Paiste, Päärn, juhendajaKirsimäe, Kalle, juhendajaJansons, MartinšTartu Ülikool. Loodus- ja täppisteaduste valdkond2017-06-302017-06-302016http://hdl.handle.net/10062/57047Sedimentary dolomite (Es-16, Es-18) and limestone (Es-3, Es-14, Es-17) from Geological Survey of Estonia have been used as reference materials in X-ray fluorescence analysis in Estonian laboratories. Homogeneity of these materials was investigated with laser-ablation inductively coupled plasma mass-spectrometry using MACS-3 and NIST612 certified reference materials for calibration. Natural limestone CAL-S from CRPG was analyzed for overall comparison. Potential application of Es’s as micro-analytical reference materials was evaluated by quantification of uncertainty due to inhomogeneity and estimation of homogeneity index. Es-17 and Es-16 were found most homogenous. More homogenous distribution and higher concentrations of Cs and Rb were found in Es-17, Es-3 and Es-16 than in MACS-3. Inhomogenous distribution of rare earth elements was observed in Es-14, Es-18 and Es-17.engLA-ICP-MShomogeneitycalcium carbonatereference materialsThesis