新的极谱催化体系连续测定岩溶地下水中钨和钼

Determination of Molybdenum,Tungsten by Highly Sensitive Catalytic Polarography and Its Application in Karst Groundwater Detection

钨、钼-二苯基乙醇酸-2,2′-联吡啶-钛铁试剂连测体系还未见报道。本文提出了在0.05mol/L的硫酸中,钨与二苯基乙醇酸,2,2′-联吡啶的络合物在-0.79V(vs.SEC)产生一个极其灵敏的极谱催化波,测定完钨后,加入少量钛铁试剂测定钼。钼于-0.20V(vis.SEC)处产生极灵敏的阴极化导数波,波形尖锐对称,易于测量。采用此种连测体系,钨钼的灵敏度都可满足要求,钨和钼的检出限分别为0.004、0.01μg/L。确定最佳条件和拟定了不经分离富集直接测定岩溶地下水中痕量钨和钼的方法。此外还对极谱波性质进行了探讨,讨论了阴、阳离子表面活性物质对极谱催化波的作用机理。

In 0.05mol/L of sulfuric acid,tungsten complex with diphenyl ethanol acid and 2,2＇-bipyridine,that have an extremely sensitive and extremely negative catalytic wave spectrum at -0.79V（vis.SEC）.After determination of tungsten,adding a small amount of tiron,molybdenum complex at -0.20V（vis.SEC） form a very sensitive and derivative wave,the wave form is symmetry sharp,easy to be measured.With this measurement system,the sensitivity of W-Mo can meet the requirements.The detection limits of tungsten and molybdenum are 0.004 and 0.01μg/L,respectively.The optimum conditions and detecting trace W-Mo in karst groundwater directly without separation and enrichment were developed.In addition,the nature of the polarographic wave and the cationic surfactant＇s influence on the catalytic wave mechanism were discussed.