Chemical ionization mass spectrometry of quaternary amines

Abstract

Abstract-Chemical ionization mass spectra of eleven biomedically significant quaternary amines are reported. The samples are converted to volatile compounds by known thermal decompositions. Chemical ionization of the compounds gives simple, easily identifiable spectra which are useful €or the analysis of the original samples.

Surface chemical ionization mass spectrometry

“…In no case were ions characteristic of the quaternary amines observed. The highest masses observed for the compounds studied were the ions resulting from protonation of the amine formed by the loss of CH3X (6). Recently Ohashi and co-workers have reported the successful use of in-beam electron impact ionization to produce useful spectra of several amino acids.…”

“…The drift field strength was 129 Vkm-Torr, sufficient to produce substantial amounts of fragmentation characteristic of these two structural isomers preferential solvation of the product ion favors formation of RCOOH2+-OH2 from (RCOOR')H+.OH, over formation of RCOOH2+ from (RCOOH')H+. Inasmuch as the origins and analytical utility of all of the various ions observed in the CI spectra of esters have been discussed extensively in previous work (6,8,14), there is no ease of identifying esters from their water CI spectra at high E / P in the drift tube source, Figure 3 compares the spectra of ethyl butyrate and propyl propionate at 129 V/cm-Torr. The MH+ ions at m / e 117 are present for both esters, but none of the other peaks are identical.…”

“…There is one important difference between methane (6,8) and water CI spectra of esters which should be noted, and that is the complete absence of M+ and (M -1)+ ions in the water CI spectra. The absence of these peaks is a great advantage when attempting to assess the isotopic or chemical purity of a compound from its water CI spectrum at low E / P .…”

Chemical Ionization—A Mass‐Spectrometric Analytical Procedure of Rapidly Increasing Importance

“…several quasimolecular ions (cf. footnote [*I on p. 436), as is the case with certain quaternary nitrogen compounds [75]. If in this latter case only one pyrolysis product is formed, the presence of a covalent compound can be simulated (e. to chemical (incidentally, this was the first application of CI to structure analysis).…”

Field desorption mass spectrometry of quaternary ammonium salts: Cluster ion formation

“…mass spectra the substance must be vaporized. In the case of quaternary ammonium salts this will lead to thermal decomposition products which may be analysed by both e.i.m.s.l and c.i.m.s.. 2 By means of f.d.m.s., however, the direct analysis of organic salts is possible. In f.d.…”