title: Dissipation Pattern, Processing Factors, and Safety Evaluation for Dimethoate and Its Metabolite (Omethoate) in Tea (Camellia Sinensis).
abstract: Residue levels of dimethoate and its oxon metabolite (omethoate) during tea planting, manufacturing, and brewing were investigated using a modified QuEChERS sample preparation and gas chromatography. Dissipation of dimethoate and its metabolite in tea plantation followed the first-order kinetic with a half-life of 1.08-1.27 d. Tea manufacturing has positive effects on dimethoate dissipation. Processing factors of dimethoate are in the range of 2.11-2.41 and 1.41-1.70 during green tea and black tea manufacturing, respectively. Omethoate underwent generation as well as dissipation during tea manufacturing. Sum of dimethoate and omethoate led to a large portion of 80.5-84.9% transferring into tea infusion. Results of safety evaluation indicated that omethoate could bring higher human health risk than dimethoate due to its higher hazard quotient by drinking tea. These results would provide information for the establishment of maximum residue limit and instruction for the application of dimethoate formulation on tea crop.
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Pan
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China; Key Laboratory of Tea Quality and safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Hong-Ping
authors.initials: HP
authors.lastname: Chen
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Ming-Lu
authors.initials: ML
authors.lastname: Zhang
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China; Key Laboratory of Tea Quality and safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Wang
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China; Key Laboratory of Tea Quality and safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China; Key Laboratory of Tea Quality and safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry*; D004117:Dimethoate / Q000031:analogs & derivatives* / Q000032:analysis*; D005504:Food Analysis; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D013662:Tea / Q000737:chemistry*
chemical_list: D013662:Tea; C002302:dimethoxon; D004117:Dimethoate