Simultaneous determination of tartrazine,riboflavine, curcumin and erythrosine by derivative spectrophotometry

A quaternary mixture of Tartrazine (E-102), Riboflavine (E-101), Curcumin (E-100) and Erythrosine (E-127) can be analysed, by means of a previous extraction step using methyl isobutyl ketone (MIBK) as extracting agent, and resolving the binary mixtures obtained in the aqueous and organic phases by derivative spectrophotometry with measurements at the “zero-crossing” wavelengths and by derivative ratio spectra. The established conditions of extraction and the proposed methods have been applied to determine these colorants in several synthetic mixtures with good recoveries.