Combined capillary gas chromatography/ion trap mass spectrometry quantitative methods using labeled or unlabeled internal standards

Ion trap tandem mass spectrometric evidence for the metabolism of 3,4-(methylenedioxy)methamphetamine to the potent neurotoxins 2,4,5-trihydroxymethamphetamine and 2,4,5-trihydroxyamphetamine

“…The rationalizations of the various daughter ions are included in Figure 1. The m/z 295 ion in the daughter ion mass spectrum is due to the contribution of 13C and 15N isotopes of the protonated molecule; the parent + 1 ion is commonly observed in the daughter ion mass spectra obtained with an ion trap mass spectrometer due to the inherent difficulty in isolation of ions at a single m/z value (14).…”

Applications of mass spectrometry to toxicology

“…An interesting innovative approach to metabolism studies that involves the use of stable isotopes has been developed by Abramson and his co-workers (120,122). They have introduced the chemical reaction interface (CRI) mass spectrometer for quantitative metabolism studies.…”

An automatic reaction control chemical ionization technique in ion trap detector for quantitative plasma profding of arecoline in treated alzheimer patients

“…Choice of internal standard. The selection of internal standar d s (labeled or unlabeled) for ion traps in quantitation s has been discussed in earlier works [18,19]. In these, the traps were operated in rf-only, rf/dc or rf Idc tandem mass spectrometry modes under electron ionization.…”