Development of a group-specific immunoassay for sulfonamides. Application to bee honey analysis

A set of haptens has been synthesized in order to raise generic polyclonal antibodies against sulfonamides using different strategies. After the screening of all the immunorreagents, a highly sensitive enzyme-linked immunosorbent assay was set-up for simultaneous determination of six of these antibiotics. The developed procedure allows the screening of: sulfathiazole, sulfamethoxypyridazine, sulfapyridine, sulfamethizole, sulfasalazine and N(4)-phtalylsulfathiazole with good accuracy and precision at level 0.13ng mL(-1) in buffer. The suitability of developed ELISA for its application to honey analysis has been investigated. The antimicrobials were extracted from samples with acetate buffer, and cleaned up by solid phase extraction. The mean recovery found for honey samples, spiked from 1.5 to 4.5ng mL(-1) equivalents of sulfathiazole (24-72microg sulfathiazole kg(-1) honey), was 106%.