DECAY STUDY OF PESTICIDE-RESIDUES IN APPLE SAMPLES

A method for monitoring pesticides in apple samples, including Soxhlet extraction, an evaporation step and capillary gas chromatography with nitrogen-phosphorus detection, is applied to a decay study of the car bamate pesticide ethiofencarb. The evaporation step is carried out by a surface nitrogen flow and the recoveries of ethiofencarb measured in standard solutions of ethyl acetate and apple extracts. The results o f the decay studies show that ethiofencarb is degraded in the apple pe el faster than in the interior of the fruit. The methodology is then a pplied to decay studies in the laboratory of the organophosphorus pest icides, diclofluanid, fenitrothion and malathion.