铂-丁二酮肟络合吸附波测定微量铂

Polarographic determination of trace platinum using platinum-dimethyglyoxime complex adsorption wave

铂和丁二酮肟在pH 4.1的HAc^NaAc支持电解质中,形成具有电活性络合物。在单扫示波极谱-0.88 V(vs.SCE)左右出现良好还原波。此波峰高与铂的浓度在1.0×10-8~4.0×10-6mol/L范围内呈线性关系。检出限为2.6×10-9mol/L。并成功的用于贵金属合成样及合金样品中铂量的测定。

In the solution of HAc-NaAc （pH 4.10）, the polarographic adsorption wave of Pt（Ⅳ）-dimethylglyoxime （DMG） complex has been investigated in detail. The peak potential is at -0.88 V （vs. SCE） on oscillopolarograph. The concentration of platinum is proportional to the peak height of the second order derivative wave in the range of 1. 0 × 10^-8 -4.0 × 10^-6 mol/L. The detection limit is down to 2.6 × 10^-9 mol/L. The method has been successfully applied to the mensuration of platinum in alloy samples. The results are in agreement with atomic adsorption spectrometric method and RSD is ≤0.16% （ n = 3）. A sensitive and direct polarographic method for the determination of trace amount of Pt（ Ⅳ ） has been developed.