Abstract: A method was developed for the multiresidue determination of 6 pyrethroid pesticides in Flammulina velutipes by gas chromatography with electron capture detection. Samples were extracted with acetonitrile and cleaned up on a florisil column before GC-ECD analysis. A good linear relationship with a determination coefficient above 0.996 was found for bifenthrin, fenpropathrin and lambda-cyhalothrin in the range of 0.005－0.5 mg/L and for other three pyrethroid pesticides in the range of 0.01－1.0 mg/L. The mean recoveries for the 6 pyrethroid pesticides ranged from 85.54% to 102.27% in a blank sample of Flammulina velutipes with a relative standard deviation (RSD) between 1.24% and 9.58%. The limit of detection was 5μg/L for bifenthrin, fenpropathrin and cyhalothrin and 10μg/kg for beta-cypermethrin, fenvalerate and deltamethrin. The method was accurate, precise and sensitive, and therefore could meet the requirements for pesticide residue analysis.

Key words: Flammulina velutipes, pyrethroids, pesticide residue, gas chromatography