1. Qualitative and Quantitative Analysis of Ejiao-Related Animal Gelatins through Peptide Markers Using LC-QTOF-MS/MS and Scheduled Multiple Reaction Monitoring (MRM) by LC-QQQ-MS/MS
- Author
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Wen-Jie Wu, Li-Feng Li, Hau-Yee Fung, Hui-Yuan Cheng, Hau-Yee Kong, Tin-Long Wong, Quan-Wei Zhang, Man Liu, Wan-Rong Bao, Chu-Ying Huo, Shangwei Guo, Haibin Liu, Xiangshan Zhou, Deng-Feng Gao, and Quan-Bin Han
- Subjects
Swine ,Organic Chemistry ,Pharmaceutical Science ,Equidae ,Analytical Chemistry ,authentication ,Ejiao ,gelatin ,peptide marker ,database-independent strategy ,de novo sequencing ,Tandem Mass Spectrometry ,Chemistry (miscellaneous) ,Drug Discovery ,Animals ,Gelatin ,Molecular Medicine ,Cattle ,Horses ,Physical and Theoretical Chemistry ,Peptides ,Biomarkers - Abstract
Donkey-hide gelatin, also called Ejiao (colla corii asini), is commonly used as a food health supplement and valuable Chinese medicine. Its growing popular demand and short supply make it a target for fraud, and many other animal gelatins can be found as adulterants. Authentication remains a quality concern. Peptide markers were developed by searching the protein database. However, donkeys and horses share the same database, and there is no specific marker for donkeys. Here, solutions are sought following a database-independent strategy. The peptide profiles of authentic samples of different animal gelatins were compared using LC-QTOF-MS/MS. Fourteen specific markers, including four donkey-specific, one horse-specific, three cattle-specific, and six pig-specific peptides, were successfully found. As these donkey-specific peptides are not included in the current proteomics database, their sequences were determined by de novo sequencing. A quantitative LC-QQQ multiple reaction monitoring (MRM) method was further developed to achieve highly sensitive and selective analysis. The specificity and applicability of these markers were confirmed by testing multiple authentic samples and 110 batches of commercial Ejiao products, 57 of which were found to be unqualified. These results suggest that these markers are specific and accurate for authentication purposes.
- Published
- 2022