溶出伏安法测定水中痕量钴

Determination of Trace Cobalt in wa-ter by Stripping Voltammetry

在０．０１ｍｏｌ／ＬＮＨ＿３·Ｈ＿２Ｏ－ＮＨ＿４Ｃｌ和３．０×１０￣（－５）ｍｏＬ／Ｌ安息香缩氨基硫脲体系中，钴产生一灵敏的还原波，其峰电位是－０．９４Ｖ（ｖｓ·ＳＣＥ），峰电流与钴的浓度在２．０×１０￣（－８）～１．０×１０￣（－６）ｍｏｌ／Ｌ范围内成直线关系，检测限为５．０×１０￣（－９）ｍｏｌ／Ｌ，该法测定水中痕量钴结果令人满意。

A new method for the determination oftrace cobalt is described.In 0.01mol/LNH_3·H_2O-NH_4Cl and 3.0×10￣(-5) mol/Lbenzoin thiosemicarbazone solution,Co(Ⅱ)produces a very sensitive reduction peak.The peak potential is -0. 94V (vs. SCE).The change of the peak height is linear withconcentration of cobalt in the range of 2.0×10￣(-8)～1.0×10￣(-6)mol/L. The detectionlimit is 5.0×10￣(-9)mol/L,The method hasbeen used for the determination of tracecobalt in water with satisfactory results.