PRECONCENTRATION AND DETERMINATION OF SYNTHETIC FOOD DYE FAST GREEN FCF (E143) USING AMINATED ALUMINA

Abstract

The conditions for solid-phase extraction of the synthetic food dye Fast Green FCF (E 143) by basic and modified with polyhexamethylene guanidine alumina (Al2O3-PHMG) were determined. The equilibration time for extraction of E143 dye was 15 min for the both adsorbents. Quantitative extraction of E143 dye with Al2O3-PHMG was achieved in the ranges of pH 1.0–3.0 and pH 6.5–7.5. The maximum extraction of the dye by basic alumina was observed in the pH range of 2.0–5.0 and did not exceed 80%. The adsorption capacity of adsorbents for E143 dye was 20 µmol g-1 for Al2O3, 35 µmol g-1 for Al2O3-PHMG at pH 1 and 11 µmol g-1 at pH 6.5. The experimental adsorption isotherms for Al2O3-PHMG at pH 1 and pH 6.5 are best fitted the Langmuir model. The adsorption isotherm for Al2O3 in the segment of growth of the adsorption capacity is best fitted the Freundlich model. When extracting E143 dye, the surface of the adsorbents acquired a color characteristic for the dye in solution. In this case, an intense band with a maximum at 620 nm was observed in the diffuse reflectance spectra of the surface of the adsorbents. The procedure of adsorption-photometric determination of E143 dye in the variant of diffuse reflectance spectroscopy using Al2O3-PHMG was proposed. Limit of detection, calculated by the 3s-criterion, was 7 µg L-1 when using 10 mL of solution. The analytical range of dye concentrations was 0.02–3.0 mg L-1. The relative standard deviation did not exceed 0.08 (n=10). The selectivity of preconcentration of E143 at pH 1.0 was higher than at pH 6.5. The developed procedure was used for determination of the Fast Green FCF dye in a model solution based on the soft drink. For citation: Didukh-Shadrina S.L., Buyko O.V., Losev V.N., Chash-ool N.N. Preconcentration and determination of synthetic food dye Fast Green FCF (E143) using aminated alumina. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 3. P. 27-35. DOI: 10.6060/ivkkt.20236603.6714.