DEVELOPMENT OF SIMULTANEOUS ANALYSIS FOR ORGANONITROGEN AND PYRETHROID PESTICIDES WITH GC MS

A method was developed for determining 8 organonitrogen pesticides (is oprocarb, propoxur, chlorpropham, bendiocarb, pirimicarb, carbaryl, di chlofluanid and chinomethionat) and 8 pyrethroid pesticides (cyhalothr in, permethrin, cyfluthrin, cypermethrin, flucythrinate, fenvalerate, fluvalinate and deltamethrin) in fruits and vegetables by means of GC/ MS. Pesticides were extracted from fruits and vegetables using a mixtu re of the dichloromethane, cyclohexane, and acetone (1 : 1 : 1), then the extracts were applied to a Florisil mini column for cleanup. No se rious disturbing peaks were seen in the selected ion monitoring mode i n GC/MS analysis, and the quantitation limits were 1 ppb for organonit rogen pesticides and 5 ppb for pyrethroid pesticides. Organonitrogen p esticides were spiked at 10 ppb and pyrethroid pesticides were spiked at 50 ppb in 9 kinds of samples. Except for bendiocarb, recoveries of pesticides were in the range of 63 approximately 77%. The proposed met hod is satisfactory for the screening of residual pesticides in vegeta bles and fruits.