Author(s):
1. Darija Knežević Ratković, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
2. Irena Kasagić-Vujanović, Republic of Srpska, Bosnia and Herzegovina

Abstract:
Hydrophilic interaction liquid chromatography (HILIC) become method of choice in the analysis of small polar compounds latelly. Retention mechanism in HILIC system involves the distribution of the analyte between the mobile phase and a partially immobilized water layer on the surface of the stationary phase. Apart from partitioning, surface adsorption and ion–exchange are included in the retention mechanism as well. In addition, hydrophobic interactions can affect tested substances separation process. Retention mechanisms in HILIC are very complex. Interactions between mobile and stationary phase depend on multiple factors: analyte properties, type of the stationary phase, and mobile phase composition. Thus, the separation mechanism differs for each pair of mobile and stationary phase. The aim of this paper was to investigate retention mechanisms of amitriptyline and its impurities A, B, C, D, F and G on 4 different HILIC stationary phases: silica, amide, diol and amino. In HILIC region, partitioning was dominant only on amino stationary phase, while on all the other stationary phases adsorption model fitted data better. The explanation for this phenomenon lies in fact that adsorption and/or partition occurs only in case of stationary phases that does not have conspicuous surface charge. Otherwise, ionic interactions are very dominant.

Key words:
retention mechanisms, hydrophilic interaction liquid chromatography, adsorption, partition, amitriptyline

Date of abstract submission:
31.07.2023.

Conference:
Contemporary Materials 2023 - Savremeni materijali

Applied paper from author