Linear sweep voltammetric studies on the complex of alizarin red s with aloe polysaccharide and determination of aloe polysaccharide

A new electrochemical method for the determination of aloe polysaccharide based on its interaction with alizarin red s was established on a pretreated glassy carbon electrode in pH 3.5 Britton–Robinson buffer solution by linear sweep voltammetry in this work. The decrease of the second order derivative linear sweep voltammetric reductive peak current of alizarin red s is in proportion to aloe polysaccharide concentration due to the formation of a complex between them in the range from 0.032 to 0.448 μmol L−1, and the detection limit is 0.0051 μmol L−1 (3σ). The binding ratio and the binding constant of the complex were calculated as 1:1 and 2.75 × 104, respectively. Different kinds of complex samples of aloe polysaccharide were detected satisfactorily by this method.