摘要
本文基于Ｓ２－能与Ａｇ＋生成难溶化合物的特征，在银微盘电极上研究了Ｓ２－的示差脉冲溶出伏安法（ＤＰＳＶ）．该法不要镀汞，不需搅拌，在较稀的支持电解质溶液中就能实施．ＤＰＳＶ于０．１０ｍｏｌ／ＬＨＡｃ－ＮａＡｃ及０．０１ｍｏｌ／ＬＥＤＴＡ介质中，能检出１．０×１０－８ｍｏｌ／Ｌ的Ｓ２－，Ｓ２－的浓度为１．０×１０－７～９．０×１０－７ｍｏｌ／Ｌ及１．０×１０－６～８．０×１０－６ｍｏｌ／Ｌ范围与峰电流有良好的线性关系．该法用于湖水中Ｓ２－的测定，结果令人满意，加标回收率为９５．７％，与标准分析法比较相对误差为－６．２％．
S 2- may combine with Ag + to form insoluble Ag 2S. On this absis the cathodic stripping volammetry of S 2- at silver microdisk electride was investigated in this paper. DPSV for the determintion of S 2- was carried out in very dilute media no stirring. The opfimal experimental condition were discussed. A good proportionality between the peak current of DPSV and sulphion concentration in the range of 1.0×10 -7 ～8.0×10 -6 mol/L has been observed. The detection limit is about 1.0×10 -8 mol/L S 2- . This method was successfully applied to the direct determination of trace sulphur in lake water. This result is in agreement with that of photometric method.
关键词
银微盘电极
溶出伏安法
硫
测定
湖泊
水
silver microdisk eldctrode\ differdnfial pulse stripping voltammetry\ trace sulphur
