介绍了用二甲基偶氮磺Ⅲ分光光度法分析银催化剂中微量钡的测定条件。用稀盐酸可定量浸溶试样中微量钡,与银和其它不溶物分离。在25毫升容量瓶中加pH=2.4缓冲溶液5毫升,10~(-4)Μ二甲基偶氮磺Ⅲ10毫升,直接显色,于波长660毫微米处,进行测定。钡在0—70微克/25毫升符合比耳定律,铈及载体共存元素(Ca、Mg、Al、Fe、Ti、Si、K、Na)均无干扰。手续简便、快速、准确。 This paper introduces the determination of trace barium in silver by dimethylsulfoxide spectrophotometry. Diluted hydrochloric acid can be used to quantitatively leach a trace amount of barium in the sample and separate it from silver and other insolubles. In 25 ml volumetric flask add pH = 2.4 buffer solution 5 ml, 10 ~ (-4) Μ Dimethylsulfonamide III10 ml, direct color, measured at a wavelength of 660 nm. Barium at 0-70 μg / 25 ml conforms to Beer’s Law, with no interference with the coexisting elements of cerium and the carrier (Ca, Mg, Al, Fe, Ti, Si, K, Na). Procedures are simple, fast and accurate.