碳糊电极吸附溶出伏安法测定游离钙  

Determination of Free Calcium at a Carbon Paste Electrode Adsorptive Stripping Voltammetric Method

作　　者：刘宁[1] 宋俊峰[1] 

机构地区：[1]西北大学分析科学研究所,西安710069

出　　处：《分析化学》2005年第9期1261-1264,共4页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(No.20475043)资助项目

摘　　要：基于Ca(Ⅱ)-茜素红S (ARS)络合物在碳糊电极上的还原波,建立了吸附溶出伏安测定游离钙的新方法.在1.5×10-2 mol/L KOH-2.0×10-5 mol/L ARS介质中, Ca(Ⅱ)-ARS络合物在碳糊电极上于-0.89 V处产生一吸附还原波.当富集电位为.0.1 V,富集时间90 s,扫描速度为100 mV/s时,该络合物单扫描阴极溶出峰的二阶导数峰电流与游离钙离子浓度在3.0×10-8～2.0×10-6 mol/L范围内呈线性关系;检出限为9.4×10-9 mol/L.在0.2 mol/L HCl中清洗2 min,该电极重现性良好.该方法可用于血清、牛奶和自来水中游离钙的测定.A cathodic adsorptive stripping voltammetric method for the determination of free calcium is described, based on the reduction of calcium-alizarin red S （ARS） complex at a carbon paste electrode （CPE）. In 1.5 × 10^-2 mol/L potassium hydroxide solution containing 2.0 × 10^-5 mol/L ARS, the complex adsorbed on the CPE surface yields a reduction wave with peak potential -0.89 V. When accumulation potential is -0. 1 V, accumulation time is 90 s and scan rate is 100 mV/s, the second-order derivative cathodic stripping peak current of the adsorbed complex is proportional to free calcium concentration in the range of 3.0 × 10^-8- 2.0 × 10^-6 mol/L by single sweep voltammetry. The detection limit is 9.4 × 10^-9 mol/L. With rinsing the CPE in 0.2 mol/L HCl solution for 2 min, it shows good reproducibility. The proposed method has been applied to the rapid determination of free calcium in serum, milk and tap water.

关 键 词：钙 碳糊电极 吸附溶出伏安法 单扫描伏安法 游离钙 测定 富集时间 钙离子浓度 络合物 扫描速度 

分 类 号：O657.1[理学—分析化学]