吸附伏安法测定纯铝中痕量钛

Determination of Traces Titanium in Pure Aluminum by Adsorptive-Stripping Voltammetry

在含有16％乙醇的盐酸溶液中，钛（IV）与钽试剂（BPHA）配合物在-0．3V（vs·SCE）或开路情况下吸附于玻璃碳电极表面，在-0．3— -0．8V范围内以250mV·S^-1扫描速度进行溶出，溶出峰电位为-0．57V，钛（IV）浓度在1-35ng·mL^-1（-0．3V下富集2min）；D0．06-2ng·mL^-1（开路富集4min）范围内与峰高呈良好的线性关系，相关系数分别为0．989和0．998，体系选择性好，灵敏度高，操作简单，用于纯铝中痕量钛的测定，重现性好，结果准确。

It was found that in an＇acidic solution of 0.12mol·L^-1HCI containing 16% （by Volume） of alcohol and 2×10^-4mol·L^-1 of benzoylphenylhydroxy amine （BPHA）, titanium（IV）forms with BPHA a stable chelate which is absorbed and preconcentrated on the stationary mercury plated glassy carbon electrode under open circuit condition or at -0.3V （vs .SCE）.A sensitive stripping peak is observed at -0.57V （vs-SCE） at a scanning rate of 250 mV·s^-1 in the potential range between -0.3V to -0.8V. When the time of preconcentration was set at 4 min （under open circuit condition） or at 2rain （at -0.3V）,linear relationships between peak height and concentration of titanium（IV） in the ranges of 0.06-2ng·mL^-1（and 1-35ng·mL^-1）were obtained, with Values of correlation coefficient of 0.998 and 0.989,and with their detection limits of 0.0076ng·mL^-1 and 0.153ng·mL^-1,respectively. The method has been satisfactorily applied to the determination of traces of Ti（IV） in pure aluminum samples giving RSD＇s of 1.2% to 1.3%.