Identification and quality evaluation of Chinese rice wine using UPLC-PDA-QTOF/MS with dual-column separation

Chinese rice wine (CRW) is a well-known drink and functional food that is used in traditional Chinese medicine. However, there is still a lack of quality control and evaluation methods for CRWs.

The study aimed to establish a new method that can serve both as quality control and evaluation method and, as well as an identification method for CRWs.

Compound identification in different CRW samples and determination of uracil, xanthine, uridine, adenine, guanosine, 5-hydroxymethylfurfural, and adenosine contents from 29 CRW samples from 14 brands were performed using UPLC-PDA/TOF-MS. The dual-column chromatographic separation of CRW was performed using CORTECS T3 coupled to HSS T3. The optimal mobile phase consisted of water with 0.1% formic acid, 40 mM ammonium acetate, and methanol: acetonitrile (2:1). Furthermore, to compare the UPLC fingerprints between CRWs of different brands, a similarity analysis was performed to classify the CRW samples. Finally, network pharmacology and in vitro efficacy and toxicity tests were used to investigate the biological function of the seven components and CRWs.

A total of 55 compounds were unambiguously or tentatively identified. Among them, nucleoside, pyrimidines and purines were reported in CRW for the first time. The seven components were successfully determined, and their contents showed large variations among different brands of CRW, which was consistent with the results of the chromatographic fingerprint similarities. The results of in vitro efficacy and toxicity tests indicated that CRWs and seven components had obvious protective effect on H9c2 cell injury induced by the H₂O₂ model. Network pharmacology analysis showed that these seven compounds might be the main active components of CRW that promote blood circulation and ventilation.

This study revealed that dual-column chromatographic separation is an effective method for quantitative and chromatographic fingerprint analyzes of complex samples, and seven compounds can be used for the quality evaluation and control of CRWs.