Extraction of sunset yellow and allura red by ion-pair formation with aliquat-336 in IBMK.: Simultaneous spectrophotometric determination by bivariate calibration and derivative spectrophotometry

A new and simple extraction-electrophotometric method for the determination of Allura Red (AR, F.D. & C. Red # 40) and Sunset Yellow (SY, F.D. & C. Yellow #6) in mixtures, based on the extraction of ion-pairs formed between dyes and tricaprylylmethylammonium chloride (Aliquat-336) into IBMK (isobutyl methyl ketone), is described. With the proposed method, calibration graphs are linear from 0.1 to 2.0 mu g mL(-1) for AR and 0.1 to 2.6 mu g mL(-1) for SY. The bivariate calibration method was applied for resolution of binary mixtures of the dyes and the results were compared with those given by first derivative spectrophotometry. The methods were applied to the determining of both compounds in commercially available food products.