痕量铋的半二甲酚橙分光光度系的研究及其在纯钨分析中的应用

Study on the spectrophotometric system of Bi-semixylenol orange and its application to the analysis of tungsten metal

层析纯半二甲酚橙与Bi的分光光度系。反应产物为1:2螯合物,其摩尔吸光率为4.2×10~4l·mol^(-1)·cm^(-1)。在10ml 中含 Bi4～8μg 或25ml 中含 Bi8～20μg 的范围内 Bi 量与吸光度的线性关系成立。回归系数为0.99997。用此法可测定金属钨中的痕量铋,但须先用 Mg-HEDTA 作配位缓冲剂、DDTC 作萃取剂进行富集。

Studied in this paper is the spectrophotome-tric system of Bi-semixylenol orange of chroma-tographic purity.The reaction product has beenfound to be a 1:2 chelate with a molar absorpti-vity ■=4.2×10~4l·mol^(-1)·cm^(-1) A linear relationship between the amount of Bi and absorbance isestablished over the range of 4～8 μg of Bi in 10ml or 8～20μg in 25 ml with a regression coeffici-ent of 0.99997.Trace amount of Bi in tungstenmetal has been successfully determined with theproposed method following a preconcentrationstep'with DDTC as the extractant and Mg-HEDTAas ligand buffer