title: Multiresidue analysis of pesticides in fruits and vegetables using solid-phase extraction and gas chromatographic methods.
abstract: A new extraction and cleanup procedure with gas chromatography was developed for the sensitive determination of acephate, dimethoate, malathion, diazinon, quinalphos, chlorpyrifos, profenofos, alpha-endosulfan, beta-endosulfan, chlorothalonil and carbaryl using 1-chloro-4-fluorobenzene as an internal standard in fruits and vegetables. Several extracting and eluting solvents for solid-phase extraction were investigated. The overall extracting solvent with a mixture of acetone:ethyl acetate:hexane (10:80:10, v/v/v) and a eluting solvent of 5% acetone in hexane used with the RPC18 cartridge gave the best recovery for all of the investigated pesticides, and minimized the interference from co-extractants. Under the optimal extraction and clean-up conditions, recoveries of 85 - 99% with RSD < 5.0% (n = 3) for most of the pesticides at the 0.02 - 0.5 mg/kg level were obtained. The limit of detection was between 0.005 - 0.01 mg/kg and the limit of quantification was 0.01 mg/kg. This analytical procedure was characterized with high accuracy and acceptable sensitivity to meet requirements for monitoring pesticides in crops.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Malaya, Lembah Pantai, Kuala Lumpur, Malaysia.
authors.forename: Asha
authors.initials: A
authors.lastname: Lal
authors.forename: Guanhuat
authors.initials: G
authors.lastname: Tan
authors.forename: Meekin
authors.initials: M
authors.lastname: Chai
mesh_terms: D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014675:Vegetables / Q000737:chemistry*
chemical_list: D010575:Pesticides