Measurement of hydrogen/deuterium ratios in ethanol/ethanol-O-d mixtures by chemical ionization mass spectrometry with tetramethylsilane as reagent gas

Selective reagents in chemical ionization mass spectrometry: trimethylsilyl adduct ions

“…Reaction 2 is the monosolvation of the trimethylsilyl ion with a Lewis base and -( 2) is the dissociation energy of the 73+-M bond or the trimethylsilyl ion 0003-2700/85/0357-2022$01.50/0 affinity of TMSA (M). By analogy to the standard definitions of proton and electron affinities TMSA(M) = -AH( 2) = Mif(73-M)+ -{( +) -{(M,g) (3) An order of bond energies or trimethylsilyl ion affinities has been established for a few compounds which shows trends with molecular structure similar to trends noted for proton affinities (12)(13)(14)(15). The heat of reaction (1), on the other hand, is the difference in trimethylsilyl ion affinities of the two compounds and it is always less negative than the heat of reaction (2).…”

Formation of trimethylsilyl molecular adduct ions in desorption-chemical-ionization mass spectrometry of nonvolatile organic compounds

“…The initial molecular SIMS measurements (2) were, in fact, made after recognizing the significance of the static SIMS condition (7) whereby the primary particle flux is so low that individual surface molecules do not experience multiple impacts during measurement. Introduction of fast atom bombardment (FAB), in which neutral argon primary beams were used (5,6), permitted widespread adaptation of molecular SIMS to magnetic sector instruments and, with the assistance of a glycerol sample matrix, realization of the inherent potential in the SIMS method for identification of high molecular weight compounds (8)(9)(10)(11). Bombardment with heavier primary particles, such as cesium (12)(13)(14) and xenon (15)(16)(17), substantially increased secondary molecular ion abundances and permitted still higher molecular weight identifications to be made in both the static SIMS (18) and FAB/glycerol matrix (19) modes.…”