High and low energy collision mass spectrometry/mass spectrometry of aza and amino polynuclear aromatic compounds in coal-derived liquids

Abstract

Comparisons are made between collision-induced dissociation

Capillary liquid chromatography with MS3 for the determination of enkephalins in microdialysis samples from the striatum of anesthetized and freely–moving rats

“…In principle, further improvements in sensitivity and selectivity may be achieved by utilizing higher stages of mass spectrometry 15, 16. With each stage of mass spectrometry, both chemical noise and signal decrease; however, chemical noise decreases faster 17, 18.…”

Susceptibility of environmentally important heterocycles to chemical disinfection: reactions with aqueous chlorine, chlorine dioxide, and chloramine

“…The concern over the detrimental nature of environmental polynuclear aromatic hydrocarbons (PAH) to health has recently been expanded to include their heterocyclic analogues (1)(2)(3)(4). Although the major focus of investigation has been the analysis of these heterocycles from effluents and residuals of energy-generating processes involving fossil fuels (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), azaarenes (16)(17)(18) and dibenzothiophene (19,20) have been observed in groundwater and surface waters and as constituents of particulates and sediments.…”

Utilization of natural isotopic abundance ratios in tandem mass spectrometry

“…Specificity can be further increased by using ancillary techniques (8) in conjunction with the two stages of mass analysis inherent in MS/MS. These techniques include selective methods of ionization (9), collision-induced dissociation accompanied by charge inversion (10), chemical derivatization of the bulk sample prior to MS/MS (11), and preseparation during evaporation of the sample into the ion source (11).…”