Characterisation of Reactive Organic Compounds in Gases and Particulate Matter

In WP I the aerosols from a large variety of anthropogenic source and model aerosols are characterized with respect to reactive organic compounds and provided for exposure experiments.

The composition of pollutants depends strongly from geographic location and atmospheric conditions and is therefore difficult to interpret. Therefore, emissions of typical anthropogenic combustion sources are investigated. The consortium has extensive experience in operating emission sources and sampling systems. A wide range of technical equipment at the University of Western Finland and at the University of Rostock: boiler burners, automotive engine test setups and marine diesel engines. For tests and standard reference measurements flame soot and ash particles are prepared. Modern fuel formulations (bio-fuel) are taken into account which are known to hold a higher oxygen content.

Modern methods of mass spectrometry and measurement techniques for chemical and physical methods are applied to characterize the emission aerosol comprehensively. Mass spectrometric methods are additionally adapted to characterize the biological response. Both resonance enhanced multi photon ionisation and single photon ionisation set up the basis for the mass spectrometric methods.

For the analysis of aerosols, gas- and particle-phase are applied in combination, but also separately to account for the fact that reactive organic substances frequently occur in a gaseous fraction as vapour in the gas phase, but also as liquid or solid fraction condensed on the aerosol particles.

The reactive organic compounds (ROC) in the gas phase of the aerosol are characterized by photoionization – mass spectrometry, the particles by aerosol – time-of-flight-mass-spectrometry (ATOF). Additionally, physical parameters of the particles like number- and mass concentration are determined on-line. Both particulate matter and gas phase are collected and provided for off-line analysis purposes in WP III.
During work in progress, the analytical focus will be shifted to the potential recurrent markers which are based on the results determined in WP II and WP III. Aim is an emission assessment based on (bio-) statistical concepts which combine the results from WP I together with those of the analytical approaches in WP II and WP III.