微分电位溶出法测定空气和水中微量铅

Determination of the trace lead in water or air by the method for differential electric potential dissolution

本文研究了在镀汞、银汞电极上铅的溶出行为 ,当 p H为 3.0～ 6 .0时 ,在乙酸钠——乙酸溶液中 ,铅的溶出电位为 - 0 .44 5 V,具有良好的溶出峰形。并且建立了用微分电位溶出银汞电极分析空气和水中微量铅的方法 ,该法克服了玻碳电极法反复镀汞的麻烦。本方法对四份水样进行回收率试验 ,其回收率均在 90 %以上 ,变异系数小于 10 %。

The dissolution action,which is on the silve mercury electrode while plating mercury,has been studied in this thesis.When pH is between 3.0 and 6.0 in the CH 3COONa-CH 3COOH solution.The dissolution potential for the lead is -0.445 voltage and a good shape of the dissolution peak curve can be formed.The method,which can analyse the trace lead in water or air with silver mercury electrode by differential potential,has been established.The method gets rid of the trouble of plating mercury over and over again with glass carbon electrode.The experiment for the rate of recovery has been conducted in the four water samples.Its rate of recovery is all over 90% and the variation coefficient is less than 10%.So the method has the higher degree of preciseness and better accuracy.