酸性铬蓝K的电化学行为及其与β-环糊精超分子体系的研究

Studies on the Electrochemical Behavior of Acid Chrome Blue K and the Supermolecular System of Acid Chrome Blue K with β-Cyclodextrin by Polarography

本文研究了酸性铬蓝K的极谱分析法。结果表明,在pH=10.0的NH3-NH4Cl底液中,酸性铬蓝K产生一峰形好、稳定、灵敏的还原峰,其峰电位约为-0.56V(vsSCE),峰电流及二阶导数极谱峰高随酸性铬蓝K浓度变化的线性范围在8.0×10-8mol/L～3.0×10-5mol/L(r=0.996～0.9999),检测限为2.0×10-8mol/L,精密度RSD=0.646%(n=10),标准回收率在99.4%～103.4%之间,平均回收率为100.97%,可望用于酸性铬蓝K的定量分析。此外,本文还研究了β-环糊精对酸性铬蓝K电化学行为的影响和超分子体系;利用等摩尔系列法测定了酸性铬蓝K与β-环糊精形成的包结物的包结比为1∶1,用电流法测定其包结常数为33.4L/moL;并且测定了酸性铬蓝K的还原峰电流和扫描速度、客体浓度及pH值的关系,峰电位与pH值的关系,初步讨论电极反应机理。

The polarographic method was employed to investigate the supramolecular system of acid chrome blue K （ ACB K） and with β-cyclodextrin. It was shown that the reducing peak formed by ACB K in NH3-NH4Cl solution at pH = 10. 0 was well-defined,stable and sensitive with a peak potential near -0. 56V （vs. SCE）. Variations of ACB K concentrations with peak currents and the peak height of second derivative polaregraph fell in the linear regions of 8.0 × 10^8 mol/L - 3.0 × 10 ^-5 mol/L （ r = 0. 996 - 0. 9999）, The detection limit was 2.0 × 10^-8 mol/L,RSD was 0. 646% （n = 10） and the standard recovery was 99.4 % - 103.4% ,The polaregraphic method established is capable of application in the quantitative analyses of ACB K. In addition, the effects of β-cyclodextrin on the electrochemical behavior of ACB K were also studied. The inclusion rate was calculated by equimolar series method, which is 1：1. The inclusion constant was calculated by electric current method for the determination of ACB K and β-cyclodextrin, which is 33.4 L/moL. The possible mechanism of electrode reaction was also studied.