THE USE OF A CHROMATOGRAPHIC COLUMN PACKED WITH AMIDE SORBENT FOR THE ANALYSIS OF PARABENS

Abstract

The article investigates the applicability of the amino column XBridge Amide 150×4.6 mm for separation of 4-hydroxybenzoic acid esters (parabens) — based on experience with hydrophilic interaction liquid chromatography used for analysis of various compounds. The study analysed the retention times, elution order and resolution between the peaks of parabens and impurity A (4-hydroxybenzoic acid) while using acetonitrile : phosphate buffer mobile phases containing 7–10 % of acetonitrile and acetonitrile : water mobile phases containing 96–99 % of acetonitrile, and the above-mentioned column. It was demonstrated that reversed-phased chromatography was preferable for separation of paraben homologues, while hydrophilic interaction chromatography was preferable for analysis of 4-hydroxybenzoic acid impurity. When analysing potential mechanisms of retention of compounds by the XBridge Amide column it was suggested that, unlike amino groups, amide groups of the sorbent do not have affinity for phenolic hydroxyl groups of parabens in hydrophilic interaction liquid chromatography.

Keywords

• hplc
• hydrophilic interaction liquid chromatography
• 4-hydroxybenzoic acid esters (parabens)
• amide sorbent
• impurities determination