稀土(Ⅲ)-DBN-偶氮胂配合物极谱吸附波的研究

STUDIES ON THE POLAROGRAPHIC ADSORPTIVE WAVE OF RARE EARTH(Ⅲ)DBNARSENAZO COMPLEX

在ｐＨ９．０的ＮＨ３ＮＨ４Ｃｌ缓冲液中，稀土（Ⅲ）与ＤＢＮ偶氮胂在－０．６８Ｖ（ｖｓ·ＳＣＥ）处产生一灵敏的极谱波，二次导数峰高与稀土浓度在３．６×１０－８～８．０×１０－７ｍｏｌ／Ｌ范围内呈良好的线性关系，检测限为２．６×１０－８ｍｏｌ／Ｌ．探讨了该极谱波的性质和电极反应机理，用本法测定了球墨铸铁中的稀土总量，结果满意．

A sensitive adsorptive wave of Rare Earth(Ⅲ) DBNarsenazo complex is obtained by using single-sweep polarography in 0.5 mol/L NH3NH4Cl buffer solution at pH9.0.The peak potential is -0.68 V(vs.SCE).The peak height is proportional to the concentration of RE(Ⅲ) over the range from 3.6×10-8 to 8.0×10-7 mol/LThe limit of detection is 2.6×10-8 mol/L.The properties of the polarographic wave and the electrode reaction mechanism are discussed in detail.The method has been applied to the determination of the trace RE(Ⅲ) in several nodular cast iron with satisfactory results.