ИСТИНА

Fluorescence polarization immunoassays (FPIAs) for several pesticides were developed and optimized for parallel detection of several analytes using the same procedures for sample preparartion and assay performance. Tracers for FPIAs of triazophos, carbaryl, thiabendazole and tetraconazole were synthesized and the tracers’ structures were confirmed by HPLC-MS/MS. The influence of tracer cross-linking bridge length on the assay sensitivity was estimated. For triazophos and carbaryl analysis the use of EDF-labeled tracers allowed to achieve the best assay sensitivity and minimum reagent consumption in comparison with other alkyldiaminefluoresceinthiocarbamyl-labeled tracers and in comparison with 4-aminomethylfluorescein-labeled tracers. For thiabendazole and tetraconazole analysis 4-aminomethylfluorescein-labeled tracers allowed achieving the best assay sensitivity and minimum reagent consumption in comparison with aminofluorescein-labeled and alkyldiaminefluoresceinthiocarbamyl-labeled tracers. Measurements of fluorescence polarization were performed using a portable device Sentry-200. Total time for sample prepapration and detection of pesticides is lower than 1 h. The limits of detection of triazophos, carbaryl, thiabendazole and tetraconazole in wheat were 40, 20, 20 and 200 μg/kg, and the lower limits of quantification were 40, 60, 40 and 600 μg/kg, respectively. The results obtained by FPIA correlated well with those obtained by HPLC-MS/MS.