9-Fluoreneacetyl-tagged, solid-phase reagent for derivatization in direct plasma injection.

We describe here a resin-based derivatization reagent, containing a 9-fluoreneacetyl tag on a controlled-pore substrate, for direct injection analysis of amphetamine in plasma. On-line, pre-column derivatization was performed by direction injection of diluted plasma sample into an sodium dodecyl sulfate-containing mobile phase. Amphetamine was trapped in the hydrophobic derivatization column and derivatized at elevated temperature by the activated solid-phase reagent. The derivatized 9-fluoreneacetyl amphetamide was separated by reversed-phase high-performance liquid chromatography with a step gradient and determined by fluorescence detection. The synthesis scheme, characterization, and optimization of the derivatization conditions for the solid-phase reagent are described. The method was evaluated by reproducibility tests and single blind spiking analysis. This solid-phase reagent combined with a surfactant containing mobile phase provided a sensitive and simple procedure for on-line derivatization in direct injection analysis of biological fluids.