Department of Chemistry, Faculty of Sciences, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
Department of Mathematics and Computation, Faculty of Sciences, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
Talanta. 2019 May 1;196:153-162. doi: 10.1016/j.talanta.2018.12.046. Epub 2018 Dec 15.
The simultaneous determination of two food colorants (cochineal (E-120) and erythrosine (E-127)) was achieved by means of excitation-emission fluorescence matrices and three-way PARAFAC decomposition together with the use of a calibration set that contained binary mixtures of both analytes. In the measured conditions, the amount of cochineal present in the sample affected the fluorescence signal of erythrosine since cochineal caused a quenching effect in the fluorescence of the other food additive. However, the signal of cochineal was not affected by the presence of erythrosine. A calibration line for erythrosine was built for each different concentration level of cochineal. The slopes of these regressions were different depending on the amount of quencher, whereas the intercepts were statistically equal to 0 at a 95% confidence level. The quantification of erythrosine was possible using the regression "amount of cochineal" versus "the slope of the calibration line for erythrosine". Using this procedure, the mean of the absolute values of the relative errors in prediction for mixtures of both colorants were 5.86% (n = 10) for cochineal and 4.17% (n = 10) for erythrosine. Both analytes were unequivocally identified by the correlation between the pure spectra and the PARAFAC excitation and emission spectral loadings. Pitted cherries in syrup were analyzed. Cochineal and erythrosine were detected in those cherries at a concentration of 185.05 mg kg and 10.76 mg kg, respectively. These concentration values were statistically equal to the ones obtained with a HPLC/DAD method.
同时测定了两种食用色素（胭脂红（E-120）和赤藓红（E-127）），方法是通过激发-发射荧光矩阵和三向 PARAFAC 分解以及使用包含两种分析物的二元混合物的校准集。在测量条件下，样品中胭脂红的含量会影响赤藓红的荧光信号，因为胭脂红会使另一种食品添加剂的荧光猝灭。然而，胭脂红的信号不受赤藓红的存在影响。为每个不同浓度水平的胭脂红建立了赤藓红的校准线。这些回归的斜率取决于猝灭剂的量，而截距在 95%置信水平下统计上等于 0。可以使用回归“胭脂红的量”与“赤藓红的校准线斜率”来定量赤藓红。使用此程序，两种色素混合物的预测相对误差绝对值的平均值分别为胭脂红的 5.86%（n=10）和赤藓红的 4.17%（n=10）。通过纯光谱与 PARAFAC 激发和发射光谱负荷之间的相关性，可以明确识别这两种分析物。分析了糖浆中的去核樱桃。在这些樱桃中检测到胭脂红和赤藓红的浓度分别为 185.05mg/kg 和 10.76mg/kg。这些浓度值与 HPLC/DAD 方法获得的值在统计学上是相等的。
