Identification of five gelatins by ultra performance liquid chromatography/time-of-flight mass spectrometry (UPLC/Q-TOF-MS) using principal component analysis

An ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC/Q-TOF-MS) method coupled with a principal component analysis (PCA) was developed and applied toward identifying donkey-hide gelatin, bovine-hide gelatin, pig-hide gelatin, tortoise shell glue, and deerhorn glue. The UPLC-MS data of the trypsin digested samples were subjected to principal component analysis (PCA) in order to classify these five gelatins. Additionally, marker peptides given by the loadings plot of PCA were identified based on a comparison of recorded LC–MS data with a previously reported database of the corresponding gelatin variants. The results from this study indicate that the proposed method is reliable, and it has been successfully applied to the identification of variants of gelatins commonly used in Traditional Chinese Medicine (TCM).