Sr isotopes and italian wines: an attempt to characterize traceability for the wine origin and marketing

The assignment of geographical origin of highly valuable products such as wine, is of considerable importance within the European Union. Conventional chemical methods of analysis are not always able to evaluate unambiguously the regional provenance of wine. Therefore, stable isotope ratio of bioelements such as C, N, O, S and isotope ratios of heavy elements (Pb and Sr) have been also applied to provide additional information of wine regional origin. The application of Sr isotopes to the characterization of wine dates as back as the ‘90s (Horns et al., 1993). In these two decades, however, no clear-cut evidence has been achieved on the thoroughly usefulness of Sr isotopes for wine characterization. In fact, isotopic ambiguity has been found for wines from certain areas throughout the world (e.g. Vorster et al., 2010). The first data of Sr-isotope ratios of Italian wines were carried out by Wolff-Bönisch et al. (1998), who reported analyses of wines from the Vesuvius and Etna volcanic districts, finding obvious differences. Recently, Mercurio et al. (2011) have determined the isotopic composition of wines from the Phlegrean Fields area, and Castorina and Masi (2011) have carried out a study of wines from Romagna. In this work, we present the Sr isotopic composition of several Italian wines aimed at evaluating the potential of this geochemical tracer of provenance. Although a larger database is needed, nevertheless, the results obtained with this study confirm that Sr isotopes can be used as a valuable tool for constraining the geographical origin of wine, at least combined with the application of other isotopic systematics and/or multi-element analysis.