食品着色剂大多含有对人体有害的物质, 需要严格控制其用量。利用吸收光谱法和荧光光谱法测量出了五种常见的食品着色剂亮蓝、胭脂红、苋菜红、柠檬黄、日落黄的吸收光谱和荧光光谱。当溶液浓度较小时, 对五种着色剂进行了光谱强度和溶液浓度的线性拟合, 拟合得到的线性区间非常小, 利用线性关系对溶液浓度进行定标存在较大的局限性, 在高浓度时必须进行稀释。利用非线性拟合的方法在较大的浓度范围内探究了五种着色剂的光谱强度与溶液浓度的关系, 在此基础上, 分别用线性定标法(先稀释)和非线性定标法对一种饮料中的着色剂含量进行了测量, 并对两种方法的测量结果进行了比较, 为扩大溶液的定标范围提供了一种参考方法和实验依据。

Food colorants mostly contain substances harmful to human body, so their dosage should be strictly controlled. Absorption and fluorescence spectra of five common food colorants bright blue, carmine, amaranth, lemon yellow and sunset yellow were measured by absorption spectroscopy and fluorescence spectroscopy. When the concentration of solution is small, the linear fitting of spectral intensity and solution concentration of five colorants is carried out. The linear interval obtained by fitting is very small. There are great limitations in calibrating solution concentration by using linear relationship, and dilution must be carried out at high concentration. The relationship between the spectral intensity of five colorants and the concentration of solution was studied in a large concentration range by using the method of non-linear fitting, on this basis, using method of linear scaling (dilution) and nonlinear calibration method for a drink of colorants content were measured, and the measuring results of two methods are compared, to expand the selection range of solution provides a reference method and experimental basis.