Emilie Grazioli et Anthony Bonilla L3 Biologie Parcours Environnement Université de Nimes, France

1. Characterization of strontium isotopic composition of vineyard rocks, soils, grape juices and vine leaves for a recognition of geographical origins of wine from the Domaine du Mas Rouge, in Vic-La-Gardiole (Hérault, France) Emilie Grazioli et Anthony Bonilla L3 Biologie Parcours Environnement Université de Nimes, France Introduction : Agricultural food products like wine, can be identified with a method consisting in finding strontium isotopic composition (87Sr/86 Sr). Indeed, the ratio between 87 and 86 isotopes of strontium (87Sr/86 Sr) is used as a marker, allowing a link between land (soils and rocks) and wines from this region. Materials and method : Samples : Samples of rocks, soils, juices, vine leaves of three vineyard parcels (Le Chêne, Vigne du Lac and Terres Rouges, in Vic-La-Gardiole, Hérault, France). Physical preparation : The leaves were crushed with liquid nitrogen. The rocks were ground. The soils were sieved. The grapes were pressed to give juice. Separation of strontium : Basic separation of strontium was performed in a clean room class 100 and required upstream weighing and partial or total dissolution of samples To retrieve the strontium, the solutions obtained during the various attacks were placed on a resin that captured the strontium and eliminated the other elements. Strontium Sr Resin, a special resin, was used Results :: Conclusion and perspectives : The study showed a correlationbetween the strontium isotopic composition of rocks, soils and grape juices. However, an anomaly was observed: the leaves are much more enriched in 87Sr as soils and rocks. An analysis of the strontium isotope composition of fertilizers may be carried out to verify that the enrichment of the leaves is related to the addition of these products (these products were sampled and are available for review). Further analyses of the wine should be done to study the exact correlation between the rocks, soils, grape juices and the final product: the wine from the Domaine du Mas Rouge. The aim of the study is to investigate the marking 87Sr/86Sr of rocks, soil and vine leaves in three vineyard parcels in this area to verify that the strontium isotopic composition is transmitted from rocks to the soil, and from soils to plants. This approach is preliminary to a more comprehensive study which will include wines produced by the wine-grower 87Sr/86Sr = ? Figure 3 : isotopic composition of samples Soils Discussions Rocks • There is an enrichment of 87Sr leaves in comparison to soil, rock and grape juices. It may be explained by : • - Use of fertilizers : a recent study on coffee has shown that fertilizers have isotopic composition (87Sr/86 Sr) higher than samples • Mixing processes : simulations were made and gave coherent rate that can justify this enrichment • There is an enrichment of 87Sr soils in comparison of rocks. Indeed, this enrichment can be explained by leaching of rocks that releases the chemical elements in the soil (including strontium). References : Lancelot, J., Herreiras, J., Verdoux, P., Lurton, L. (1999). The use of strontium isotopes geochemistry for a high resolution identification of wines from the Rhone Valley. Fifth European Symposium of Food Authenticity, La Baule, 9-11 June 1999 Techer, I., (2006). Authentification de l’origine géographique du café « Bourbon piontu » de l’île de la Réunion par le marquage isotopique en Sr Techer, I., Lancelot, J., Descroix, F., Guyot, B., (2008). Sr isotopes in cofee beans : fertilization influence on a regional tracer Juices Leaves 87Sr/86Sr = ? Figure 1 : Strontium isotopic composition transmit from rocks to wine The shift to mass spectrometer was essential to separate the different isotopes of strontium. It provided the following results: reports 87Sr/86 Sr, 86Sr / 88Sr and errors measures Wine