Abstract
A simultaneous clean-up method for analysis of residual organochlorine and organophosphorus pesticides in vegetables and fruits was established as follows. The pesticides were extracted from vegetable or fruit homogenates with acetonitrile. The extract was concentrated on a rotary evaporator under reduced pressure after addition of sodium p-toluenesulfonate solution, then the residue in the concentration flask was washed with ethanol and applied to an Amberlite XAD-8 column. The column was washed with 200ml of water and 100ml of 5% sodium chloride solution-methanol mixture, and then eluted with 200ml of methanol.
By this method, the organochlorine and organophosphorus pesticides tested were simultnaeously eluted, and substances interfering with the gas liquid chromatographic determination were efficiently removed. The recoveries of the pesticides added to vegetable or fruit homogenates were in the range of 76.1-93.0% for organochlorine pesticides and 79.8-98.9% for organophosphorus pesticides. This clean-up method can be applied as a simple quantitative method for residue analysis of organochlorine and organophosphorus pesticides in vegetables (except aromatics) and fruits.
