柱后衍生高效液相色谱法测定虾中14种磺胺类药物残留量

Determination of 14 sulfonamide residues in shrimps by high performance liquid chromatography coupled with post-column derivatization

建立了虾中14种磺胺类药物残留量的柱后衍生高效液相色谱检测方法。样品在加入内标物磺胺吡啶后用乙酸乙酯提取，提取液浓缩后用4 mL 乙酸乙酯溶解残余物，用盐酸溶液反萃取，正己烷去脂，盐酸溶液经滤膜过滤后，加入乙腈、甲醇和3.5 mol / L 乙酸钠溶液（体积比为5：5：20）的混合溶液混匀后，经高效液相色谱分离，用荧光胺衍生试剂进行柱后衍生，荧光检测器检测。采用基质标样添加法绘制标准曲线，内标法定量。对柱后衍生系统参数进行了优化，确定了荧光胺溶液的浓度、流速和反应温度分别为0.2 g / L、0.15 mL / min 和50℃。14种磺胺类药物在5～200μg / L 范围内具有良好的线性。磺胺类药物的定量限（LOQ，S / N =10）为1.0～5.0μg / kg。在1.0～100.0μg / kg 添加水平内，磺胺类药物的平均回收率为77.8％～103.6％，相对标准偏差（ RSD）为2.9％～9.1％（ n =6）。实验结果表明该方法灵敏、准确，重复性好，适用于虾中磺胺类药物的残留检测。

A method for the determination of 14 sulfonamide residues in shrimps by high per-formance liquid chromatography coupled with post-column derivatization was established. The sulfonamide residues were extracted with ethyl acetate after adding sulfapyridine as internal standard. The extracts were vacuum-concentrated and reverse-extracted by 2 mol / L hydrochlo-ric acid solution for clean-up,and then the hydrochloric acid solution was defatted with n-hex-ane. The solution after filtration was blended with a mixed solution of methanol,acetonitrile and 3. 5 mol / L sodium acetate solution（5 ：5 ：20,v / v / v）. The sulfonamides were separated on a C18 column by RP-HPLC and on-line derivatized with a fluorescamine and detected with a fluo-rescence detector. The standard addition method was used for quantitative analysis. The param-eters of post-column derivatization system,such as concentration of fluorescamine solution, velocity of reagent solution and reaction temperature,were optimized. The calibration curves of the method showed good linearity in the range of 5 - 200 μg / L. The limits of quantification （LOQ,S / N = 10）were 1. 0 - 5. 0 μg / kg for the 14 sulfonamides. The recoveries were 77. 8% -103. 6% in the spiked range of 1. 0-100. 0 μg / kg in shrimps with the relative standard deviations of 2. 9% -9. 1%（n = 6）. The results indicated that the method is sensitive,efficient and more accurate. It is suitable for the simultaneous determination of the 14 sulfonamide residues in shrimps.