Electroanalytical method of Acid red 1 and its supramolecular system with cyclodextrins

In this paper, electroanalytical method of Acid red 1 (AR 1) has been established and the supramolecular system of AR 1 with cyclodextrins has been studied by polarography and voltammetry. In a supporting electrolyte of 0.1 mol l−1 NaCl solution, a sensitive second derivative reduction peak (ip″) of AR 1 was found by Linear Sweep Voltammetry (LSV). The potential peak is −830 mV (vs. SCE). The peak current (ip″) is proportional to the concentration over the range 5.0 × 10−7–2.0 × 10−3 mol l−1 (r = 0.9961–0.9986) and the limit of detection (LOD) is 2.0 × 10−7 mol l−1. The recovery of AR 1 varied from 99.19% to 102.9% and the relative standard deviation (RSD) was 1.8%. AR 1 can form 1:1 inclusion complex with 10 CDs. The inclusion constants were calculated by “electric current method”. Furthermore, the inclusion ability of different kind of cyclodextrins was compared, which provided some elemental data for application of AR 1 and cyclodextrins.