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 H2O2 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 mu g/l levels, by using beta-phenylehylamine as internal standard. (C) 1999 Elsevier Science B.V. All rights reserved.