UHPLC-MS/MS同时测定牛奶中5种头孢类药物残留

Simultaneous Determination of Five Cephalosporins Residues in Milk by UHPLC-MS/MS

目的建立采用UHPLC-MS/MS同时测定牛奶中5种头孢菌素类药物残留的方法。方法牛奶样品(约5 g)加10 mL Na2EDTA-McIlvaine提取液提取后,涡旋离心,取中层清液,加入0.1 mol·L-1 NaOH溶液调节pH至8.5,取上清液过HLB固相萃取柱富集并净化。富集浓缩后以Waters ACQUITY UPLC BEH(2.1 mm×50 mm,1.7μm)色谱柱为分离柱,以0.1%甲酸溶液和乙腈为流动相进行梯度洗脱。采用电喷雾正离子源,以多反应监测模式进行质谱检测。结果牛奶中5种头孢菌素类药物在1~20倍定量限浓度范围内有良好的线性关系,所得回收率为88.1%~114%,重复性试验RSD(n=6)均<6.55%,检出限为0.7~1.6μg·kg-1。结论本方法专属性好、灵敏度高、准确性好,可多组分同时测定牛奶中的头孢类药物残留。

OBJECTIVE To establish a method for simultaneous determination of 5 cephalosporins residues in milk by UHPLC-MS/MS.METHODS Milk samples(about 5 g)were extracted by 10 mL Na2EDTA-McIlvaine,centrifuged by a vortex,then get the middle-level clear liquid,the pH was adjusted to 8.5 by adding 0.1 mol·L-1 NaOH solution,the supernatant were enriched and purified by HLB solid phase extraction column.The separation and analysis was performed on a Waters ACQUITY UPLC BEH(2.1 mm×50 mm,1.7μm)after enrichment and concentration.The mobile phase consisted of 0.1%formic acid and acetonitrile(gradient elution).Electrospray positive ion source was used for mass spectrometry detection by multiple reaction monitoring mode.RESULTS The five cephalosporins residues in milk had a good linear relationship within the quantitative limit of 20 times.The recoveries were 88.1%-114%,the RSD of repeatability test(n=6)was<6.55%,and the detection limit was 0.7-1.6μg·kg-1.CONCLUSION The method has good specificity,sensitivity and accuracy,and can be used for the simultaneous determination of cephalosporins residues in milk.