UPLC fingerprint combined with principal component analysis for quality control of Rheum palmatum

Rheum palmatum is one of the three genuine Rhubarb in Chinese Pharmacopeia and widely used in clinic as a purgative medicine. To effective quality evaluation of R. palmatum, a UPLC fingerprint method was established. Twenty batches of R. palmatum were analyzed, together with R. tanguticum, R. officinale and Polygonum cuspidatum. Fourteen common peaks were detected and four of them were identified by comparing with reference substances. The similarity degrees of 20 batches of R. palmatum were between 0.94 and 1.00. Rhubarbs from different original plants, along with confusable variety P. cuspidatum, can be readily distinguished through their fingerprint profiles. Principal component analysis was performed by using SIMCA 14.1 to compare three different rhubarbs. The results showed that three species of rhubarb can be distinguished well, indicating their discrepancies in chemical components. The established UPLC fingerprint is stable and reliable, which can be used for quality evaluation of R. palmatum, as well as comparison of rhubarbs from different original plants and its confusable variety. This study provides theoretical guidance for comprehensively improving the quality control level of R. palmatum.