Laser mass spectra of simple aliphatic and aromatic amino acids

Abstract

Mass spectra ot amino acids have been studied using the LAMM A laser microprobe. Quasl-molecular Ions, ( + H)+ and ( -H)~, are produced In high yields. The major neutral fragment loss from ( + H)+ corresponds to HCOOH. Loss

High-energy collisions of protonated enantiopure amino acids with a chiral target gas

“…The formation of this product ion is consistent with the proton transfer model for the fragmentation of protonated amino acids [23][24][25]. The observation of the iminium ion is in good agreement with earlier reports [31][32][33][34]. However, it is in contrast to the suggested theoretical explanation for the absence of the iminium ion, which was reported for Trp fragmentation by Rogalewicz and co-workers [35].…”

“…The intensity of ions with m/z = 159 is a factor of five smaller than that for the m/z = 188 peak. It is one of the highest relative abundances of the iminium ion fragment under TrpH + CID that has been reported this far [24,29,[31][32][33][34].…”

Roadmap for fragmentation of protonated methylarginines in the gas phase

“…Summarized in row-3, a second universal primary fragmentation channel is the loss of water to form the proposed cyclic daughter ion with the depicted structure I, where a new amide bond is formed at N [30,31]. These product ions are highly favorable in Arg and MMA.…”

Direct determination of the ionization energy of histidine with VUV synchrotron radiation

“…However, for histidine [27], the results are inconclusive and we cannot compare our nanoparticle thermal impact studies to these experiments. There is a plethora of techniques dealing with the generation and subsequent fragmentation of protonated histidine [28][29][30][31][32][33]. While direct comparison of fragmentation channels from these studies with the neutral case is not necessarily valid, the fragmentation behavior in these systems could act as a guide to the identity of the daughter ions.…”