Biological Detection Using Self-Ionization Optimization in an Ion Trap Mass Spectrometer

Abstract

For a few years now, mass spectrometry techniques have contributed significantly to the investigation of biomaterials. Characterization of active molecules from biological organisms is one of the areas in which mass spectrometry and tandem mass spectrometry have been applied frequently. Various configurations of mass spectrometry have been used in bacterial taxonomy for the preferential detection of chemical taxonomic markers. Our purpose was to carry out a preliminary study and exploration of a new taxonomic profiling approach: self-ionization for MH⁺ generation followed by structural determination by collision-induced dissociation investigation. Fatty acid methyl ester profiles from electron impact (EI) mass spectrum analysis have been chosen as specific biomarkers to differentiate different samples. The fragmentation pathways of biological material in the ion trap mass spectrometer are the result of the co-existence of different ionization processes: EI ionization and self-ionization due to the high efficiency of large molecule reactions induced from EI fragment ions. The corresponding neutrals of the ions have a relatively low basicity compared to the analyzed substrate. This will be discussed further.