title: Mixed liquids for single-drop microextraction of organochlorine pesticides in vegetables.
abstract: A new approach for the extraction of nine kinds of organochlorine pesticides (OCPs) from vegetable samples coupling single-drop microextraction with gas chromatography-mass spectrometry was presented. Experimental parameters, such as organic solvent, exposure time, agitation and organic drop volume were controlled and optimized. An effective extraction was achieved by suspending a 1.00microL mixed drop of p-xylene and acetone (8:2, v/v) to the tip of a microsyringe immersed in a 2mL donor aqueous solution and stirred at 400rpm. The approach was applied to the determination of OCPs in vegetable samples with a linearity range of 0.05-20ng mL(-1) for alpha-, beta-, gamma-, delta-hexachlorobenzene (BHC) and dicofol, 0.5-20ng mL(-1) for dieldrin and 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (DDD) or 0.5-50ng mL(-1) for 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and 2-(2-chlorophenyl)-2 (4-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT). Correspondingly, the determination limit at an S/N of 3 ranged from 0.05ng mL(-1) for alpha-, beta-, gamma-, delta-BHC to 0.2ng mL(-1) for dicofol, dieldrin or p,p'-DDT. The relative recoveries were from 63.3 to 100%, with repeatability ranging from 8.74 to 18.9% (relative standard deviation, R.S.D.). The single-drop microextraction was proved to be a fast and simple approach for the pre-concentration of organochlorine pesticides in vegetable samples.
authors: Department of Chemistry and the Key Laboratory of Analytical Sciences of the Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors: Maosheng
authors: M
authors: Zhang
authors: Jiarong
authors: J
authors: Huang
authors: Changlin
authors: C
authors: Wei
authors: Binbin
authors: B
authors: Yu
authors: Xiaoqing
authors: X
authors: Yang
authors: Xi
authors: X
authors: Chen
mesh_terms: D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D012997:Solvents; D014675:Vegetables / Q000737:chemistry*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D012997:Solvents