HILIC Chromatography An Insight on the Retention Mechanism
Aikaterini I Piteni, Maria G Kouskoura* and Catherine K Markopoulou
Laboratory of Pharmaceutical Analysis, Department of Pharmaceutical Technology, School of Pharmacy, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- *Corresponding Author:
- Maria G Kouskoura
Laboratory of Pharmaceutical Analysis
Department of Pharmaceutical Technology
School of Pharmacy, Faculty of Health Sciences
Aristotle University of Thessaloniki
54124 Thessaloniki, Greece
E-mail: [email protected]
Received date: June 15, 2016; Accepted date: June 21, 2016; Published date: June 27, 2016
Citation: Piteni AI, Kouskoura MG, Markopoulou CK (2016) HILIC Chromatography – An Insight on the Retention Mechanism. J Chromatogr Sep Tech 7:326. doi:10.4172/2157-7064.1000326
Copyright: © 2016 Piteni AI, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Hydrophilic interaction chromatography (HILIC) could be characterized as a complex chromatographic system that involves multiple mechanisms. These are partitioning as well as polar and ionic interactions. Among several HILIC columns, ZIC-HILIC can be used to separate small organic ionic compounds. The presence of both positive and negative charge on the stationary phase may facilitate separations of both anionic and cationic analytes. Based on the Partial Least Squares methodology, an attempt to clarify the mechanism on this column revealed that the forces dominating are mainly determined by structural features. Consequently, the physicochemical properties which are related to the analytes’ structure may heighten or attenuate the process. Ionic interactions are stronger for analytes containing moieties with basic properties since the interaction with the sulfonyl group is facilitated. The partition mechanism is prevailing for those analytes that are not sufficiently ionized at the experimental conditions (mobile phase pH 3 and 6.5) and for analytes that can create halogen bonds. Moreover, the stagnant water layer on the silica bed enhances the retention of water soluble compounds due to the increased hydrophilic interactions.