比值导数波谱法分析混合色素

Simultaneous Determination of Mixed Colorants by Derivative Ratio Spectrum Method

本文叙述了比值导数波谱法的原理，该法以混合物的波谱除以干扰组分的标准波谱而得到比值波谱，以比值波谱对波长求导得到比值导数波谱，由此得到的波谱可完全消除干扰组分的吸光度贡献。采用此法能方便地对二组分混合体系进行分析，如选择合适的零交点，则可对三组分混合体系进行分析。利用此法对胭脂红、日落黄及柠檬黄三种色素的二组分及三组分混合体系进行了分析，均获较好的结果。

The principle of derivative ratio spectrum method is described. The mehtod is based on the simultaneous use of the first derivative of ratio spectra and measurements of ze ro-crossing wavelengths. The ratio spectrum is obtained by dividing the amplitude of the ab sorption spectrum of the mixture by a standard spectrum of one of the components, and the subsequent derivation against wavelength results to the first derivative of the ratio spectrum.The concentrations of the other two components are then determined from their respective calibration graphs established by measuring the ratio derivative analytical signal at the select ed zero-crossing points. This method has been applied to the dctermination of binary and ternary mixtures of Tartrazine, Sunset Yellow and Ponceau 4R with satisfactory results.