铍与DBC-偶氮氯膦的配合吸附波的研究及矿样中痕量铍的测定

Polarographic Complex Adsorption Wave of Beryllium with DBC-Chlorophosphonazo and Determination of Beryllium in Rocks

在pH3.5的Na_3C_6H_5O_7-HCl介质中,DBC-偶氮氯膦(二溴一氯-偶氮氯膦)在示波极谱上于-1.25V(vs·SCE)处出现一试剂波,加入铍后,于-1.33V处出现一稳定的还原波,该波在2.2×10^(-8)～4.0×10^(-7)mol/L内与铍离子浓度成正比,检出限为1.1×10^(-8)mol/L。本法直接用于矿石中痕量铍的测定,结果较好。

In a solution of Na_3C_6H_5O_7-HCl with pH 3.5, DBCChlorophosphonazo gives a reduction peak at-1.25V (vs. SCE)on a single-sweep polarograph. When beryllium is added, a new and stable reduction peak at-1.33V appears. The peak height is proportional to the concentration of beryllium in the range of 2.2×10^(-8)～4.0×10^(-7)mol/L. The detection limit is 1.1×10^(-8)mol/L. It can be used to determine trace beryllium in rocks and gives good results. The polarographic wave is due to the adsorption of the complex of Be with DBC-Chlorophosphonazo, and the ratio of Be to DBC-Chlorophosphonazo is 1: 2.