偶氮胂Ⅲ是测定稀土元素、钇、钪的较灵敏的试剂之一。但是稀土元素存在时测定钪的选择性,以及反之,钪存在时测定稀土元素的选择性,在络合物形成的最佳pH条件下,用分光光度测定都是不够满意的。在分析这些样品时,稀土元素和钪必须预先分离。 Arsenazo Ⅲ is one of the more sensitive reagents for the determination of rare earth elements, yttrium and scandium. However, the determination of scandium selectivity in the presence of rare earth elements and, conversely, the determination of rare earth element selectivity in the presence of scandium are unsatisfactory with spectrophotometric determination at the optimum pH for complex formation. In analyzing these samples, the rare earth elements and scandium must be separated beforehand.