碘化钾一乙基紫分光光度法测定微量铋

SPECTROPHOTOMETRIC DETERMINATION OF BISMUTH AS ION-ASSOCIATION COMPLEX WITH POTASSIUM IODIDE AND ETHYL VIOLET

研究了在弱酸介质中，铋（Ⅲ）一碘化钾一乙基紫体系的离子缔合显色反应。提出直接在水溶液中光度测定微量铋的高灵敏度方法。表现在尔吸光系数ε＝１．４２×１０￣５Ｌ，ｍｏｌ￣（－１）·ｃｍ￣（－１）．还对干扰情况进行了详细试验。将此法应用于钢铁中铋的分析，效果良好。

Based on the formation of ion- association of bismuth(Ⅲ)with potassium iodlue and ethyl violet in a weak acid medium and in the presence of arabic gum,a highly sensitive spectrophotometric method has been developed for the determination of bismuth,The absorption maximum of the water soluble ion- association complex is at 540 nm,and its apparent molar absorptivity is1. 42 ×10￣5 L·mol￣(-1)·cm￣(-1). Beer’s law is obeyed over the range 0～15μg/2 5 ml of bismuth. the interference of diverse ions has been studied. The method can be used direct determination of bismuth in iron and steel with satisfactory results.