DOI: https://doi.org/10.55373/mjchem.v24i4.99

Keywords: Dispersive liquid-liquid microextraction, deep eutectic solvent, azo dyes, tartazine and acid orange

Abstract

Azo dyes in beverages pose a major health threat to public health and restricted in many countries. To ensure the integrity of beverages, the presence of permitted azo dyes/food colourants should be monitored to be within the permissible limit. A simple, easily accessible and cheap approach for the determination of azo dyes (acid orange 20 and tartrazine) namely, dispersive liquid-liquid microextraction (DLLME) based on deep eutectic solvent (DES) was developed. DES was prepared by heating a mixture of a hydrogen bond donor (fatty acid) and a hydrogen bond acceptor (quaternary ammonium salt) at 80 °C with the ratio of 1:3. The prepared DES was added into the aqueous sample solution and followed by a disperser solvent (tetrahydrofuran). The mixture was sonicated and centrifuged to allow the formation of two-layer phases. The DES phase was transferred into a vial before analysed quantitative ly using UV-Vis spectrophotometer. Under optimum conditions, the developed DLLME method showed the limit of detection (LOD) and limit of quantification (LOQ) of 0.007–0.034 mg L-1 and 0.025‒0.1141 mg L-1, respectively for both analytes. Intra-day and inter-day precision were 2.1–3.2 % and 5.4‒9.4 %, respectively. The recoveries for spiked samples were in the range of 90.9‒110.1 %. Based on the results obtained, the developed DLLME-DES method has a great potential as a sample preparation technique for the determination of azo dyes in aqueous samples.