ELECTRON-IMPACT AND CHEMICAL IONIZATION DETECTION OF NICOTINE AND COTININE BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY IN RAT PLASMA AND BRAIN

Nicotine and its metabolite, cotinine, were measured in rat plasma and brain by gas chromatography mass spectrometry. Both agents were extracted from plasma and brain, separated on a capillary column, and quantified by single-ion monitoring. The major fragment ions of nicotine and cotinine at m/z 84 and m/z 98, respectively, were monitored by electron-impact ionization detection and the protonated molecular ions at m/z 163 and m/z 177, respectively, were monitored by chemical ionization detection. Both compounds were quantified using deuterium-labeled nicotine and cotinine, respectively, as internal standards.