HR: 17:30h
AN: A54A-07    [Abstracts]
TI: Two-Step Single Particle Mass Spectrometry for On-Line Monitoring of Polycyclic Aromatic Hydrocarbons Bound to Ambient Fine Particulate Matter
AU: * Zimmermann, R
EM: ralf .zimmermann@gsf.de
AF: GSF-National Research Center for Environment and Health Institute for Ecological Chemistry, Ingolstädter Landstrasse 1, Oberschleissheim, 85764, Germany
AU: * Zimmermann, R
EM: ralf .zimmermann@gsf.de
AF: Analytical Chemistry Institute of Physics University of Augsburg, Universitätsstraße 1, Augsburg, 86159, Germany
AU: Bente, M
AF: GSF-National Research Center for Environment and Health Institute for Ecological Chemistry, Ingolstädter Landstrasse 1, Oberschleissheim, 85764, Germany
AU: Bente, M
AF: Analytical Chemistry Institute of Physics University of Augsburg, Universitätsstraße 1, Augsburg, 86159, Germany
AU: Sklorz, M
AF: GSF-National Research Center for Environment and Health Institute for Ecological Chemistry, Ingolstädter Landstrasse 1, Oberschleissheim, 85764, Germany
AB: Polycyclic aromatic hydrocarbons (PAH) are formed as trace products in combustion processes and are emitted to the atmosphere. Larger PAH have low vapour pressure and are predominantly bound to the ambient fine particulate matter (PM). Upon inhalation, PAH show both, chronic human toxicity (i.e. many PAH are potent carcinogens) as well as acute human toxicity (i.e. inflammatory effects due to oxi-dative stress) and are discussed to be relevant for the observed health effect of ambient PM. Therefore a better understanding of the occurrence, dynamics and particle size dependence of particle bound-PAH is of great interest. On-line aerosol mass spectrometry in principle is the method of choice to investigate the size resolved changes in the chemical speciation of particles as well the status of internal vs. external mixing of chemical constituents. However the present available aerosol mass spectrometers (ATOFMS and AMS) do not allow detection of PAH from ambient air PM. In order to allow a single particle based monitoring of PAH from ambient PM a new single particle laser ionisation mass spectrometer was built and applied. The system is based on ATOFMS principle but uses a two- step photo-ionization. A tracked and sized particle firstly is laser desorbed (LD) by a IR-laser pulse (CO2-laser, λ=10.2 μm) and subsequently the released PAH are selectively ionized by an intense UV-laser pulse (ArF excimer, λ=248 nm) in a resonance enhanced multiphoton ionisation process (REMPI). The PAH-ions are detected in a time of flight mass spectrometer (TOFMS). A virtual impactor enrichment unit is used to increase the detection frequency of the ambient particles. With the current inlet system particles from about 400 nm to 10 μm are accessible. Single particle based temporal profiles of PAH containing particles ion (size distribution and PAH speciation) have been recorded in Oberschleissheim, Germany from ambient air. Furthermore profiles of relevant emission sources (e.g. gasoline and diesel engine, wood combustion) and the obtained chemical profiles were compared with the ones from the ambient PAH containing particles.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting