分光光度法中过量显色剂隐色的研究——Ⅳ.铍试剂Ⅲ三阶导数光度法测定岩石中痕量铍

Study on Colour Hiding of Excess Reagents in Spectrophotometry ——Ⅳ. Determination of Trace Beryllium in Rock by Third-Derivative Spectrophotometry Using Beryllon Ⅲ

本文在EDTA和甘露醇存在下以Sn为共沉淀剂,沉淀富集痕量Be,分离大量Fe、Al和Ti等干扰元素。痕量Be测的定采用草酸存在下铍试剂Ⅲ(隐色)三阶导数光度法。显色体系灵敏度高,检出限为1ng Be/ml,且允许共存离子量较大。方法经GSD系列标样和硅酸盐岩石试样中痕量Be测定验证,其结果与推荐值(或原结果)相符。方法精密度好,对于含Be0.0091％硅酸盐岩石测定其RSD(n=6)为1.66％。

Trace amounts of beryllium is preconcentrated by coprecipitation with Sn(OH)4 and separated from major iron, aluminium and titanium etc. at ca. pH 9 in the presence of EDTA and mannitol. Beryllium can be determined with beryllon Ⅲ by third-derivative spectrophotometry after hiding excess beryllon Ⅲ.The method is sensitive(DL: lng Be/ml). Trace amounts of beryllium in rocks is determined with satisfactory results and the relative standard deviation for a sample containing 0.0091% of beryllium is 1.66%(n = 6).