title: Response surface optimization for determination of pesticide multiresidues by matrix solid-phase dispersion and gas chromatography.
abstract: An optimized multiresidue analysis method based on matrix solid-phase dispersion (MSPD) and gas chromatography (GC) is proposed for the determination of organochlorines and pyrethroids in the tea samples. Response surface methodology (RSM) was used to optimize the extraction conditions of MSPD, such as the sorbent type, eluent composition, dichloromethane concentration and eluting volume. Desirability function approach was employed to optimize the pesticide recoveries and matrix cleanup. Compromising the recoveries and cleanup degree, MSPD was carried out with Florisil as the sorbent and n-hexane-dichloromethane (1:1, v/v) as the eluent. The pesticide recoveries in tea samples were better than 80% spiked in the concentration range of 0.01-0.05mg/kg and the relative standard deviations were lower than 7%. The quantification limits of the pesticides were in the range of 0.002-0.06mg/kg, which were lower than the maximum residue limits of the pesticides in tea samples established by the European Union.
authors.affiliation: Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Yan-Yun
authors.initials: YY
authors.lastname: Hu
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
authors.forename: You-Zhao
authors.initials: YZ
authors.lastname: He
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Sheng
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D017633:Magnesium Silicates / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D010573:Pesticide Residues / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013662:Tea / Q000737:chemistry*
chemical_list: D006843:Hydrocarbons, Chlorinated; D017633:Magnesium Silicates; D010573:Pesticide Residues; D011722:Pyrethrins; D013662:Tea; C005013:Florisil; D008752:Methylene Chloride