18O标记联合高效液相色谱-高分辨率质谱技术定量测定阿胶中的明胶

摘要

In this work, trypsin-catalyzed 18O labeling combined with high performance liquid chromatography-linear ion trap/Orbitrap high-resolution mass spectrometry (HPLC-LTQ/Orbitrap MS/MS) was used to study the 18O labeling characteristics of marker peptides in donkey-hide gelatin. Moreover, the method was applied to quantify donkey-hide gelatin and bovine-hide gelatin in their mixtures. Under trypsin catalysis, all the marker peptides of donkey-hide gelatin were labeled by two 18O atoms. The measured ratios for 18O-labeled and 16O-labeled peptide mixtures at ratios of 20:1, 10:1, 5:1, 1:1 and 1:5 were 19.66, 10.24, 5.01, 1.00 and 0.20, respectively. The measured ratios for mixtures of donkey-hide gelatin and bovine-hide gelatin at ratios of 1:10, 1:1 and 10:1 using 18O-labeled characteristic peptides as the internal standard were 0.10, 1.02 and 9.72, respectively. The results showed that trypsin-catalyzed 18O labeling combined with HPLC-LTQ/Orbitrap MS/MS should be a promising method to quantify the target gelatin and control the quality of donkey-hide gelatin product.%采用胰蛋白酶催化的18O标记联合高效液相色谱-高分辨率串联质谱技术(high performance liquid chromatography-linear ion trap/Orbitrap high-resolution mass spectrometry,HPLC-LTQ/Orbitrap MS/MS)研究阿胶的特征性多肽的18O标记情况和明胶混合物中阿胶、牛皮明胶的定量情况.结果表明,阿胶的特征性多肽均能被2?个18O原子标记,当18O和16O标记多肽以20∶1、10∶1、5∶1、1∶1和1∶5的质量比例混合时,检测到的18O与16O标记多肽比值分别为19.66、10.24、5.01、1.00和0.20.当阿胶和牛皮明胶质量比以1∶10、1∶1和10∶1混合,以18O标记物为内标,检测到的阿胶与明胶比值分别为0.10、1.02和9.72.因此,胰蛋白酶催化的18O标记联合HPLC-LTQ/Orbitrap?MS/MS适用于阿胶产品中目标明胶的含量检测,可为阿胶产品的质量控制提供技术支撑.