Journal of liquid chromatography & related technologies vol:32 issue:18 pages:2642-2653
The adenine base of 2',3'-dideoxyadenosine-5'-triphosphate (ddATP) was chosen as the target for precapillary derivatization for its analysis by CE with fluorescence detection. Several fluorophores, such as chloroacetaldehyde, 9-fluorenylmethyloxycarbonylchloride (FMOC), fluorescamine (Fluram), o-phthaldialdehyde (OPA) and complexation with terbium (Tb), gadolinium (Gd), and phenanthroline (phen) were tried. Precapillary derivatization of ddATP with chloroacetaldehyde showed poor peak shape for the epsilon-ddATP adduct and degradation peaks of epsilon-adenine, possibly due to the low sample pH of 4.0. Precapillary derivatization of ddATP with OPA/-mercaptoethanol, Fluram, and FMOC showed no fluorescent derivatization products. Complexation of ddATP with Tb-Gd-phen produced a sharp fluorescent peak. The sensitivity of the Tb-Gd-ddATP-phen complex was found to be 20 times higher than UV detection of ddATP.