Bottled Mineral Waters as Unconventional Sampling in Hydro-Geological Research

Bottled mineral waters originate from groundwater aquifers, their chemical composition being initially determined by geochemical water-rock interaction processes. The waters used for bottling originate from different parts of the hydrological cycle and have a unique hydro-geochemical fingerprint. As water moves through the water cycle, the isotopic composition of oxygen and hydrogen in the water molecule may change. Determining 18O and 2H can help to characterize the source of bottled water and the natural conditions of the parent water body, of the recharge area, and the influence of various processes during infiltration and water flow within the water body. Usually, the chemical composition is reported on the label of bottled waters, while stable isotopes data are often unreported and are sometimes available from scientific publications. Bottled waters from selected sites of Europe where chemical and stable isotopic composition were available have been considered and accompanying data reinterpreted. The available data have been reinterpreted by obtaining results comparable, within limitations, to traditional sampling and analytical procedures, demonstrating the usefulness of the adopted methodology in emergency cases. Therefore, the utilization of isotopic values of bottled waters should be limited to the observation of general trends in isotopic composition of feeding waters, while more local studies are advised for a better understanding of the hydrogeological circuits.