Single and Simultaneous Solid-Phase Extraction and UV–Vis Determination for Monitoring E129, E133 and E110 in Foodstuffs

Abstract

A column solid-phase extraction method based on adsorption of allura red (AR), brilliant blue (BB) and sunset yellow (SY) onto Dowex Optipore V493 adsorbent was developed for single and simultaneous preconcentration and spectrophotometric determination of AR, BB and SY. Effects of extraction parameters including pH, sample and eluent flow rates, amount of adsorbent, eluent type and volume, ionic strength and sample volume, etc., were investigated and optimized. At the optimum conditions, detection limits of the method were determined to be 0.55, 0.20 and 0.58 µg L−1 for AR, BB and SY, respectively. Dynamic ranges were linear between 0.055–6.0 µg mL−1 for AR, 0.020–4.2 µg mL−1 for BB and 0.058–10.0 µg mL−1 for SY. Preconcentration factor was determined to be 100. Relative standard deviations were below than 4%. In addition, adsorption isotherms with related to retentions of AR, BB and SY on the resin were investigated. Finally, recommended procedure was applied to foodstuff samples containing AR, BB and SY dyes. AR contents of real samples were determined between 20.40–27.21 µg/mL and 6.85–21.25 µg/g for liquid and solid samples, respectively. BB concentrations of real samples were determined between 5.06–43.30 µg/mL and 3.15–10.05 µg/g for liquid and solid samples, respectively. SY contents of liquid and solid samples were determined between 3.04–29.67 µg/mL and 18.55–121.46 µg/g, respectively. In order to prove applicability of the method, analyte addition technique was performed. Satisfactorily quantitative recovery results were obtained between 95 and 102%.