Simultaneous determination of Sunset Yellow FCF and Sudan I by solid-phase spectrophotometry

Abstract

A new, sensitive and simple spectrophotometric method for the simultaneous determination of Sunset Yellow FCF and Sudan I in mixtures is proposed. The method is based on the isolation of Sunset Yellow FCF on Sephadex diethylaminoethyl (DEAE) A-25 gel (pH 5.0) and the isolation of the Sudan I on C₁₈silica gel (pH 5.0) measuring, directly, their absorbances in the solid phase at λ= 487 nm in both cases. The concentration ranges applicable were between 15 and 500 ng ml^–1 for Sunset Yellow FCF and between 20 and 200 ng ml^–1 for Sudan I with detection limits of 3.5 and 4.4 ng ml^–1, respectively. The method was applied to the determination of mixtures of both compounds in synthetic colourings used as additives in food, drugs and cosmetic products.