UPLC-MS/MS测定牛奶中三氮脒和氮氨菲啶残留

Determination of Diminazene Aceturate and Isometamidium Chiorde in Milk by UPLC-MS/MS

建立超高效液相色谱-串联质谱法测定牛奶中三氮脒和氮氨菲啶残留量的方法。样品经过乙腈[含0.2%(V/V)的50%(V/V)乙酸水溶液]提取,经40℃蒸干、15%乙腈水溶液溶解和正己烷除脂后,以乙腈和0.1%甲酸水溶液为流动相梯度洗脱,进行检测,外标法定量。结果表明, 2种兽药残留物在50~1 000 ng/mL范围内呈现良好线性关性,相关系数(r)均大于0.999。2种兽药残留物方法的检出限为5μg/kg,方法的定量限为10μg/kg。在添加量为5, 10和50μg/kg的加标回收试验下, 2种兽药加标回收率为80.8%~95.3%, SRSD范围为2.0%~4.2%(n=6)。该方法前处理操作简便、分析速度快、灵敏度高,填补牛奶中三氮脒和氮氨菲啶检测方法的空白,实现牛奶中2种目标化合物的准确定量分析,为牛奶及其制品的质量监测提供理论和技术支撑。

An ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method was developed for the determination of diminazene aceturate and isometamidium chiorde residues in milk.The samples were extracted with acetonitrile[containing 0.2%(V/V)in 50%(V/V)acetic acid aqueous solution],after being evaporated to dryness at 40℃,dissolved in methanol and then rinsed with N-hexane,cleaned up by gradient elution of acetonitrile and 0.1%formic acid aqueous solution as mobile phase,and quantified by external standard method.The results showed that the two veterinary drug residues showed good linearity in the range of 50-1000 ng/mL with the correlation coefficients(r)greater than 0.999.The limits of detection(S_(LOD))of the method were 5μg/kg,and the limits of quantification(S_(LOQ))of the method were 10μg/kg.The recoveries of the two veterinary drugs spiked at the spiked levels of 5,10 and 50μg/kg.The recoveries of the four veterinary drugs were 80.8%-95.3%with the SRsp range of 2.0%-4.2%.The method was simple,fast and sensitive.This study fills the gap of the method for the determination of diminazene aceturate and isometamidium chiorde in milk,and achieves the accurate quantitative analysis of the two target compounds in milk,which provided theoretical and technical support for the quality monitoring of milk and its products.