流动注射催化动力学电位法测定痕量钨的研究

Determination of Tungsten by Flow injection Catalytic Potentiometry

［目的］为扩大孔雀绿选择电极的应用范围，自制了孔雀绿离子选择性流通电极；为提高痕量鹤的测定速 度及测定的选择性，进行了痕量钨流动注射测定方法的实验研究。〔方法］以饱和甘汞电极为参比电极，孔雀绿离子 选择性流通电极为指示电极，用组装的流动注射电位分析仪测定了钢样中的痕量钨。［结果］孔雀绿离子选择性流通 电极性能良好，在２０±０．０２℃，该电极的Ｎｅｒｎｓｔ响应系数为５７．５ｍｖ。在选定的实验条件下，标准曲线的回归方程为 Ｈ＝９３，６３－０．８３Ｃｗ，相关系数ｒ＝０．９９７，标准曲线的线性范围为５．０μｇ．ｍｌ^(－１)～５０．０μｇ．ｍｌ^(－１)平行试验的相对标准偏差 为：ＲＳＤ＝２．９０％（ｎ＝６）。回收试验的回收率的．６％～１０１．１％（ｎ＝５）。［结论］测定了７０－１１中低合金钢中钨含 量，测量值与标准值十分接近，测量的标准偏差为Ｓ＝０．０１７５％，该法具有自动化程度高，分析速度快，干扰物质少等 特点，适合于大批含钨样品的测定。

Objective ]: A new flow injection catalytic potentiometric method for determining tungsten is proposed. It is based on the tungsten (N ) catalysis to the reaction between malachite green and TiCl3,. [Methods ]: The malachite green ion selective flow electrode was used to follow the variation of the concentration of malachite green to determine tungsten. [Results ]: The regression equation of the standard curve was H= 93. 63-0. 83Cw, r= 0. 997 The linear range of the method is 5. 0ug/ml^50. oug/ml for W (Ⅵ ). The relative standard deviation of parallel experiment was 2. 90%, the recover ratio was 99. 6% ~101. 1 %. [Conclusion ]: The method shows high automation and selectivity. The content of tungsten in standard steel sample is determined. The result obtained is very close to the specified value of standard sample.