Marsili Nilda R, Lista Adriana, Band Beatriz S Fernandez, Goicoechea Héctor C, Olivieri Alejandro C
Cátedra de Química Analítica, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Santa Fe (S3000ZAA) CC. 242, Argentina.
Analyst. 2005 Sep;130(9):1291-8. doi: 10.1039/b504378f. Epub 2005 Jul 28.
This article reports on the first application of a modified version of the bilinear least-squares model to absorbance-pH second-order data recorded for complex samples. The latter are composed of fruit drink powders, where four different analytes and additional background components occur. The analytes are the common juice colorants tartrazine, yellow sunset, allura red and indigo carmine. The data have been measured after generating a double pH gradient within a flow injection system. The selected chemometric methodology adequately exploits the second-order advantage, needed to take into account the background interferents present in real samples. Due to severe spectral overlapping between the acid and basic forms of each of the colorants in the working pH range, other second-order multivariate calibration methods such as parallel factor analysis and multivariate curve resolution-alternating least-squares could not be successfully applied to the presently studied samples. Recoveries of 94.8, 104.7, 109.3 and 105.3% were obtained for yellow sunset, indigo carmine, allura red and tartrazine respectively in the real test samples.
本文报道了双线性最小二乘模型的改进版本首次应用于复杂样品吸光度 - pH二阶数据的情况。这些复杂样品由果汁饮料粉组成，其中含有四种不同的分析物以及其他背景成分。分析物为常见的果汁色素柠檬黄、日落黄、诱惑红和靛蓝胭脂红。数据是在流动注射系统中产生双pH梯度后测量得到的。所选的化学计量学方法充分利用了二阶优势，以考虑实际样品中存在的背景干扰物。由于在工作pH范围内每种色素的酸式和碱式之间存在严重的光谱重叠，其他二阶多元校正方法，如平行因子分析和多元曲线分辨交替最小二乘法，均无法成功应用于当前研究的样品。在实际测试样品中，日落黄、靛蓝胭脂红、诱惑红和柠檬黄的回收率分别为94.8%、104.7%、109.3%和105.3%。
