Analysis by liquid chromatography of desipramine in aqueous solutions and plasma application of dichlorotriazinylaminofluorescein (DTAF) as a pre-column fluorescent derivatising agent for selected secondary amines.
Dichlorotriazinylaminofluorescein (DTAF) has been proposed as a fluorescent derivatising agent for secondary aliphatic amines. In this report, its applicability as a pre-column reagent is demonstrated by its use in the analysis of aqueous solutions and plasma samples of the tricyclic antidepressant, desipramine. Samples were processed by liquid-solid extraction onto XAD-2 resin, followed by DTAF derivatisation of the fraction of the column effluent containing analyte. The reaction mixture was then subjected to HPLC using a dual column switching configuration that was designed to (a) separate excess DTAF from the reaction product, and to (b) achieve the necessary analytical resolution. Fluorometric detection of the analyte in column effluent afforded a sensitivity of 150 fmol of desipramine injected on-column, a 2-3 order of magnitude increase in sensitivity relative to previously described methods. DTAF appears to be a convenient reagent for fluorescence derivatisation of N-methyl secondary amines prior to their HPLC analysis.
Siegler
R
R
Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66045, USA.
Sternson
L A
LA