1. Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
2. Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
3. Institute for Atmospheric and Environmental Sciences, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany
4. Bioenergy and Catalysis Laboratory, Paul Scherrer Institute, 5232 Villigen, Switzerland