Capillary electrophoresis-laser-induced fluorescence detection of amphetamine in the brain.

Prefrontal cortex microdialysis was done in rats that had received intraperitoneal amphetamine (AMPH). Samples were derivatized with 10(-4) M fluorescein isothiocyanate and incubated for 18 h. AMPH was separated by capillary electrophoresis (CE) and detected by laser-induced fluorescence detection (LIFD) from 30 to 150 min after injection. The limit of mass detection was 3 amol, which is three orders of magnitude lower than that in gas chromatography-mass spectrometry, and the limit of concentration detection was 3 x 10(-9) M. The results showed that CE-LIFD is a good method for detecting AMPH in brain dialysates of rats.