Gas chromatographic-mass spectrometric determination of plasma selegiline using a deuterated internal standard

A gas chromatographic-mass spectrometric method is described for the determination of plasma selegiline. Tetradeuteroselegiline was synthesized and served as the internal standard. Human plasma samples (1 ml) containing 1-6 ng of selegiline were acidified, washed with diethyl ether-hexane, then alkalinized and extracted with heptane-isoamyl alcohol. Analytical separations were performed on a dimethylsilicone capillary column. Detection was by selected ion monitoring of the electron impact generated m/z 96 and 100 alpha-cleavage fragments of drug and internal standard, respectively.