1. Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, 5232 Villigen, Switzerland
2. Empa, Laboratory for Air Pollution and Environmental Technology, 8600 Duebendorf, Switzerland
3. Paul Scherrer Institute, Bioenergy and Catalysis Laboratory, 5232 Villigen, Switzerland
4. École polytechnique fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland