Capillary zone electrophoresis separation of low concentration stimulants in human urine with laser-induced fluorescence detection

Capillary zone electrophoresis separation with laser-induced fluorescence (LIF) detection for the determination of fluorescein isothiocyanate (FITC) derivatized stimulants (ephedrine, phenylpropanolamine and heptaminol) was demonstrated. A simple electrophoretic buffer system composed of 30 mM triethylamine was selected and high voltage of 16 kV was applied for the capillary electrophoresis separations. Stimulants in human urine were extracted by organic solvents and then derivatized with FITC. By employing a semiconductor laser-induced fluorescence detector, low concentration stimulants of 22 ng/mL can be detected within 10 min. Operation conditions for derivatization and separation were discussed. This simple CZE-LIF method with sensitive detection provided the possibility to develop the on-chip stimulants screening methods for doping control.