SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF TARTRAZINE, SUNSET YELLOW AND PONCEAU 4R IN COMMERCIAL PRODUCTS BY PARTIAL LEAST-SQUARES AND PRINCIPAL COMPONENT REGRESSION MULTIVARIATE CALIBRATION METHODS

Three multivariate calibration methods, partial least squares (PLS-1 a nd PLS-2) and principal component regression (PCR), were proposed and successfully applied to the simultaneous determination of three dyes, Tartrazine (E-102), Sunset Yellow (E-110) and Ponceau 4R (E-124) in mi xtures by ultraviolet-visible absorption spectrophotometry. The design ed and optimized training set of calibration was applied to the determ ination of the three dyes in several synthetic mixtures, containing 1. 6-20.0 mg/L of Tartrazine, 3.2-40.0 mg/L of Sunset Yellow and 3.2-36.0 mg/L of Ponceau 4R. 94.5-105.3% recovery values were obtained. Three commercial foods that contained the three dyes were also satisfactoril y analyzed without separation step. The results obtained by the applic ation of the three chemometric approaches in the commercial products a re discussed and compared with those obtained by an HPLC method and ve ry similar values were found by all methods. Repeatability and reprodu cibility studies (with the Student's and F tests) were achieved over t wo series of nine standards for each dye, showing no significant diffe rences at the 95% confidence level.