A5010765737- Mass Spectrometry Techniques and Applications
- Atmospheric Ozone and Climate
- Analytical Chemistry and Chromatography
- Spectroscopy and Laser Applications
- Advanced Chemical Physics Studies
- Atmospheric chemistry and aerosols
- Metabolomics and Mass Spectrometry Studies
- Advanced Proteomics Techniques and Applications
- Microfluidic and Capillary Electrophoresis Applications
- Pesticide and Herbicide Environmental Studies
- Chemical Reaction Mechanisms
- Atmospheric and Environmental Gas Dynamics
- Photochemistry and Electron Transfer Studies
- Insect and Pesticide Research
- Protein Structure and Dynamics
- Photodynamic Therapy Research Studies
- Crystallization and Solubility Studies
University of Wollongong
2018-2025
Sustainable Horizons Institute
2025
Here we report the development and optimization of a mass spectrometry imaging (MSI) platform that combines an atmospheric-pressure matrix-assisted laser desorption/ionization with plasma postionization (AP-MALDI-PPI) trapped ion mobility (TIMS). We discuss optimal parameters for operating source, characterize behavior variety lipid classes in positive- negative-ion modes, explore capabilities using murine brain tissue. The instrument generates high signal-to-noise numerous species, spectra...
Reactions with mobile protons occur under electrospray ionization (ESI) in many applications of mass spectrometry. Understanding how protonation isomers (protomers) form and molecular structure influences protomer interconversion provides fundamental insight into ESI mechanisms, which can then be exploited to rationalize ion mobility activation processes for robust analyte detection. Using ten arylamine systems, this paper establishes the key substrate properties that influence isomerism....
The influence of oriented electric fields on chemical reactivity and photochemistry is an area increasing interest. Within a molecule, different protonation sites offer the opportunity to control location charge thus orientation fields. New techniques are needed discriminate between isomers in order understand this effect. This investigation reports UV-photodissociation action spectroscopy two (protomers) 1,3-diazanaphthalene (quinazoline) arising from nitrogen at either 1- or 3-position. It...
Electrospray ionization (ESI) is used to deliver analytes for mass analysis across a huge range of spectrometry applications. Despite its ubiquitous application and many mechanistic investigations, it remains that fundamental understanding ESI processes not complete. In particular, all the factors influence populations protonation isomers are elusive such challenge optimize experimental conditions favor one isomer over another. The molecule para-aminobenzoic acid has emerged as an archetype...
The detection and assignment of protonation isomers, termed protomers, gas-phase ions remains a challenge in mass spectrometry. With the emergence ion-mobility techniques combined with tuneable-laser photodissociation spectroscopy, new experimental combinations are possible to now meet this challenge. In paper, differences fragmentation electronic spectroscopy singly protonated (S)-nicotine (nicH+) analysed using action ultraviolet region field asymmetric ion mobility spectrometry (FAIMS)....
Understanding how neutral molecules become protonated during positive-ion electrospray ionization (ESI) mass spectrometry is critically important to ensure analytes can be efficiently ionized, detected, and unambiguously identified. The ESI solvent one of several parameters that alter the dominant site protonation in polyfunctional thus, turn, significantly change collision-induced dissociation (CID) spectra relied upon for compound identification. Ciprofloxacin─a common fluoroquinolone...
Proton-transfer reactions are commonplace during electrospray ionization (ESI) mass spectrometry experiments and often responsible for imparting charge to analyte molecules. Multiple protonation-site isomers (protomers) can arise polyfunctional molecules these interconvert via solvent-mediated proton transfer various stages of the ESI process. Studying populations interconversion protonation provides key insight into process, ion–molecule interactions, ion dissociation mechanisms. An...
Certain chemical groups give rise to characteristic excited-state deactivation mechanisms. Here, we target the role of a protonated N-N group in indazole by comparison its isomer that lacks this group, benzimidazole. Gas-phase and benzimidazole ions are investigated at room temperature using picosecond laser pump-probe photodissociation experiments linear ion-trap. Excited state lifetimes measured across range pump energies (4.0-5.4 eV). The 1ππ* from 390 ± 70 ps 4.0 eV energy ≤18 4.6...
Iodinate anions are important in the chemistry of atmosphere where they implicated ozone depletion and particle formation. The atmospheric iodine is a complex overlay neutral–neutral, ion–neutral, photochemical processes, many reactions intermediates remain poorly characterized. This study targets visible spectroscopy photostability gas-phase hypoiodite anion (IO–), initial product I– + O3 reaction, by mass spectrometry equipped with resonance-enhanced photodissociation total ion-loss action...
Ubiquitous but wily to define! Ion mobility mass spectrometry together with DFT determines the fundamental coexisting isomers in glyphosate and aminomethylphosphinic acid (AMPA) complexes, including unique selectivity due metal or ligand.
Here we report the development and optimization of a mass spectrometry imaging (MSI) platform that combines atmospheric-pressure matrix-assisted laser desorption/ionization with plasma post-ionization (AP-MALDI-PPI) trapped ion mobility (TIMS). We discuss optimal parameters for operating source, characterize behaviour variety lipid classes in positive- negative-ion modes explore capabilities using murine brain tissue. The instrument generates high signal-to-noise numerous species, spectra...
Iodinate anions are important in the chemistry of atmosphere where they implicated ozone depletion and particle formation. The atmospheric iodine is a complex overlay neutral-neutral, ion-neutral photochemical processes, many reactions intermediates remain poorly characterised. This study targets visible spectroscopy photostability gas-phase hypoiodite anion (IO−), initial product I− + O3 reaction, by mass spectrometry equipped with resonance-enhanced photodissociation total ion-loss action...
Protonation or deprotonation sites mediate many cases of biological photochemistry.For example, flavin ions have several photobiological functions such as initiating DNA repair (occurring in some bacteria and frogs for example) are central to quantum mechanical compass used by birds navigation.These pathways involve various stages protonation deprotonation, isomers redox states.Furthermore, intermediate radicals (which formed the photoredox pathways) possible (protomers) that challenging...
Iodine oxides (I x O y ) are atmospherically important due to their high reactivity with ozone.The I -anion has been detected in the atmosphere, along IO 2 -and 3 -however, -is yet be directly despite being a key intermediate formation.a A recent gas phase study b confirms -will react ozone form -with subsequent step-wise reactions -then -.The aim of present is investigate photodepletion -within visible range 650 -450 nm (15385 -22222 cm -1 via photodetachment and photodissociation...
Iodinate anions are important in the chemistry of atmosphere where they implicated ozone depletion and particle formation. The atmospheric iodine is a complex overlay neutral-neutral, ion-neutral photochemical processes, many reactions intermediates remain poorly characterised. This study targets visible spectroscopy photostability gas-phase hypoiodite anion (IO−), initial product I− + O3 reaction, by mass spectrometry equipped with resonance-enhanced photodissociation total ion-loss action...