The Experts below are selected from a list of 30024 Experts worldwide ranked by ideXlab platform
Pengyue Zhao - One of the best experts on this subject based on the ideXlab platform.
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the comparison of dispersive solid phase extraction and multi plug filtration Cleanup method based on multi walled carbon nanotubes for pesticides multi residue analysis by liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2015Co-Authors: Pengyue Zhao, Na Zou, Shuangyu Song, Yua ZhangAbstract:Abstract In this study, dispersive-Solid Phase Extraction (d-SPE) Cleanup and multi-plug filtration Cleanup (m-PFC) methods were compared for 25 representative pesticides in six matrices (wheat, spinach, carrot, apple, citrus and peanut) by QuEChERS-LC-ESI-MS/MS detection. The type of sorbents in dispersive-SPE (d-SPE) was optimized for the above matrices. Multi-walled carbon nanotubes (MWCNTs), which mixed other materials like PSA (Primary Secondary Amines), GCB (Graphitized Carbon Black) and C18 (Octadecyl-silica), showed brilliant Cleanup performance in multi residue monitoring (MRM) pesticide residue analysis. Cleanup effects with d-SPE and m-PFC methods were examined. When spiked at 3 concentration levels of 10, 100, 500 μg/kg in above matrices, for both d-SPE and m-PFC methods, the recoveries ranged from 70 to 110% with relative standard deviations (RSDs) lower than 20%. Limits of quantification (LOQs) for both Cleanup methods ranged from 1 to 25 μg/kg. Matrix-matched calibrations were performed with the coefficients of determination more than 0.99 between concentration levels of 10–1000 μg/kg. It was found that m-PFC was more convenient and effective than d-SPE with the same sorbents, due to the increased contact time and contact area between the extracts and compressed sorbents. The study demonstrated that m-PFC method could be used as a rapid, convenient and high-throughput Cleanup method for analysis of pesticide residues.
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rapid multiplug filtration Cleanup with multiple walled carbon nanotubes and gas chromatography triple quadruple mass spectrometry detection for 186 pesticide residues in tomato and tomato products
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Pengyue Zhao, Baoyong Huang, Yongtao Han, Nan Zou, Canping PanAbstract:This study reports the development and validation of a novel rapid Cleanup method based on multiple-walled carbon nanotubes in a packed column filtration procedure for analysis of pesticide residues followed by gas chromatography-triple-quadruple tandem mass spectrometry detection. The Cleanup method was carried out by applying the streamlined procedure on a multiplug filtration Cleanup column with syringes. The sorbent used for removing the interferences in the matrices is multiple-walled carbon nanotubes mixed with anhydrous magnesium sulfate. The proposed Cleanup method is convenient and time-saving as it does not require any solvent evaporation, vortex, or centrifugation procedures. It was validated on 186 pesticides and 3 tomato product matrices spiked at two concentration levels of 10 and 100 μg kg(-1). Satisfactory recoveries and relative standard deviations are shown for most pesticides using the multiplug filtration Cleanup method in tomato product samples. The developed method was successfully applied to the determination of pesticide residues in market samples.
Juan Baztan - One of the best experts on this subject based on the ideXlab platform.
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Volunteer beach Cleanups: civic environmental stewardship combating global plastic pollution
Sustainability Science, 2020Co-Authors: Bethany Jorgensen, Marianne Krasny, Juan BaztanAbstract:Marine litter, the majority of which is plastic, is one of the most pressing global environmental challenges impacting the planet. One way coastal communities respond to this challenge is through the environmental stewardship practice of volunteer beach Cleanups. Beyond providing temporarily cleaner local beaches, how might these beach Cleanups have broader impacts in the global struggle against plastic pollution? Using the lenses of environmental stewardship and civic ecology, we conducted a content analysis of primary source materials created by 50 groups involved in volunteer beach Cleanups. We collected data on the scale at which groups coordinate volunteer beach Cleanups, the roles they play in conducting these Cleanups, how they interact with other volunteer beach Cleanup groups, and the other forms of stewardship they conduct, if any. Within our sample, we identified groups coordinating volunteer beach Cleanups at five geographic scales: local, sub-national, national, multi-national, and global. Within the groups operating at each scale, we found groups conducting environmental stewardship in the forms of education, advocacy, research, and monitoring in addition to their conservation work through beach Cleanups. Our findings demonstrate that groups branch out their impacts by combining different forms of environmental stewardship targeting plastic pollution, and they collaborate to scale up their actions in ways that contribute to plastic pollution governance. Connecting these findings with the literature on the broader impacts of civic ecology practices allows us to theorize how volunteer beach Cleanup groups branch out and scale up their efforts to weave a global net of ocean stewardship.
Canping Pan - One of the best experts on this subject based on the ideXlab platform.
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determination of 12 carbamate insecticides in typical vegetables and fruits by rapid multi plug filtration Cleanup and ultra performance liquid chromatography tandem mass spectrometry detection
Journal of Chromatographic Science, 2020Co-Authors: Liuwei Zhao, Jiaqi Wang, Canping Pan, Cong Liu, Yu Wang, Qi Ding, Yuechao Feng, Huijuan Zhou, Li JiaAbstract:A multiresidue method for determining 12 carbamate pesticides in purple cabbage, orange, watermelon, cucumber, cowpea and Lactuca sativa L. employing multi-plug filtration Cleanup (m-PFC) and ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) was developed. M-PFC was carried out by Cleanup at dispersive solid phase extraction (d-SPE), one m-PFC tip-filtration, two m-PFC tip-filtration and other methods (1-3 m-PFC Cleanups). Results demonstrated that filtration simplified the Cleanup method compared with d-SPE and other m-PFC methods (1-3 m-PFC Cleanups). The method validation results showed that the method was linear, selective and accurate. The limits of quantification (LOQs) were 0.05-5.0 μg/kg, and the recoveries were in the range of 70.1-119.9% in different matrices. Although matrix effects were observed, they were successfully compensated using matrix-matched calibration. Finally, the developed method was successfully applied to detect pesticides in real samples.
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rapid multiplug filtration Cleanup with multiple walled carbon nanotubes and gas chromatography triple quadruple mass spectrometry detection for 186 pesticide residues in tomato and tomato products
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Pengyue Zhao, Baoyong Huang, Yongtao Han, Nan Zou, Canping PanAbstract:This study reports the development and validation of a novel rapid Cleanup method based on multiple-walled carbon nanotubes in a packed column filtration procedure for analysis of pesticide residues followed by gas chromatography-triple-quadruple tandem mass spectrometry detection. The Cleanup method was carried out by applying the streamlined procedure on a multiplug filtration Cleanup column with syringes. The sorbent used for removing the interferences in the matrices is multiple-walled carbon nanotubes mixed with anhydrous magnesium sulfate. The proposed Cleanup method is convenient and time-saving as it does not require any solvent evaporation, vortex, or centrifugation procedures. It was validated on 186 pesticides and 3 tomato product matrices spiked at two concentration levels of 10 and 100 μg kg(-1). Satisfactory recoveries and relative standard deviations are shown for most pesticides using the multiplug filtration Cleanup method in tomato product samples. The developed method was successfully applied to the determination of pesticide residues in market samples.
Yua Zhang - One of the best experts on this subject based on the ideXlab platform.
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the comparison of dispersive solid phase extraction and multi plug filtration Cleanup method based on multi walled carbon nanotubes for pesticides multi residue analysis by liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2015Co-Authors: Pengyue Zhao, Na Zou, Shuangyu Song, Yua ZhangAbstract:Abstract In this study, dispersive-Solid Phase Extraction (d-SPE) Cleanup and multi-plug filtration Cleanup (m-PFC) methods were compared for 25 representative pesticides in six matrices (wheat, spinach, carrot, apple, citrus and peanut) by QuEChERS-LC-ESI-MS/MS detection. The type of sorbents in dispersive-SPE (d-SPE) was optimized for the above matrices. Multi-walled carbon nanotubes (MWCNTs), which mixed other materials like PSA (Primary Secondary Amines), GCB (Graphitized Carbon Black) and C18 (Octadecyl-silica), showed brilliant Cleanup performance in multi residue monitoring (MRM) pesticide residue analysis. Cleanup effects with d-SPE and m-PFC methods were examined. When spiked at 3 concentration levels of 10, 100, 500 μg/kg in above matrices, for both d-SPE and m-PFC methods, the recoveries ranged from 70 to 110% with relative standard deviations (RSDs) lower than 20%. Limits of quantification (LOQs) for both Cleanup methods ranged from 1 to 25 μg/kg. Matrix-matched calibrations were performed with the coefficients of determination more than 0.99 between concentration levels of 10–1000 μg/kg. It was found that m-PFC was more convenient and effective than d-SPE with the same sorbents, due to the increased contact time and contact area between the extracts and compressed sorbents. The study demonstrated that m-PFC method could be used as a rapid, convenient and high-throughput Cleanup method for analysis of pesticide residues.
Steven J Lehotay - One of the best experts on this subject based on the ideXlab platform.
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confirmatory and quantitative analysis of β lactam antibiotics in bovine kidney tissue by dispersive solid phase extraction and liquid chromatography tandem mass spectrometry
Analytical Chemistry, 2005Co-Authors: Clifton K Fagerquist, And Alan R Lightfield, Steven J LehotayAbstract:A simple, rapid, rugged, sensitive, and specific method for the confirmation and quantitation of 10 β-lactam antibiotics in fortified and incurred bovine kidney tissue has been developed. The method uses a simple solvent extraction, dispersive solid-phase extraction (dispersive-SPE) Cleanup, and liquid chromatography−tandem mass spectrometry (LC/MS/MS) for confirmation and quantitation. Dispersive-SPE greatly simplifies and accelerates sample Cleanup and improves overall recoveries compared with conventional SPE Cleanup. The β-lactam antibiotics tested were as follows: deacetylcephapirin (an antimicrobial metabolite of cephapirin), amoxicillin, desfuroylceftiofur cysteine disulfide (DCCD, an antimicrobial metabolite of ceftiofur), ampicillin, cefazolin, penicillin G, oxacillin, cloxacillin, naficillin, and dicloxacillin. Average recoveries of fortified samples were 70% or better for all β-lactams except DCCD, which had an average recovery of 58%. The LC/MS/MS method was able to demonstrate quantitative r...
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comparison of solid phase extraction sorbents for Cleanup in pesticide residue analysis of fresh fruits and vegetables
Journal of Separation Science, 2002Co-Authors: Frank J Schenck, Steven J Lehotay, Victor A VegaAbstract:Sample extracts of various commodities, obtained using the US Food and Drug Administration (acetone extraction) and Canadian Pest Management Regulatory Agency (acetonitrile extraction) methods for pesticides were subjected to Cleanup with solid phase extraction (SPE) columns. Graphitized carbon black (GCB), octadecylsilyl (C-18), strong anion exchange (SAX), aminopropyl (-NH 2 ), and primary secondary amine (PSA) SPE columns were evaluated. The relative sample Cleanup provided by these SPE columns was evaluated using gas chromatography with electron capture, flame photometric, and mass spectrometric detection. The -NH 2 and PSA columns were found to provide the most effective Cleanup, removing the greatest number of sample matrix interferences. The GCB columns removed most of the visible plant pigment in the extracts, but did little to eliminate the fatty acid matrix interferences seen by the detectors. Likewise, the C-18 and SAX columns did little to eliminate matrix interferences. Using an acetone extraction followed by a PSA Cleanup, both polar and nonpolar pesticides present in samples at 1.0 ng/g could be recovered.
