QuEChERS结合超高效液相色谱-串联质谱法测定牛奶中莫昔克丁残留

目的建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)检测莫昔克丁在牛奶中残留的分析方法。方法采用1%乙酸乙腈振荡提取,离心后取上清液加乙二胺-N-丙基硅烷吸附剂N-(n-Propyl)ethylenediamine,PSA]和十八烷基键合硅胶(C18)混合净化,上清液氮气吹干后用50%乙腈水溶液定容后供LC-MS/MS测定。结果在0.0005~0.20 mg/L浓度范围内线性良好,相关系数为0.9993。莫昔克丁在牛奶中的添加水平为0.002~0.20mg/kg,平均回收率为75.0%~82.6%,相对标准偏差为3.6%~4.8%。结论本方法快速、灵敏度高,适用于牛奶中莫昔克丁的检测。

Determination of moxidectin in milk by QuEChERS-ultra performance liquid chromatography tandem mass spectrometry

Objective To establish a method for the determination of moxidectin residues in milk by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Methods The moxidectin was extracted by oscillation with 1% acetic acid acetonitrile, after centrifugation, the liquid supernatant purified by N-(n-Propyl) ethylenesilane(PSA) and C18 absorbent, the supernatant was dried with nitrogen and dissolved with 50% acetonitrile aqueous solution. Finally, it was determined by UPLC-MS/MS. Results The linearity was good in the concentration range of 0.0005~0.20 mg/L, and the correlation coefficient(r) was 0.9993. The average recoveries was 75.0%-82.6%, and the relative standard deviations was 3.6%~4.8%, when the addition levels of moxidectin were 0.002-0.20 mg/kg in milk. Conclusion This method is fast, sensitive and is suitable for the detection of moxidectin in milk.