Prechromatographic Chemical Derivatization in Liquid Chromatography

A facile, versatile procedure for the preparation of fatty acid esters suitable for glc or hplc analyses

“…[2]), it would suppress acylium ion formation, which is acid catalyzed (eq. [3]) (14). Presumably acylium ions are the active species that react with 1 to form the methyl esters.…”

“…The chromatographic separation and analysis of fatty acids from complex natural lipid mixtures is normally carried out on some suitable derivative of the acids (1)(2)(3)(4). For example, gas chromatography I (glc) is conveniently carried out on the reasonably volatile methyl esters (1,4).…”

“…Since very few naturally occurring fatty acids possess chromophores which absorb above 220 nm (9, it is necessary to derivatize the acids in order to achieve adequate sensitivity. Derivatives commonly used for this purpose, for example aryl esters, have chromophores that absorb at appropriate wavelengths (3). There are many ways of converting carboxylic acids into esters, although in principle most reactions are of the general type set out in eq.…”

L'analyse des acides gras en électrophorèse capillaire

“…Du fait de leur présence dans des matrices complexes et de l'absence de groupement chromophore en leur sein (groupement chromophore permettant leur détection aisée dans la gamme classique de l'UV), les quelques méthodes de séparation utilisées jusque dans les années 80 ont pour la plupart nécessité une transformation de ces acides. Ainsi en chromatographie liquide haute performance (HPLC) ont-ils souvent été estérifiés, avant ou après la sépa-ration, afin de leur conférer soit une forte absorbance, soit une fluorescence [1][2][3][4][5][6]. À l'heure actuelle, leur analyse est encore pour l'essentiel, réalisée par chromatographie en…”

Alumina-based Fiber for Solid Phase Microextraction of Alcohols from Gaseous Samples

“…Several precolumn derivatization methods have been reported for the determination of alcohols using high-performance liquid chromatography (HPLC). These methods involve derivatization with reagents such as phenylisocyanate 16 and 3,5-dinitrobenzyl chloride 17 for the determination of aliphatic alcohols with ultraviolet (UV) detection. Sensitive determinations of aliphatic alcohols with fluorometric detection after precolumn derivatization have also been reported.…”