title: Determination of organophosphorus pesticides and their major degradation product residues in food samples by HPLC-UV.
abstract: A simple method based on dispersive solid-phase extraction (DSPE) and dispersive liquid-liquid microextraction method based on solidification of floating organic droplets (DLLME-SFO) was developed for the extraction of chlorpyrifos (CP), chlorpyrifos-methyl (CPM), and their main degradation product 3,5,6-trichloro-2-pyridinol (TCP) in tomato and cucumber samples. The determination was carried out by high performance liquid chromatography with ultraviolet detection (HPLC-UV). In the DSPE-DLLME-SFO, the analytes were first extracted with acetone. The clean-up of the extract by DSPE was carried out by directly adding activated carbon sorbent into the extract solution, followed by shaking and filtration. Under the optimum conditions, the proposed method was sensitive and showed a good linearity within a range of 2-500 ng/g, with the correlation coefficients (r) varying from 0.9991 to 0.9996. The enrichment factors ranged from 127 to 138. The limit of detections (LODs) were in the range of 0.12-0.68 ng/g, and the relative standard deviations (RSDs) for 50 ng/g of each analytes in tomato samples were in the range of 3.25-6.26 % (n = 5). The proposed method was successfully applied for the extraction and determination of the mentioned analytes residues in tomato and cucumber samples, and satisfactory results were obtained.
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University, Chongqing, 400045, China.|Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, Tsinghua University, Beijing, 100084, China.
authors.forename: Guilong
authors.initials: G
authors.lastname: Peng
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University, Chongqing, 400045, China. heqiang0980@163.com.
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.affiliation: Mathematics and Physics, Armed Police College, Chengdu, 610213, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University, Chongqing, 400045, China.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mmereki
authors.affiliation: Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, Tsinghua University, Beijing, 100084, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Zhong
mesh_terms: D004390:Chlorpyrifos / Q000031:analogs & derivatives; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005504:Food Analysis; D005506:Food Contamination; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods; D009943:Organophosphorus Compounds / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods; D012996:Solutions
chemical_list: D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D010575:Pesticides; D012996:Solutions; D004390:Chlorpyrifos; C007031:chlorpyrifos-methyl
keywords: Activated carbon; CP; CPM; DLLME-SFO; DSPE; TCP