The MaSMob-Lion project started on Aug. 1, 2021 and lasts through Aug. 31, 2023, in total 25 months. The outgoing phase (Aug. 1, 2021-Aug. 31, 2022) was carried out in the partner organisation, Indiana University–Purdue University Indianapolis (IUPUI) in the United States, under the supervision of Prof. Carlos Larriba. Mobility and mass data have been collected for altogether 40 ions, including amino acids and ammonium ions and clusters. Ammonium samples were analysed in positive mode and amino acid samples were analysed in both positive and negative polarities under nitrogen and air for 0%, 20% and 40% humidity at 24 oC, 34 oC and 41 oC. In the return phase, further experiments on mobility-mass measurements were carried out in the University of Helsinki in collaboration with Dr. Juha Kangasluoma, where one more temperature condition (14 °C) was achieved. Measurements of a series of alkylammonium ions were also performed at the return host, the University of Tartu. Data collected during both outgoing and return phases have been processed and a manuscript is to be submitted.
The project results have been presented at four conferences: American Association for Aerosol Research (AAAR 40th Annual Conference, Oct. 18-22, 2021, oral), 70th American Society for Mass Spectrometry (ASMS2022, June 5-9, 2022, poster), 11th International Aerosol Conference (IAC2022, Sept. 4-9, 2022, oral) and European Aerosol Conference (EAC) 2023 (Sept. 2-8, oral); and at one workshop: 23rd Finnish-Estonian Air Ion and Aerosol Workshop (May 29-30, 2023, oral). In addition, the ER has established collaborations with researchers from Aarhus University, University of Minnesota and University of Helsinki in performing quantum chemistry calculations of the studied ion systems and interpreting the results. The ER has also seconded in Airmodus Oy in Helsinki Finland. During the secondment, in addition to learning practices in company production and R&D work, the ER performed measurements on a DMA-MS setup coupled with a PSM in collaboration with Dr. Juha Kangasluoma et al. from the University of Helsinki.
Performed work:
- Mobility-mass measurements under different temperature and humidity conditions in air and nitrogen (outgoing and return phases)
- Characterisation of the dependence of the mass-mobility relation on ion structure, T, RH and the influence of polarisation (outgoing and return phases).
- Parameterisation using the effective diameter approach and comparison with derivation using coefficients suggested in the ISO15900 (return phase).
- Measurement of activation diameter together with mass-mobility data (secondment&return phase).
- Investigation of the supersaturation needed for activation in relation to the ion structure and mass (return phase).
