Immunoassay for iprodione: key estimation for residue analysis and method validation with chromatographic technique

This work reports on the fundamental characteristics of a commercial enzyme-linked immunosorbent assay (ELISA) for iprodione and the application to residue analysis in agricultural samples. The ELISA had enough analytical sensitivity (I50 value 4.0 ng g(-1); limit of detection 0.3 ng g(-1)) to determine a trace of iprodione residue and had a high selectivity. Only administering simple dilution of sample extracts very easily surmounted the most troublesome matrix interference in ELISA for pesticide residue analysis. Consequently, a rapid and simple detection method for iprodione was reached by the combination of the sample dilution and the devised extraction method in which it required no instruments for extraction. The average recovery values from spiked samples with the ELISA were between 106.4 and 115.8% with the average coefficients of variation between 3.0 and 4.0%. The results obtained with the ELISA correlated well with those by the reference chromatographic method for all tested agricultural samples (r>0.993). These findings strongly indicate that the proposed ELISA was an adequate and reliable detection method for iprodione residues.