桑色素-镍络合体系的单扫描极谱法研究

Study on the Single-sweep Polarography of Ni(Ⅱ)-Morin

采用单扫描极谱法研究了金属镍与桑色素形成络合物的条件及反应机理.在pH = 7.00的B-R缓冲体系中,桑色素与镍络合并在-1.13 V(vs,SCE)处产生1个灵敏的还原波,其峰高与桑色素浓度在8.00×10-6～1.90×10-5mol·L-1范围内呈现良好的线性关系,r=0.996 7,检出限为6.00×10-6 mol·L-1.测得镍与桑色素的配位比为1:2,表观稳定常数为 2.22×1011 .

In this paper the reaction mechanism and conditions of Ni（ Ⅱ ） and Morin to combine a complex is studied by single-sweep polarography. In B-R buffer solution （pH = 7.00）, a sensitive absorptive complex wave of Ni（ Ⅱ ）-Morin was obtained by single-sweep polarography. The peak potential （Ep） is about-1.13V（vs,SCE） . The change of peak height with the concentration of Morin is linear in the range from 8.00 10^-6 to 1.90 10^-5 mol L^-1. r=0. 9967. The composition of the complex was detected as Ni（ Ⅱ ） ： Morin= 1：2. The stability constant was determined as K= 2.22 × 10^11.