Secondary processes in atmospheric pressure chemical ionization-ion trap mass spectrometry: a case study of orotic acid.
Atmospheric pressure chemical ionization is known for producing unusual artifacts of the ionization process in some cases. In this work, processes occuring in atmospheric pressure chemical ionization/MS of orotic acid that afforded ions accompanying protonated and deprotonated orotic acid molecules in the spectra were studied. Two processes ran in parallel in the ion source: decarboxylation of neutral orotic acid and collision-induced dissociation of its protonated or deprotonated form. A procedure discerning pre-ionization decomposition and post-ionization dissociation by manipulating ion source parameters was proposed. Experiments with isotopically labeled solvents confirmed ion-molecule reactions of the product of collision-induced dissociation of protonated orotic acid with solvent molecules in the ion source and even under vacuum in the ion trap.
Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University in Olomouc, Olomouc, Czech Republic.
Petr
P
Fryčák
Jaromír
J
Jirkovský
Václav
V
Ranc
Petr
P
Bednář
Vladimír
V
Havlíček
Karel
K
Lemr
D041961:Deuterium Exchange Measurement; D007477:Ions / Q000737:chemistry; D009963:Orotic Acid / Q000737:chemistry*; D011522:Protons; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
D007477:Ions; D011522:Protons; D009963:Orotic Acid