“…The S2 PICOFOX (Bruker Nano GmbH, Germany), a benchtop spectrometer, has been used in the TXRF laboratory of the Centre for Geodynamics and Geo chronology since 2009. Initially, the TXRF laboratory was specialized in the analysis of liquid samples as water [Pashkova, Revenko, 2013a, 2013bPashkova et al, 2013], brines [Pashkova, Revenko, 2015;Pashkova et al, 2013], milk [Smagunova, Pashkova, 2013;Pashkova et al, 2018b], tea [Maltsev et al, 2019a[Maltsev et al, , 2021a, and beverages [Maltsev et al, 2019b[Maltsev et al, , 2022. Nowadays we also use TXRF for different solid samples with a complex mineral matrix.…”