fastGC - Development of hyper-fast gas chromatography for online photoionisation mass spectrometry
Components of organic aerosol are known to have complex impacts on human health and climate. The investigation of dynamic changes in combustion processes, such as in logwood combustion or car-driving at different speeds, requires measurement techniques of appropriate time resolution to follow qualitative and quantitative changes in complex organic emissions. Single-photon (SPI) and resonance-enhance multi-photon ionisation (REMPI) as soft ionisation techniques combined with time-of-flight mass spectrometry (TOFMS) fulfil the requirements. However, solely based on molecular mass no identifications of compounds can be carried out. The hyphenation of fast gas chromatography with a novel Peltier-modulator for sampling to SPI/REMPI-TOFMS can overcome this issue and separate isobars while compounds of equal retention time but different mass are separated through different peaks in the mass spectra. Hence, single volatile to semi-volatile compounds can be analysed with moderate time resolution during dynamic combustion processes. The focus here will be on alkylated polycyclic aromatic hydrocarbons (PAH) and phenolic species, which both can be analysed by SPI- and REMPI-TOFMS with low limits of detection. Alkylated PAHs, which are mainly emitted by combustion processes using fossil fuels, have recently moved towards the centre stage of PAH research because it has been shown that they can cover significantly different toxicological properties than their unsubstituted basic structures. Phenolic species are known to be emitted by mainly biomass combustion and are long suspected to mitigate toxicological effects of other compounds of the combustion aerosol. Among the toxicological assessment of emission, the data can be valuable to predict possible conversion processes in ambient air, e.g. ozone formation potential or the formation of secondary organic aerosol. Finally, the Fast-GC-SPI/REMPI setup can be further utilised in an additional hyphenation to a thermal-optical carbon analyser to investigated particle-bound organic species and cover the full volatility range of organic aerosol emission.
fastGC - Development of hyper-fast gas chromatography for online photoionisation mass spectrometry
Components of organic aerosol are known to have complex impacts on human health and climate. The investigation of dynamic changes in combustion processes, such as in logwood combustion or car-driving at different speeds, requires measurement techniques of appropriate time resolution to follow qualitative and quantitative changes in complex organic emissions. Single-photon (SPI) and resonance-enhance multi-photon ionisation (REMPI) as soft ionisation techniques combined with time-of-flight mass spectrometry (TOFMS) fulfil the requirements. However, solely based on molecular mass no identifications of compounds can be carried out. The hyphenation of fast gas chromatography with a novel Peltier-modulator for sampling to SPI/REMPI-TOFMS can overcome this issue and separate isobars while compounds of equal retention time but different mass are separated through different peaks in the mass spectra. Hence, single volatile to semi-volatile compounds can be analysed with moderate time resolution during dynamic combustion processes. The focus here will be on alkylated polycyclic aromatic hydrocarbons (PAH) and phenolic species, which both can be analysed by SPI- and REMPI-TOFMS with low limits of detection. Alkylated PAHs, which are mainly emitted by combustion processes using fossil fuels, have recently moved towards the centre stage of PAH research because it has been shown that they can cover significantly different toxicological properties than their unsubstituted basic structures. Phenolic species are known to be emitted by mainly biomass combustion and are long suspected to mitigate toxicological effects of other compounds of the combustion aerosol. Among the toxicological assessment of emission, the data can be valuable to predict possible conversion processes in ambient air, e.g. ozone formation potential or the formation of secondary organic aerosol. Finally, the Fast-GC-SPI/REMPI setup can be further utilised in an additional hyphenation to a thermal-optical carbon analyser to investigated particle-bound organic species and cover the full volatility range of organic aerosol emission.