基于液相色谱-串联质谱法的肉类特征肽段鉴别及掺假测定

建立了液相色谱-串联质谱技术鉴别肉类特征肽段及定量检测羊肉中常见外源肉掺假的方法。样品经蛋白质提取、胰蛋白酶水解和固相萃取小柱净化后，利用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱（UPLC-Q/Exactive-HRMS）和Proteinpilot软件，实现蛋白质和多肽的鉴定；再通过基本局部比对搜索工具（BLAST）与Uniprot数据库对比分析，筛选出羊肉、鸭肉、猪肉和鸡肉的20个物种特征性多肽标志物；最后利用高效液相色谱-三重四极杆质谱（UPLC-QqQ-MS）系统对羊肉、鸭肉、猪肉和鸡肉的特征性多肽进行了验证和多反应监测（MRM）定量研究。将鸭肉、猪肉和鸡肉分别按照质量分数为1%、5%、10%、20%、50%的比例掺加到羊肉中，得到鸭肉最低掺假检出限为0.25%、猪肉最低掺假检出限为0.17%、鸡肉最低掺假检出限为0.10%。

Identification of meat marker peptides and detection of adulteration by liquid chromatography-tandem mass spectrometry

A liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the identification of meat marker peptides and quantitative detection of common exogenous meat in mutton adulteration. Samples were prepared by protein extraction, trypsin hydrolysis, and solid phase extraction. Proteins and peptides were identified using ultra-performance liquid chromatography-quadrupole/electrostatic orbitrap-high resolution mass spectrometry (UPLC-Q/Exactive-HRMS) combined with Proteinpilot software. Twenty species-specificity marker peptides in mutton, duck, pork, and chicken were identified by comparison of the basic local alignment search tool (BLAST) with the Uniprot database. Verification and multiple reaction monitoring (MRM) of these marker peptides were performed quantitatively using a UPLC-triple-quadrupole mass spectrometry (QqQ-MS) system. Duck, pork, and chicken were added to mutton at mass percentages of 1%, 5%, 10%, 20%, and 50%. The limit of detection for the adulterants was 0.25% for duck, 0.17% for pork, and 0.10% for chicken.