The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Jiye Hu - One of the best experts on this subject based on the ideXlab platform.
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residue dissipation and risk assessment of tebuconazole Thiophanate methyl and its metabolite in table grape by liquid chromatography tandem mass spectrometry
Food Chemistry, 2018Co-Authors: Bizhang Dong, Nannan Pang, Yuanping Yang, Jiye HuAbstract:Abstract An efficient method was developed and validated for simultaneous determination of tebuconazole, Thiophanate-methyl and its metabolite carbendazim in grape and soil using QuEChERS procedure and liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 83.2%–105.4%, the limit of detection (LOD) ranged from 2.1 × 10 −5 to 8.7 × 10 −4 mg L −1 , and the limit of quantitation (LOQ) was 0.1 mg kg −1 . The field results showed that tebuconazole and Thiophanate-methyl in soil and grape were rapidly dissipated with half-lives less than 24.7 days. The terminal residues of all analytes in grape were lower than the maximum residue limit (MRL) set by China (2 mg kg −1 for tebuconazole; 3 mg kg −1 for both Thiophanate-methyl and carbendazim). Risk assessment showed that tebuconazole, Thiophanate-methyl and its metabolite would be unlikely to cause health problems. However, carbendazim, the higher active metabolites of Thiophanate-methyl, should receive more concerns.
Yongquan Zheng - One of the best experts on this subject based on the ideXlab platform.
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effect of household canning on the distribution and reduction of Thiophanate methyl and its metabolite carbendazim residues in tomato
Food Control, 2014Co-Authors: Fengshou Dong, Zenglong Chen, Youpu Cheng, Yuanbo Li, Jun Xu, Yongquan ZhengAbstract:Tomato in the field was sprayed with Thiophanate-methyl to quantify the effect of household processing on pesticide residues. Changes in the residue levels of Thiophanate-methyl and its metabolite carbendazim in tomatoes were assessed during home-canning processing. Pesticide residues in tomato were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after washing, peeling, homogenization, simmering, and sterilization. Results showed that washing with tap water reduced Thiophanate-methyl residues by 25.0% and carbendazim residues by 13.0%. The peeling process yielded 84.2% loss in Thiophanate-methyl and 87.3% loss in carbendazim from tomatoes. Peeling is thus the most effective step to remove pesticide residues from tomatoes. Homogenization, simmering, and sterilization exerted limited effects on the removal of Thiophanate-methyl and carbendazim. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PFs of the peeling process for Thiophanate-methyl and carbendazim were 0.19 and 0.14, respectively.
Bizhang Dong - One of the best experts on this subject based on the ideXlab platform.
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residue dissipation and risk assessment of tebuconazole Thiophanate methyl and its metabolite in table grape by liquid chromatography tandem mass spectrometry
Food Chemistry, 2018Co-Authors: Bizhang Dong, Nannan Pang, Yuanping Yang, Jiye HuAbstract:Abstract An efficient method was developed and validated for simultaneous determination of tebuconazole, Thiophanate-methyl and its metabolite carbendazim in grape and soil using QuEChERS procedure and liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 83.2%–105.4%, the limit of detection (LOD) ranged from 2.1 × 10 −5 to 8.7 × 10 −4 mg L −1 , and the limit of quantitation (LOQ) was 0.1 mg kg −1 . The field results showed that tebuconazole and Thiophanate-methyl in soil and grape were rapidly dissipated with half-lives less than 24.7 days. The terminal residues of all analytes in grape were lower than the maximum residue limit (MRL) set by China (2 mg kg −1 for tebuconazole; 3 mg kg −1 for both Thiophanate-methyl and carbendazim). Risk assessment showed that tebuconazole, Thiophanate-methyl and its metabolite would be unlikely to cause health problems. However, carbendazim, the higher active metabolites of Thiophanate-methyl, should receive more concerns.
Fengshou Dong - One of the best experts on this subject based on the ideXlab platform.
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effect of household canning on the distribution and reduction of Thiophanate methyl and its metabolite carbendazim residues in tomato
Food Control, 2014Co-Authors: Fengshou Dong, Zenglong Chen, Youpu Cheng, Yuanbo Li, Jun Xu, Yongquan ZhengAbstract:Tomato in the field was sprayed with Thiophanate-methyl to quantify the effect of household processing on pesticide residues. Changes in the residue levels of Thiophanate-methyl and its metabolite carbendazim in tomatoes were assessed during home-canning processing. Pesticide residues in tomato were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after washing, peeling, homogenization, simmering, and sterilization. Results showed that washing with tap water reduced Thiophanate-methyl residues by 25.0% and carbendazim residues by 13.0%. The peeling process yielded 84.2% loss in Thiophanate-methyl and 87.3% loss in carbendazim from tomatoes. Peeling is thus the most effective step to remove pesticide residues from tomatoes. Homogenization, simmering, and sterilization exerted limited effects on the removal of Thiophanate-methyl and carbendazim. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PFs of the peeling process for Thiophanate-methyl and carbendazim were 0.19 and 0.14, respectively.
Li Zhu - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of Thiophanate methyl and its metabolite carbendazim in tea using isotope dilution ultra performance liquid chromatography tandem mass spectrometry
Journal of Chromatographic Science, 2014Co-Authors: Hongping Chen, Xin Liu, Chuanpi Wang, Qinghua Wang, Ying Jiang, Peng Yin, Li ZhuAbstract:A rapid method has been developed for the determination of Thiophanate methyl and its metabolite carbendazim in tea samples using ultra-high-performance liquid chromatography tandem mass. Dispersive solid-phase extraction was optimized and employed as a sample preparation technique without concentration and solvent exchange. Degradation of Thiophanate methyl and its isotope were observed and they declined at the similar rate during sample preparation. The results showed that calibration by isotope internal standards was reliable to correct the degradation. With the extraction solvent at pH range of 2.3– 10.3, difference for Thiophanate methyl degradation was not much significant due to the buffer action of tea matrix solution. Matrix effects were dependent on the nature of the analytes and tea categories, but calibrated effectively by isotope internal standards. Recoveries ranged 97.2–110.6%, and relative standard deviations were <25.0%. The limit of quantification was both 0.010 mg kg 21 for Thiophanate methyl and carbendazim. The developed method was utilized to measure concentrations of Thiophanate methyl and carbendazim in tea samples from seven provinces of China, as well as to investigate the degradation of Thiophanate methyl in tea crop.
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Simultaneous Determination of Thiophanate-Methyl and Its Metabolite Carbendazim in Tea Using Isotope Dilution Ultra Performance Liquid Chromatography–Tandem Mass Spectrometry
Journal of Chromatographic Science, 2013Co-Authors: Hongping Chen, Xin Liu, Chuanpi Wang, Qinghua Wang, Ying Jiang, Peng Yin, Li ZhuAbstract:A rapid method has been developed for the determination of Thiophanate methyl and its metabolite carbendazim in tea samples using ultra-high-performance liquid chromatography tandem mass. Dispersive solid-phase extraction was optimized and employed as a sample preparation technique without concentration and solvent exchange. Degradation of Thiophanate methyl and its isotope were observed and they declined at the similar rate during sample preparation. The results showed that calibration by isotope internal standards was reliable to correct the degradation. With the extraction solvent at pH range of 2.3– 10.3, difference for Thiophanate methyl degradation was not much significant due to the buffer action of tea matrix solution. Matrix effects were dependent on the nature of the analytes and tea categories, but calibrated effectively by isotope internal standards. Recoveries ranged 97.2–110.6%, and relative standard deviations were
