Adsorption and desorption properties of macroporous resins for flavonoids from the extract of Chinese wolfberry (Lycium barbarum L.)

Five different macroporous resins (AB-8, D101, X-5, NKA and ADS-7) have been evaluated for the adsorption and desorption properties of flavonoids extracted from Lycium barbarum L. The influences of phase contact time, solution pH, initial flavonoids concentration and ethanol concentration were also studied by static adsorption/desorption method. Then the kinetic adsorption data were simulated with both pseudo-first-order and pseudo-second-order equations and the latter performed better. Furthermore, the adsorption isotherm data were fitted well by both Langmuir and Freundlich models. Considering the desorption results of the macroporous resins, D101 was selected as the most suitable one. Accordingly, chromatography column packed with D101 was used to separate and purify flavonoids. At last, the content of flavonoids in the solute increased from 0.58% to 10.77%.