Transcript Powerpoint template for scientific posters (Swarthmore College)

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)
Introduction :
Emilie Grazioli et Anthony Bonilla
L3 Biologie Parcours Environnement
Université de Nimes, France
Materials and method :
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.
Samples :
Results :
:
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).
Conclusion and perspectives :
The study showed a correlation
between 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.
Physical preparation :
The leaves were crushed with liquid nitrogen. The
rocks were ground. The soils were sieved. The
grapes were pressed to give juice.
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
=?
Soils
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).
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
Figure 3 : isotopic composition of samples
Discussions
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.
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
Juices
Leaves
87Sr/86Sr
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).
=?
Figure 1 : Strontium
isotopic composition
transmit from rocks to
wine
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
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