Simultaneous Determination Of Tartrazine, Patented Blue V And Brilliant Blue FCF By Spectrophotometry With Chemometric Algorithms

Mixtures containing tartrazine (TAN) and brilliant blue (BB) or patented blue (PB) were investigated in this work. The optimal pH for the simultaneous determination of these dyes is 1.5 and 7 (for pH=7: ε430(ТАN)=3.2·104, ε635(ТАN)=5.3·102, ε430(PB)=3.3·103, ε635(PB)=8.7·104; for pH=1.5: ε430(ТАN)=2.1·104, ε630(ТАN)=9.6·102, ε430(BB)=9.3·103, ε630(BB)=8.3·104). Classification models, that allow to identify mixtures containing TAN and BB, TAN and PB, chlorophyll and quinoline yellow with BB or PB, have been developed using methods of hierarchical cluster analysis, factor analysis (FA), partial least squares (PLS) and principal component analysis (PCA). Model solutions of dyes and 12 real objects (tarkhun, low-alcohol drinks, tonics and absinthe of various brands) were used for the classification. The best classification results were achieved at pH 1.5 using PLS and PCA. Quantitative models, based on the additivity of spectral signals and PLS, have been developed for determining the permittivity of these dyes in the simultaneous presence. In order to make it possible to analyse alcoholic drinks, the dependence of the molar attenuation coefficient on the dielectric conductivity of solvents was studied. The obtained regression equations were taken into account in the calibration for absorbance additivity. Methods for the quantitative determination of the investigated dyes were developed for the concentration range 0.2-2.0∙10-5 М.