铋－2，3，4－三羟基－4′－磺基－偶氮苯配合物吸附波的研究

Studies on the Adsorptive Complex Wave of Bis-muth-2,3,4-Trthydroxy-4′-Sulfoazobenzene

在０．０６ｍｏｌ／Ｌ柠檬醚钠－０．００３ｍｏｌ／ＬＨＣ１（ｐＨ６．５）介质中，２，３，４－三羟基－４′－磺基－偶氮苯和铋产生灵敏的单扫描极谱导数峰，铋含量在０～６．７×１０￣（－６）ｍｏｌ／Ｌ范围内与波高成线性关系，检测限２．４×１０￣（－８）ｍｏｌ／Ｌ。用提出的方法测定了锡中的铋，并对反应机理进行了研究。

A sensitive polar ographic adsor ptive com plex waveof bismuth-2,3,4-trihydroxy-4′-sulfoazobenzene wasobtained by using single sweep polarography in 0.06mol/L sodium citrate -O.003mol/L HC1 at pH=6.5.The peakappeared at-0.32V(vs.SCE) and the peak current waslinearly related to the concentration of bismuth in the range from 4.8×10￣(-8) to 6.7×10￣(-6)mol/L.The limit ofdetection for bismuth is 2.4×10￣(-8) mol/L.According tothe experimental data,it has been proved that this wave isthe reduction of Bi(Ⅲ) in the com plex. The proposedmethed has been applied to the deter mination of bismuthin high purity tin and crude tin with satisfactory results.The mechanism of the electrode reaction has beenstudied.