偶氮氯磷Ⅲ吸光光度法测定工业碳酸锂中微量钙

ABSORPTIOPHOTOMETRIC MICRO-ANALYSIS OF CALCIUM IN INDUSTRIAL LITHIUM CARBONATE WITH CHLOROPHOSPHORAZO Ⅲ AS A CHROMOGENIC REAGENT

研究了工业碳酸锂中微量钙的测定方法。采用偶氮氯磷Ⅲ［２，７－双－（４－氯─２－膦苯偶氮）－１，８－二羟基苯酚－３，６－二磺酸］作显色剂，在ｐＨ＝２．３─２．７条件下，钙离子与偶氮氯磷Ⅲ生成水溶性蓝色配合物，最适测定波长为λ＝６５８ｎｍ，摩尔吸光系数ε＝３．１×１０４，有色溶液稳定６小时，钙含量在０─１μｇ／ｍＬ范围内服从比耳定律。该显色剂用于工业碳酸锂中微量钙的测定与原子吸收法相比较，结果一致。

A method has been studied for the determination of microamounts of calcium in industrial lithium carbonate, In the pH 2.3-2.7 region,chlorophosphonazo Ⅲ as a color reagent and calcium ion give a watersolubility blue co-ordination compound. The Most applicable wave length λ for determination is 658nm, and the Molar absorptivity ε is 3.1×10 4,The colored solution can be steadied for 6 hours, Beer's law is obeyed when Ca2+ concentration is in the range of 0 to 1 μg/mL, It's the same result that the method is compared with AAS.