碱土金属中微量钡的分析,目前尚无理想而简便的方法。光谱法、原子吸收法等均因稳定性、重现性较差和仪器设备复杂、昂贵等原因,不宜推广应用。近年来,以2,7-双-(邻-磺基苯偶氮)-1,8-二羟基萘-3,6-二磺酸(简称偶氮磺Ⅲ、磺基偶氮Ⅲ或SulphonazoⅢ)为显色试剂,分光光度测定钡,国外已有报导。磺基偶氮Ⅲ是变 Alkaline earth metals in the analysis of trace barium, there is no ideal and easy way. Spectroscopy, atomic absorption and so on are due to stability, poor reproducibility and equipment complexity, expensive and other reasons, should not be extended. In recent years, 2,7-bis- (o-sulfophenylazo) -1,8-dihydroxynaphthalene-3,6-disulfonic acid (abbreviated as azosulfan III, sulfoazo III or Sulphonazo III) For chromogenic reagents, barium spectrophotometry, foreign reports have been. Sulfoazo III is a variable