionic metabolites, which are not able to be analyzed by conventional methods such as liquid extraction and gas chromatography/mass spectrometry, are effectively analyzed by SPE and high-flow pneumatically assisted electrospray mass spectrometry. This paper reports the first HPLC/MS identification of these metabolites in surface water and groundwater.

Quorum Sensing Inhibition by Asparagopsis taxiformis, a Marine Macro Alga: Separation of the Compound that Interrupts Bacterial Communication

Directory of Open Access Journals (Sweden)

Anton Hartmann

2013-01-01

Full Text Available The majority of the marine algal species, though completing their life cycle in seawater, are rarely susceptible to fouling, making them an important source of quorum sensing (QS inhibitory substances. The separation and characterization of QS inhibitors are crucial for any potential application. Thirty marine macroalgae were tested for QS inhibition activity by using Chromobacterium violaceum CV026 as the reporter strain, and among them, Asparagopsis taxiformis showed antibacterial, as well as antiquorum, sensing activities. Cinnamaldehyde (75 mM and methanol were used as positive and negative controls, respectively. The antiquorum sensing activity of A. taxiformis was further confirmed using the sensor strain, Serratia liquefaciens MG44, having green fluorescent protein (gfp. Methanolic extract of the alga was fractionated by solid phase extraction (SPE, and each fraction was tested for QS inhibition. Two types of activities were observed—zone of clearance (antibacterial activity and zone of inhibition with or without finger-like projections (QS inhibition. Out of five SPE cartridges, Bond Elut PH showed clear separation of these two fractions. The Ion Cyclotron Resonance Fourier Transformation Mass Spectrometer (ICR-FT/MS analysis of the fractions further supported the bioassay results. The presence of strong QS inhibitory compound in A. taxiformis indicates its potential use in antifouling preparations.

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.

GCR and SPE Radiation Effects in Materials

Science.gov (United States)

Waller, Jess; Rojdev, Kristina; Nichols, Charles

2016-01-01

This Year 3 project provides risk reduction data to assess galactic cosmic ray (GCR) and solar particle event (SPE) space radiation damage in materials used in manned low-earth orbit, lunar, interplanetary, and Martian surface missions. Long duration (up to 50 years) space radiation damage is being quantified for materials used in inflatable structures (1st priority), and space suit and habitable composite materials (2nd priority). The data collected has relevance for nonmetallic materials (polymers and composites) used in NASA missions where long duration reliability is needed in continuous or intermittent space radiation fluxes.

Automated solid-phase extraction-liquid chromatography-tandem mass spectrometry analysis of 6-acetylmorphine in human urine specimens: application for a high-throughput urine analysis laboratory.

Science.gov (United States)

Robandt, P V; Bui, H M; Scancella, J M; Klette, K L

2010-10-01

An automated solid-phase extraction-liquid chromatography- tandem mass spectrometry (SPE-LC-MS-MS) method using the Spark Holland Symbiosis Pharma SPE-LC coupled to a Waters Quattro Micro MS-MS was developed for the analysis of 6-acetylmorphine (6-AM) in human urine specimens. The method was linear (R² = 0.9983) to 100 ng/mL, with no carryover at 200 ng/mL. Limits of quantification and detection were found to be 2 ng/mL. Interrun precision calculated as percent coefficient of variation (%CV) and evaluated by analyzing five specimens at 10 ng/mL over nine batches (n = 45) was 3.6%. Intrarun precision evaluated from 0 to 100 ng/mL ranged from 1.0 to 4.4%CV. Other opioids (codeine, morphine, oxycodone, oxymorphone, hydromorphone, hydrocodone, and norcodeine) did not interfere in the detection, quantification, or chromatography of 6-AM or the deuterated internal standard. The quantified values for 41 authentic human urine specimens previously found to contain 6-AM by a validated gas chromatography (GC)-MS method were compared to those obtained by the SPE-LC-MS-MS method. The SPE-LC-MS-MS procedure eliminates the human factors of specimen handling, extraction, and derivatization, thereby reducing labor costs and rework resulting from human error or technique issues. The time required for extraction and analysis was reduced by approximately 50% when compared to a validated 6-AM procedure using manual SPE and GC-MS analysis.

Speciation of mercury in soil and sediment by selective solvent and acid extraction

Energy Technology Data Exchange (ETDEWEB)

Han, Y. [Metara Inc., 1225 East Arques Ave, Sunnyvale, CA (United States); Kingston, H.M.; Boylan, H.M.; Rahman, G.M.M.; Shah, S.; Richter, R.C.; Link, D.D.; Bhandari, S. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA (United States)

2003-02-01

In order to characterize the mercury hazard in soil, a sequential extraction scheme has been developed to classify mercury species based on their environmental mobility and/or toxicity for either routine lab analysis or on-site screening purposes. The alkyl mercury species and soluble inorganic species that contribute to the major portion of potential mercury toxicity in the soil are extracted by an acidic ethanol solution (2% HCl+10% ethanol solution) from soil matrices as ''mobile and toxic'' species. A High-Performance Liquid Chromatography (HPLC) system coupled with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) detection has been developed to further resolve the species information into soluble inorganic species (Hg{sup 2+}), methylmercury(II) (MeHg{sup +}) and ethylmercury(II) (EtHg{sup +}) species. Alternatively, these species can be separated into ''soluble inorganic mercury'' and ''alkyl mercury'' sub-categories by Solid-Phase Extraction (SPE). A custom Sulfydryl Cotton Fiber (SCF) material is used as the solid phase medium. Optimization of the SCF SPE technique is discussed. Combined with a direct mercury analyzer (DMA-80), the SCF SPE technique is a promising candidate for on-site screening purposes. Following the ethanol extraction, the inorganic mercury species remaining in soil are further divided into ''semi-mobile'' and ''non-mobile'' sub-categories by sequential acid extractions. The ''semi-mobile'' mercury species include mainly elemental mercury (Hg) and mercury-metal amalgams. The non-mobile mercury species mainly include mercuric sulfide (HgS) and mercurous chloride (Hg{sub 2}Cl{sub 2}). (orig.)

Preparation and characterization of standardized pomegranate extract-phospholipid complex as an effective drug delivery tool

Directory of Open Access Journals (Sweden)

Amisha Kamlesh Vora

2015-01-01

Full Text Available Punicalagins, a pair of anomeric ellagitannins, present in Punica granatum (Pomegranates are known to possess excellent antioxidant activity in vitro, but poor oral bioavailability. The reasons cited for poor bioavailability are their large molecular size, poor lipophilicity, and degradation by colonic microflora into less active metabolites. The objective of the present research work was to complex the standardized pomegranate extract (SPE with phospholipid to formulate standardized pomegranate extract-phospholipid complex (SPEPC, characterize it and check its permeability through an ex vivo everted gut sac experiment. SPEPC was prepared by mixing SPE (30% punicalagins and soya phosphatidylcholine (PC in 1:1 v/v mixture of methanol and dioxane and spray-drying the mixture. The complex was characterized by infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy. It was evaluated for its octanol solubility, dissolution, and permeability by everted the gut sac technique. The characterization methods confirmed the formation of complex. Increased n-octanol solubility of the complex proved its increased lipophilicity. Dissolution studies revealed that the phospholipid covering may prevent the punicalagins to be released in gastro-intestinal tract, thus preventing their colonic microbial degradation. SPEPC showed better apparent permeability than SPE in an everted gut sac technique. Hence, it could be concluded that phospholipid complex of SPE may be of potential use in increasing the permeability and hence the bioavailability of punicalagins.

Capturing [11C]CO2 for use in aqueous applications

International Nuclear Information System (INIS)

Vandehey, Nicholas T.; O’Neil, James P.

2014-01-01

We present a simple method for trapping [ 11 C]CO 2 gas and releasing it into a buffered solution using an ion-exchange cartridge. Sodium hydroxide cartridges captured >99% of [ 11 C]CO 2 following NaOH activation. A sodium bicarbonate solution eluted >99% of trapped radioactivity. Trapping [ 11 C]CO 2 directly in small volumes of several solutions was less effective than cartridge methods. The recommended methods allow for fast and simple production of highly concentrated carbon-11 containing aqueous solutions for use in filling phantoms, calibrating detectors, or (bio)geochemical experiments. - Highlights: • An ion exchange resin can trap [ 11 C]CO 2 gas and release it with saturated bicarbonate. • Elution from cartridge requires as little as 300 µL volume, with eluant at pH=10. • SPE trap-and-release provided better results than trapping in solution

A SIMPLE AND FAST EXTRACTION METHOD FOR ORGANOCHLORINE PESTICIDES AND POLYCHLORINATED BIPHENYLS IN SMALL VOLUMES OF AVIAN SERUM

Science.gov (United States)

A solid-phase extraction (SPE) method was developed using 8 M urea to desorb and extract organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) from avian serum for analysis by capillary gas chromatography with electron capture detection (GC-ECD). The analytes were ...

Determination of Inorganic Arsenic in Natural Water by Solid Phase Extraction

International Nuclear Information System (INIS)

Nazaratul Ashifa Abdullah Salim; Amares Chatt, A.

2011-01-01

Arsenic (As) is generally known for its toxicity. The toxicity and mobility of As in the environment are dependent on the chemical forms or species in which it exists. Arsenic (III) and (V) are the most often determined species in environmental water, soil and sediment, while organic As species are common constituents of biological tissue and fluids. It is well known that inorganic As, such as arsenite (As(III)) and arsenate (As(V)) are more toxic than their organic counterparts. This study is conducted to investigate the separation of each As inorganic species using solid phase extraction (SPE) technique. The technique utilizes SPE column for selective retention of As species, followed by elution and measurement of eluted fractions by inductively coupled plasma mass spectrometry (ICP-MS) for total As. Several type of SPE columns namely strongly anion exchange (SAX), strongly cation exchange (SCX), weakly anion exchange (WAX) and weakly cation exchange (WCX) were tested using three different types of media including deionized water, succinic acid and acetic acid containing inorganic As species. The SPE technique is suitable for on-site separation and preservation of As species from water. (author)

Motion-Based pH Sensing Based on the Cartridge-Case-like Micromotor.

Science.gov (United States)

Su, Yajun; Ge, Ya; Liu, Limei; Zhang, Lina; Liu, Mei; Sun, Yunyu; Zhang, Hui; Dong, Bin

2016-02-17

In this paper, we report a novel cartridge-case-like micromotor. The micromotor, which is fabricated by the template synthesis method, consists of a gelatin shell with platinum nanoparticles decorating its inner surface. Intriguingly, the resulting cartridge-case-like structure exhibits a pH-dependent "open and close" feature, which originates from the pH responsiveness of the gelatin material. On the basis of the catalytic activity of the platinum nanoparticle inside the gelatin shell, the resulting cartridge-case-like structure is capable of moving autonomously in the aqueous solution containing the hydrogen peroxide fuel. More interestingly, we find out that the micromotor can be utilized as a motion-based pH sensor over the whole pH range. The moving velocity of the micromotor increases monotonically with the increase of pH of the analyte solution. Three different factors are considered to be responsible for the proportional relation between the motion speed and pH of the analyte solution: the peroxidase-like and oxidase-like catalytic behavior of the platinum nanoparticle at low and high pH, the volumetric decomposition of the hydrogen peroxide under the basic condition and the pH-dependent catalytic activity of the platinum nanoparticle caused by the swelling/deswelling behavior of the gelatin material. The current work highlights the impact of the material properties on the motion behavior of a micromotor, thus paving the way toward its application in the motion-based sensing field.

Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions.

Science.gov (United States)

Vidal, Lorena; Robin, Orlane; Parshintsev, Jevgeni; Mikkola, Jyri-Pekka; Riekkola, Marja-Liisa

2013-04-12

Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101-107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14-46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent. Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and π-π interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples. Copyright © 2013 Elsevier B.V. All rights reserved.

A generic method for the determination of acrylamide in thermally processed foods.

Science.gov (United States)

Gökmen, Vural; Senyuva, Hamide Z

2006-07-07

A generic sample preparation method for the determination of acrylamide in foods was developed. The method entails extraction with methanol, purification with Carrez I and II solutions, evaporation and solvent change to water, and cleanup with Oasis HLB solid-phase extraction (SPE) cartridge. The final extract was analyzed by liquid chromatography-mass spectrometry (LC-MS) for quantitation. The chromatographic separation was performed on ODS-3 column using the isocratic mixture of 0.01 mM acetic acid in 0.2% aqueous solution of formic acid at a flow rate of 0.6 ml/min at 25 degrees C. The recoveries of acrylamide from potato chips, biscuits and coffee ranged between 92.8 and 101.5% with relative standard deviations of 4.1% or less. The limit of detection (LOD) and the limit of quantitation (LOQ) were 2 ng/g and 6 ng/g in the basis of signal to noise ratios of 3:1 and 9:1, respectively.

[Determination of emamectin benzoate residue in vegetables by high performance liquid chromatography with fluorescence detection].

Science.gov (United States)

Zhang, Yan; Wu, Yinliang; Hu, Jiye; Wang, Hongwei; Pan, Canping; Liu, Fengmao

2008-01-01

A method was developed for the determination of emamectin benzoate residue in cabbage and mushroom using solid-phase extraction (SPE) and high performance liquid chromatography (HPLC) with fluorescence detection. The sample was extracted with ethyl acetate. Further cleanup was performed on a propylsulfonic acid solid phase extraction cartridge, followed by the derivatization with trifluoroacetic anhydride in the presence of N-methylimidazole. The amount of derivatized emamectin benzoate was determined by fluorescence detector after separation by HPLC. The detection limit was 0.10 microg/kg for cabbage and mushroom samples. The recoveries of emamectin benzoate in cabbage and mushroom samples were 78.6%-84.9%. The inter-day relative standard deviation (RSD) and intra-day RSD were 2.7%-6.0% and 3.1%-8.9%, respectively, at the fortified levels of 1.0-20.0 microg/kg. The calibration curve of emamectin benzoate in vegetables at the concentration range of 0.002 mg/L to 0.10 mg/L was linear (r = 0.9999).

Anti-Inflammatory Effects of Spirulina platensis Extract via the Modulation of Histone Deacetylases

Directory of Open Access Journals (Sweden)

Tho X. Pham

2016-06-01

Full Text Available We previously demonstrated that the organic extract of Spirulina platensis (SPE, an edible blue-green alga, possesses potent anti-inflammatory effects. In this study, we investigated if the regulation of histone deacetylases (HDACs play a role in the anti-inflammatory effect of SPE in macrophages. Treatment of macrophages with SPE rapidly and dose-dependently reduced HDAC2, 3, and 4 proteins which preceded decreases in their mRNA levels. Degradation of HDAC4 protein was attenuated in the presence of inhibitors of calpain proteases, lysosomal acidification, and Ca2+/calmodulin-dependent protein kinase II, respectively, but not a proteasome inhibitor. Acetylated histone H3 was increased in SPE-treated macrophages to a similar level as macrophages treated with a pan-HDAC inhibitor, with concomitant inhibition of inflammatory gene expression upon LPS stimulation. Knockdown of HDAC3 increased basal and LPS-induced pro-inflammatory gene expression, while HDAC4 knockdown increased basal expression of interleukin-1β (IL-1β, but attenuated LPS-induced inflammatory gene expression. Chromatin immunoprecipitation showed that SPE decreased p65 binding and H3K9/K14 acetylation at the Il-1β and tumor necrosis factor α (Tnfα promoters. Our results suggest that SPE increased global histone H3 acetylation by facilitating HDAC protein degradation, but decreases histone H3K9/K14 acetylation and p65 binding at the promoters of Il-1β and Tnfα to exert its anti-inflammatory effect.

Determination of gabapentin in human plasma by capillary electrophoresis-laser induced fluorescence detection with and without solid-phase extraction

International Nuclear Information System (INIS)

Cao, L.; Liang, S.; Tan, X.; Meng, J.

2012-01-01

We have developed two methods for the quantitation of gabapentin in human plasma. They are based on capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) with and without solid-phase extraction (SPE) and the derivatizing reagent 5-(4,6-dichlorotriazinyl)amino fluoresencin. The conditions for derivatization, separation and extraction were investigated in detail, and the optimal labeling conditions include a temperature of 40 0 C, a reaction time of 30 min, and the use of a borate buffer of pH 9.0 as the reaction medium. A borate buffer of pH 9.2 served as a background electrolyte for CE separations. The CE-LIF and SPE-CE-LIF methods have linear ranges of 5-200 nmol L -1 and 0.2-10 nmol L -1 , respectively, and the limits of detection are 0.5 and 0.02 nmol L -1 , respectively. The SPE-CE-LIF method was successfully applied to the determination of gabapentin in blood plasma samples. (author)

A novel superparamagnetic surface molecularly imprinted nanoparticle adopting dummy template: an efficient solid-phase extraction adsorbent for bisphenol A.

Science.gov (United States)

Lin, Zhenkun; Cheng, Wenjing; Li, Yanyan; Liu, Zhiren; Chen, Xiangping; Huang, Changjiang

2012-03-30

Leakage of the residual template molecules is one of the biggest challenges for application of molecularly imprinted polymer (MIP) in solid-phase extraction (SPE). In this study, bisphenol F (BPF) was adopted as a dummy template to prepare MIP of bisphenol A (BPA) with a superparamagnetic core-shell nanoparticle as the supporter, aiming to avoid residual template leakage and to increase the efficiency of SPE. Characterization and test of the obtained products (called mag-DMIP beads) revealed that these novel nanoparticles not only had excellent magnetic property but also displayed high selectivity to the target molecule BPA. As mag-DMIP beads were adopted as the adsorbents of solid-phase extraction for detecting BPA in real water samples, the recoveries of spiked samples ranged from 84.7% to 93.8% with the limit of detection of 2.50 pg mL(-1), revealing that mag-DMIP beads were efficient SPE adsorbents. Copyright © 2012 Elsevier B.V. All rights reserved.

Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

Directory of Open Access Journals (Sweden)

Afrida Kurnia Putri

2012-10-01

Full Text Available A characterization of activated carbon (ACs prepared from rice husks (RHs under base treated condition as a new sorbent for solid-phase extraction (SPE to extract 4-nonylphenol isomers (4-NPs in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance interaction of non-polar sorbent with analyte in the water matrices. In this case, silanol groups from ash content may affect the extraction efficiency for 4-NPs. The ACs made from RHs were chemically impregnated with ZnCl2 and carbonized at 800oC. To investigate the role of silica, three types of ACs were prepared, i.e., untreated ACs (AC–Si, contain silica, base treated ACs (AC–B–Si, remain some silica inside, and ACs made by base treated RHs (AC–B, no silica, the surface area obtained from these treatments were 1352 m2/g, 1666 m2/g, and 1712m2/g respectively.  ACs made by base treatment has the highest surface area (related to BET, which indicat that silica removal process promotes the formation of open pore system on ACs and enhances the surface area of ACs. However, extraction efficiency measured by GC-MS in SPE process showed the reversal trends (i.e., AC–Si= 32.08%, AC–B–Si= 82.63%, AC–B=51.78%, among them the AC–B–Si sorbent reveal the best performance in SPE process. It is indicated that although silica usually exhibits low specific surface area, but control presence of silica as a polar functional group has a positive influence in the interaction between non-polar sorbent and 4-NPs.

Technical note: New applications for on-line automated solid phase extraction

OpenAIRE

MacFarlane, John D.

1997-01-01

This technical note explains the disadvantages of manual solid phase extraction (SPE) techniques and the benefits to be gained with automatic systems. The note reports on a number of general and highly specific applications using the Sample Preparation Unit OSP-2A.

Selective extraction of phospholipids from dairy products by micro-solid phase extraction based on titanium dioxide microcolumns followed by MALDI-TOF-MS analysis

DEFF Research Database (Denmark)

Calvano, Cosima; Jensen, Ole; Zambonin, Carlo

2009-01-01

A new micro-solid phase extraction (micro-SPE) procedure based on titanium dioxide microcolumns was developed for the selective extraction of phospholipids (PLs) from dairy products before matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis. All...... the extraction steps (loading, washing, and elution) have been optimized using a synthetic mixture of PLs standard and the procedure was subsequently applied to food samples such as milk, chocolate milk and butter. The whole method demonstrated to be simpler than traditional approaches and it appears very...

Determination of colloidal and dissolved silver in water samples using colorimetric solid-phase extraction.

Science.gov (United States)

Hill, April A; Lipert, Robert J; Porter, Marc D

2010-03-15

The increase in bacterial resistance to antibiotics has led to resurgence in the use of silver as a biocidal agent in applications ranging from washing machine additives to the drinking water treatment system on the International Space Station (ISS). However, growing concerns about the possible toxicity of colloidal silver to bacteria, aquatic organisms and humans have led to recently issued regulations by the US EPA and FDA regarding the usage of silver. As part of an ongoing project, we have developed a rapid, simple method for determining total silver, both ionic (silver(I)) and colloidal, in 0.1-1mg/L aqueous samples, which spans the ISS potable water target of 0.3-0.5mg/L (total silver) and meets the US EPA limit of 0.1mg/L in drinking water. The method is based on colorimetric solid-phase extraction (C-SPE) and involves the extraction of silver(I) from water samples by passage through a solid-phase membrane impregnated with the colorimetric reagent DMABR (5-[4-(dimethylamino)benzylidene]rhodanine). Silver(I) exhaustively reacts with impregnated DMABR to form a colored compound, which is quantified using a handheld diffuse reflectance spectrophotometer. Total silver is determined by first passing the sample through a cartridge containing Oxone, which exhaustively oxidizes colloidal silver to dissolved silver(I). The method, which takes less than 2 min to complete and requires only approximately 1 mL of sample, has been validated through a series of tests, including a comparison with the ICP-MS analysis of a water sample from ISS that contained both silver(I) and colloidal silver. Potential earth-bound applications are also briefly discussed. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Development of magnetic micro-solid phase extraction for analysis of phthalate esters in packaged food.

Science.gov (United States)

Makkliang, Fonthip; Kanatharana, Proespichaya; Thavarungkul, Panote; Thammakhet, Chongdee

2015-01-01

A novel, simple and low cost magnetic multi-walled carbon nanotubes-poly (vinyl alcohol) cryogel-micro-solid phase extraction (magnetic-MWCNTs-PVA cryogel-μ-SPE) sorbent was synthesized by incorporating magnetic particles and MWCNTs into a PVA cryogel. The magnetic-MWCNTs-PVA cryogel-μ-SPE sorbent developed, with a large surface area and macro-porous structure, provided good sorbent-to-sorbent reproducibility (%RSDclear chicken soup samples in the range 0.02-0.07 μg mL(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

SPE dose prediction using locally weighted regression

International Nuclear Information System (INIS)

Hines, J. W.; Townsend, L. W.; Nichols, T. F.

2005-01-01

When astronauts are outside earth's protective magnetosphere, they are subject to large radiation doses resulting from solar particle events (SPEs). The total dose received from a major SPE in deep space could cause severe radiation poisoning. The dose is usually received over a 20-40 h time interval but the event's effects may be mitigated with an early warning system. This paper presents a method to predict the total dose early in the event. It uses a locally weighted regression model, which is easier to train and provides predictions as accurate as neural network models previously used. (authors)

Automated microfluidic devices integrating solid-phase extraction, fluorescent labeling, and microchip electrophoresis for preterm birth biomarker analysis.

Science.gov (United States)

Sahore, Vishal; Sonker, Mukul; Nielsen, Anna V; Knob, Radim; Kumar, Suresh; Woolley, Adam T

2018-01-01

We have developed multichannel integrated microfluidic devices for automated preconcentration, labeling, purification, and separation of preterm birth (PTB) biomarkers. We fabricated multilayer poly(dimethylsiloxane)-cyclic olefin copolymer (PDMS-COC) devices that perform solid-phase extraction (SPE) and microchip electrophoresis (μCE) for automated PTB biomarker analysis. The PDMS control layer had a peristaltic pump and pneumatic valves for flow control, while the PDMS fluidic layer had five input reservoirs connected to microchannels and a μCE system. The COC layers had a reversed-phase octyl methacrylate porous polymer monolith for SPE and fluorescent labeling of PTB biomarkers. We determined μCE conditions for two PTB biomarkers, ferritin (Fer) and corticotropin-releasing factor (CRF). We used these integrated microfluidic devices to preconcentrate and purify off-chip-labeled Fer and CRF in an automated fashion. Finally, we performed a fully automated on-chip analysis of unlabeled PTB biomarkers, involving SPE, labeling, and μCE separation with 1 h total analysis time. These integrated systems have strong potential to be combined with upstream immunoaffinity extraction, offering a compact sample-to-answer biomarker analysis platform. Graphical abstract Pressure-actuated integrated microfluidic devices have been developed for automated solid-phase extraction, fluorescent labeling, and microchip electrophoresis of preterm birth biomarkers.

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.

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

Science.gov (United States)

Mazzoni, Michela; Rusconi, Marianna; Valsecchi, Sara; Martins, Claudia P. B.; Polesello, Stefano

2015-01-01

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. PMID:25834752

Comparison of dialysis and solid-phase extraction for isolation and concentration of dissolved organic matter prior to Fourier transform ion cyclotron resonance mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Tfaily, Malak M.; Cooper, William T. [Florida State University, Department of Chemistry and Biochemistry, Tallahassee, FL (United States); Hodgkins, Suzanne; Chanton, Jeffrey P. [Florida State University, Department of Earth, Ocean and Atmospheric Science, Tallahassee, FL (United States); Podgorski, David C. [Florida State University, Department of Chemistry and Biochemistry, Tallahassee, FL (United States); Florida State University, National High Magnetic Field Laboratory, Tallahassee, FL (United States)

2012-08-15

We compare two methods, solid-phase extraction (SPE) and dialysis, commonly used for extraction and concentration of dissolved organic matter (DOM) prior to molecular characterization by electrospray ionization (ESI) and ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry. Spectra of DOM samples from Minnesota and Sweden peatlands that were extracted with styrene divinyl benzene polymer SPE sorbents included ions with formulas that had higher oxygen to carbon (O/C) ratios than spectra of DOM from the same samples after de-salting by dialysis. The SPE method was not very effective in extracting several major classes of DOM compounds that had high ESI efficiencies, including carboxylic acids and organo-sulfur compounds, and that out-competed other less-functionalized compounds (e.g., carbohydrates) for charge in the ESI source. The large abundance of carboxylic acids in the dialysisextracted DOM, likely the result of in situ microbial production, makes it difficult to see other (mainly hydrophilic) compounds with high O/C ratios. Our results indicate that, while dialysis is generally preferable for the isolation of DOM, for samples with high microbial inputs, the use of both isolation methods is recommended for a more accurate molecular representation. (orig.)

Potency of a novel saw palmetto ethanol extract, SPET-085, for inhibition of 5alpha-reductase II.

Science.gov (United States)

Pais, Pilar

2010-08-01

The nicotinamide adenine dinucleotide phosphate (NADPH)-dependent membrane protein 5alpha-reductase irreversibly catalyses the conversion of testosterone to the most potent androgen, 5alpha-dihydrotestosterone (DHT). In humans, two 5alpha-reductase isoenyzmes are expressed: type I and type II. Type II is found primarily in prostate tissue. Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). The mechanisms of the pharmacological effects of SPE include the inhibition of 5alpha-reductase, among other actions. Clinical studies of SPE have been equivocal, with some showing significant results and others not. These inconsistent results may be due, in part, to varying bioactivities of the SPE used in the studies. The aim of the present study was to determine the in vitro potency of a novel saw palmetto ethanol extract (SPET-085), an inhibitor of the 5alpha-reductase isoenzyme type II, in a cell-free test system. On the basis of the enzymatic conversion of the substrate androstenedione to the 5alpha-reduced product 5alpha-androstanedione, the inhibitory potency was measured and compared to those of finasteride, an approved 5alpha-reductase inhibitor. SPET-085 concentration-dependently inhibited 5alpha-reductase type II in vitro (IC(50)=2.88+/-0.45 microg/mL). The approved 5alpha-reductase inhibitor, finasteride, tested as positive control, led to 61% inhibition of 5alpha-reductase type II. SPET-085 effectively inhibits the enzyme that has been linked to BPH, and the amount of extract required for activity is very low compared to data reported for other extracts. It can be concluded from data in the literature that SPET-085 is as effective as a hexane extract of saw palmetto that exhibited the highest levels of bioactivity, and is more effective than other SPEs tested. This study confirmed that SPET-085 has prostate health-promoting bioactivity that also corresponds favorably to

Development of a method for rapid and simultaneous monitoring of particulate and dissolved radiocesium in water with nonwoven fabric cartridge filters

International Nuclear Information System (INIS)

Hideki Tsuji; Tetsuo Yasutaka; Yoshihiko Kondo; Yasukazu Suzuki

2014-01-01

A method for the rapid and simultaneous monitoring of particulate and dissolved 137 Cs concentration in water was developed. This method uses pleated polypropylene nonwoven fabric filter to collect particulate radiocesium, and nonwoven fabric impregnated with Prussian blue (PB) to absorb dissolved radiocesium. The fabric was placed into cylindrical plastic cartridges (SS-cartridge and PB-cartridge). Traditional monitoring methods, such as evaporative concentration, often require time for pre-processing. However, this method described requires much less pre-processing time before the detection. Experiments conducted with simulated river water demonstrated that almost all of the suspended solids weight was collected in the SS-cartridge, and that more than 92 % of dissolved 137 Cs was absorbed onto the two PB-cartridges by 2.5 L/min flow rate when the range of the pH was 6-8. This device was applied to monitor Abukuma River water at two locations and the results were compared with those obtained using the filtrating and evaporative concentration method. The suspended solids concentration in river water, calculated by weight gain of the SS-cartridge and by sediment weight after filtration with a 0.45-μm membrane filter, agreed well. The radioactivity of the particulate and dissolved 137 Cs also agreed well in one of the two replications of this method. In addition, the required time for pre-processing was reduced by 60 times that by filtrating and evaporative concentration method. This method can separately collect and concentrate particulate and dissolved radiocesium rapidly and simultaneously in the field. (author)

Cone-shaped membrane liquid phase micro extraction

International Nuclear Information System (INIS)

Hong, Heng See; Sanagi, M.M.; Ibrahim, W.A.W.; Naim, A.A.

2008-01-01

A novel sample pre-treatment technique termed cone-shaped membrane liquid phase micro extraction (CSM-LPME) was developed and combined with micro-liquid chromatography (micro-LC) for the determination of selected pesticides in water samples. Several important extraction parameters such as types of extraction solvent, agitation rate, pH value, total exposure time and effect of salt and humic acids were investigated and optimized. Enrichment factors of >50 folds were easily achieved within 20 min of extraction. The new developed method demonstrated an excellent performance in terms of speed, cost effectiveness, reproducibility, as well as exceptional low detection limits. Current work provides a great interest to further investigate on the applicability of the CSM-LPME technique in analytical chemistry and explores the possibility of replacing conventional extraction techniques such as soxhlet, solid phase extraction (SPE) and solid phase micro extraction (SPME). (author)

Analysis of Free Amino Acids in Different Extracts of Orthosiphon stamineus Leaves by High-Performance Liquid Chromatography Combined with Solid-Phase Extraction.

Science.gov (United States)

Shafaei, Armaghan; Halim, Nor Hidayah Ab; Zakaria, Norhidayah; Ismail, Zhari

2017-10-01

Orthosiphon stamineus (OS) Benth is a medicinal plant and native in Southeast Asia. Previous studies have shown that OS leaves possess antioxidant, cytotoxic, diuretic, antihypertensive, and uricosuric effects. These beneficial effects have been attributed to the presence of primary and secondary metabolites such as polyphenols, amino acids, and flavonoids. To develop and validate an high-performance liquid chromatography (HPLC)-diode array detector (DAD) method combined with solid-phase extraction that involves precolumn derivatization with O -phthaladehyde for simultaneous analysis of free amino acids in OS leaves extracts. OS leaves were extracted with water (OS-W), ethanol (OS-E), methanol (OS-M), 50% ethanol (OS-EW), and 50% methanol (OS-MW). The extracts were treated by C18 cartridge before derivatization, resulting in great improvement of separation by Zorbox Eclipse XDB-C 18 column. The HPLC-DAD method was successfully developed and validated for analyzing the contents of free amino acids in OS extracts. The results showed that l-aspartic acid with 0.93 ± 0.01 nmol/mg was the major free amino acid in OS-W extract. However, in OS-E, OS-M, OS-EW, and OS-MW, l-glutamic acid with 3.53 ± 0.16, 2.17 ± 0.10, 4.01 ± 0.12, and 2.49 ± 0.12 nmol/mg, respectively, was the major free amino acid. Subsequently, l-serine, which was detected in OS-W, OS-E, and OS-M, was the minor free amino acid with 0.33 ± 0.02, 0.12 ± 0.01, and 0.06 ± 0.01 nmol/mg, respectively. However, l-threonine with 0.26 ± 0.02 and 0.19 ± 0.08 nmol/mL in OS-EW and OS-MW, respectively, had the lowest concentration compared with other amino acid components. All validation parameters of the developed method indicate that the method is reliable and efficient to simultaneously determine the free amino acids content for routine analysis of OS extracts. The HPLC-DAD method combined with solid phase extraction was successfully developed and validated for simultaneous determination and

Development of analytical techniques for water and environmental samples (2)

Energy Technology Data Exchange (ETDEWEB)

Eum, Chul Hun; Jeon, Chi Wan; Jung, Kang Sup; Song, Kyung Sun; Kim, Sang Yeon [Korea Institute of Geology Mining and Materials, Taejon (Korea)

1998-12-01

The purpose of this study is to develop new analytical methods with good detection limit for toxic inorganic and organic compounds. The analyses of CN, organic acids, particulate materials in environmental samples have been done using several methods such as Ion Chromatography, SPE, SPME, GC/MS, GC/FID, SPLITT (split-flow thin cell fractionation) during the second year of this project. Advantage and disadvantage of several distillation method (by KS, JIS, EPA) for CN analysis in wastewater were investigated. As the results, we proposed new distillation apparatus for CN analysis, which was proved to be simpler, faster and to get better recovery than conventional apparatus. And ion chromatograph/pulsed amperometric detector (IC/PAD) system instead of colorimetry for CN detection was setup to solve matrix interference. And SPE(solid phase extraction) and SPME (solid phase micro extraction) as liquid-solid extraction technique were applied to the analysis of phenols in wastewater. Optimum experimental conditions and factors influencing analytical results were determined. From these results, It could be concluded that C{sub 18} cartridge and polystyrene-divinylbenzene disk in SPE method, polyacrylate fiber in SPME were proper solid phase adsorbent for phenol. Optimum conditions to analyze phenol derivatives simultaneously were established. Also, Continuous SPLITT (Split-flow thin cell) Fractionation (CSF) is a new preparative separation technique that is useful for fractionation of particulate and macromolecular materials. CSF is carried out in a thin ribbon-like channel equipped with two splitters at both inlet and outlet of the channel. In this work, we set up a new CSF system, and tested using polystyrene latex standard particles. And then we fractionated particles contained in air and underground water based on their sedimentation coefficients using CSF. (author). 27 refs., 13 tabs., 31 figs.

Multiwalled carbon nanotubes as a solid-phase extraction adsorbent for the determination of three barbiturates in pork by ion trap gas chromatography-tandem mass spectrometry (GC/MS/MS) following microwave assisted derivatization

Energy Technology Data Exchange (ETDEWEB)

Zhao Haixiang [College of Science, China Agricultural University, Beijing 100094 (China); Inspection Technology and Equipment Institute, Chinese Academy of Inspection and Quarantine, Beijing 100025 (China); Department of Basic Agricultural Science, Hebei North College, Zhangjiakou Hebei 075131 (China); Wang Liping [College of Science, China Agricultural University, Beijing 100094 (China); Qiu Yueming [Inspection Technology and Equipment Institute, Chinese Academy of Inspection and Quarantine, Beijing 100025 (China); Zhou Zhiqiang [College of Science, China Agricultural University, Beijing 100094 (China)]. E-mail: zqzhou@cau.edu.cn; Zhong Weike [Inspection Technology and Equipment Institute, Chinese Academy of Inspection and Quarantine, Beijing 100025 (China); Li Xiang [Inspection Technology and Equipment Institute, Chinese Academy of Inspection and Quarantine, Beijing 100025 (China)

2007-03-14

A new method was developed for the rapid screening and confirmation analysis of barbital, amobarbital and phenobarbital residues in pork by gas chromatography-tandem mass spectrometry (GC/MS/MS) with ion trap MSD. The residual barbiturates in pork were extracted by ultrasonic extraction, cleaned up on a multiwalled carbon nanotubes (MWCNTs) packed solid phase extraction (SPE) cartridge and applied acetone-ethyl acetate (3:7, v/v) mixture as eluting solvent and derivatized with CH{sub 3}I under microwave irradiation. The methylated barbiturates were separated on a TR-5MS capillary column and detected with an ion trap mass detector. Electron impact ion source (EI) operating MS/MS mode was adopted for identification and external standard method was employed for quantification. One precursor ion m/z 169 was selected for analysis of barbital and amobarbital and m/z 232 was selected for phenobarbital. The product ions were obtained under 1.0 V excitation voltage. Good linearities (linear coefficient R > 0.99) were obtained at the range of 0.5-50 {mu}g kg{sup -1}. Limit of detection (LOD) of barbital was 0.2 {mu}g kg{sup -1} and that of amobarbital and phenobarbital were both 0.1 {mu}g kg{sup -1} (S/N {>=} 3). Limit of quatification (LOQ) was 0.5 {mu}g kg{sup -1} for three barbiturates (S/N {>=} 10). Satisfying recoveries ranging from 75% to 96% of the three barbiturates spiked in pork were obtained, with relative standard deviations (R.S.D.) in the range of 2.1-7.8%.

Multiwalled carbon nanotubes as a solid-phase extraction adsorbent for the determination of three barbiturates in pork by ion trap gas chromatography-tandem mass spectrometry (GC/MS/MS) following microwave assisted derivatization

International Nuclear Information System (INIS)

Zhao Haixiang; Wang Liping; Qiu Yueming; Zhou Zhiqiang; Zhong Weike; Li Xiang

2007-01-01

A new method was developed for the rapid screening and confirmation analysis of barbital, amobarbital and phenobarbital residues in pork by gas chromatography-tandem mass spectrometry (GC/MS/MS) with ion trap MSD. The residual barbiturates in pork were extracted by ultrasonic extraction, cleaned up on a multiwalled carbon nanotubes (MWCNTs) packed solid phase extraction (SPE) cartridge and applied acetone-ethyl acetate (3:7, v/v) mixture as eluting solvent and derivatized with CH 3 I under microwave irradiation. The methylated barbiturates were separated on a TR-5MS capillary column and detected with an ion trap mass detector. Electron impact ion source (EI) operating MS/MS mode was adopted for identification and external standard method was employed for quantification. One precursor ion m/z 169 was selected for analysis of barbital and amobarbital and m/z 232 was selected for phenobarbital. The product ions were obtained under 1.0 V excitation voltage. Good linearities (linear coefficient R > 0.99) were obtained at the range of 0.5-50 μg kg -1 . Limit of detection (LOD) of barbital was 0.2 μg kg -1 and that of amobarbital and phenobarbital were both 0.1 μg kg -1 (S/N ≥ 3). Limit of quatification (LOQ) was 0.5 μg kg -1 for three barbiturates (S/N ≥ 10). Satisfying recoveries ranging from 75% to 96% of the three barbiturates spiked in pork were obtained, with relative standard deviations (R.S.D.) in the range of 2.1-7.8%

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

DEFF Research Database (Denmark)

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

2013-01-01

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

Application of cation-exchange solid-phase extraction for the analysis of amino alcohols from water and human plasma for verification of Chemical Weapons Convention.

Science.gov (United States)

Kanaujia, Pankaj K; Tak, Vijay; Pardasani, Deepak; Gupta, A K; Dubey, D K

2008-03-28

The analysis of nitrogen containing amino alcohols, which are the precursors and degradation products of nitrogen mustards and nerve agent VX, constitutes an important aspect for verifying the compliance to the CWC (Chemical Weapons Convention). This work devotes on the development of solid-phase extraction method using silica- and polymer-based SCX (strong cation-exchange) and MCX (mixed-mode strong cation-exchange) cartridges for N,N-dialkylaminoethane-2-ols and alkyl N,N-diethanolamines, from water. The extracted analytes were analyzed by GC-MS (gas chromatography-mass spectrometry) in the full scan and selected ion monitoring modes. The extraction efficiencies of SCX and MCX cartridges were compared, and results revealed that SCX performed better. Extraction parameters, such as loading capacity, extraction solvent, its volume, and washing solvent were optimized. Best recoveries were obtained using 2 mL methanol containing 10% NH(4)OH and limits of detection could be achieved up to 5 x 10(-3) microg mL(-1) in the selected ion monitoring mode and 0.01 microg mL(-1) in full scan mode. The method was successfully employed for the detection and identification of amino alcohol present in water sample sent by Organization for Prohibition of Chemical Weapons (OPCW) in the official proficiency tests. The method was also applied to extract the analytes from human plasma. The SCX cartridge showed good recoveries of amino alcohols from human plasma after protein precipitation.

Pipette-tip solid-phase extraction using polypyrrole as efficient adsorbent for extraction of avermectins and milbemycins in milk.

Science.gov (United States)

Florez, Diego Hernando Ângulo; Teixeira, Roseane Andrade; da Silva, Ricky Cássio Santos; Pires, Bruna Carneiro; Dutra, Flávia Viana Avelar; Borges, Keyller Bastos

2018-05-01

In this work, we developed a HPLC method for the multidetermination of avermectins (AVM) (abamectin-ABA 1b and ABA 1a, eprinomectin-EPR, and ivermectin-IVM) and milbemycins (moxidectin-MOX) in milk samples using polypyrrole (PPy) as adsorbent material in pipette-tip solid-phase extraction (PT-PPy-SPE). PPy was characterized by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray diffraction and the data agreed with the literature. The sample preparation included the clean-up of the milk by protein precipitation (PP) with acetonitrile and extraction of the analytes by PT-PPy-SPE. The chromatographic method was developed in reverse phase and isocratic mode with flow rate at 1.2 mL min -1 and ultraviolet detection at 250 nm. The mobile phase composition was acetonitrile:methanol:water (55:25:20, v/v/v). The studied parameters and the optimized conditions for the sample preparation were washing solvent (300 μL water), volume and type of eluent (500 μL methanol), volume and pH of sample (1 mL and pH 10), amount of adsorbent material (50 mg PPy), and without addition of salt (NaCl). The method was linear over the concentration range from 20 to 3000 ng mL -1 with coefficients of correlation (r) ≥ 0.99 for all analytes and recoveries around 100%. The method developed and validated was used for the analyses of real milk samples from cow treated with Ivomec ® (IVM 3.5%), in which were found 21.51 ± 2.94 ng mL -1 of IVM. Finally, the results proved that PT-PPy-SPE coupled to HPLC-UV was economical, simple, and easy-to-perform technique. Graphical abstract Pipette-tip solid phase extraction using polypirrole as adsorbent material for determination of avermectins and milbemycins in milk.

CE with a boron-doped diamond electrode for trace detection of endocrine disruptors in water samples.

Science.gov (United States)

Browne, Damien J; Zhou, Lin; Luong, John H T; Glennon, Jeremy D

2013-07-01

Off-line SPE and CE coupled with electrochemical detection have been used for the determination of bisphenol A (BPA), bisphenol F, 4-ethylphenol, and bisphenol A diglycidyl ether in bottled drinking water. The use of boron-doped diamond electrode as an electrochemical detector in amperometric mode that provides a favorable analytical performance for detecting these endocrine-disrupting compounds, such as lower noise levels, higher peak resolution with enhanced sensitivity, and improved resistance against electrode passivation. The oxidative electrochemical detection of the endocrine-disrupting compounds was accomplished by boron-doped diamond electrode poised at +1.4 V versus Ag/AgCl without electrode pretreatment. An off-line SPE procedure (Bond Elut® C18 SPE cartridge) was utilized to extract and preconcentrate the compounds prior to separation and detection. The minimum concentration detectable for all four compounds ranged from 0.01 to 0.06 μM, having S/N equal to three. After exposing the plastic bottle water container under sunlight for 7 days, the estimated concentration of BPA in the bottled drinking water was estimated to be 0.03 μM. This proposed approach has great potential for rapid and effective determination of BPA content present in water packaging of plastic bottles that have been exposed to sunlight for an extended period of time. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals.

Science.gov (United States)

Barbera, Giorgia La; Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Montone, Carmela Maria; Chiozzi, Riccardo Zenezini; Laganà, Aldo

2017-04-21

Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE), a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high-performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals

Directory of Open Access Journals (Sweden)

Giorgia La Barbera

2017-04-01

Full Text Available Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE, a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high–performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

Determination and validation of a simple high-performance liquid chromatographic method for simultaneous assay of iprodione and vinclozolin in human urine.

Science.gov (United States)

Carlucci, Giuseppe; Pasquale, Dorina Di; Ruggieri, Fabrizio; Mazzeo, Pietro

2005-12-15

A method based on solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) was developed for the simultaneous determination of 3-(3,5-diclorophenyl)-5-ethenyl-5-methyl-2,4-oxazolidinedione (vinclozolin) and 3-(3,5-diclorophenyl)-N-(1-methylethyl)-2,4-dioxo-1-imidazolidinecarboxamide (iprodione) in human urine. Urine samples containing vinclozolin and iprodione were collected by solid phase extraction using C(18) cartridges. The chromatographic separation was achieved on a Spherisorb ODS2 (250 mm x 4.6 mm, 5 microm) column with an isocratic mobile phase of acetonitrile-water (60:40, v/v). Detection was UV absorbance at 220 nm. The calibration graphs were linear from 30 to 1000 ng/mL for the two fungicides. Intra- and inter-day R.S.D. did not exceed 2.9%. The quantitation limit was 50 ng/mL for vinclozolin and 30 ng/mL for iprodione, respectively.

Preparation of a New Adsorbent from Activated Carbon and Carbon Nanofiber (AC/CNF for Manufacturing Organic-Vacbpour Respirator Cartridge

Directory of Open Access Journals (Sweden)

Mehdi Jahangiri

2013-01-01

Full Text Available In this study a composite of activated carbon and carbon nanofiber (AC/CNF was prepared to improve the performance of activated carbon (AC for adsorption of volatile organic compounds (VOCs and its utilization for respirator cartridges. Activated carbon was impregnated with a nickel nitrate catalyst precursor and carbonnanofibers (CNF were deposited directly on the AC surface using catalytic chemical vapor deposition. Deposited CNFs on catalyst particles in AC micropores, were activated by CO2 to recover the surface area and micropores.Surface and textural characterizations of the prepared composites were investigated using Brunauer, Emmett andTeller’s (BET technique and electron microscopy respectively. Prepared composite adsorbent was tested forbenzene, toluene and xylene (BTX adsorption and then employed in an organic respirator cartridge in granularform. Adsorption studies were conducted by passing air samples through the adsorbents in a glass column at an adjustable flow rate. Finally, any adsorbed species not retained by the adsorbents in the column were trapped in a charcoal sorbent tube and analyzed by gas chromatography. CNFs with a very thin diameter of about 10-20 nmwere formed uniformly on the AC/CNF. The breakthrough time for cartridges prepared with CO2 activated AC/CNF was 117 minutes which are significantly longer than for those cartridges prepared with walnut shell- based activated carbon with the same weight of adsorbents. This study showed that a granular form CO2 activated AC/CNF composite could be a very effective alternate adsorbent for respirator cartridges due to its larger adsorption capacities and lower weight.

Enhanced Glucose Uptake in Human Liver Cells and Inhibition of Carbohydrate Hydrolyzing Enzymes by Nordic Berry Extracts

Directory of Open Access Journals (Sweden)

Giang Thanh Thi Ho

2017-10-01

Full Text Available A Western lifestyle with low physical activity and a diet rich in sugar, fat and processed food contribute to higher incidences of diabetes and obesity. Enhanced glucose uptake in human liver cells was observed after treatment with phenolic extracts from different Nordic berries. All berry extracts showed higher inhibition against α-amylase and α-glucosidase than the anti-diabetic agent acarbose. Total phenolic content and phenolic profiles in addition to antioxidant activities, were also investigated. The berries were extracted with 80% methanol on an accelerated solvent extraction system (ASE and then purified by C-18 solid phase extraction (SPE. Among the ASE methanol extracts, black chokeberry, crowberry and elderberry extracts showed high stimulation of glucose uptake in HepG2 cells and also considerable inhibitory effect towards carbohydrate hydrolyzing enzymes. SPE extracts with higher concentrations of phenolics, resulted in increased glucose uptake and enhanced inhibition of α-amylase and α-glucosidase compared to the ASE extracts. Crowberry and cloudberry were the most potent 15-lipoxygenase inhibitors, while bog whortleberry and lingonberry were the most active xanthine oxidase inhibitors. These results increase the value of these berries as a component of a healthy Nordic diet and have a potential benefit against diabetes.

Characteristics of a cartridge NEG (St101 Zr-Al)

International Nuclear Information System (INIS)

Hisamatsu, Hiromi; Shimamoto, Masayuki; Kanazawa, Ken-ichi; Ishimaru, Hajime

1990-01-01

The report addresses the application of a non-evaporable getter (NEG) pump to an accelerator (storage ring). Tests are performed to determine major characteristics of the non-evaporable getter pump in an effort to provide a method for its efficient use. Test results show that with an St101 cartridge NEG pump, it is possible to produce an ultrahigh vacuum in a system with a surface area of about 10 4 cm 2 through baking at 410K for two hours. Once activated at 1000K, a NEG pump recovers a pumping performance in a subsequent test run at 723K, though the pumping speed decreases by several tens of percent. The St-101 cartridge type NEG pump is at least 2 Pam 3 in pumping capacity for carbon monoxide. The pumping speed decreases with an increasing amount of occluded carbon monoxide. Upon activation, most of the occluded carbon monoxide diffuses into the pump while only little of it is released into the gas phase. Its diffusion through the surface of the NEG pump can occur even at room temperature, indicating that if a leak takes place, the pump would absorb the gas continuously. Thus, if a leak occurs during activation, the pump would occlude a large amount of gas and therefore, activation should be carried out with careful checking for a leak. (N.K.)

Optimization of matrix solid-phase dispersion for the rapid determination of salicylate and benzophenone-type UV absorbing substances in marketed fish.

Science.gov (United States)

Tsai, Dung-Ying; Chen, Chien-Liang; Ding, Wang-Hsien

2014-07-01

A simple and effective method for the rapid determination of five salicylate and benzophenone-type UV absorbing substances in marketed fish is described. The method involves the use of matrix solid-phase dispersion (MSPD) prior to their determination by on-line silylation gas chromatography tandem mass spectrometry (GC-MS/MS). The parameters that affect the extraction efficiency were optimized using a Box-Behnken design method. The optimal extraction conditions involved dispersing 0.5g of freeze-dried powdered fish with 1.0g of Florisil using a mortar and pestle. This blend was then transferred to a solid-phase extraction (SPE) cartridge containing 1.0g of octadecyl bonded silica (C18), as the clean-up co-sorbent. The target analytes were then eluted with 7mL of acetonitrile. The extract was derivatized on-line in the GC injection-port by reaction with a trimethylsilylating (TMS) reagent. The TMS-derivatives were then identified and quantitated by GC-MS/MS. The limits of quantitation (LOQs) were less than 0.1ng/g. Copyright © 2014 Elsevier Ltd. All rights reserved.

Method development for determination of herbicides and insecticides in surface waters using solid-phase extraction and high performance liquid chromatography

International Nuclear Information System (INIS)

Lebre, Daniel Temponi

2000-01-01

Determination of low concentrations of pesticides in surface and ground waters requires high sensitivity analytical techniques. Solid-Phase Extraction (SPE) has been successfully employed to pre concentrate and extract pesticides compounds from water samples. High Performance Liquid Chromatography (HPLC) coupled with UV/Vis detector was used to separate and quantify the extracted compounds. In this work, samples of surface waters with known concentrations of herbicides (atrazine, simazine and trifluralin) and insecticides (aldicarb, carbofuran and carbaryl) were extracted by using SPE off-line technique. The compounds were separated and quantified by reverse phase HPLC with UV detection at 220 ηm. The extraction efficiency was compared between two columns filled with different materials: C 18 -bonded silica phase (500 mg) and copolymer styrenedivynilbenzene resin (250 mg). The results were evaluated as the percent recovery of compounds obtained using different solvents at different concentrations. The results showed that recovery of the analytes greater than 80 % were obtained in SPE columns filled with C 18 bonded silica phase with 6 mL of acetonitrile. Once the optimum conditions were chosen for simulate water samples, the method was validated through analytical and statistical procedures and applied for surface waters. The suitability of the method was verified for the studied compounds showing good sensitivity, i. e., concentrations within the range of 0.4 to 4.0 μgL -1 of pesticides could be quantified attending the limits proposed by official regulations. (author)

Direct modification of hydrogen/deuterium-terminated diamond particles with polymers to form reversed and strong cation exchange solid phase extraction sorbents.

Science.gov (United States)

Yang, Li; Jensen, David S; Vail, Michael A; Dadson, Andrew; Linford, Matthew R

2010-12-03

We describe direct polymer attachment to hydrogen and deuterium-terminated diamond (HTD and DTD) surfaces using a radical initiator (di-tert-amyl peroxide, DTAP), a reactive monomer (styrene) and a crosslinking agent (divinylbenzene, DVB) to create polystyrene encapsulated diamond. Chemisorbed polystyrene is sulfonated with sulfuric acid in acetic acid. Surface changes were followed by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). Finally, both polystyrene-modified DTD and sulfonated styrene-modified DTD were used in solid phase extraction (SPE). Percent recovery and column capacity were investigated for both phenyl (polystyrene) and sulfonic acid treated polystyrene SPE columns. These diamond-based SPE supports are stable under basic conditions, which is not the case for silica-based SPE supports. Copyright © 2010. Published by Elsevier B.V.

Effects of Saw Palmetto Extract on Urodynamic Parameters, Bladder Muscarinic and Purinergic Receptors and Urinary Cytokines in Rats with Cyclophosphamide-Induced Cystitis.

Science.gov (United States)

Nasrin, Sweety; Masuda, Eiji; Kugaya, Haruna; Osano, Ayaka; Ito, Yoshihiko; Yamada, Shizuo

2014-01-01

To clarify the effect of saw palmetto extract (SPE), a phytotherapeutic agent, on urodynamic parameters, bladder muscarinic and purinergic receptors, and urinary cytokines in rats with cystitis induced by cyclophosphamide (CYP). Saw palmetto extract (60 mg/kg per day) was administered orally twice a day for 7 days to rats. The urodynamic parameters in CYP (150 mg/kg i.p.)-treated rats were monitored by a cystometric method under anesthesia. The muscarinic and purinergic receptors in the bladder and submaxillary gland were measured by radioreceptor assays using [N-methyl-(3) H] scopolamine chloride([(3) H]NMS) and αβ-methylene-ATP [2,8-(3) H] tetrasodium salt ([(3) H]αβ-MeATP), respectively. Urinary cytokines (interleukin-1β [IL-1β], IL-6 and L-17) were measured with enzyme linked immunosorbent assay kits. Micturition interval and micturition volume were significantly decreased and the frequency of micturition and basal pressure were significantly increased in the CYP-treated rats compared with sham-operated rats. Orally administered SPE significantly increased the micturition interval and micturition volume and decreased the frequency of micturition and basal pressure. The maximal number of sites (Bmax ) for the specific binding of [(3) H]NMS and [(3) H]αβ-MeATP was significantly decreased in the bladder. The decrease in receptors was attenuated by repeated treatment with SPE. An elevation in urinary cytokine (IL-1β and IL-17) levels were seen, and this increase was effectively suppressed by SPE treatment. Saw palmetto extract attenuates the alteration of urodynamic parameters, pharmacologically relevant receptors, and urinary cytokines in CYP-treated rats. Therefore, SPE may be a potential therapeutic agent for improving the clinical symptoms of cystitis. © 2013 Wiley Publishing Asia Pty Ltd.

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...

Design and construction of an on-line SPE-SFE-CGC system

Directory of Open Access Journals (Sweden)

Pinto Jair S. S.

2001-01-01

Full Text Available The construction of an on-line SPE-SFE-CGC system is described. The home-made system is of low cost and of easy construction and maintenance, making possible the analysis of organic micropollutants in liquid samples such as water in a fraction of the time spent using traditional methods.

Isolation and Purification of Unstable Iridoid Glucosides from Traditional Chinese Medicine by Preparative High Performance Liquid Chromatography Coupled with Solid-phase Extraction

Institute of Scientific and Technical Information of China (English)

LI Cun-man; XIAO Yuan-sheng; XUE Xing-ya; FENG Jia-tao; ZHANG Xiu-li; LIANG Xin-miao

2011-01-01

An efficient preparative method was successfully developed for isolation and purification of unstable components from medicinal plant extracts, using a combined method of preparative high performance liquid chro matography(HPLC) and solid-phase extraction(SPE). The aim of this study was to obtain an effective method with high preparative efficiency and importantly to avoid the transformation of unstable compounds. The preparative HPLC system was based on an LC/MS controlled four-channel autopurification system. The SPE method was per formed with a C1s packing material to trap the target compounds and to remove the acidic additive derived from the mobile phase. Using this method, the unstable iridoid glucosides(IGs) as model compounds were successfully iso lated and purified from the extract of Hedyotis diffusa Willd. Six IGs(including one new minor IG) and one nucleo tide compound were simultaneously obtained, each with a purity of ＞91% as determined by HPLC. The structures of the isolated compounds were identified by UPLC/Q-TOF MS, UV, ID and/or 2D NMR. It was demonstrated that the combination of preparative HPLC with SPE is a versatile tool for preparative purification of unstable compounds from complex natural products.

Do insulin cartridges really provide a lower risk of potential diabetes complications than traditional vials?

Science.gov (United States)

Al-Sharayri, Mohammad G; Aljbori, Tariq M; Migdadi, Qusai M; Al-Omoush, Marwa B; Jaarah, Ayman R

2014-09-01

Recently, many publicly funded healthcare organizations suffered from an economical crisis. This forced some organizations to utilize less costly alternatives where possible. Insulin cartridges and vials are examples. Many patients are questioning the difference between the two alternatives as they contain the same active ingredient. To find out if insulin cartridges really provide a lower risk of potential diabetes complications than traditional vials. A questionnaire was used to ask two random samples of diabetic patients about the development of some diabetes complications. The first sample (n = 41) consisted of patients using cartridges; the second sample (n = 40) consisted of patients using vials. Patients were randomly selected from the endocrine clinic and the out-patient pharmacy in Al-Hussein Hospital in King Hussein Medical Center in Amman- Jordan. 44% of respondents in the first sample did not suffer from any complication; on the other hand, the percentage was only 15% of respondents in the second sample. All respondents (100%) in the first sample suffered from only 2 complications or less; however, 25% of the respondents in the second sample suffered from 3 or more complications. Nephropathy complications, were slightly higher in the first sample; 22% compared to 15% in the second sample. On the other hand, all complications reported in the second sample were higher; 30% for neuropathy, 65% for retinopathy complications and 42.5% for extremities damage compared to only 9.7%, 7.3% and 26.8% respectively in the first sample. In general, respondents who were using cartridges reported a lesser incidence of diabetes complications. Although many organizations suffered from an economical crisis, the cost-effectiveness aspect should be taken into consideration when purchasing medical alternatives. This will provide higher quality of life for patients and eventually lower hidden and future costs for the organizations.

Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

Energy Technology Data Exchange (ETDEWEB)

Freeze, Ronald [Iowa State Univ., Ames, IA (United States)

1997-10-08

Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 μl injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few μl of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

Trace-level mercury ion (Hg2+) analysis in aqueous sample based on solid-phase extraction followed by microfluidic immunoassay.

Science.gov (United States)

Date, Yasumoto; Aota, Arata; Terakado, Shingo; Sasaki, Kazuhiro; Matsumoto, Norio; Watanabe, Yoshitomo; Matsue, Tomokazu; Ohmura, Naoya

2013-01-02

Mercury is considered the most important heavy-metal pollutant, because of the likelihood of bioaccumulation and toxicity. Monitoring widespread ionic mercury (Hg(2+)) contamination requires high-throughput and cost-effective methods to screen large numbers of environmental samples. In this study, we developed a simple and sensitive analysis for Hg(2+) in environmental aqueous samples by combining a microfluidic immunoassay and solid-phase extraction (SPE). Using a microfluidic platform, an ultrasensitive Hg(2+) immunoassay, which yields results within only 10 min and with a lower detection limit (LOD) of 0.13 μg/L, was developed. To allow application of the developed immunoassay to actual environmental aqueous samples, we developed an ion-exchange resin (IER)-based SPE for selective Hg(2+) extraction from an ion mixture. When using optimized SPE conditions, followed by the microfluidic immunoassay, the LOD of the assay was 0.83 μg/L, which satisfied the guideline values for drinking water suggested by the United States Environmental Protection Agency (USEPA) (2 μg/L; total mercury), and the World Health Organisation (WHO) (6 μg/L; inorganic mercury). Actual water samples, including tap water, mineral water, and river water, which had been spiked with trace levels of Hg(2+), were well-analyzed by SPE, followed by microfluidic Hg(2+) immunoassay, and the results agreed with those obtained from reduction vaporizing-atomic adsorption spectroscopy.

EPA Region 8, Memo on Desktop Printer Ink Cartridges Policy & Voluntary Printer Turn-in

Science.gov (United States)

This memo requests EPA Region 8 users to voluntarily turn-in their desktop printers and notifies users of the Region 8 policy to not provide maintenance or ink and toner cartridges for desktop printers.

Plate performance in liquid-liquid extraction

International Nuclear Information System (INIS)

Wadkins, R.P.

1984-01-01

The relative effectiveness of perforated, nozzle, and burred plates from a capacity and extraction standpoint were studied in a pulsed liquid-liquid extraction system. The experiments were conducted in a 3.8 x 10 -2 m diameter column using a mixture of aluminum nitrate, nitric acid, and uranyl nitrate as the aqueous phase, and tributyl phosphate dissolved in AMSCO 125-90 W as the organic phase. The uranium was extracted from the aqueous phase to the organic phase. A standard cartridge was made for each type of plate and consisted of an assembly of plates spaced 5.08 x 10 -2 m apart. Each plate had 3.2 x 10 -3 m holes spaced on 6.1 x 10 -3 -m centers, and contained 23% free area. 16 references, 4 figures, 1 table

Amino-modified diamond as a durable stationary phase for solid-phase extraction.

Science.gov (United States)

Saini, Gaurav; Yang, Li; Lee, Milton L; Dadson, Andrew; Vail, Michael A; Linford, Matthew R

2008-08-15

We report the formation of a highly stable amino stationary phase on diamond and demonstrate its use in solid-phase extraction (SPE). This process consists of spontaneous and self-limiting adsorption of polyallylamine (PAAm) from aqueous solution onto oxidized diamond. Thermal curing under reduced pressure or chemical cross-linking with a diepoxide was shown to fix the polymer to the particles. The resulting adsorbents are stable under even extreme pH conditions (from at least pH 0-14) and significantly more stable than a commercially available amino SPE adsorbent. Coated diamond particles were characterized by X-ray photoelectron spectroscopy (XPS) and diffuse reflectance Fourier transform-infrared spectroscopy (DRIFT). Model silicon surfaces were characterized by spectroscopic ellipsometry and wetting. Solid-phase extraction was demonstrated using cholesterol, hexadecanedioic acid, and palmitoyloleoylphosphatidylcholine as analytes, and these results were compared to those obtained with commercially available materials. Breakthrough curves indicate that, as expected, porous diamond particles have higher analyte capacity than nonporous solid particles.

Innovative separation and preconcentration technique of coagulating homogenous dispersive micro solid phase extraction exploiting graphene oxide nanosheets.

Science.gov (United States)

Ghazaghi, Mehri; Mousavi, Hassan Zavvar; Rashidi, Ali Morad; Shirkhanloo, Hamid; Rahighi, Reza

2016-01-01

A uniquely novel, fast, and facile technique is introduced for the first time in which a scant amount of graphene oxide (GO), without modification, has been utilized in dispersive mode of solid phase extraction (SPE) for an efficient yet simple separation. The proposed method of coagulating homogenous dispersive micro solid phase extraction (CHD-µSPE) is based on coagulation of homogeneous GO solution with the aid of polyetheneimine (PEI). CHD-µSPE use full adsorption capacity of GO because in this method was used GO solution obtained from synthesis process without drying step and stacking nanosheets. In optimized condition, 30 µL GO solution (7 mg mL(-1)), obtained in synthesis process, was injected into 1.5 mL the sample solution followed by immediate injection of 53 µL PEI solution (1 mg mL(-1)). After inserting PEI, GO sheets aggregate and can be readily separated by centrifugation. PEI not only cause aggregation of GO, but also form three-dimensional network of GO with easy handling in following separation steps. Lead, cadmium, and chromium were selected as model analytes and the effecting parameters including the amount of GO, concentration of PEI, sample pH, extraction time, and type of desorption solvent were investigated and optimized. The results indicate that the proposed CHD-µSPE method can be successfully applied GO in dispersive mode of SPE without effecting on good capability adsorption of GO. The novel method was applied in determination of lead, cadmium, and chromium in water, human saliva, and urine samples by electrothermal atomic absorption spectrometry. The detection limits are as low as 0.035, 0.005, and 0.012 µg L(-1) for Pb, Cd, and Cr respectively. The intra-day precisions (RSDs) were lower than 3.8%. CHD-µSPE method showed a good linear ranges of 0.24-15.6, 0.015-0.95 and 0.039-2.33 µg L(-1) for Pb, Cd and Cr respectively. Method performance was investigated by determination of mentioned metal ions in river water, human urine and

Graphene/TiO2 nanocomposite based solid-phase extraction and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for lipidomic profiling of avocado (Persea americana Mill.).

Science.gov (United States)

Shen, Qing; Yang, Mei; Li, Linqiu; Cheung, Hon-Yeung

2014-12-10

Phospholipids possess important physiological, structural and nutritional functions in biological systems. This study described a solid-phase extraction (SPE) method, employing graphene and titanium dioxide (G/TiO2) nanocomposite as sorbent, for the selective isolation and enrichment of phospholipids from avocado (Persea americana Mill.). Based on the principal that the phosphoryl group in the phospholipid can interact with TiO2 via a bridging bidentate mode, an optimum condition was established for SPE, and was successfully applied to prepare avocado samples. The extracts were monitored by matrix-assisted laser desorption ionization time-of-flight/tandem mass spectrometry (MALDI-TOF/MS) in both positive-ion and negative-ion modes. Results showed that phospholipids could be efficiently extracted in a clean manner by G/TiO2 based SPE. In addition, the signals of phospholipids were enhanced while the noise was reduced. Some minor peaks became more obvious. In conclusion, the nanocomposite material of G/TiO2 was proved to be a promising sorbent for selective separation of phospholipids from crude lipid extract. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Screening of 439 Pesticide Residues in Fruits and Vegetables by Gas Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry Based on TOF Accurate Mass Database and Q-TOF Spectrum Library.

Science.gov (United States)

Li, Jian-Xun; Li, Xiao-Ying; Chang, Qiao-Ying; Li, Yan; Jin, Ling-He; Pang, Guo-Fang; Fan, Chun-Lin

2018-05-03

Because of its unique characteristics of accurate mass full-spectrum acquisition, high resolution, and fast acquisition rates, GC-quadrupole-time-of-flight MS (GC-Q-TOF/MS) has become a powerful tool for pesticide residue analysis. In this study, a TOF accurate mass database and Q-TOF spectrum library of 439 pesticides were established, and the parameters of the TOF database were optimized. Through solid-phase extraction (SPE), whereby pesticides are extracted from fruit and vegetable substrates by using 40 mL 1% acetic acid in acetonitrile (v/v), purified by the Carbon/NH₂ SPE cartridge, and finally detected by GC-Q-TOF/MS, the rapid analysis of 439 pesticides in fruits and vegetables can be achieved. The methodology verification results show that more than 70 and 91% of pesticides, spiked in fruits and vegetables with concentrations of 10 and 100 μg/kg, respectively, saw recoveries that conform to the European Commission's criterion of between 70 and 120% with RSD ≤20%. Eighty-one percent of pesticides have screening detection limits lower than 10 μg/kg, which makes this a reliable analysis technology for the monitoring of pesticide residues in fruits and vegetables. This technology was further validated for its characteristics of high precision, high speed, and high throughput through successful detection of 9817 samples during 2013-2015.

Detection and genotyping of human papillomavirus in self-obtained cervicovaginal samples by using the FTA cartridge: new possibilities for cervical cancer screening.

NARCIS (Netherlands)

Lenselink, C.H.; Bie, R.P. de; Hamont, D. van; Bakkers, J.M.J.E.; Quint, W.G.V.; Massuger, L.F.A.G.; Bekkers, R.L.M.; Melchers, W.J.G.

2009-01-01

This study assesses human papillomavirus (HPV) detection and genotyping in self-sampled genital smears applied to an indicating FTA elute cartridge (FTA cartridge). The study group consisted of 96 women, divided into two sample sets. All samples were analyzed by the HPV SPF(10)-Line Blot 25. Set 1

A Method for Multiple Mycotoxin Analysis in Wines by Solid Phase Extraction and Multifunctional Cartridge Purification, and Ultra-High-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

Science.gov (United States)

Tamura, Masayoshi; Takahashi, Ayumi; Uyama, Atsuo; Mochizuki, Naoki

2012-01-01

An analytical method using two solid phase extractions and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was developed for the identification and quantification of 14 mycotoxins (patulin, deoxynivalenol, aflatoxins B1, B2, G1, G2, M1, T-2 toxin, HT-2 toxin, zearalenone, fumonisins B1, B2, B3, and ochratoxin A) in domestic and imported wines. Mycotoxins were purified with an Oasis HLB cartridge, followed by a MultiSepTM #229 Ochra. As a result, sufficient removal of the pigments and highly polar matrices from the red wines was achieved. UHPLC conditions were optimized, and 14 mycotoxins were separated in a total of 13 min. Determinations performed using this method produced high correlation coefficients for the 14 mycotoxins (R > 0.990) and recovery rates ranging from 76 to 105% with good repeatability (relative standard deviation RSD < 12%). Twenty-seven samples of domestic and imported wines were analyzed using this method. Although ochratoxin A (OTA) and fumonisins (FMs) were detected in several samples, the FM levels were less than limits of quantification (LOQs) (1 μg/L), and even the largest of the OTA levels was below the EU regulatory level (2 μg/L). These results suggest that the health risk posed to consumers from the wines available in Japan is relatively low. PMID:22822458

Simultaneous Detection of Sulfamethoxazole, Diclofenac, Carbamazepine, and Bezafibrate by Solid Phase Extraction and High Performance Liquid Chromatography with Diode Array Detection

Science.gov (United States)

Zhou, Z.; Jiang, J.-Q.

2014-05-01

A method of solid phase extraction (SPE) coupled with high performance liquid chromatography and diode array detection (HPLC-DAD) was studied for the simultaneous determination of sulfamethoxazole (SMX), diclofenac (DCF), carbamazepine (CBZ), and bezafi brate (BZF) in test solutions. The target compounds were extracted by SPE from samples, and the resulting elutes were analyzed using a HPLC-DAD system at wavelengths of 270, 280, 290, and 230 nm for SMX, DCF, CBZ, and BZF, respectively. This method shows good recoveries for SMX, DCF, CBZ, and BZF with mean recoveries of 89.7 ± 9.3%, 86.1 ± 7.6%, 95.0 ± 6.5%, and 94.0 ± 5.4%, respectively.

Positive detection of exfoliated colon cancer cells on linear stapler cartridges was associated with depth of tumor invasion and preoperative bowel preparation in colon cancer.

Science.gov (United States)

Ikehara, Kishiko; Endo, Shungo; Kumamoto, Kensuke; Hidaka, Eiji; Ishida, Fumio; Tanaka, Jun-Ichi; Kudo, Shin-Ei

2016-08-31

The aim of this study was to investigate exfoliated cancer cells (ECCs) on linear stapler cartridges used for anastomotic sites in colon cancer. We prospectively analyzed ECCs on linear stapler cartridges used for anastomosis in 100 colon cancer patients who underwent colectomy. Having completed the functional end-to-end anastomosis, the linear stapler cartridges were irrigated with saline, which was collected for cytological examination and cytological diagnoses were made by board-certified pathologists based on Papanicolaou staining. The detection rate of ECCs on the linear stapler cartridges was 20 %. Positive detection of ECCs was significantly associated with depth of tumor invasion (p = 0.012) and preoperative bowel preparation (p = 0.003). There were no marked differences between ECC-positive and ECC-negative groups in terms of the operation methods, tumor location, histopathological classification, and surgical margins. Since ECCs were identified on the cartridge of the linear stapler used for anastomosis, preoperative mechanical bowel preparation using polyethylene glycol solution and cleansing at anastomotic sites using tumoricidal agents before anastomosis may be necessary to decrease ECCs in advanced colon cancer.

Organochlorine pesticide contamination of ground water in the city of Hyderabad.

Science.gov (United States)

Shukla, Gangesh; Kumar, Anoop; Bhanti, Mayank; Joseph, P E; Taneja, Ajay

2006-02-01

Organochlorine pesticides are ubiquitous and persistent organic pollutants used widely throughout the world. Due to the extensive use in agriculture, organic environmental contaminants such as HCH, DDT along with other organochlorine pesticides are distributed globally by transport through air and water. The main aim of present study is to determine contamination levels of organochlorine pesticides in the ground water of Hyderabad City. Water samples were collected from 28 domestic well supplies of the city. For this study, random sampling technique was applied, all the samples were collected in high purity glass bottles and refrigerated at 4 degrees C until analysis. Solid Phase Extraction (SPE) is used for the extraction of organochlorine pesticide residues in water sample. The collected water samples were pre-filtered through a 0.45 microg glass fiber filter (Wattman GF/F) to remove particulate matter and were acidified with hydrochloric acid (6N) to pH 2.5. Methanol modifier (BDH, for pesticide residue analysis, 10 mL) was added to water sample for better extraction. SPE using pre-packed reversed phase octadecyl (C-18 bonded silica) contained in cartridges was used for sample preparation. Prior to the extraction, the C-18 bonded phase, which contains 500 mg of bonded phase, was washed with 20 mL methanol. The sample was mixed well and allowed to percolate through the cartridges with flow rate of 10-15 mL/min under vacuum. After sample extraction, suction continued for 15 min to dry the packing material and pesticides trapped in the C-18 bonded phases were eluted by passing 10 mL hexane and fraction was evaporated in a gentle steam of Nitrogen. In all samples pesticide residues were analyzed by GC (Chemito-8510) with Ni63 ECD detector. Helium was used as carrier gas and nitrogen was used as make up gas. The injection technique was split/split less. All the samples analyzed were found to be contaminated with four pesticides i.e. DDT, beta-Endosulfan, alpha

Environmental impacts and resource losses of incinerating misplaced household special wastes (WEEE, batteries, ink cartridges and cables)

DEFF Research Database (Denmark)

Bigum, Marianne Kristine Kjærgaard; Damgaard, Anders; Scheutz, Charlotte

2017-01-01

The contribution of misplaced special waste (sWEEE, lamps, CRT, batteries, ink cartridges and cables) to environmental impacts from incineration of residual household waste was quantified through life cycle assessment (LCA)-modelling. Misplaced special waste was quantified to constitute less than 1...... and batteries. However as shown by sensitivity analysis, lack of good data on the transfer of rare and hazardous metals to the flue gas in the incineration process should receive further investigation before the environmental impacts from misplaced incinerated special waste can fully be concluded upon. Although...... special waste (sWEEE, lamps, CRT, batteries, ink cartridges, and cables)....

Proceedings of the 1992 SPE oil and gas economics, finance and management conference

International Nuclear Information System (INIS)

Anon.

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

Gulf Coast Section SPE Production Operations Study Group-technical highlights from a series of frac pack treatment symposiums

Energy Technology Data Exchange (ETDEWEB)

McLarty, J.M.; DeBonis, V.

1995-12-31

One of the main functions of the SPE is to provide a means for collection, dissemination, and exchange of technical information and to provide technical forums that afford opportunities for members to maintain and upgrade their technical competence. The large chapters (such as Houston SPE) located near many oil company headquarters have the advantage of being able to bring together a cross section of service company and operator personnel representing operations and research from major and independent operators. This paper describes a series of 1-day symposiums on frac pack technology that were organized by the Houston-based Gulf Coast Section SPE Production Operations Study Group. These study sessions provided a means for the local members of the industry to further develop a new technology as a team. Publishing the major focus and contributions of the seminars will allow sharing of the technology with chapters outside of Houston.

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

Integrated electrokinetically driven microfluidic devices with pH-mediated solid-phase extraction coupled to microchip electrophoresis for preterm birth biomarkers.

Science.gov (United States)

Sonker, Mukul; Knob, Radim; Sahore, Vishal; Woolley, Adam T

2017-07-01

Integration in microfluidics is important for achieving automation. Sample preconcentration integrated with separation in a microfluidic setup can have a substantial impact on rapid analysis of low-abundance disease biomarkers. Here, we have developed a microfluidic device that uses pH-mediated solid-phase extraction (SPE) for the enrichment and elution of preterm birth (PTB) biomarkers. Furthermore, this SPE module was integrated with microchip electrophoresis for combined enrichment and separation of multiple analytes, including a PTB peptide biomarker (P1). A reversed-phase octyl methacrylate monolith was polymerized as the SPE medium in polyethylene glycol diacrylate modified cyclic olefin copolymer microfluidic channels. Eluent for pH-mediated SPE of PTB biomarkers on the monolith was optimized using different pH values and ionic concentrations. Nearly 50-fold enrichment was observed in single channel SPE devices for a low nanomolar solution of P1, with great elution time reproducibility (electrophoresis in our integrated device with ∼15-fold enrichment. This device shows important progress towards an integrated electrokinetically operated platform for preconcentration and separation of biomarkers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Innovative separation and preconcentration technique of coagulating homogenous dispersive micro solid phase extraction exploiting graphene oxide nanosheets

Energy Technology Data Exchange (ETDEWEB)

Ghazaghi, Mehri [Department of Chemistry, College of Science, Semnan University, P.O. Box: 35131-19111, Semnan (Iran, Islamic Republic of); Mousavi, Hassan Zavvar, E-mail: hzmousavi@semnan.ac.ir [Department of Chemistry, College of Science, Semnan University, P.O. Box: 35131-19111, Semnan (Iran, Islamic Republic of); Rashidi, Ali Morad [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Entrance Blvd., Olympic Village, P.O. Box: 14857-33111, Tehran (Iran, Islamic Republic of); Shirkhanloo, Hamid [Occupational and Environmental Health Research Center (OEHRC), Iranian Petroleum Industry Health Research Institute (IPIHRI), Tehran (Iran, Islamic Republic of); Rahighi, Reza [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Entrance Blvd., Olympic Village, P.O. Box: 14857-33111, Tehran (Iran, Islamic Republic of); Department of Research and Development, Sharif Ultrahigh Nanotechnologists (SUN) Company, P.O. Box: 13488-96394, Tehran (Iran, Islamic Republic of)

2016-01-01

A uniquely novel, fast, and facile technique is introduced for the first time in which a scant amount of graphene oxide (GO), without modification, has been utilized in dispersive mode of solid phase extraction (SPE) for an efficient yet simple separation. The proposed method of coagulating homogenous dispersive micro solid phase extraction (CHD-µSPE) is based on coagulation of homogeneous GO solution with the aid of polyetheneimine (PEI). CHD-µSPE use full adsorption capacity of GO because in this method was used GO solution obtained from synthesis process without drying step and stacking nanosheets. In optimized condition, 30 µL GO solution (7 mg mL{sup −1}), obtained in synthesis process, was injected into 1.5 mL the sample solution followed by immediate injection of 53 µL PEI solution (1 mg mL{sup −1}). After inserting PEI, GO sheets aggregate and can be readily separated by centrifugation. PEI not only cause aggregation of GO, but also form three-dimensional network of GO with easy handling in following separation steps. Lead, cadmium, and chromium were selected as model analytes and the effecting parameters including the amount of GO, concentration of PEI, sample pH, extraction time, and type of desorption solvent were investigated and optimized. The results indicate that the proposed CHD-µSPE method can be successfully applied GO in dispersive mode of SPE without effecting on good capability adsorption of GO. The novel method was applied in determination of lead, cadmium, and chromium in water, human saliva, and urine samples by electrothermal atomic absorption spectrometry. The detection limits are as low as 0.035, 0.005, and 0.012 µg L{sup −1} for Pb, Cd, and Cr respectively. The intra-day precisions (RSDs) were lower than 3.8%. CHD-µSPE method showed a good linear ranges of 0.24–15.6, 0.015–0.95 and 0.039–2.33 µg L{sup −1} for Pb, Cd and Cr respectively. Method performance was investigated by determination of mentioned

Recent advances in column switching sample preparation in bioanalysis.

Science.gov (United States)

Kataoka, Hiroyuki; Saito, Keita

2012-04-01

Column switching techniques, using two or more stationary phase columns, are useful for trace enrichment and online automated sample preparation. Target fractions from the first column are transferred online to a second column with different properties for further separation. Column switching techniques can be used to determine the analytes in a complex matrix by direct sample injection or by simple sample treatment. Online column switching sample preparation is usually performed in combination with HPLC or capillary electrophoresis. SPE or turbulent flow chromatography using a cartridge column and in-tube solid-phase microextraction using a capillary column have been developed for convenient column switching sample preparation. Furthermore, various micro-/nano-sample preparation devices using new polymer-coating materials have been developed to improve extraction efficiency. This review describes current developments and future trends in novel column switching sample preparation in bioanalysis, focusing on innovative column switching techniques using new extraction devices and materials.

Simultaneous determination of multiresidual phenyl acetanilide pesticides in different food commodities by solid-phase cleanup and gas chromatography-mass spectrometry.

Science.gov (United States)

Li, Yongjun; Wang, Meiling; Yan, Hongfei; Fu, Shanliang; Dai, Hua

2013-03-01

An efficient and sensitive multiresidue method has been developed for quantification and confirmation of 25 phenyl acetanilide pesticides in a wide variety of food commodities including maize, spinach, mushroom, apple, soybean, chestnut, tea, beef, cattle liver, chicken, fish, and milk. Analytes were extracted with acetone-n-hexane (1:2, v/v) followed by cleanup using SPE. Several types of adsorbents were evaluated. Neutral aluminum and graphitized carbon black cartridge showed good cleanup efficiency. The extract was determined by GC-MS in the selected ion monitoring mode using one target and two qualitative ions for each analyte. The limits of detection were 0.01 mg/kg for all analytes. The average recoveries ranged from 66.9 to 110.6% (mean 88.8%) and RSDs were in the range 2.0-19% (mean 10.5%) across three fortification levels. The proposed method was successfully applied to real samples in routine analysis and a satisfactory result was obtained. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of Ketorolac in the Effluent from a Hospital Treating Plant and Kinetics Study of Its Photolytic Degradation

Directory of Open Access Journals (Sweden)

Hector Hugo Ortega Soto

2017-01-01

Full Text Available In this work, two specific, sensitive, and rapid analytical methods were developed. One of them was for the determination of ketorolac in a hospital wastewater treatment plant where there is no interference with other organic substances; the other one was for the determination of the degradation kinetics in aqueous medium. Ketorolac was extracted from wastewater samples through solid-phase extraction (SPE cartridges, then it was identified and quantified by high-performance liquid chromatography (HPLC. Ketorolac was detected in concentrations between 0.1376 and 0.2667 μg/L. Photolytic degradation was performed on aqueous solutions of ketorolac tromethamine reference substance, at a concentration of 50 μg/mL. Samples were in direct contact with ultraviolet light in a dark chamber, equipped with two mercury lamps (254 nm at a radiation source of 15 W. The results of the photolytic degradation were adjusted to a first-order model, obtaining a half-life of 4.8 hrs.

Behavioral response and pain perception to computer controlled local anesthetic delivery system and cartridge syringe

Directory of Open Access Journals (Sweden)

T D Yogesh Kumar

2015-01-01

Full Text Available Aim: The present study evaluated and compared the pain perception, behavioral response, physiological parameters, and the role of topical anesthetic administration during local anesthetic administration with cartridge syringe and computer controlled local anesthetic delivery system (CCLAD. Design: A randomized controlled crossover study was carried out with 120 children aged 7-11 years. They were randomly divided into Group A: Receiving injection with CCLAD during first visit; Group B: Receiving injection with cartridge syringe during first visit. They were further subdivided into three subgroups based on the topical application used: (a 20% benzocaine; (b pressure with cotton applicator; (c no topical application. Pulse rate and blood pressure were recorded before and during injection procedure. Objective evaluation of disruptive behavior and subjective evaluation of pain were done using face legs activity cry consolability scale and modified facial image scale, respectively. The washout period between the two visits was 1-week. Results: Injections with CCLAD produced significantly lesser pain response, disruptive behavior (P < 0.001, and pulse rate (P < 0.05 when compared to cartridge syringe injections. Application of benzocaine produced lesser pain response and disruptive behavior when compared to the other two subgroups, although the result was not significant. Conclusion: Usage of techniques which enhance behavioral response in children like injections with CCLAD can be considered as a possible step toward achieving a pain-free pediatric dental practice.

Comparison of Radiation Transport Codes, HZETRN, HETC and FLUKA, Using the 1956 Webber SPE Spectrum

Science.gov (United States)

Heinbockel, John H.; Slaba, Tony C.; Blattnig, Steve R.; Tripathi, Ram K.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Clowdsley, Martha S.;

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.

Micro versus macro solid phase extraction for monitoring water contaminants: a preliminary study using trihalomethanes.

Science.gov (United States)

Alexandrou, Lydon D; Spencer, Michelle J S; Morrison, Paul D; Meehan, Barry J; Jones, Oliver A H

2015-04-15

Solid phase extraction is one of the most commonly used pre-concentration and cleanup steps in environmental science. However, traditional methods need electrically powered pumps, can use large volumes of solvent (if multiple samples are run), and require several hours to filter a sample. Additionally, if the cartridge is open to the air volatile compounds may be lost and sample integrity compromised. In contrast, micro cartridge based solid phase extraction can be completed in less than 2 min by hand, uses only microlitres of solvent and provides comparable concentration factors to established methods. It is also an enclosed system so volatile components are not lost. The sample can also be eluted directly into a detector (e.g. a mass spectrometer) if required. However, the technology is new and has not been much used for environmental analysis. In this study we compare traditional (macro) and the new micro solid phase extraction for the analysis of four common volatile trihalomethanes (trichloromethane, bromodichloromethane, dibromochloromethane and tribromomethane). The results demonstrate that micro solid phase extraction is faster and cheaper than traditional methods with similar recovery rates for the target compounds. This method shows potential for further development in a range of applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of antibiotics such as macrolides, ionophores and tiamulin in liquid manure by HPLC-MS/MS.

Science.gov (United States)

Schlüsener, Michael P; Bester, Kai; Spiteller, Michael

2003-04-01

A method for the analysis of several macrolide and ionophore antibiotics as well as tiamulin in liquid manure was developed. Reversed-phase liquid chromatography and atmospheric pressure chemical ionisation (APCI) tandem mass spectrometry was used for detection.High-performance liquid chromatographic (HPLC) separation of the antibiotics was achieved in 35 min. The analytes were extracted with ethyl acetate and the extracts were cleaned up by solid-phase extraction on a diol SPE cartridge. Recovery experiments with spiked liquid manure concentrations varying from 6 to 2,000 microg kg(-1) gave constant recovery rates. The recovery rates for the macrolides erythromycin, roxithromycin and oleandomycin were 75-94%, that for the ionophore salinomycin was 119%, while that for the pleuromutilin tiamulin was 123%, when using a macrolide internal standard. The relative standard deviation was found to be 15-36% and the limits of detection were 0.4-11.0 micro g kg(-1). The maximum concentrations found in manure samples were 43 micro g kg(-1) for tiamulin and 11 micro g kg(-1) for salinomycin.

Influence Factors Regarding the Effectiveness of Automated Ballistic Comparison on 0.38 Special Caliber Bullets and Cartridge Cases.

Science.gov (United States)

Dos Santos, Lehi Sudy; Vieira Muterlle, Palloma

2018-03-01

Factors influencing effectiveness of automated comparisons, test-fired bullets, and cartridge cases from 0.38 Special revolvers were logged into the Evofinder ® Ballistic ID System. Tests were performed as follows: First test correlated test-fires of the same type, second test compared different types of ammunition components, third test replicated the second test in a larger database, and fourth test replicated the third test with students having no previous firearm identification experience. System effectiveness with projectiles in the first test was 0.89. With cartridge cases, effectiveness was 0.79 with combined results, but analysis of separate results by breech face and firing pin revealed low effectiveness by breech face (0.40). In the second, third, and fourth tests, effectiveness with projectiles were 0.61, 0.51, and 0.44. In addition, these tests had effectiveness with cartridge cases equivalent to 0.55, 0.43, and 0.44. Results are useful to establish routine protocols, system improvements, or comparative assessment of other electronic systems. © 2018 American Academy of Forensic Sciences.

A patterned abrasion caused by the impact of a cartridge case may simulate an atypical muzzle imprint mark.

Science.gov (United States)

Kramer, Lena; Nadjem, Hadi; Glardon, Matthieu; Kneubuehl, Beat P; Pollak, Stefan; Große Perdekamp, Markus; Pircher, Rebecca

2016-05-01

In contact shots, the muzzle imprint is an informative finding associated with the entrance wound. It typically mirrors the constructional components being in line with the muzzle or just behind. Under special conditions, other patterned skin marks located near a gunshot entrance wound may give the impression to be part of the muzzle imprint. A potential mechanism causing a patterned pressure abrasion in close proximity to the bullet entrance site is demonstrated on the basis of a suicidal shot to the temple. The skin lesion in question appeared as a ring-shaped excoriation with a diameter corresponding to that of the cartridge case. Two hypotheses concerning the causative mechanism were investigated by test shots: - After being ejected, the cartridge case ricocheted inside a confined space (car cabin in the particular case) and secondarily hit the skin near the gunshot entrance wound. - The ejection of the cartridge case failed so that the case became stuck in the ejection port and its mouth contacted the skin when the body collapsed after being hit.

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.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparative separation and structural identification of impurities of a new α{sub 2}-Adrenoceptor agonist using stacking injection, LC-MS{sup n} and LC-SPE-NMR

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Josiane O.; Thomasi, Sérgio S.; Venâncio, Tiago; Oliveira, Regina V., E-mail: oliveirarv@ufscar.br [Universidade Federal de São Carlos (UFSCar), SP (Brazil). Departamento de Química; Pitta, Ivan R.; Lima, Maria do Carmo A. de [Universidade Federal de Pernambuco (NUPIT/UFPE), Recife, PE (Brazil). Núcleo de Pesquisa em Inovação Tecnológica

2017-07-01

Identifying impurities in drug substances has become one of the most important issues in pharmaceutical analysis since it can have a significant impact on the efficacy of new pharmaceutical products. Due to the purity requirements, in this paper a new synthetic α{sub 2}-adrenoceptor agonist, called LPSF-PT-31, was purified and its impurities were characterized by liquid chromatography multistage mass spectrometry (LC-MS{sup n}) and liquid chromatography-solid phase extraction-nuclear magnetic resonance (LC-SPE-NMR). The purification step was conducted using a semi-preparative liquid chromatography and stacked injections as a new approach to drug purification. As a result, a total yield of 75% of the pure LPSF-PT-31 and 2.9 L day{sup -}'1 in solvent reduction was obtained. The combination of semi-preparative stacking injection, LC-MS{sup n}, and LC-SPE-NMR, demonstrated to be efficient to purify active drugs and unambiguously identify its impurities. In addition, isolation and identification of drug impurities in the early stages of development can improve the synthetic pathway, preventing the formation of impurities or minimizing this formation to minimum levels. (author)

Solid-phase extraction versus matrix solid-phase dispersion: Application to white grapes.

Science.gov (United States)

Dopico-García, M S; Valentão, P; Jagodziñska, A; Klepczyñska, J; Guerra, L; Andrade, P B; Seabra, R M

2007-11-15

The use of matrix solid-phase dispersion (MSPD) was tested to, separately, extract phenolic compounds and organic acids from white grapes. This method was compared with a more conventional analytical method previously developed that combines solid liquid extraction (SL) to simultaneously extract phenolic compounds and organic acids followed by a solid-phase extraction (SPE) to separate the two types of compounds. Although the results were qualitatively similar for both techniques, the levels of extracted compounds were in general quite lower on using MSPD, especially for organic acids. Therefore, SL-SPE method was preferred to analyse white "Vinho Verde" grapes. Twenty samples of 10 different varieties (Alvarinho, Avesso, Asal-Branco, Batoca, Douradinha, Esganoso de Castelo Paiva, Loureiro, Pedernã, Rabigato and Trajadura) from four different locations in Minho (Portugal) were analysed in order to study the effects of variety and origin on the profile of the above mentioned compounds. Principal component analysis (PCA) was applied separately to establish the main sources of variability present in the data sets for phenolic compounds, organic acids and for the global data. PCA of phenolic compounds accounted for the highest variability (77.9%) with two PCs, enabling characterization of the varieties of samples according to their higher content in flavonol derivatives or epicatechin. Additionally, a strong effect of sample origin was observed. Stepwise linear discriminant analysis (SLDA) was used for differentiation of grapes according to the origin and variety, resulting in a correct classification of 100 and 70%, respectively.

Advanced functional materials in solid phase extraction for ICP-MS determination of trace elements and their species - A review.

Science.gov (United States)

He, Man; Huang, Lijin; Zhao, Bingshan; Chen, Beibei; Hu, Bin

2017-06-22

For the determination of trace elements and their species in various real samples by inductively coupled plasma mass spectrometry (ICP-MS), solid phase extraction (SPE) is a commonly used sample pretreatment technique to remove complex matrix, pre-concentrate target analytes and make the samples suitable for subsequent sample introduction and measurements. The sensitivity, selectivity/anti-interference ability, sample throughput and application potential of the methodology of SPE-ICP-MS are greatly dependent on SPE adsorbents. This article presents a general overview of the use of advanced functional materials (AFMs) in SPE for ICP-MS determination of trace elements and their species in the past decade. Herein the AFMs refer to the materials featuring with high adsorption capacity, good selectivity, fast adsorption/desorption dynamics and satisfying special requirements in real sample analysis, including nanometer-sized materials, porous materials, ion imprinting polymers, restricted access materials and magnetic materials. Carbon/silica/metal/metal oxide nanometer-sized adsorbents with high surface area and plenty of adsorption sites exhibit high adsorption capacity, and porous adsorbents would provide more adsorption sites and faster adsorption dynamics. The selectivity of the materials for target elements/species can be improved by using physical/chemical modification, ion imprinting and restricted accessed technique. Magnetic adsorbents in conventional batch operation offer unique magnetic response and high surface area-volume ratio which provide a very easy phase separation, greater extraction capacity and efficiency over conventional adsorbents, and chip-based magnetic SPE provides a versatile platform for special requirement (e.g. cell analysis). The performance of these adsorbents for the determination of trace elements and their species in different matrices by ICP-MS is discussed in detail, along with perspectives and possible challenges in the future

[Determination of five representative ultraviolet filters in water by gas chromatography-mass spectrometry].

Science.gov (United States)

Ding, Yiran; Huang, Yun; Zhao, Tingting; Cai, Qian; Luo, Yu; Huang, Bin; Zhang, Yuxia; Pan, Xuejun

2014-06-01

A method for the determination of five representative organic UV filters: ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), 4-methylbenzylidene camphor (4-MBC), octocrylene (OC), homosalate (HMS) in water was investigated. The method was ased on derivatization, solid phase extraction (SPE), followed by determination with gas chromatography-mass spectrometry (GC-MS). The variables involved in the derivatization of BP-3 and HMS were optimized, and SPE conditions were studied. For derivatization, 100 microL N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) was used as derivatization reagent and reacted with BP-3 and HMS at 100 degrees C for 100 min. For SPE, the pH value of water sample was adjusted to 3-5. The Oasis HLB cartridges were employed and the solution of ethyl acetate and dichloromethane (1 : 1, v/v) was used as the eluting solvent, and good recoveries of the target compounds were obtained. The limits of detection (LODs) and the limits of quantification (LOQs) for the five target compounds in water samples were 0.5-1.2 ng/L and 1.4-4.0 ng/L, respectively. The recoveries of spiked water samples were 87.85%-102.34% with good repeatability and reproducibility (RSD < 5%, n = 3) for all the target compounds. Finally, the validated method was applied to analysis the representative UV filters in water samples collected from a wastewater treatment plant in Kunming city of Yunnan province.

Miniaturized solid-phase extraction of macrolide antibiotics in honey and bovine milk using mesoporous MCM-41 silica as sorbent.

Science.gov (United States)

Du, Li-Jing; Yi, Ling; Ye, Li-Hong; Chen, Yu-Bo; Cao, Jun; Peng, Li-Qing; Shi, Yu-Ting; Wang, Qiu-Yan; Hu, Yu-Han

2018-02-16

A simple and effective method of miniaturized solid-phase extraction (mini-SPE) was developed for the simultaneous purification and enrichment of macrolide antibiotics (MACs) (i.e. azithromycin, clarithromycin, erythromycin, lincomycin and roxithromycin) from honey and skim milk. Mesoporous MCM-41 silica was synthesized and used as sorbent in mini-SPE. Several key parameters affecting the performance of mini-SPE procedure were thoroughly investigated, including sorbent materials, amount of sorbent and elution solvents. Under the optimized condition, satisfactory linearity (r 2  > 0.99), acceptable precision (RSDs, 0.3-7.1%), high sensitivity (limit of detection in the range of 0.01-0.76 μg/kg), and good recoveries (83.21-105.34%) were obtained. With distinct advantages of simplicity, reliability and minimal sample requirement, the proposed mini-SPE procedure coupled with ultrahigh performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry could become an alternative tool to analyze the residues of MACs in complex food matrixes. Copyright © 2018 Elsevier B.V. All rights reserved.

Safety limits of half-mask cartridge respirators for organic solvent vapors

International Nuclear Information System (INIS)

Anon.

1975-01-01

Recent studies of the effective service life (safety limits) for typical half-mask cartridge respirators have shown these devices to be unsuitable for certain organic vapors, e.g., methanol, methylamine, vinyl chloride, and dichloromethane, because the effective service life is too short. For these vapors other forms of protection such as air-supplied respirators are recommended. The experimentally determined service life for many vapors is shorter--sometimes significantly shorter--than predicted by adsorption theory

Graphene oxide bound silica for solid-phase extraction of 14 polycyclic aromatic hydrocarbons in mainstream cigarette smoke.

Science.gov (United States)

Shi, Rui; Yan, Lihong; Xu, Tongguang; Liu, Dongye; Zhu, Yongfa; Zhou, Jun

2015-01-02

Polycyclic aromatic hydrocarbons (PAHs) were considered as a source of carcinogenicity in mainstream cigarette smoke (MSS). Accurate quantification of these components was necessary for assessing public health risk. In our study, a solid-phase extraction (SPE) method using graphene oxide (GO) bound silica as adsorbent for purification of 14 PAHs in MSS was developed. During SPE process, large matrices interferences of MSS were adsorbed on SPE column. The result of FTIR spectra demonstrated that these matrices interferences were adsorbed on GO mainly through OH and CO groups. The concentrations of PAHs in MSS extract were determined by gas chromatography-mass spectrometry (GC-MS). The limit of detection (LOD) and limit of quantification (LOQ) of the developed method for 14 PAHs ranged from 0.05 to 0.36 ng/cig and 0.17 to 1.19 ng/cig, respectively. The accuracy of the measurement of 14 PAHs was from 73 to 116%. The relative standard deviations of intra- and inter-day analysis were less than 7.8% and 13.9%, respectively. Moreover, the developed method was successfully applied for analysis of real cigarette containing 1R5F reference cigarette and 12 top-selling commercial cigarettes in China. Copyright © 2014 Elsevier B.V. All rights reserved.