Sorption of Anthocyanins on Bentonite Clay

Patterns of the static sorption of anthocyanins on bentonite clay are determined. It is found that the approach used for static sorption is an alternative to dynamic solid phase purification on DIAPAK C18 concentrating cartridges. A way of determining the relative sorption capacity of anthocyanins characterized by different structures on bentonite clay using the Langmuir equation is proposed. It is shown that the sorption capacity falls as the structure of the glycoside radicals becomes more complicated (from pentoside to hexoside and then to di- and trisaccharides). The acylation of glycoside radicals by malonic acid has a weak effect on sorptive activity, while acylation by substituted cinnamic acids improves sorption.