Laboratory analyses and experiments:
To analyse samples collected during field-observations (e.g. filter-packs), analysis techniques include: ion chromatography, ICP-MS mass spectrometry, radioactive counting, etc. Measurements of oxygen and sulfur isotopes in volcanic sulfate can be used to determine the dominant oxidation pathways in volcanic sulfur oxidation and to distinguish between primary sulphate (direct aerosol emissions) and secondary sulphate (aerosols produced from sulfur oxidation in the gas phase).
In addition, dedicated laboratory experiments may be of use to help fill the knowledge gaps in our understanding of emission and near-source processes, for example regarding better quantifying aspects of high-temperature chemistry or the multi-phase chemistry at low-temperature in the near-source plume. Possible tools may include: the CESAM chamber for heterogeneous chemistry studies, HELIOS chamber for atmospheric studies with natural irradiation, flow reactors (high/low-temperature). Laboratory facilities are also in development to directly measure high-temperature (magmatic) emissions.