2．5次微分溶出伏安法测定茶叶中痕量锌

Determination of Trace Amounts ofZinc in Tea by2.5th Differential Stripping Voltammetry

本文报告了测定痕量锌的一种新方法。在０．０１ｍｏｌ／ＬＨＡｃ－０．０１ｍｏｌ／ＬＮａＡｃ溶液中，锌和乙醛酸缩氨基硫脲形成的配合物产生一个很灵敏的还原峰，峰电位是－０．８２Ｖ（ｖｓ·ＳＣＥ），锌的浓度在２．０×１０￣（－８）～８．０×１０￣（－７）ｍｏｌ／Ｌ范围内与峰高呈直线关系，检测限是６．０×１０￣（－９）ｍｏｌ／Ｌ，该方法用于测定茶叶中痕量锌，结果令人满意。

new method for thedetermination oftrace amounts ofzic. is described.In0.01mol/LHAC-0.01mol/LNaAC solution,Zn-glyoxalic acid thiosemicarbazone(GATSC)complex produces a very sensitive reduc-tion peak. The peak height is linear withcoricentration of zinc in the range of 2.0×10￣(-8)～8.0×10￣(-7)mol/L.The detection limitis 8.6 ×10￣(-9)mol/L. The method has beenused for the determination of trace amountsof zinc in tea with satisfactory results.