DETECTION OF ARYLOXYPHENOXYPROPIONATE HERBICIDES BY ENZYME-LINKED IMMUNOSORBENT ASSAY

In this study, we developed a general and broad class-selective indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for detecting aryloxyphenoxypropionate herbicides. A multideterminant artificial antigen was prepared from haptens of two herbicides (fenoxaprop-p-ethyl and cyhalofop-butyl) conjugated to the carrier protein Bovine serum albumin (BSA). The polyclonal antibodies (PAbs) were obtained by immunizing New Zealand white rabbits. Characterization studies of the PAbs showed that they had high affinity and specificity for the two herbicides. The 50% inhibitory concentration (IC50) values for fenoxaprop-p-ethyl and cyhalofop-butyl were 0.185 mg L-1 and 0.045 mg L-1 with a limit of detection (LOD, IC10) of 0.004 mg L-1 and 0.002 mg L-1, respectively. There were no obvious cross-reactivities with most of the aryloxyphenoxypropionates tested, except for metamifop (CR% = 55.56%). The recoveries of fenoxaprop-p-ethyl, cyhalofop-butyl and metamifop in environmental and agricultural samples (tap water, paddy water, soil, rice and soybean) ranged from 86.86-114.52%, 82.07-119.11% and 82.51-114.46%, respectively. These results demonstrate that the established ELISA could be used as a tool for detecting aryloxyphenoxypropionate multiresidues.