Combined use of β‐cyclodextrin and ionic liquid as electrolyte additives in EKC for separation and determination of carob's phenolics—A study of the synergistic effect

Abstract

In this work, a simple, reliable, and fast capillary electrophoretic method was developed and validated for the simultaneous determination of 12 polyphenolic compounds, the most frequently found in carob's pulp and seeds. The present work deals with the development of a novel dual electrophoretic system based on the combined use of β-CD and ionic liquid (IL) as buffer additives. A baseline separation of the target analytes was achieved in less than 10 min by using a BGE consisting of 35 mM borate along with 15 mM β-CD and 3 mM l-alanine tert butyl ester lactate (l-AlaC 4 Lac) IL as buffer additives at pH 9.5, a temperature of 25°C, and an applied voltage of 30 kV. The application of the developed electrophoretic method to real samples enabled the identification and quantification of the main phenolic constituents of both ripe and unripe carob pulp extracts. The results revealed the predominance of gallic acid in both ripe (183.92 μg/g carob pulp) and unripe (205.10 μg/g carob pulp) carob pulp and highlighted the great influence of the ripening stage on carobs polyphenolic composition, with unripe pods being more enriched in polyphenols (total phenolics detected: 912.58 and 283.13 μg/g unripe and ripe carob pulp).

Evaluation of cyclodextrin‐ and cyclofructan‐based chiral selectors for the enantioseparation of psychoactive substances in capillary electrophoresis

“…Increasing the running buffer concentration resulted in a decrease in the electrophoretic mobilities ( μ ep ) of all analytes (e.g., MDPV, from 8.7 × 10 −3 cm 2 /V min at 5 mM phosphate to 4.7 × 10 −3 cm 2 /V min at 40 mM phosphate) and the electroosmotic flow (EOF) (e.g., MDPV, from 8.7 × 10 −3 cm 2 /V min at 5 mM phosphate to 4.3 × 10 −3 cm 2 /V min at 40 mM phosphate), thus lengthening the migration times and improving the resolution. The reduction of EOF upon BGE concentration increase is possibly attributed to the decrease of zeta potential, which is a consequence of the increase of buffer viscosity and ionic strength [52, 53]. Among the examined concentrations, 20 mM phosphate was selected as the optimal as it provided the best resolution (0.3 ≤ R s ≤ 1.3) combined and the shortest analysis time ( t R < 11 min).…”

“…Structures of all analytes used in this study phosphate to 4.3 × 10 −3 cm 2 /V min at 40 mM phosphate), thus lengthening the migration times and improving the resolution. The reduction of EOF upon BGE concentration increase is possibly attributed to the decrease of zeta potential, which is a consequence of the increase of buffer viscosity and ionic strength [52,53]. Among the examined concentrations, 20 mM phosphate was selected as the optimal as it provided the best resolution (0.3 ≤ R s ≤ 1.3) combined and the shortest analysis time (t R < 11 min).…”

Capillary electromigration methods for food analysis and Foodomics: Advances and applications in the period March 2021 to March 2023

“…The use of other additives to the BGE has been also demonstrated as a useful tool to improve the resolution and separation capabilities of CE-based methods. For instance, the combined use of β-cyclodextrin and ionic liquids was recently reported to the detection and quantification of polyphenols present in carob samples [44]. In the same line, the use of cyclodextrin-modified graphene quantum dots has been presented for the determination of polyphenols in dietary supplements in less than 13 min.…”