Determination of 35 sulfonamides in pork by magnetic molecularly imprinted polymer-based dispersive solid-phase...

Sulfonamide residues in foods of animal origin are potential risks to consumer health, so it is very important to inspect them. Among the previously reported instrumental methods, the best method can only be used to determine at most 22 sulfonamides. Thus, an instrumental method capable of determining more sulfonamide species is desirable.

In this study, sulfadoxine was used as a template to synthesize a type of magnetic molecularly imprinted polymer that could recognize 35 sulfonamides. After characterization, this composite was used to develop a dispersive solid-phase extraction method for extraction and purification of the 35 sulfonamides in pork, followed by determination using an ultra-performance liquid chromatography photodiode array method. This composite exhibited high adsorption capacity (11.01-19.21 μg mg^-1 ) and high recovery (>89.01%), and could be reused at least ten times. Due to the enrichment effect during sample preparation (enrichment factor 22-66), the limits of detection for determination of the 35 drugs in pork were in the range of 0.08-0.53 ng g^-1 . The detection results for some real pork samples were consistent with a liquid chromatographic-tandem mass spectrometric method. After comparison, the present method showed generally better performances than the previously reported sample preparation methods and instrumental methods for detection of sulfonamides.

The method developed in the present study could be used as a practical tool for routine detection of sulfonamide residues in pork samples. © 2022 Society of Chemical Industry.