Development of a chemiluminescent enzyme‐linked immunosorbent assay for five sulfonamide residues in chicken muscle and pig muscle

BACKGROUND: An enzyme‐linked immunosorbent assay (ELISA) based on polyclonal antibodies with enhanced chemiluminescent (ECL) detection of sulfonamides in food samples has been optimised and characterised. The specificity of the assay was assessed by determining cross‐reactivities with a set of 16 sulfonamides. The aim of this study was to develop a method for determining sulfonamides with high sensitivity. RESULTS: The sensitivity of the developed ECL‐ELISA was higher than that of colorimetric ELISA. The sensitivities of five of the sulfonamides (sulfisozole, sulfathiazole, sulfameter, sulfamethoxypyridazine and sulfapyridine) ranged from 0.73 to 2.92 µg L^?1, with limits of detection of 0.10–0.43 µg L^?1. The coefficients of variation of intra‐assay and inter‐assay studies carried out over 5 days were mostly less than 10%. Recovery studies of chicken muscle and pig muscle were performed with simple and rapid extraction. Good recoveries (62.1–110.3%) were achieved and the results correlated well with those obtained using high‐performance liquid chromatography analysis. CONCLUSION: This study has provided an effective analytical technique for the rapid and reliable determination of residues of sulfisozole, sulfathiazole, sulfameter, sulfamethoxypyridazine and sulfapyridine in food samples with high sensitivity. To the authors' knowledge, this is the first report on chemiluminescent ELISA for sulfonamide analysis. Copyright © 2008 Society of Chemical Industry