Determination of Organophosphorus Pesticide Residues in Teaby Solid-phase Extraction Gas Chromatography

A method for the determination of 16 organophosphorus pesticide residues in tea by Gas Chromatography - Nitrogen Phosphorus Detector(GC-NPD) with ultrasonic extraction was established. Tea samples were extracted with 10 mL of acetone, and then cleaned by homemade PSA/activated carbon SPE cartridge and eluted with acetonitrile-toluene (1∶3,V/V). 16 organophosphorus pesticides were well separated and detected with high repeatability and precision. The recovery rate of the method was between 62.8％ and 109.1％. The relative standard deviation was less than 14.7％. The limit of detection of 16 organophosphorus was between 0.01 mg/kg and 0.16 mg/kg. The method is reliable rapid and is, suitable for the analysis of pesticide residues in real samples.