HPLC测定牛奶中阿莫西林和青霉素G的残留

建立了高效液相色谱(HPLC)同时测定牛奶中阿莫西林和青霉素G的方法。牛奶样品用乙腈提取脱蛋白,离心取上清液,旋转蒸发干后,用磷酸二氢钾溶液溶解定容,经HYPERSEP C18固相萃取柱净化。以C18柱为分离柱,以乙腈和水为流动相,梯度洗脱。该方法采用外标法,在1.0 ng/mL～100.0 ng/mL范围内,青霉素G和阿莫西林的峰面积与对应的浓度成良好的线性关系(r=0.999 5、0.999 7)。在低、中、高三个水平下的加标回收率为89.25%～94.13%,相对标准偏差(RSD)1.02%～1.43%(n=3)。该方法简便快捷,可适用于牛奶中阿莫西林和青霉素G的同时测定。

Determination of Amoxicillin and Penicillins G residues in milk by HPLC

A method was establised for the determination of amoxicillin and penicillins G in mlik by high performance liquid chromatography （HPLC）. Samples were extracted by acetonitrile and the ex- tract was centrifuged and evaporated to dry,then dissolved in potassium dihydrogen phosphate solution and purified by HYPERSEP CIs solid phase extraction. The extracted was analyzed in HPLC in a C18 column with acetonitrile and water as eluent and quantified by external standard method. A good linear relationship （ r = 0. 999 5,0. 999 7 ） existed for both residues in concentration range of 1.0 ng/mL to100.0 ng/mL. The average recoveries from milk at the three concentrations are ranged from 89.25% to 4.13% ,with relative standard deviation（RSD） from 1.02% - 1.43% （n = 3）. The method is easy and and can be apply to determinate amoxicillin and penicillins G residues in mlik.