Molecularly Imprinted Polymer Online Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography−UV for the Determination of Three Sulfonamides in Pork and Chicken

A selective imprinted amino-functionalized silica gel sorbent was prepared by combining a surface molecular imprinting technique with a sol–gel process for online solid-phase extraction−HPLC determination of three trace sulfonamides in pork and chicken muscle. The imprinted functionalized silica gel sorbent exhibited selectivity and fast kinetics for the adsorption and desorption of sulfonamides. With a sample loading flow rate of 4 mL min−1 for 12.5 min, enhancement factors and detection limits for three sulfonamides (S/N = 3) were achieved. The precision (RSD) for nine replicate online sorbent extractions of 5 µg L−1 sulfonamides was less than 4.5%. The sorbent also offered good linearity (r2 > 0.99) for online solid-phase extraction of trace levels of sulfonamides. The method was applied to the determination of sulfonamides in pork and chicken muscle samples. The prepared polymer sorbent shows promise for online solid-phase extraction for HPLC determination of trace levels of sulfonamides in pork and chicken samples.