Determination of Orange II and the supramolecular system of Orange II with cyclodextrins by polarography

Abstract

In this paper, a method for the determination of Orange II has been established and the supramolecular system of Orange II with cyclodextrins has been studied by polarography. A sensitive and stable linear-sweep voltammetric peak was obtained at −364 mV (vs SCE) in HAc–NaAc (pH 3.62) buffer solution. The peak current ( i p″) is proportional to the concentration over the range 1×10 −8–1×10 −3 mol l −1 ( r=0.9887–0.9986) and the limit of detection is 2.0×10 −9 mol l −1 . The mean recovery of Orange II was 99.1% and the relative standard deviation was 1.6%. Orange II can form 1:1 inclusion complex with 6 CDs. The inclusion constants were calculated by “electric current method”. Furthermore, the inclusion ability of different kinds of cyclodextrins was compared, which provided some elemental data for application of Orange II and cyclodextrins.