Turak Fatma, Dinç Mithat, Dülger Oznur, Ozgür Mahmure Ustun
Department of Chemistry, Faculty of Science and Art, Yıldız Technical University, 34220 Istanbul, Turkey.
Tekirdag City Food Control Laboratory, 59000 Tekirdag, Turkey.
Int J Anal Chem. 2014;2014:650465. doi: 10.1155/2014/650465. Epub 2014 Feb 12.
Four simple, rapid, and accurate spectrophotometric methods were developed for the simultaneous determination of two food colorants, Carmoisine (E122) and Ponceau 4R (E124), in their binary mixtures and soft drinks. The first method is based on recording the first derivative curves and determining each component using the zero-crossing technique. The second method uses the first derivative of ratio spectra. The ratio spectra are obtained by dividing the absorption spectra of the binary mixture by that of one of the components. The third method, derivative differential procedure, is based on the measurement of difference absorptivities derivatized in first order of solution of drink samples in 0,1 N NaOH relative to that of an equimolar solution in 0,1 N HCl at wavelengths of 366 and 451 nm for Carmoisine and Ponceau 4R, respectively. The last method, based on the compensation method is presented for derivative spectrophotometric determination of E122 and E124 mixtures with overlapping spectra. By using ratios of the derivative maxima, the exact compensation of either component in the mixture can be achieved, followed by its determination. These proposed methods have been successfully applied to the binary mixtures and soft drinks and the results were statistically compared with the reference HPLC method (NMKL 130).
开发了四种简单、快速且准确的分光光度法，用于同时测定二元混合物和软饮料中的两种食用色素，即胭脂红（E122）和丽春红4R（E124）。第一种方法基于记录一阶导数曲线并使用零交叉技术测定每种成分。第二种方法使用比率光谱的一阶导数。比率光谱是通过将二元混合物的吸收光谱除以其中一种成分的吸收光谱获得的。第三种方法，导数微分法，基于测量饮料样品在0.1N NaOH溶液中相对于在0.1N HCl中的等摩尔溶液在366nm（胭脂红）和451nm（丽春红4R）波长处的一阶导数差吸光度。最后一种基于补偿法的方法用于导数分光光度法测定光谱重叠的E122和E124混合物。通过使用导数最大值的比率，可以实现混合物中任何一种成分的精确补偿，然后进行测定。这些方法已成功应用于二元混合物和软饮料，并将结果与参考HPLC方法（NMKL 130）进行了统计学比较。
