Spectroscopic studies of impurities on ice
Gabriela Ondrušková1,2
, Ján Krausko1
, Dominik Heger1,2
1 Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A8, 625 00 Brno, Czech Republic
2 Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University, Kamenice 5/A29, 625 00
Brno, Czech Republic
Presenting author: Gabriela Ondrušková, Supervisor: Dominik Heger
The substances present in the air as pollutants may end up on ice and snow due to the
processes called global distillation or grasshopper effect which involve the transport of
chemical substances from warmer to colder region of the earth. These effects explain the
high concentrations of the pollutants on poles. Ice and snow belong among important
reaction media in which an accumulation and concentration enhancement of various types
of impurities occurs. The knowledge of the location and chemical speciation of these
impurities in ice and snow under various conditions is still rather limited, although crucial
for the estimation of the compounds reactivity [1]. It is expected that the compounds
(photo)reactivity differ depending on their particular location in/on the ice, e.g., if they are
present on the surface of ice or in the spaces between ice crystals.
Therefore, we experimentally examined two scenarios that occur in the nature:
freezing of solutions and deposition of the compounds from the gaseous phase. These two
preparation methods yielded very contrasting results as examined by fluorescence [2].
Detailed analysis revealed distinct compounds behaviour during slow (at 253 K) and fast
(at 77 K) freezing. It was observed that impurity crystals are formed at slow freezing
whereas amorphous solution forms at fast freezing. Under the condition of vapor
deposition to ice surface the temperature dependence was observed: at higher
temperature of deposition (253 K) impurities formed crystals whereas at lower
temperature of deposition (77 K) the amorphous structures formed [2].
Within our experiments, naphthalene and 1-methylnaphthalene were utilized as model
compounds whose fluorescence spectroscopic properties are amply understood. At room
temperature naphthalene is crystalline whereas 1-methylnaphthalene is liquid;
comparison of the behaviour is currently under the scrutiny.
The results of our research have implications for the understanding of impurities in the
environment as the selected substances servers as models for other compounds.
1. Yang, X.; Neděla, V.; Runštuk, J.; Ondrušková, G.; Krausko, J.; Vetráková, Ľ.; Heger, D.
Evaporating brine from frost flowers with electron microscopy and implications for
atmospheric chemistry and sea-salt aerosol formation. Atmos. Chem. Phys. 2017, 17
(10), 6291-6303.
2. Ondrušková, G.; Krausko, J.; Stern, J. N.; Hauptmann, A.; Loerting, T.; Heger, D. Distinct
Speciation of Naphthalene Vapor Deposited on Ice Surfaces at 253 or 77 K: Formation
of Submicrometer Sized Crystals or an Amorphous Layer. J. Phys. Chem. C 2018, Just
Accepted Manuscript
3. Krausko, J.; Malongwe, J. K. E.; Bičanová, G.; Klán, P.; Nachtigallová, D.; Heger, D.
Spectroscopic Properties of Naphthalene on the Surface of Ice Grains Revisited: A
Combined Experimental–Computational Approach. J. Phys. Chem. A 2015, 119 (32),
8565-8578
4. Krausko, J.; Ondrušková, G.; Heger, D. Comment on “Photolysis of Polycyclic Aromatic
Hydrocarbons on Water and Ice Surfaces” and on “Nonchromophoric Organic Matter
Suppresses Polycyclic Aromatic Hydrocarbon Photolysis in Ice and at Ice Surfaces”. J.
Phys. Chem. A 2015, 119 (43), 10761-10763