Contact person: Ivana Tomášková
The laboratory is used for the analysis of stable isotopes of elements important in the physiology of plants and animals, i.e. C, N, S, O, and H. Given that individual isotopes have a different number of neutrons in their nucleus, they also enter physiological processes in different proportions. This makes it possible to trace the place of origin of a plant/tree, trace the migration of animals, or estimate the climatic conditions in the past based on the representation of oxygen isotopes in individual annual rings. The device has the potential to generate practical outputs as well, as it is possible to verify the origin of wood on the market based on stable isotopes. Research is currently underway on samples from oak boreholes within the Czech Republic; its aim is to find a specific representation of selected stable isotopes for oaks from individual regions of the Czech Republic. As part of zoological studies, experiments analysing the quality of food from animal fur are carried out.
We use an elemental analyser configured with a Thermo Fisher Delta V Plus stable isotope mass spectrometer. It is a continuous system that uses helium as a carrier gas. The elemental analyser quantitatively converts the carbon in the sample to carbon dioxide and the nitrogen to nitrogen gas, which is then sent to a mass spectrometer for stable isotope analysis.
A mass spectrometer consists of five main components: inlet, source, ionization chamber, magnet, and collection dishes. Gas samples enter the mass spectrometer through an inlet and, once in the source, the CO2 molecules are bombarded with high-energy electrons that knock an electron off the CO2 molecule and ionize it. The ions are then accelerated through ionization chamber where they encounter a magnetic field that changes their flight path based on their ratio of atomic mass to charge. Lighter ions are deflected more than heavier ions. Depending on their mass, different ions hit different collecting dishes, where they generate an electrical signal proportional to the number of incident ions. The integrated signals from each collection dish can then be used to calculate the ratio of heavy to light isotopes.