eCite Digital Repository

A stationary pseudophase semi-permanent coating for open-tubular capillary liquid chromatography and electrochromatography


Ahmed, MA and Felisilda, BM and Wuethrich, A and Quirino, JP, A stationary pseudophase semi-permanent coating for open-tubular capillary liquid chromatography and electrochromatography, Journal of Chromatography A, 1657 Article 462553. ISSN 0021-9673 (2021) [Refereed Article]

Copyright Statement

Crown Copyright 2021 Published by Elsevier B.V. All rights reserved.

DOI: doi:10.1016/j.chroma.2021.462553


We describe the chromatographic and electrochromatographic separation of small neutral and charged analytes using a fused silica capillary with a stationary pseudophase semi-permanent coating of didodecyldimethyl ammonium bromide (DDAB) aggregates. The coating was prepared by flushing the capillary with a DDAB solution that was rinsed out with the mobile phase. Our studies (i.e., electroosmotic flow measurements by capillary electrophoresis, chromatographic retention of a neutral probe and atomic force microscopy) suggested the formation of DDAB patchy admicelle, complete admicelle, or larger aggregates at the solid surface - liquid interface inside the capillary, depending on the concentration of DDAB used in coating the capillary. The analytical figures of merit for open tubular liquid chromatography (OT-LC, pressure driven) and open tubular capillary electrochromatography (OT-CEC, voltage driven) using a capillary coated with 0.5 mM DDAB and mobile phase/background solution of 25 mM borate buffer at pH 9.5 with 10% MeOH were the following: LOD = 3.0-5.0 μg/mL (OT-LC) and 2.5-5.0 μg/mL (OT-CEC); linearity R2 > 0.99 (peak area (OT-LC) and corrected peak area (OT-CEC)), intraday and interday repeatability%RSD < 5% (n = 12) for retention/migration time, peak area (OT-LC) and corrected peak area (OT-CEC). The reversed-phase and anion-exchange property of the stationary pseudophase was studied by the addition of organic solvents and sodium chloride to the mobile phase, respectively. We also demonstrate the increase in the ks of the tested analytes by implementing successive multiple ionic layer (SMIL) coating strategies with DDAB in combination with a cationic and/or anionic polyelectrolyte. The use of a stationary pseudophase coating is potentially an easy alternative way to conduct open-tubular liquid chromatography and electrochromatography.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Analytical chemistry
Research Field:Separation science
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the chemical sciences
UTAS Author:Ahmed, MA (Dr Mohamed Ahmed)
UTAS Author:Felisilda, BM (Dr Bren Mark Felisilda)
UTAS Author:Quirino, JP (Associate Professor Lito Quirino)
ID Code:151290
Year Published:2021
Web of Science® Times Cited:3
Deposited By:Chemistry
Deposited On:2022-07-26
Last Modified:2022-08-26

Repository Staff Only: item control page