Analysis of the Results of Using Amino, Amide and Nitrile Sorbents in Hydrophilic Interaction Liquid Chromatography

Abstract

The article summarises the results of studies of hydrophilic interaction liquid chromatography performed from 2013 until 2017. The analysis of results obtained during separation of a number of model mixtures of compounds having different nature helped to compare the characteristics of columns packed with amino, amide and nitrile sorbents. It was demonstrated that columns packed with amino sorbents could be used for the analysis of both hydrophilic compounds and some hydrophobic compounds containing acidic (4-hydroxybenzoic acid) and potentially acidic groups (nitro groups of nitro compounds; phenolic hydroxyl groups of butylhydroxyanisole isomers and parabens). It was discovered that chromatographic columns packed with nitrile and amide sorbents have common properties and can be used for the analysis of hydrophilic compounds (hydroxycarbamide) and platinum coordination compounds, but cannot be used for the analysis of butylhydroxyanisole isomers, esters of p-hydroxybenzoic acid and nitrate esters of isosorbide. The article offers hypotheses about possible mechanisms of interaction between test substances and sorbents. It was concluded that the increase in the acetonitrile content in mobile phases, which increases the retention time of the test substances and results in better resolution between their peaks, illustrates the mechanism of hydrophilic interaction liquid chromatography.