DETERMINATION OF PROCYMIDONE IN VEGETABLES BY A COMMERCIAL COMPETITIVE-INHIBITION ENZYME-IMMUNOASSAY

An ELISA commercial kit was used to quantitate residues of Procymidone at very low levels (< 20 mu g/kg) in pepper samples. Samples were ext racted with ethyl acetate-sodium sulphate and an aliquot is evaporated to dryness and reconstituted in 10 mi of light petroleum. Sample clea n up is accomplished by aspirating 2 mi of the light petroleum extract through a silica gel solid phase disposable cartridge. Following aspi ration, the sample was eluted with 2 mi of ethyl ether-petroleum ether (1:1). The eluted fraction was evaporated and dissolved with sonicati on in 2 mi of water before immunoassay analysis. The limit of Procymid one detection was 0.6 mu g/kg. The assay logarithmic response was line ar from 5 to 80 mu g/kg of Procymidone residue. Intra-assay percentage coefficients of variation (%C.V.) ranged from 3.5 to 18.0 and inter-a ssays %C.V.s varied from 8.0 to 16.0. Comparison studies between gas c hromatography with electron capture detection and ELISA analyses showe d an acceptable coincidence at levels of 8 mu g/kg. However, lower lev els of ca. 2 mu g/kg were detectable by ELISA only. No cross-reactivit y problems were found in the ELISA test associated with the presence o f other dichloroaniline derivatives and other pesticides studied.