FATE OF ALDICARB AND ITS METABOLITES IN V ERNA LEMON

A gas chromatograph equiped with a nitrogen-selective thermoionic dete ctor was used to identify and determine aldicarb plus its two major me tabolites, aldicarb sulfoxide and aldicarb sulfone in soil, leaves and fruits of lemon field plots. Aldicarb and its metabolites were extrac ted with acetone-water The filtrate was purified with petroleum ether and extracted after acidification with methylene chloride. Separation was achieved on a 2 m x 0.4 i.d. column packed with 6% QF-1 + 4% SE-30 on Chromaosorb Q; temperature programmed from 130 to 190-degrees-C at 30-degrees-C min-1 after 5 min of injection. The limits of detection for aldicarb compounds were bellow 0.4 ppb in vegetable materials. Res idues values in lemon fruits of 303 ppb were found 45 days after appli cation. Level uper to 200 ppb fixed as maximun contaminant level by WH O, EEC and Spanish Legislation.