酸度分布-吸收光谱法用于灰色体系中食用色素的定量分析

Quantitative Analysis of Pigments in a Gray System by pH Distribution-Absorption Spectra

利用合成色素随pH变化的分布分数曲线和吸收光谱构成两维波谱信息，建立了灰色体系中色素的定量分析方法。约束背景双线性分解法（CBBL）结合数值遗传算法（NGA）用于两维矩阵的数据处理。推导了型体总数与两维矩阵的有效秩之间的关系。吸光度矩阵的主成分数根据残余矩阵的残差平方和与噪声水平相比较而确定，对标准样品及模拟灰色体系样品的研究表明该法确定的主成分数与理论值一致。对胭脂红、日落黄和柠檬黄的模拟灰色体系样品中各组分及市售饮料中的日落黄进行了测定，结果表明该方法具有较高的准确度。

Combining the two-dimensional information which consisted of the absorption spectra and the distribution curve of species along with the pH values, a quantitative analytical method for the determination of the pigments in a gray system was proposed. Constrained background bilinerization and numeric genetic algorithm were applied to solve the data matrix. The relationship between total species and the theoretical rank of the two-dimensional matrix was deduced and it was found that the rank of data matrix was smaller than the total species in Samle. The rank of the absorbance matrix can be calculated by comparing the Square sum of the residual matrix with the noise level. The study of samples of standard and synthetic gray system indicated that the principal component number calculated by this methed was consistent with the theoretical value. The components in synthetic sample which consisted of ponceau 4R, tartrazine and sunset yellow and the sunset yellow in some orange drink were determined by this method.The result showed Ihat this method had high accuracy.