title: Simultaneous determination of chlorpyrifos and 3,5,6-trichloro-2-pyridinol in duck muscle by modified QuEChERS coupled to gas chromatography tandem mass spectrometry (GC-MS/MS).
abstract: A rapid, specific, and sensitive method based on modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) coupled to gas chromatography tandem mass spectrometry (GC-MS/MS) was developed and validated for simultaneous determination of chlorpyrifos (CP) and its metabolite 3,5,6-trichloro-2-pyridinol (TCP) in duck muscle. The residues of CP and TCP were extracted by acidified acetonitrile. The fat layer of the extract was removed under -20 °C, then the organic layer was evaporated. The analytes were derivatized by N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) and cleaned up by a mixture of 150 mg MgSO4, 25 mg graphitized carbon black (GCB), and 50 mg N-propylethylenediamine (PSA) to remove interference. The final extract was analyzed by GC-MS/MS. Recovery values at the spiking concentrations ranged from 86.2 to 92.3 % for CP and from 74.8 to 81.8 % for TCP, with relative standard deviations (RSDs) lower than 9.5 and 12.3, respectively. The correlation coefficients of CP (from 2 to 2,000 μg/kg) and TCP (from 1 to 1,000 μg/kg) were equal to or higher than 0.998. The limits of detection (LODs) were 0.3 and 0.15 μg/kg, and the limits of quantification (LOQs) were 1.0 and 0.5 μg/kg for CP and TCP in duck muscle, respectively. The average intra- and inter-day accuracy ranged from 84.6 to 91.2 % for CP and 75.6 to 82.3 % for TCP, and the intra- and inter-day precisions were from 5.8 to 8.2 % for CP and 6.5 to 11.9 % for TCP. Furthermore, the CP and TCP residues in duck muscle samples were detected for dietary risk assessment using the validated method.
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Plant Pest Control; Agricultural Ministry Key Laboratory for Pesticide Residue Detection; Zhejiang Province Key Laboratory for Food Safety; Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, 310021, Hangzhou, Zhejiang, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: He
authors.forename: Ting
authors.initials: T
authors.lastname: Zhou
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ji
authors.forename: Mingrong
authors.initials: M
authors.lastname: Qian
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000818:Animals; D005591:Chemical Fractionation / Q000379:methods*; D004390:Chlorpyrifos / Q000032:analysis* / Q000302:isolation & purification; D004372:Ducks; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis* / Q000302:isolation & purification; D011728:Pyridones / Q000032:analysis* / Q000302:isolation & purification; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D010575:Pesticides; D011728:Pyridones; C012587:3,5,6-trichloro-2-pyridinol; D004390:Chlorpyrifos