Application of the selected macroporous resin for the separation and identification of flavonoids from Chinese Radix Pueraria Lobata by HPLC-Q-TOF-MS

A systematic investigation was conducted on the adsorption and desorption properties of macroporous resins including D101, ADS7, HPD600, XAD2 and HPD100 for flavonoids of Radix Pueraria Lobata. Based on the results of the adsorption capacity, desorption ratio, and physical properties of the investigated resins, ADS7 was selected for the purification of flavonoids in this study. On the basis of the correlation coefficients, the experimental results fitted the pseudo-second-order model compared to the pseudo-first model. The separation parameters of the RPL flavonoids were optimised through dynamic adsorption/desorption experiments with a column packed with ADS7. The breakthrough point was found at 30 mL of RPL flavonoids solution, while at 105 mL of 60 % ethanol, the flavonoids were completely desorbed. Furthermore, the total flavonoid content was 3.16 mg/g. HPLC-Q-TOF-MS analysis helped identify five isoflavones, including puerarin, 3′-methoxy puerarin, daidzin, 3′-hydroxy puerarin and daidzein from radix pueraria Lobata.