Multi-residue analysis of sulfonamide antibiotics in honey samples by on-line solid phase extraction using molecularly imprinted polymers coupled to liquid chromatography-tandem mass spectrometry

This work reports the development of a sensitive and automated online solid phase extraction method using molecularly imprinted polymers (MISPE) coupled to high performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) (HPLC), for the identification and quantification of six sulfonamide antibiotics, namely sulfapiridyne, sulfadoxine, sulfaquinoxaline, sulfacetamide, sulfachloropyridazine and sulfamonomethoxine in honey samples from the Cuban market. The samples were hydrolyzed in acidic media to release the sugar-bound sulfonamides before injection into the preconcentration system. Polymer composition was selected using a combinatorial approach. Several parameters affecting the performance of the MISPE method were optimized to reduce nonspecific binding with the non-imprinted polymer and achieve a selective rebinding of the target antimicrobials. Method validation was performed according to Commission Decision 2002/657/EC in terms of linearity, recoveries, precision, specificity, decision limit (CC α ) and detection capability (CC β ). Intraday recoveries at three concentration levels (1, 10 and 20 μg Kg-1) were between 84.3 and 104.7% (RSD < 11.6%) while interday average recoveries were in the ranges 65.5–119.3% (RSDs < 10.4%). The values of CC α and CC β values were in the ranges 0.1–4.2 and 0.2–4.4 μg kg −1 , respectively. The limits of detection and quantitation for the investigated sulfonamides ranged from 0.004–1.050 µg kg −1 and 0.014–3.499 µg kg −1 , respectively. The method described has been applied to the analysis of honey samples from Cuban producers.