Fast atom bombardment (FAB) and chemical ionization (CI) mass spectrometry of γ-carboxyglutamic acid, 5-substituted-4,4-dicarboxyprolines, and their monodecarboxy derivatives glutamic acid and 5-substituted-4-carboxyprolines

1988 ◽  
Vol 66 (9) ◽  
pp. 2177-2180 ◽  
Author(s):  
R. Capasso ◽  
P. Pucci ◽  
G. Randazzo ◽  
A. Malorni
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Chemical Ionization ◽  
Fast Atom Bombardment ◽  
Renal Stones ◽  
Biological Matrices ◽  
Ionization Technique ◽  
Fab Mass Spectrometry ◽  
Carboxyglutamic Acid

DL-γ-Carboxyglutamic acid (Gla) reacts easily and quantitatively with aldehydes to give the racemic diastereoisomers of 5-substituted-4,4-dicarboxyprolines. After heating at 100 °C for 30 minutes these amino acids lose a carboxyl group from C-γ of Gla and C-4 of the proline ring to give glutamic acid and the racemic diastereoisomers of cyclic analogs of glutamic acid respectively. This paper reports a study of the above-mentioned compounds by using FAB mass spectrometry in comparison with CI analysis. FAB turned out to be an adequate ionization technique for dealing with such nonvolatile and thermolabile amino acids, and may thus allow the development of a rapid and sensitive method for detecting γ-carboxyglutamic acid in urine and in other biological matrices in pathological cases (i.e., renal stones and blood serum).

Fast-Atom Bombardment Mass Spectrometry in Heterogeneous Atmospheric Chemistry

2002 ◽  
Vol 8 (2) ◽  
pp. 131-138 ◽  
Author(s):  
G.B. Pronchev ◽  
I.A. Korobeinikova ◽  
A.N. Yermakov
Keyword(s):  
Mass Spectrometry ◽  
Atmospheric Aerosols ◽  
Atmospheric Chemistry ◽  
Fast Atom Bombardment ◽  
Atmospheric Water ◽  
Ferric Ions ◽  
Fab Mass Spectrometry ◽  
Essential Components ◽  
The Given ◽  
Heterogeneous Atmospheric Chemistry

The application of fast-atom bombardment (FAB) mass spectrometry to solving the problems of heterogeneous atmospheric chemistry is briefly reviewed. The method is useful in studying the state of surfaces and molecules adsorbed thereon and looks appropriate in investigations of the dynamics and mechanisms of chemical reactions occurring both on a surface and in a volume of moving particulate matter suspended in a gas. It was shown that composition of atmospheric aerosols and components dissolved in atmospheric water (clouds, fogs, mists etc.) can be determined by the FAB technique. The given method, as was found in our investigations, allows the discrimination of ferrous and ferric ions. Detection limits for concentrations of H2SO4 and Fe(II / III) ions as essential components of atmospheric water determined in model experiments are established at the level of 10−6 M.

Study of formation and fragmentation of ionic complexes of polydentate ligands with Al(III) and glycerol by fast atom bombardment mass spectrometry. Part 1: Polydentate ligands

1996 ◽  
Vol 74 (11) ◽  
pp. 2221-2228
Author(s):  
Mandapati Saraswathi ◽  
Jack M. Miller
Keyword(s):  
Mass Spectrometry ◽  
Fast Atom Bombardment ◽  
Polyethylene Glycols ◽  
Metal Chelation ◽  
Ionic Complexes ◽  
Polydentate Ligands ◽  
Fragment Ions ◽  
Fab Mass Spectrometry ◽  
Aluminum Ions ◽  
Complexation Reactions

The complexation reactions of aluminum ions with polydentate ligands such as 12-crown-4,15-crown-5,18-crown-6, 1,10-dithia-18-crown-6, dicyclohexyl-18-crown-6, dibenzo-18-crown-6, and dibenzo-24-crown-8 and acyclic analogs mono-, di-, tri-, tetra-, penta-, and hexaethylene glycols were studied using FAB mass spectrometry. These cyclic ligands form (M + 117)+, (M + 157)+, (M + 231)+, and (M + 253)+ ions with different aluminum-containing species. Collisionally activated dissociations of these adduct ions gave fragment ions, initially due to the loss of ligands directly attached to aluminum, followed by insertion of aluminum into the remaining ligand skeleton. Further fragmentation of the metal-containing species gave ions corresponding to consecutive losses of C2H4O units. Fragmentations of deuterium-labelled ions were used to help in establishing fragmentation pathways. Selectivity towards metal chelation is observed in this order: 12-crown-4 < 15-crown-5 < 18-crown-6. The elemental compositions of adduct ions were confirmed by high-resolution measurements. The formation of (M + Al − 2H)+ ion, obtained by the displacement of two hydroxy protons, is more favored for tetra- and pentaethylene glycols. Key words: crown ethers, polyethylene glycols, aluminum(III)–glycerol, ionic complexes and ion dissociations.

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