电堆积毛细管电泳法检测食品中四环素类抗生素残留

Analysis of tetracycline antibiotic residues in food by capillary electrophoresis with stacking

建立了一种采用电堆积方式在线富集的毛细管电泳检测牛奶、鸡蛋和蜂蜜中(包括四环素、土霉素、强力霉素在内)3种四环素类抗生素残留的方法.对影响富集倍数和分离的主要因素进行了优化.最佳运行缓冲液为20mmol/L的柠檬酸盐溶液,pH为2.5,分离电压20kV;进样量25kV×30s.在优化条件下,四环素、土霉素和强力霉素的富集倍数分别为86,54和54;检出限为1.7～2.1,1.8～2.2和1.9～2.2μg/kg;定量下限均为20μg/kg,仅为欧盟标准中最大残留限量的1/5(牛奶)和1/10(鸡蛋).方法可应用于鸡蛋、牛奶和蜂蜜中3种四环素类抗生素残留的检测.

The method of capillary electrophoresis with stacking was developed to determine the three tetracycline antibiotic residues including tetracycline, oxytetracycline and doxyeyeline in milk, egg and honey. The important parameters influencing enrichment factors and separation were optimized. The opti- mal running buffer was 20 mmol/L citrate solution at pH 2.5. The separation voltage was 20 kV. The sample size was 25 kVX 30 s. Under the optimum conditions, the enrichment factors were 86, 54 and 54, and the limits of detection were 1.7 - 2.1 9g/kg, 1.8 - 2.2 μg/kg and 1.9 - 2.2μg/kg for tetracycline, oxytetracycline and doxycycline, respectively. The limits of quantification were all 20 μg/kg, which was only 1/5 （milk） and 1/10 （egg） of the maximum residual limits demanded by the regulation of European Union. The method can be applied to determine these three tetracycline antibiotic residues in milk, egg and honey.