We studied the Pb, Sr, U isotopic composition and the concentration of toxic elements in sediment core samples collected in Lake Balaton at a sediment trap that was deep dredged in 1979, to analyze their changes in the last 40 years. Pb isotopic composition pro les of cores taken from the sediment trap showed a shift in 206 Pb/ 207 Pb from 1.206 ± 0.002 to 1.185 ± 0.002 going from bottom towards the top of the sediment, at 80-100 cm depth. Concomitantly Pb concentration together with Zn, Sb, Cu, Cd and Fe showed elevated, 2-4 times higher values in the top phase of the sediment. Calculated Pb isotopic composition of pollutant Pb fraction was 1.177 ± 0.005 in the case of the 206 Pb/ 207 Pb and 2.456 ± 0.004 for 208 Pb/ 207 Pb, which shows good agreement with literature data for lead ores in Poland and Germany, but it is distinct from literature data for leaded fuel concerning Middle and Eastern Europe. The marked change of the Pb signatures enabled the construction of a sediment deposition rate map. U and Mo showed a characteristic concentration peak in positioned exactly at the depth of Pb signature transition. Isotopic signature of U based on 234 U and 235 U also showed similar pattern. We suggest that the deposition of U and Mo can be related to cyanobacterial blooms in Lake Balaton in late1970s and early1980s.

We studied the Pb, Sr, U isotopic composition and the concentration of toxic elements in sediment core samples collected in Lake Balaton at a sediment trap that was deep dredged in 1979, to analyze their changes in the last 40 years. Pb isotopic composition profiles of cores taken from the sediment trap showed a shift in 206Pb/207Pb from 1.206 ± 0.002 to 1.185 ± 0.002 going from bottom towards the top of the sediment, at 80–100 cm depth. Concomitantly Pb concentration together with Zn, Sb, Cu, Cd and Fe showed elevated, 2–4 times higher values in the top phase of the sediment. Calculated Pb isotopic composition of pollutant Pb fraction was 1.177 ± 0.005 in the case of the 206Pb/207Pb and 2.456 ± 0.004 for 208Pb/207Pb, which shows good agreement with literature data for lead ores in Poland and Germany, but it is distinct from literature data for leaded fuel concerning Middle and Eastern Europe. The marked change of the Pb signatures enabled the construction of a sediment deposition rate map. U and Mo showed a characteristic concentration peak in positioned exactly at the depth of Pb signature transition. Isotopic signature of U based on 234U and 235U also showed similar pattern. We suggest that the deposition of U and Mo can be related to cyanobacterial blooms in Lake Balaton in late1970s and early1980s.

Purpose We analyzed the isotopic composition of four elements, Sr, Pb, U, and Mg, in bottled natural mineral waters and medicinal waters. We aimed to develop a robust geochemistry-based analytical operation procedure to authenticate mineral waters. Methods A simplified sample preparation method using ion exchange and corona-ether-based chromatographic workflow was developed together with the optimization of HR-ICP-MS (NU-Attom ES) measurement methods. Findings: We found a large diversity in Pb and Sr isotope ratios and the shift of 234U/235U isotopic composition of samples compared to in laboratory reference material derived from NIST2710 SRM. The resolving power of 26Mg/24Mg was limited. 4 samples out of the 25 differed, barely significantly, from the average of all samples. The three Pb isotopic parameters correlated with each other but not all the variations could be explained by one single parameter. Sr, Mg, and U signatures were independent of each other, and Pb isotopic signatures, PCA could not reduce the dimensionality of the data without a large information loss. Using isotopic identification parameters directly, all the different aquifers could be distinguished. The parameter values did not change in a 4-years interval. Originality: We report the first multi-isotopic, ICP-MS-based method for food authentication, which is readily applicable in a commercial framework.