Extraction of sunset yellow and allura red by ion-pair formation with aliquat-336 in IBMK. Simultaneous spectrophotometric determination by bivariatecalibration 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. Ye llow #6) in mixtures, based on the extraction of ion-pairs formed between d yes and tricaprylylmethylammonium chloride (Aliquat-336) into IBMK (isobuty l methyl ketone), is described. With the proposed method, calibration graph s 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 bina ry mixtures of the dyes and the results were compared with those given by f irst derivative spectrophotometry. The methods were applied to the determin ing of both compounds in commercially available food products.