在研究稀土元素光度分析法时,曾经发现,某些稀土元素单独存在时,并不与试剂产生有色反应。但当它们与另一些稀土元素共存时,则可以参与反应。例如在PH2—3时,偶氮硝羧只与铈组元素产生有色反应,但当有钇组元素共存时,钇组元素显著地参与反应而造成相当严重的干扰。同样,溴邻苯三酚红(BPR)在PH<5.0时,不与任何单一稀土元素反应。但是,当轻重稀土元素共存时,却可产生 In the study of rare earth elemental spectrophotometry, we have found that some rare earth elements exist alone, does not produce a color reaction with the reagent. However, when they co-exist with other rare earth elements, they can participate in the reaction. For example, at PH2-3, azocarboxylaze produces only a color reaction with the cerium group element, but when the group of yttrium group elements coexist, the group of yttrium group elements participate significantly in the reaction and cause quite serious disturbances. Similarly, bromopyrogallol red (BPR) does not react with any single rare earth element at pH <5.0. However, when light and heavy rare earth elements coexist, they can be produced