偶氮类显色剂与铋离子形成多元化合物的研究过去有很多报道.为使测定方法既有高灵敏度又有好选择性,本文选用DBC-偶氮胂-铋-钪显色体系进行铋的光度分析,在0.24mol·L~(-1)盐酸介质中,试剂与铋在适量钪的存在下,形成稳定的蓝紫色络合物,最大吸收波长为635nm,表观摩尔吸光系数为9.1×10~4,铋浓度在0～0.6μg·ml~(-1)范围内符合比耳定律.该体系对大多数常见离子允许量达到数拾毫克.大大提高了测定铋的选择性. Azo reagent and bismuth ions to form a variety of compounds in the past there are many reports.To make the determination method has both high sensitivity and good selectivity, this article selected DBC-arsenazo - bismuth - scandium color system bismuth Photometric analysis showed that the reagent and bismuth in the presence of appropriate amount of scandium formed a stable blue-violet complex in 0.24 mol·L -1 HCl medium with a maximum absorption wavelength of 635 nm and an apparent molar absorptivity of 9.1 × 10 ~ 4, Beer’s law is obeyed in the range of 0 ~ 0.6μg · ml ~ (-1) for bismuth concentration.The system allows the most common ions to reach several tens of milligrams, which greatly improves the determination of bismuth selectivity.