钙-茜素红S的示波行为及应用

Oscillographic Behavior of Calcium-Alizarin Red S and Its Application

在0.1 mol/L KOH底液中,研究了Ca2+与ARS形成络合物的示波行为,并根据其在dE/dt-E曲线阴极支-0.83V产生一灵敏切口的示波特性建立了测定葡萄糖酸钙口服液及片剂中钙含量的二次微分简易示波伏安法。当Ca2+浓度在4.0×10-7～1.9×10-5mol/L时.二次微分简易示波伏安图上Ca-ARS的峰高与Ca2+浓度呈线性关系:相关系数为0.9973;检出限为3×10-7mol/L。对2.0×10-6mol/L Ca2+6次测定的RSD为1.2％.

The oscillographic behavior of calcium-alizarin red S (Ca-ARS) on the mercury electrode has been investigated in 0.1 mol/L KOH solution. ARS can cause a sharp,incision on cathodic branch of dE/dt-E curve in 0.1 mol/L KOH, but the incision decreased gradually and a new incision of Ca-ARS coordination compound appeared when Ca2+ was added to the solution. Based on these oscillographic characteristics, second order differential simple oscillographic voltammetry was used for the determination of calcium content in the gluconate calcium oral liquid and its tablet. The linear range of Ca2+ is 4.0 x 10(-7) similar to1.9 x 10(-5) mol/L, and detection limit is x 10(-7) mol/L. The, RSD. for 2.0 x 10(-6) mol/L Ca2+ is 1.2% (n = 6) Compared with polarography and other methods, oscillographic voltammetry with second order differential is. a convenient method due to its cheap equipment and rapid measurement and no need for O-2-eliminated.