Adsorption Property of Supported Ionic Liquids for Flavonoids
The effects of adsorption time,solid-liquid ratio,sample concentration,flow rate on the adsorption properties of supported ionic liquids(the N-methylimidazolium functionalized silica,SilprMin) for flavonoids were investigated.The results indicated that the adsorption equilibrium for tested compounds,genistein,luteolin and quercetin,was achieved within 30 min,the adsorption efficiencies of these three compounds were improved with the increase of solid-liquid ratio,and decreased with the increase of their concentrations.Moreover,the adsorption isotherm data of the three tested compounds were in good concordance with the Langmuir model.The saturated adsorption capacity of SilprMim for genistein,luteolin and quercetin was 47.7,52.5 and 63.2 mg/g,respectively.Adsorption efficiency of SilprMim could reach more than 90% at a sample flow rate of 0.5~1.5 mL/min.Using methanol as eluent,the saturated desorption efficiencies of genistein,luteolin and quercetin were 86.1%,83.3% and 84.6%,respectively.The elution order of the three tested flavonoids was genistein,luteolin and quercetin.SilprMim had strong adsorption and separation capacity for three tested flavonoids,which was hopeful to be applied in separation and purification of naturally occurring flavonoids.