The main tools, we use to reach our scientific goals are Atmospheric-Pressure-interface – Time-Of-Flight (APi-TOF) mass spectrometers with different Chemical Ionization (CI) systems.

Core technology, the APi-TOF mass spectrometer, is manufactured by Tofwerk A.G., Switzerland ( and delivered by Aerodyne Research Inc., MA, USA. ( We develop and construct systems for chemical ionization that serve our purposes best. The core ionization scheme, nitrate ion (NO3-) based ionization, was originally developed by Fred Eisele and his coworkers at National Centre of Atmospheric Research, Colorado. We adopted the technique, and connected it with an APi-TOF 2011. That combination has proven to be superior for detection of atmospheric low volatile aerosol precursor vapours, including Sulfuric acid and Extremely Low Volatile Organic Compounds (ELVOC).

After introduction of nitrate ion CI-APi-TOF, we have developed various different ionization techniques, in order to widen the space of detectable quantities and to improve the sensitivity of technology.

APi-TOF, without any CI, can detect naturally charged molecules and clusters, this is highly useful for studying ion-induced nucleation, believed to be important in certain parts of the atmosphere. With nitrate ion – CI, we have been successfully recording the cluster formation process molecule by molecule in CERN CLOUD chamber facility ( We have also succeeded, for the first time, to resolve cluster formation mechanism in the real atmosphere, on western coast of Ireland, and northernmost Greenland, where iodic acid molecules are responsible on cluster and new particle formation.

Besides mass spectrometers, we also use different aerosol and trace gas instrumentation to support our observations.