Abstract
Ionic liquids have recently been introduced as mobile phase additives to separate ionized solutes and to improve separation abilities in reversed‐phase liquid chromatography. In this study, four ionic liquids that are composed of different lengths of alkyl chain (ethyl, butyl, hexyl, and octyl) in 1‐alkyl‐3‐methylimidazolium cation and tetrafluoroborate anion were used as the mobile phase additives and five ionizable solutes (benzylamine, benzoic acid, 4‐aminobenzoic acid, L‐phenylalanine, and L‐trypophan) that include carboxyl and/or amine were used as analytes. By changing the hydrophobic property of the ionic liquid with the length of alkyl chain of imidazolium cation, one can control the interaction between 1‐alkyl‐3‐methylimidazolium cation and the hydrophobic stationary phase. To explain the role of ionic liquids on the retention behaviors of ionized analytes, two adsorption mechanisms, the ion pairing forming mechanism and the dynamic ion‐exchange mechanism, were presented. When 1‐ethyl‐3‐methylimidazolium tetrafluoroborate was used as the additive, the retention behavior dominantly complied with the ion pairing forming mechanism and when other ionic liquids with long alkyl chain were used, the retention behavior can be explained by the dynamic ion‐exchange mechanism.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Liquid Chromatography & Related Technologies
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
