title: Residue behavior and risk assessment of mixed formulation of imidacloprid and chlorfenapyr in chieh-qua under field conditions.
abstract: A simple and rapid method based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the simultaneous determination of imidacloprid and chlorfenapyr residues in chieh-qua. Field trials were designed to investigate the dissipation and terminal residue behavior of the mixed formulation of imidacloprid and chlorfenapyr in chieh-qua in Guangzhou and Nanning areas. Risk assessment was performed by calculating the risk quotient (RQ) values. The developed analytical method exhibited recoveries of 89.9-110.3% with relative standard deviations (RSDs) of 2.8-12.5% at the spiked levels of 0.01, 0.10, and 1.00 mg/kg. The limit of detection (LOD) was 0.003 mg/kg, and the limit of quantification (LOQ) was 0.01 mg/kg for both imidacloprid and chlorfenapyr. It was found that the half-lives of imidacloprid in chieh-qua under field conditions were 3.3 and 3.5 days in Guangzhou and Nanning at a dose of 180 g ai/ha, while the half-lives of chlorfenapyr were 3.3 and 2.6 days, respectively. The terminal residues of imidacloprid and chlorfenapyr were from 0.01 to 0.21 mg/kg and from 0.01 to 0.46 mg/kg, respectively. Results of dietary exposure assessment showed that the RQ values were much lower than 1, indicating that the risk of imidacloprid and chlorfenapyr applied in chieh-qua was negligible to human health under recommended dosage and good agricultural practices. The proposed study would provide guidance for safe and reasonable use of imidacloprid and chlorfenapyr in chieh-qua cultivation in China.
authors.affiliation: Public Monitoring Center for Agro-product, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.|Key Laboratory of Testing and Evaluation for Agro-product Quality and Safety, Ministry of Agriculture, Guangzhou, 510640, China.|Laboratory of Quality and Safety Risk Assessment for Agro-product (Guangzhou), Ministry of Agriculture, Guangzhou, 510640, China.
authors.forename: Jian Xiang
authors.initials: JX
authors.lastname: Huang
authors.affiliation: Public Monitoring Center for Agro-product, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.|Key Laboratory of Testing and Evaluation for Agro-product Quality and Safety, Ministry of Agriculture, Guangzhou, 510640, China.|Laboratory of Quality and Safety Risk Assessment for Agro-product (Guangzhou), Ministry of Agriculture, Guangzhou, 510640, China.
authors.forename: Cong Yun
authors.initials: CY
authors.lastname: Liu
authors.affiliation: Public Monitoring Center for Agro-product, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.|Key Laboratory of Testing and Evaluation for Agro-product Quality and Safety, Ministry of Agriculture, Guangzhou, 510640, China.|Laboratory of Quality and Safety Risk Assessment for Agro-product (Guangzhou), Ministry of Agriculture, Guangzhou, 510640, China.
authors.forename: Da Hai
authors.initials: DH
authors.lastname: Lu
authors.affiliation: Public Monitoring Center for Agro-product, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.|Key Laboratory of Testing and Evaluation for Agro-product Quality and Safety, Ministry of Agriculture, Guangzhou, 510640, China.|Laboratory of Quality and Safety Risk Assessment for Agro-product (Guangzhou), Ministry of Agriculture, Guangzhou, 510640, China.
authors.forename: Jia Jia
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: Public Monitoring Center for Agro-product, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.|Key Laboratory of Testing and Evaluation for Agro-product Quality and Safety, Ministry of Agriculture, Guangzhou, 510640, China.|Laboratory of Quality and Safety Risk Assessment for Agro-product (Guangzhou), Ministry of Agriculture, Guangzhou, 510640, China.
authors.forename: Yi Cai
authors.initials: YC
authors.lastname: Deng
authors.affiliation: Public Monitoring Center for Agro-product, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China. wfhwqs@163.com.|Key Laboratory of Testing and Evaluation for Agro-product Quality and Safety, Ministry of Agriculture, Guangzhou, 510640, China. wfhwqs@163.com.|Laboratory of Quality and Safety Risk Assessment for Agro-product (Guangzhou), Ministry of Agriculture, Guangzhou, 510640, China. wfhwqs@163.com.
authors.forename: Fu Hua
authors.initials: FH
authors.lastname: Wang
mesh_terms: D000383:Agriculture / Q000379:methods*; D002681:China; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019662:Cucurbitaceae / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods*; D007093:Imidazoles / Q000032:analysis*; D057230:Limit of Detection; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis*; D018570:Risk Assessment; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D007093:Imidazoles; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010573:Pesticide Residues; D011722:Pyrethrins; C082359:imidacloprid; C436643:chlorfenapyr
keywords: Chieh-qua; Chlorfenapyr; Imidacloprid; Residue; Risk assessment