Abstract: An indirect enzyme-linked immunosorbent assay(ELISA)kit was developed to monitor phorate residue. The optimal concentration of coating antigen was 4 mg/L and the optimal dilution ratio of antibody was 8000. The cross-reaction ratio was less than 20%. The regression equation of inhibition rate for phorate was y = 18.846x＋6.9949 with a linear detection range of 1－5000μg/L. Results indicated that the detection limit was 4.90μg/L and IC50 was 191.37μg/L. The recovery rates were higher than 75%. The intra-assay and inter-assay coefficients were less than 10%. The developed kit can be stored at 4℃ or－20 ℃ for 270 days.

Key words: phorate, residue, enzyme-linked immunosorbent assay(ELISA), kit