Determination of Pymetrozine Residue in Tobacco Leaves with SPE and HPLC

By comparing the effect of purification for tobacco extraction with Sep-Pak Florisil,Sep-Pak silica gel and Pesticarb/NH₂ cartridges,a method for determining pymetrozine residues in flue-cured tobacco was developed.Tobacco sample was extracted with acetonitrile under ultrasonic,solid phase extracted and purified with a Pesticarb/NH₂ cartridge and determined by high-performance liquid chromatography(HPLC).The results showed that the average recoveries of pymetrozine ranged from 98.1% to 99.2% with 1.39% to 3.06% of relative standard deviations and 0.005 μg/mL of limit of detection.This method is applicable to rapid analysis of pymetrozine residue in the batch of tobacco leaf samples.