Development of Capillary Electrophoretic Method Combined with Accelerated Solvent Extraction for Simultaneous Determination of Residual Sulfonamides and Their Acetylated Metabolites in Aquatic Products

Abstract

A rapid and effective method was developed in the first time for the determination of four sulfonamides (SAs) and their N⁴-acetylated metabolites in aquatic products using capillary electrophoresis with accelerated solvent extraction (ASE). The eight residues were extracted with acetonitrile at 70 °C under 10.3 MPa pressure and two static cycles with a static time of 5 min. The eight analytes can be baseline separated with 6 min. The standard curves for the determination of eight residues by the capillary electrophoretic method have good linearity (r ² > 0.999). The method limits of quantification (LOQs) for N⁴-acetylsulfadiazine, sulfadiazine, sulfamerazine, sulfamethoxazole, sulfamethazine, N⁴-acetylsulfamethazine, N⁴-acetylsulfamerazine, and N⁴-acetylsulfamethoxazole in aquatic products were 26.4, 33.0, 33.0, 33.0, 39.6, 370, and 1,076 μg kg⁻¹, respectively. Intra- and inter-day precision (RSD) were 0.4–2.2 % and 1.4–3.5 %, respectively. Their average recoveries with three spiked levels ranged from 83 % to 116 % with the RSDs less than 4 %. The proposed method provides a rapid and simple extraction procedure with high sensitivity and recoveries, and can permit routine detection of the studied SAs residues in aquatic products at the maximum residue level.