Abstract: A high performance liquid chromatography tandem mass spectrometric (HPLC-MS-MS) method was developed for rapid determination of chloramphenicol residue in infant milk powder. D5-Chloramphenicol was used as internal standard. Samples were alkalified, extracted with ethyl acetate and centrifuged at a low temperature. Afterwards, the supernatant was concentrated by nitrogen gas blowing and dissolved again in HPLC mobile phase before HPLC-MSMS analysis. An excellent linear relationship between peak area and chloramphenicol concentration was obtained over the concentration range of 0.1 to 5 μg/L. Average recoveries of chloramphenicol in a blank matrix across three spike levels ranged from 80% to 110%, and inter-batch and intra-batch precision (RSD) was less than 15%. The limit of quantification of this method was 0.1 μg/kg. This method was rapid, simple and suitable for rapid determination of chloramphenicol residue in infant milk powder.

Key words: infant milk powder；chloramphenicol；residue；LC-MS-MS

摘要： 建立一种高效液相色谱一串联质谱法快速测定婴幼儿乳粉中氯霉素残留的方法。样品以D5-氯霉素为内标，碱化后，经乙酸乙酯提取、低温离心、氮吹浓缩，流动相复溶，采用高效液相色谱一串联质谱法测定。结果表明：在0．1-5μg/L范围内氯霉素呈良好的线性关系，高、中、低浓度回收率为80％～110％，精密度小于15％，定量限为0．1μg/kg。本方法快速、简便，适于乳粉中氯霉素残留的快速测定。

关键词: 婴幼儿乳粉; 氯霉素; 残留; LC—MS—MS