SIMULTANEOUS DETERMINATION OF TARTRAZINE, RIBOFLAVINE, CURCUMIN AND ERYTHROSINE BY DERIVATIVE SPECTROPHOTOMETRY

A quaternary mixture of Tartrazine (E-102), Riboflavine (E-101), Curcu min (E-100) and Erythrosine (E-127) can be analysed, by means of a pre vious extraction step using methyl isobutyl ketone (MIBK) as extractin g agent, and resolving the binary mixtures obtained in the aqueous and organic phases by derivative spectrophotometry with measurements at t he ''zero-crossing'' wavelengths and by derivative ratio spectra. The established conditions of extraction and the proposed methods have bee n applied to determine these colorants in several synthetic mixtures w ith good recoveries.