Electrochemical studies of determination of Basic Brown G and its interaction with cyclodextrins

In this paper, a simple, rapid, sensitive and accurate electroanalytical method of Basic Brown G (BBG) has been established by polarography and voltammetry. In ammonia–ammonium chloride (pH 9.1), a sensitive second derivative reduction peak (ip″) of BBG was found by Linear Sweep Voltammetry (LSV). The peak potential (Ep) is about −0.67 V (versus SCE). The peak current (ip″) is proportional to the concentration of BBG over the range 3.0 × 10−8–1.0 × 10−4 mol L−1 (r = 0.9935–0.9987) and the limit of detection (LOD) is 9.0 × 10−9 mol L−1. The recovery of BBG varied from 95.3 to 102% and the relative standard deviation (RSD) was 2.4% (n = 10). The method has been expected to achieve the determination of the concentration of remnants of dyes of wastewater in dye industry. In addition, the supramolecular system of BBG with cyclodextrins (CDs) has been studied. BBG can form 1:2 (BBG:CD) inclusion complex with α-CD and HP-α-CD, respectively, and 1:1 inclusion complex with other six CDs. The inclusion constants were calculated and the inclusion ability of different kinds of CDs was compared, furthermore, the inclusion mechanism is also preliminarily discussed, which provided some valuable information for further application of BBG and CDs.