Development of general immunoassays for pyrethroids: a new approach for hapten synthesis using pyrethroid metabolite analogue and application to food samples

This study describes a general and broad immunochemical approach for the detection of pyrethroids. A new approach was used for the hapten preparation in which the 3-carbon spacer arm was attached to the pyrethroids metabolite analogue, 3-phenoxybenzoic acid. Polyclonal antibodies were generated. Enzyme-linked immunosorbent assay was optimised and developed for the detection of pyrethroids. It was showed that the concentration of analyte giving 50% inhibition of colour development were 20 µg L-1 for deltamethrin, 16 µg L-1 for cypermethrin, 11 µg L-1 for fluvalinate, 15 µg L-1 for fenvalerate and 20 µg L-1 for fenpropathrin, respectively. Screening for this class of pyrethroids in Brassica campestris L., peach and green tea was accomplished by simple and rapid extraction methods. The high precision was obtained with good recoveries. Good correlations between immunoassay and gas chromatography/electron capture detector data were obtained for incurred residues of deltamethrin extracts of green tea sample.