改良柱前荧光胺衍生化-高效液相色谱法测定猪肉中11 种磺胺类药物残留

建立改良的磺胺类药物与荧光胺反应的衍生化方法，并应用于猪肉中11 种磺胺类药物的高效液相色谱-荧光法测定。选用0.1 mol/L KH2PO4溶液（pH 3.0）0.8 mL、0.3 mg/mL荧光胺溶液0.2 mL与磺胺类药物发生衍生化反应，4 ℃避光反应40 min，得到磺胺-荧光胺衍生产物。该衍生化方法稳定、可靠，衍生化产物在4 ℃条件下12 h内维持良好的稳定性。猪肉样品经0.1 mol/L KH2PO4溶液提取，HLB固相萃取柱净化，经该方法衍生化后进行高效液相色谱测定。结果表明：11 种磺胺类药物在1～200 μg/L质量浓度范围内表现出良好的线性关系（R2≥0.999 4）；方法的定量限为0.8～1.6 μg/kg；在2、50、100 μg/kg 3 个加标水平下，11 种磺胺类药物的加标回收率为62.0%～108.0%，日内、日间相对标准偏差分别为2.0%～8.8%和1.8%～8.6%。

Determination of 11 Sulfonamide Residues in Pork by Modified Fluorescamine Precolumn Derivatization-High Performance Liquid Chromatography with Fluorescence Detection

An analytical method using high performance liquid chromatography (HPLC) with fluorescence detection after modified precolumn derivatization with fluorescamine was established for the determination of 11 sulfonamide residues in pork. The optimized reaction conditions were as follows: 0.8 mL of phosphate buffer (0.1 mol/L, pH 3.0) and 0.2 mL of fluorescamine solution (0.3 mg/mL) were mixed, vortexed, and kept in darkness at 4 ℃ for 40 min. The derivatization method was stable and reliable and the resulting product was stable for 12 h at 4 ℃. The sample was extracted with 0.1 mol/L phosphate buffer solution, purified by an HLB solid phase extraction column, and then derived by this method, before being analyzed by HPLC. The calibration curves for the 11 sulfonamides showed a good linear relationship in the concentration range between 1 and 200 μg/L with a correlation coefficient higher than 0.999 4. The limit of quantification for the analytes was 0.8–1.6 μg/kg. At spiked concentrations of 2, 50 and 100 μg/kg, the developed method showed excellent recoveries ranging from 62.0% to 108.0% with intra- and inter-relative standard deviations (RSDs) of 2.0% to 8.8% and 1.8% to 8.6%, respectively.