Entstehung von nitrierten polyzyklischen aromatischen Kohlenwasserstoffen (NPAHs) im Abgas von Verbrennungskraftmaschinen mittels Laser-Fotofragmentierung
Objectives
Nitrated polycyclic aromatic hydrocarbons (NPAHs), together with their parent compounds, PAHs, are probably the abiotic class of substances which is most harmful for human health, not only in the atmosphere, but in the total environment. More than a third of the mutagenic potential of ambient air is attributable to NPAHs. Our aim is to employ photofragmentation (PF), the process of breaking chemical bonds through interaction with one or multiple photons, as a means to investigate NPAHs in the gas phase as well as adsorbed on aerosol particulate matter. High sensitivities in the low ppb or even ppt range for PF-based gas phase analysis can be achieved.
Method of Approach
Our aim is to employ photofragmentation (PF), the process of breaking chemical bonds through interaction with one or multiple photons, as a means to investigate NPAHs in the gas phase as well as adsorbed on aerosol particulate matter. High sensitivities in the low ppb or even ppt range for PF-based gas phase analysis can be achieved.
Different modalities can be distinguished, regarding the fragmentation mechanism and the way of fragment detection. Resonant fragmentation allows for a rather straight-forward system set-up; a single laser pulse can be employed for fragmentation and photoionization. Depending on the photon energy employed, the fragments can be generated in an excited state, relaxing by optical emission.
Financial Support
- DFG
Responsible
- PI: Christoph Haisch
- Peter Menzenbach