Determination of Allura red in food samples after cloud point extraction using mixed micelles

A cloud point extraction process using mixed micelles of CTAB, Triton X-114 and Triton X-100 for preconcentration and spectrophotometric determination of trace amounts of Allura red in food samples was developed. The effect of different parameters such as concentration of surfactants, electrolyte concentration, temperature and pH on the cloud point extraction of Allura red was studied in detail and a set of optimum conditions were established. A linear calibration curve in the range of 20-1400 mu g/L of Allura red was obtained. Detection limit based on 3S(b) was 7.8 mu g/L and the relative standard deviation for 75 mu g/L of Allura red was 3.87 (n = 10). The method was applied to the determination of Allura red in food samples such as candy, soft drink and jellies. (C) 2010 Elsevier Ltd. All rights reserved.