Second order advantage in the determination of Amaranth, Sunset Yellow FCF and Tartrazine by UV-Vis and Multivariate Curve Resolution-Alternating Least Squares

NATALIA LLAMAS; MARIANO GARRIDO; MARÍA SUSANA DI NEZIO; BEATRIZ S. FERNÁNDEZ BAND

ANALYTICA CHIMICA ACTA

Elsevier

Año: 2009 vol. 655 p. 38 - 42

0003-2670

A direct spectrophotometric method for the determination of three artificial colors - amaranth, sunset yellow FCF and tartrazine - in beverages samples is proposed. The spectra were recorded between 359 to 600 nm. The spectra of the samples (just filtrated), pure dyes (concentrations ranged between 0.01-1.8 mg L-1 for amaranth, 0.08-4.4 mg L-1 for sunset yellow and 0.04-1.8 mg L-1 for tartrazine) and synthetic mixtures were disposed in a column-wise augmented data matrix. This kind of data structure, analyzed by multivariate curve resolution-alternating least squares (MCR-ALS) makes it possible to exploit the so called ‘second order advantage’. MCR-ALS algorithm was applied to the experimental data under the non-negativity and equality constraints. As a result, the concentration of each dye in the samples and their corresponding pure spectra were obtained. The results were validated using internal reference materials and no significant differences were found (á = 5%) between the reference values and the ones obtained with the proposed method. The second order advantage made it possible to obtain unbiased results even in the presence of interferences.