液相色谱-三重四极杆/线性离子阱复合质谱技术检测牛奶中莫昔克丁残留

Determination of Moxidectin Residue in Milk by QTRAP LC-MS/MS

关键词:  莫昔克丁  牛奶  残留  液相色谱-三重四极杆/线性离子阱复合质谱

Key words:  Moxidectin  Milk  Residue  QTRAP LC-MS/MS

摘要:

建立了牛奶中莫昔克丁残留检测的液相色谱-三重四极杆/线性离子阱复合质谱技术（QTRAP LC-MS/MS）。样品用乙腈提取后，用Ｃ18固相萃取柱净化，上机测试。液相色谱条件：色谱柱为BEH C18（50×2.1 mm，1.7 μm），流动相为0.1%甲酸水溶液+0.1%甲酸乙腈溶液，梯度洗脱，流速为0.4 mL/min，柱温为30 ℃，进样量为5 μL。质谱条件：电喷雾正离子源（ESI+），采用多反应监测-信息依赖扫描-增强子离子扫描（MRM-IDA-EPI）方式采集。结果表明：在牛奶中，莫昔克丁在1~80 ng/mL基质匹配标准溶液浓度范围内均呈现良好的线性关系，相关系数（R2）大于0.990；牛奶中莫昔克丁的定量限为2 μg/kg。牛奶中莫昔克丁在2、40和80 μg/kg三个添加浓度平均回收率都在60%～120％之间，批内、批间RSD均小于15%。该方法简便快捷，定性准确、灵敏度高、回收率和精密度满足残留检测要求。

Abstract:

A LC-QTRAP method was established for the determination of Moxidectin residue in milk. The samples were extracted by acetonitrile, then purified with C18 SPE. LC conditions were as follows: the chromatography column is BEH C18 column of 50 mm×2.1 mm, 1.7 μm；mobile phase is acetonitrile（0.1% formic acid） and water（0.1% formic acid）; flow rate is 0.4 mL/min; column temperature is 30 ℃; injection volume is 5 μL. Mass spectrometry conditions were ESI+ and Multi-reaction Monitoring-Information Dependent Acquisition-Enhanced Product Ion (MRM -IDA - EPI) mode. The calibration curve of Moxidectin were good linear from 1 to 80 ng/mL in milk with the correlation coefficient R2 over 0.990. The limit of quantification was 2 μg/kg. The average recoveries of Moxidectin from spiked milk at three concentrations of 2, 40 and 80 μg/kg were between 60%～120％, and intra- and inter-batch RSD were <15%.