A novel approach for dispersive liquid-liquid microextraction based on the use of deep eutectic solvent as a disperser was presented for the first time. The procedure was automated based on an in-syringe flow system coupled with UV–Vis detection and demonstrated by the determination of chromium (VI) in beverages. This analytical task was used as a proof-of-concept example. The automated extraction procedure involved the aspiration of aqueous sample into a syringe pump with homogeneous mixture of extraction solvent (1-oсtanol) and deep eutectic solvent (tetrabutylammonium bromide – formic acid) containing color-forming reagent (1,5-diphenylcarbazide). This led to decomposition of deep eutectic solvent in aqueous phase resulting in dispersion of extraction solvent, oxidation of 1,5-diphenylcarbazide to 1,5- diphenylcarbazone in the presence of chromium (VI), and formation of colored chromium (III) complex with 1,5-diphenylcarbazone and its fast extraction. In this case composition of deep eutectic solvent played a key role for analyte extraction. Tetrabutylammonium bromide promoted mass transfer between aqueous phase and the extraction solvent droplets as a salting out agent, bromide ion acted as an ion-pare agent for analyte complex extraction, formic acid provided required pH value for analyte complex formation. Under the optimal conditions the limit of detection, calculated from a blank test based on 3s, was 0.2 μg L−1. The automated dispersive liquid-liquid microextraction using deep eutectic solvent as disperser can be considered as an available, efficient, rapid and environmentally friendly sample pretreatment approach.

Original languageEnglish
Article number120209
Number of pages7
StatePublished - 1 Jan 2020

    Research areas

  • Beverages, Chromium (VI), Deep eutectic solvent, Disperser solvent, Dispersive liquid-liquid microextraction, In-syringe flow system, Limit of Detection, Prunus avium/chemistry, Solvents/chemistry, Quaternary Ammonium Compounds/chemistry, Spectrophotometry, Ultraviolet, Drinking Water/analysis, Food Contamination/analysis, Syringes, Fruit and Vegetable Juices/analysis, Carbonated Beverages/analysis, Liquid Phase Microextraction/instrumentation, Malus/chemistry, 1-Octanol/chemistry, Chromium/analysis, Formates/chemistry, PRECONCENTRATION, TANDEM-MASS-SPECTROMETRY, SPECTROPHOTOMETRIC DETERMINATION, SOLIDIFICATION, CHROMATOGRAPHY, EXTRACTION, SPECIATION, PESTICIDES, CR(VI), WATER SAMPLES

    Scopus subject areas

  • Analytical Chemistry

ID: 70791375