免疫亲和注射器微萃取-高效液相色谱串联质谱法测定牛奶中玉米赤霉醇类化合物

Determination of Zeranols in Milk Using Immunoaffinity Microextraction in a Packed Syringe and High Performance Liquid Chromatograph-Tandem Mass Spectrometry

摘要:

将偶联玉米赤霉醇单克隆抗体的二氧化硅作为注射器微萃取的选择性吸附剂，建立了检测牛奶中6种玉米赤霉醇类化合物（ZERs）的免疫亲和注射器微萃取-高效液相色谱串联质谱法（IA-MEPS-LC-MS/MS）。将牛奶离心后，取中间夹层，使用免疫亲和注射器微萃取，超纯水洗涤，甲醇洗脱，洗脱液浓缩，流动相复溶后LC-MS/MS分析，采用C₁₈色谱柱分离，水-乙腈为流动相梯度洗脱。使用基质匹配外标法定量，在工作液质量浓度0.1~100.0 ng/mL时6种ZERs线性良好，相关系数在0.994 3~0.996 2；在ZERs添加水平为1 ng/g时，平均回收率在50.40%~68.34%，日内RSD在4.87%~17.64%，日间RSD在7.04%~18.75%，本方法的定量限（LOD）为0.05 ng/g，LOQ为0.2 ng/g。

Abstract:

This research prepared a selective adsorbent on the basis of SiO2 glass beads bound with zeranol monoclonal antibody and the method of immunoaffinity microextraction in a packed syringe and high performance liquid chromatograph-tandem mass spectrometry (IA-MEPS-LC-MS/MS) was further developed to detect six kinds of zeranols (ZERs) in milk. Milk samples were centrifuged, and the middle layer was extracted with IA-MEPS syringe and washed by ultra-pure water before eluted with methanol. The eluent was concentrated and then re-dissolved by mobile phase. Finally, the sample was detected by LC-MS/MS, separated on a C₁₈ column with the mobile phase of water and acetonitrile. Matrix-matched external standard method was used for quantification. The linearity of six ZERs was good within 0.1~100.0 ng/mL, and the correlation coefficient was 0.994 3~0.996 2. The average recoveries ranged from 50.40% to 68.34% at the addition level of 1 ng/g, the intra-day and the inter-day RSDs were 4.87%~17.64% and 7.04%~18.75%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) of this method were 0.05 ng/g and 0.2 ng/g, respectively.