Atmospheric aerosols are important as they have impact on earth’s climate and human health.
Organic components represent a significant fraction of atmospheric aerosols. They can be directly emitted in the atmosphere or formed in the atmosphere by oxidation of gaseous precursors.
Real-time characterisation of organic aerosol is required to understand their sources, formation and ageing (change) in the atmosphere.
There are several mass spectrometry techniques currently used for real-time characterisation of organic aerosols. However, the techniques use hard ionisation, resulting in molecular fragmentation, and/or don’t have sufficient mass resolving power to allow unambiguous chemical speciation.
Orbitrap is a high resolution mass spectrometer that has recently been coupled with an Extractive Electrospray Ionisation (EESI) source. However, detection limits of such an instrument might not be sufficient for below-ambient organic aerosol concentrations.
To overcome this limitation, this project proposes to couple Particle Into Liquid Sampler (PILS) with orbitrap MS.
PILS captures particles by growing them into droplets and collecting them using a “wetted-wall cyclone”. This is expected to have a higher collection efficiency than EESI source.
The main activities you'll be involved in as part of this research includes:
- characterisation of PILS with methanol or acetonitrile used as a solvent for the “wetted wall cyclone”
- coupling PILS and ESI-Orbitrap MS with emphasis on matching/optimising the flows
- testing PILS-ESI-Orbitrap MS system using several single component aerosols
- applying PILS-ESI-Orbitrap MS system for online characterisation of:
- organic aerosol generated in a flow-through reactor
- Brisbane ambient aerosol.
We anticipate that the proposed system will have lower detection limits than currently available online high resolution mass spectrometry techniques.
This will provide enhanced analytical capability towards the chemical characterisation of organic aerosols.
Skills and experience
This project is suitable for you as a technically-proficient student with a background in chemistry or physics.
You may be able to apply for a research scholarship in our annual scholarship round.
Contact the supervisor for more information.