Determination of Phenolic Compounds in Rhus chinensis from Different Habitats by UPLC−ECD

The mashed Rhus chinensis root was extracted by ultrasound for 50 min with 80% methanol according to the ratio of 1∶50 g/mL. The extract was centrifuged and filtered with 0.22 μm filter membrane for chromatographic separation. An ACQUIT UPLC HSS T3 column was used as the stationary phase. The mobile phase was methanol combined with 50 mmol/L citrate solution as modifier in the gradient elution mode. The detection potental was 600 mV. The samples from 11 regions were tested and analyzed by cluster analysis and principal component analysis. The findings indicated that the concentration of gallic acid, sakakin, (−)−epigallocatechin, methyl gallate, desmosol, (−)−epigallocatechin gallate, ethyl gallate, (−)−epicatechin gallate and 1,2,3,4,6−O−pentagalloylucose were linear correlated with peak areas, and the correlation coefficient were greater than 0.999. Cluster analysis and principal component analysis were carried out on the data of the samples from 11 regions, both can divid the samples into 3 categories. The established method can provide basis for improving the quality standard and strengthening the quality control of R. chinensis.