液相色谱串联质谱对掺假牛肉的鉴别及定量研究

本文以差异蛋白质组学为理论研究基础,利用高效液相色谱串联质谱(HPLC-MS/MS)实现了对猪肉或鸡肉掺假的牛肉的定性鉴别及定量分析。首先采用高分辨质谱仪(nLC-QE)分别找出牛肉、猪肉和鸡肉的相对专属性多肽链,并对其进行二级扫描,得到了三个物种的特异性离子对,进一步利用HPLC-MS/MS的多反应监测模式(MRM)对掺杂猪肉或鸡肉的牛肉进行特异性离子对验证,分别选择了牛肉、猪肉和鸡肉的9、8和7条多肽进行定性研究;并与聚合酶链式反应(PCR)技术进行比对,得到的结果一致;此外将鸡肉和猪肉以0.5、1.0、5.0、10.0、25.0%的比例掺杂于牛肉中,各选择3组离子对进行定量分析,其各自的线性相关系数均大于0.99,最低定量限为0.5%。由此表明,液相色谱串联质谱的方法可以快速地对牛肉中的猪肉和鸡肉进行鉴别并能准确定量分析。

Identification and Quantification of Adulterated Beef by Liquid Chromatography Tandem Mass Spectrometry

Differential proteomics was used as the basis for theoretical study, while high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was employed to identify and quantify beef adulterated with pork and chicken. First, polypeptides relatively specific to beef, pork, and chicken were identified using a high-resolution mass spectrometer (nLC-QE), followed by product ion scan to determine the specific ion pairs in the three types of meats. These specific ion pairs were then detected in the beef adulterated with pork or chicken using HPLC-MS/MS in multiple reaction monitoring (MRM) mode, and a qualitative study was carried out using nine, eight, and seven quantitative peptides from beef, pork, and chicken, respectively. The results were compared with those obtained from polymerase chain reaction (PCR), and the results were found to be consistent with each other. Chicken and pork were blended in beef in proportions of 0.5, 1.0, 5.0, 10.0, and 25.0%, and three quantitative peptides specific to each type of meat were selected to perform the quantitative analysis. The linear correlation coefficient for each quantitative ion pair was more than 0.99, and the limit of quantitation was 0.5% blending. The results showed that the HPLC-MS/MS method can quickly and efficiently identify pork and chicken in beef, and can be used for accurate quantitative analysis.