ENZYME-IMMUNOASSAY FOR THE DETERMINATION OF THE INSECTICIDE FENOXYCARB

A very selective polyclonal antiserum against ethyl 2-(4-phenoxyphenox y)ethylcarbamate (fenoxycarb) was raised in a rabbit by immunization w ith a 2-(4-phenoxyphenoxy)ethanol hemisuccinate-bovine serum albumin c onjugate, The antiserum was used to carry out a heterogeneous competit ive enzyme immunoassay for the selective quantification of fenoxycarb at the ng ml-l level. The effects on the assay performance of differen t pH and ionic strength values, as well as the presence of methanol as organic modifier in the diluent buffer formulation, were studied. The optimized calibration curve showed a sensitivity of 0.42 ng ml(-1). T he assay selectivity was found to be good, with no significant cross-r eactivity towards fenoxycarb-related pesticides such as chloroxuron, c ypermethrin, diclofop, p,p'-DDT, difenoxuron, permethrin and pyriproxy fen.