title: Simultaneous spectrophotometric determination of synthetic dyes in food samples after cloud point extraction using multiple response optimizations.
abstract: A sensitive cloud point extraction method for simultaneous determination of trace amounts of sunset yellow (SY), allura red (AR) and brilliant blue (BB) by spectrophotometry was developed. Experimental parameters such as Triton X-100 concentration, KCl concentration and initial pH on extraction efficiency of dyes were optimized using response surface methodology (RSM) with a Doehlert design. Experimental data were evaluated by applying RSM integrating a desirability function approach. The optimum condition for extraction efficiency of SY, AR and BB simultaneously were: Triton X-100 concentration 0.0635 mol L(-1), KCl concentration 0.11 mol L(-1) and pH 4 with maximum overall desirability D of 0.95. Correspondingly, the maximum extraction efficiency of SY, AR and BB were 100%, 92.23% and 95.69%, respectively. At optimal conditions, extraction efficiencies were 99.8%, 92.48% and 95.96% for SY, AR and BB, respectively. These values were only 0.2%, 0.25% and 0.27% different from the predicted values, suggesting that the desirability function approach with RSM was a useful technique for simultaneously dye extraction. Linear calibration curves were obtained in the range of 0.02-4 for SY, 0.025-2.5 for AR and 0.02-4 μg mL(-1) for BB under optimum condition. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.009, 0.01 and 0.007 μg mL(-1) (n=10) for SY, AR and BB, respectively. The method was successfully used for the simultaneous determination of the dyes in different food samples.
authors.affiliation: Department of Chemistry, Faculty of Science, Ilam University, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Heidarizadi
authors.affiliation: Department of Chemistry, Faculty of Science, Ilam University, Iran. Electronic address: rezatabaraki@yahoo.com.
authors.forename: Reza
authors.initials: R
authors.lastname: Tabaraki
mesh_terms: D001391:Azo Compounds / Q000032:analysis*; D001557:Benzenesulfonates / Q000032:analysis*; D002182:Candy / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004396:Coloring Agents / Q000032:analysis; D005505:Food Coloring Agents / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; D005505:Food Coloring Agents; C005915:Allura Red AC Dye; C006796:brilliant blue; C005842:6-hydroxy-5-((p- sulfophenyl)azo)-2-naphthalenesulfonic acid disodium salt
keywords: Cloud point extraction; Desirability function; Doehlert design; Multiple response optimization; Synthetic dyes