等吸收波长分光光度──直线作图法测定混合三组分体系

DETERMINATION OF THREE-COMPONENT MIXTURE BY EQUAL-ABSORPTIVE WAVELENGTH SPECTROPHOTOMETRY AND LINEAR PLOT METHOD

本文提出用于三组分干扰体系的等吸收分光光度定量分析方法。首先选取第三种组分（即干扰组分）的若干等吸收波长对，读取混合物溶液在这些波长对处的吸光度值，代入本文所推导的线性方程，采用线性作图或回归方法即可同时获得两个待测组分的浓度，然后利用吸光度的加和性可得到第三种组分（即干扰组分）的浓度，方法较为简单。利用本法对钨、钼、锗──苯基荧光酮──ＣＴＭＡＢ显色体系中的钨、钼、锗三种成份进行了定量分析，获得了较满意的结果。

A method of equal absorptive spectrophotometry was applied to the quantitative anal-ysis of three-component mixture;with overlapping spectra and serious interference. Thismethod was carried out as following: Several pairs of wavelengths with equal-absorbance of theinterfering component were selected and the absorbances of the mixture at these selected wave-lengths were recorded. Then the data were treated by using the linear equation proposed in thispaper and a linear plot was obtained. The concentrations of the first two components were thusobtained from the slop and the intercept of this linear line respectively. Basing on the property ofadditivity of absorbances.the concentration of the third component(interfering)can then be ob-tained. The method offers advantage of simplicity and it has been applied to the analysis of mix-tures of tungsten,molybdenum and germanium using the colour reaction with phenylfluorone(PF)and cetyltrimethylammoniumbromide( CTMAB).