催化动力学光度法测定氨三乙酸的研究

Catalytic Kinetics Photometric Method for the Determination of Trace Nitrilotriacetic Acid

研究了在硫酸介质中，微量氨三乙酸加速催化溴酸钾氧化偶氮氯膦Ⅲ褪色的新指示反应及其动力学条件。建立了氨三乙酸的催化光度测定新方法。灵敏度为１６７×１０－６ｍｏｌ／Ｌ，测定范围为１．０×１０－５～１．３５×１０－４ｍｏｌ／Ｌ，常见阴、阳离子不干扰测定。

A method for tbe determination of trace nitrilotriacetic(NTA) acid is proposed based on the trace NTA catalyzing the discoloring reaction of potassium bromide oxidizing chlorophosphonazo Ⅲ in sulfuric acid medium.The range of determination is 1.0×10-5-1.35×10-4mol/L.The reaction is proved to be zero order and apparent rate coeffcient K is 8.23×10-4 s-1,apparent energy of activation,E,is 287.78 kJ·mol-1 and half-life,t1/2,is 4.6 minutes.