Electroanalytical Method of Acid Blue 120 and its Supramolecular System with Cyclodextrins

Abstract

In this paper, a simple, rapid, sensitive and accurate electroanalytical method of Acid Blue 120 (AB120) has been established by polarography. In a supporting electrolyte of 0.01 mol l−1 Na2HPO4–KH2PO4 (pH 7.04) solution, a sensitive first derivative reduction peak (ip′) of AB120 was found by Linear Sweep Voltammetry (LSV). The peak potential is −820 mV (versus SCE). The peak current (ip′) is proportional to the concentration over the range 2.0 × 10−7–5.0 × 10−5 mol l−1 (r=0.9961–0.9991) and the limit of detection (LOD) is 1.0 × 10−7 mol l−1. The recovery of AB120 varied from 95.3 to 103.0% and the relative standard deviation (RSD) was 2.2% (n=8). The method has been expected to determination of wastewater in dye industry. In addition, the supramolecular system of AB120 with cyclodextrins has been studied. It can form 1:1 inclusion complex with six CDs. The inclusion constants were calculated and the inclusion ability of different kinds of CDs was compared. Furthermore, the inclusion mechanism was also preliminarily discussed, which provided some valuable information for further application of AB120 and CDs.