Multiresidue determination of sulfonamides in chicken meat by polymer monolith microextraction and capillary zone electrophoresis with field-amplified sample stacking

A method based on poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-EGDMA) monolith microextraction (PMME) and online preconcentration technique of field-amplified sample stacking (FASS) was proposed for sensitive capillary electrophoresis-ultraviolet (CE-UV) analysis of 12 sulfonamides (sulfamethazine, sulfamethoxypyridazine, sulfathiazole, sulfamerazine, sulfameter, sulfadoxine, sulfadimethoxine, sulfamonomethoxine sodium, sulfachlorpyridazine, sulfamethoxazole, sulfamethizole, and sulfisoxazole) in chicken samples. The conditions of PMME were optimized for the improvement of extraction efficiency and reduction of the matrix interferences from chicken sample. The best separation was achieved within 15 min using a buffer of 100 mM phosphate electrolyte (pH 7.3) with temperature and voltage of 20 °C and 25 kV, respectively. By applying FASS, detection limits of 3.49–16.7 ng/g were achieved with satisfactory precision (RSD ≦ 13%) and recovery (96.3–104%) over a linear range of 50–1000 ng/g for most analytes.