Simultaneous determination of sulphamerazine, sulphamethazine and sulphadiazine in honey and chicken muscle by a new monoclonal antibody-based fluorescence polarisation immunoassay.

A new monoclonal antibody (Mab) against sulphamerazine (SMR) was produced and a fluorescence polarisation immunoassay (FPIA) based on the Mab was developed and optimized for the simultaneous qualitative screening of SMR, sulphamethazine (SMZ) and sulphadiazine (SDZ). The Mab, raised from mice immunized with SMR, was bound to bovine serum albumin (BSA) using glutaraldehyde as the coupling reagent. Fluorescein-labelled SMR and SMZ (tracer) were synthesized and purified by thin layer chromatography (TLC). Cross-reactivities below 3.6% were displayed in the optimized FPIA for another 14 sulphonamides when both tracers were employed. The limits of detection (LOD) were 0.9 ng g(-1) for SMR, 2 ng g(-1) for SMZ and 3.1 ng g(-1) for SDZ. Analysis of SMR, SMZ and SDZ fortified chicken muscle and honey samples by the FPIA showed average recoveries of 86-131% with a standard deviation (SD) of 4.6-32. Comparative analyses of a SMZ-treated chicken muscle sample by both FPIA and high performance liquid chromatograph (HPLC) showed a good correlation (r = 0.9991). The study demonstrates the practical application of FPIA in screening chicken muscle and honey samples for sulphonamides residues.