Analysis of fatty acid samples by hydrophilic interaction liquid chromatography and charged aerosol detector

HILIC/CAD techniques were used in analysis of samples containing fatty acids. Amine base column appeared to be the more retentive stationary phase compared to zwitterionic and BEH silica. The retention decreased with pH mobile phases changing from 3 to 5. Acetonitrile and acetone organic modifier were compared. Acetone gave higher eluotropic strength and better peak symmetry whereas acetonitrile led to higher efficiency. The retention decreased when ammonium acetate concentration increased from 5 to 20 mM. The use of sub-2 mu m column did not show flat Van Deemter curves at high flow rates. A rapid separation of PGI2 and its main degradation product, 6-keto prostaglandin F1 alpha or was obtained in 1.6 min with a Hypersil GOLD, 50 mm x 2.1 mm, 1.9 mu m with; acetonitrile/acetate ammonium pH 5 at 20 mM (85/15; v/v at 0.7 ml/min). (C) 2015 Elsevier B.V. All rights reserved.