用UV谱考察了几种常见金属离子(Ca^2+、Mg^2+、K^+、Na^+)与溴酚蓝形成的乙醇一水溶液的吸收光谱,并用最小二乘法拟合了它们的特征吸收峰强度对应不同金属离子浓度的变化曲线。结果表明,该体系在437nm和597nm处存在2个直接影响显色的特征吸收峰,并且在597m处的吸收峰强度与金属离子对溴酚蓝的助色能力正相关,因此可利用该特征峰来筛选优化类似体系的显色材料。
The ultraviolet-visible (UV) absorption spectrums of the alcohol-aqueous solutions, which com- prised of bromophenol-blue (BPB) and several metal ions (Ca^2+、Mg^2+、K^+、Na^+), were studied. The characteristic absorption peak strengths as a function of metal cationsr concentrations were fitted through least square method. The results show that there are two characteristic UV absorption peaks at 437 nm and 597 nm directly related with chromic transition process. The 597 nm absorption peak, which has positive correlation with color-development capabilities of metal ions to BPB, can be applied to the optimization o{ similar chromic materials.