SILVER ION HIGH PERFORMANCE LIQUID CHROMATOGRAPHY OF POLYNUCLEAR AROMATIC DERIVATIVES OF POSITIONALLY ISOMERIC OCTADECENOIC FATTY ACIDS

• Published in: Journal of liquid chromatography & related technologies 2000-05, Vol.23 (9), p.1319-1330
• Main Authors: Momchilova, Sv, Nikolova-Damyanova, B.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Other chromatographic methods
• ISSN: 1082-6076; 1520-572X
• DOI: 10.1081/JLC-100100416

The chromatographic properties of positionally isomeric octadecenoic fatty acids in silver ion high performance liquid chromatography with hexane-based and dichloromethane-based mobile phases were studied after conversion in 2-naphthacyl, 2-naphthylmethyl and 9-anthrylmethyl derivatives. The retention decreased in the order 2-naphthacyl, 9-anthrylmethyl, 2-naphthylmethyl derivatives. Dichloromethane-acetonitrile mobile phases provided better resolution and 2-naphthacyl and 9-anthrylmethyl derivatives of 6-, 9-, and 11-18:1 were fully resolved with dichloromethane-acetonitrile 100:0.025 (v/v). The behavior of the aromatic derivatives, examined so far by Ag-HPLC, under comparable experimental conditions, was compared and a clear tendency of improving the resolution was observed when the number of aromatic nuclei in the aromatic fragment increased. The effect was ascribed to the increased electron-donating effect of the aromatic rings in the ester moiety, which supposedly enhanced the formation of a three center complex between double bond, a carbonyl oxygen, and silver ion. The good resolution of 9-anthrylmethyl derivatives is of potential practical value since it allows for the determination of nanogram amounts of fatty acids by silver ion HPLC with fluorescent detection.