title: Minimizing geometric isomerization of α-cypermethrin in the residue analysis.
abstract: Isomerization of chiral pesticides in residue analysis has not drawn much attention which can cause wrong decisions on the enantioselective environmental behavior. A residue analysis method for α-cypermethrin and its three acid metabolites, cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethyl cyclopropanecarboxylic acid (cis/trans-DCVA) and 3-phenoxybenzoic acid (3-PBA), in foods such as chicken, honey, milk and pork has been established, in which the isomerization of α-cypermethrin was minimized. The target compounds were determined by GC-ECD after a derivatization reaction with 1,1,1,3,3,3-hexafluoroisopropanol. The conditions of the method were optimized by Taguchi orthogonal experiment. Under the optimized conditions, good linearity was obtained with correlation coefficients ranging from 0.9964 to 0.9998. The limits of detection were 0.001-0.005 mg kg(-1). The recoveries were 70.9-114.9% with relative standard deviations of 0.6-15%. In addition, ratios of isomerization ranged only from 2.3% to 7.0%. This method was applied in commercial animal food products.
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Xueke
authors.initials: X
authors.lastname: Liu
authors.affiliation: Zhong Nong Fa Seed Industry Group Co., Ltd, Beijing 600313, PR China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Guojun
authors.initials: G
authors.lastname: Yao
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Jiayuan
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Donghui
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China. Electronic address: zqzhou@cau.edu.cn.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000818:Animals; D010575:Pesticides / Q000032:analysis; D011722:Pyrethrins / Q000032:analysis / Q000737:chemistry*
chemical_list: D010575:Pesticides; D011722:Pyrethrins; C017160:cypermethrin
keywords: Animal foods; GC–ECD; Isomerization; α-Cypermethrin