[Determination of organophosphorus pesticide multi-residues in tea by gas chromatography].

An efficient gas chromatographic method for the determination of 14 organophosphorus pesticide residues in tea by gas chromatography using micro-chemical and solid phase extraction technique has been established. The organophosphorus pesticides were extracted from tea samples with ethyl acetate and mixture of ethyl acetate-hexane(1:1, V/V). The extracts were cleaned up with a column of 3 mL Supelclean Envl-carb by GILSON ASPEC XL. The 14 organophosphorus pesticides were separated from each other through SPB-1701 capillary column(30 m x 0.53 mm i.d. x 1.0 micron) and determined by flame photometric detector. The recoveries ranged 70.8%-120% when the added levels were from 0.100 mg/kg to 1.00 mg/kg, the RSD was 2%-7% and the limits of detection were 0.01 mg/kg-0.08 mg/kg. This method is rapid, sensitive and suitable for the analysis of pesticide residues. It can also be applied to the determination of organophosphorus pesticide multi-residues in other plant samples such as vegetables, fruits and so on.