Off-line dansylation of amines using C 18 solid-phase packings: study of the fluorescence and chemiluminescence detection by post-column derivatization with oxalic acid bis(2, 4, 6-trichloro phenyl ester)/H 2O 2 in liquid chromatography. Determination of amphetamines in urine samples

Abstract

Dansylation of amines (primaries and secondaries) using C 18 solid-phase supports is described. The time of analysis and the handing sample have been markedly improved with respect to those required for solution dansylation. The dansylated amine derivates were injected onto the liquid chromatography system and fluorescence detected. The sensitivity and selectivity is better than the other dansylation procedures described in the literature and also better than other derivatization reagents such 1,2-napthoquinone 4-sulfonate (NQS) or 3,5-dinitrobenzoyl chloride (3,5-DNB). Dansyl compounds can also form chemiluminescent derivatives, therefore a post-column derivatization procedure with oxalic acid bis(2, 4, 6-trichloro phenyl ester) (TCPO) and H 2O 2 has been tested As an example of application, the derivatization procedures (pre- and post-column derivatization) have been applied for the determination of amphetamine or methamphetamine with its metabolite amphetamine, in urine samples at the μg/l levels, by using β-phenylehylamine as internal standard.