直接提取-超高压液相色谱-电喷雾串联质谱法检测原料奶及奶制品中的四环素类抗生素

Determination of tetracycline antibiotics residues in milk and dairy products by direct extraction-UPLC-ESI-MS/MS

目的建立直接提取-超高压液相色谱-电喷雾串联质谱法(UPLC-ESIMS/MS)同时测定原料奶及奶粉中土霉素、四环素、金霉素、强力霉素4种四环素类药物的分析方法。方法原料奶及奶粉样品经少量高氯酸沉淀蛋白、低温冷冻除脂后,用C18色谱柱分离,以0.1%甲酸水和乙腈为流动相进行梯度洗脱,电喷雾串联质谱正离子模式扫描,多反应监测模式(MRM)检测,外标法定量。结果 4种四环素族药物在1～1000ng/mL浓度范围内线性关系良好,相关系数r均在0.993以上。本方法的定量限为(S/N≥10)为原料奶5μg/kg,奶粉25μg/kg,在10、50、100μg/kg三个加标水平下,加标回收率为73.4%～99.4%,相对标准偏差为0.8%～14.3%(n≥6)。结论该方法简便快速、灵敏可靠、经济有效,适用于原料奶及奶粉中土霉素、四环素、金霉素和强力霉素4种四环素族药物残留的测定。

@@@@Objective A method for the simultaneous determination of oxytetracycline, tetracycline, chlortetracycline, and doxycycline residues in milk and dairy products was developed using direct extraction and ultra pressure liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS). Me-thods Samples were extracted with little perchloric acid to precipitate protein and remove Frozen grease, se-parated by C18 column with gradient elution using acetonitrile and water (containing 0.1% formic acid) and analyzed by UPLC-ESI-MS/MS under the positive mode using multiple reaction monitoring (MRM). The sam-ples were quantified with external standard method. Results The method showed a good linearity over the range of 1~1000 ng/mL for 4 compounds of tetracycline antibiotics residue with r≥0.993. The detection limit (S/N≥10) of milk was 5 μg/kg , and that of dairy products was 25 μg/kg. The recoveries were 73.4%~99.4% at the spiked level of 10, 50 μg/kg, and 100 μg/kg with relative standard deviation of 0.8%~14.3%(n≥6). Con-clusion This method is simple, accurate and reproducible, and it is suitable for the rapid analysis of tetracy-cline antibiotics in milk and dairy products.