Elemental Profile and 87Sr/86Sr Isotope Ratio as Fingerprints for Geographical Traceability of Wines: an Approach on Romanian Wines

Abstract

Wine geographical traceability is an important topic in the context of wine authentication and for that, many researchers worldwide have addressed this subject by developing different methodologies based on multivariate analysis of natural chemical composition data (inorganic or organic parameters) and isotopic signature. The goal of this work was to assess the potential of elemental composition and strontium isotope ratio ( 87 Sr/ 86 Sr) of wines from important wineproducing regions in Romania, located in relatively small geographical areas, in order to highlight reliable markers for wine geographical origin discrimination. Elemental profile determinations were performed by ICP-MS, GFAAS, and FAAS techniques after microwave acid digestion of the wine samples. The 87 Sr/ 86 Sr isotope ratio of the resulted extracts was determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS), after separating strontium and rubidium using cation-exchange chromatography with Dowex 50W-X8 resin and the complexation ability of the carboxylic acid EDTA. The variation of elemental composition (Ga, Sr, and Al), Ca/Sr ratio, and the 87 Sr/ 86 Sr ratio of the investigated wine clearly demonstrated that these variables are suitable tracers for wine geographic origin determination. The proposed methodology allowed a 100 % successful classification of wines according to the region of provenance.

Elemental Profile and 207Pb/206Pb, 208Pb/206Pb, 204Pb/206Pb, 87Sr/86Sr Isotope Ratio as Fingerprints for Geographical Traceability of Romanian Wines

“…The accuracy of the methods was evaluated by replicate analyses of known concentration samples (between 10 µL to 10 mL concentrations) and the obtained values ranged between 0.8-13.1 percent, depending on the element. The global recovery for each element was estimated and the obtained values were between 84.6-100.9% (Geana et al, 2016).…”

“…Several studies on its use for wine geographical origin assessment can be found in literature (Horn et al, 1993;Almeida and Vasconcelos, 2004;Durante et al, 2013;Catarino et al, 2016). Recently, within a research program regarding strategies for wine fingerprinting, the authors confirmed 87 Sr/ 86 Sr as a viable tool for traceability of Romanian PDO and GI wines (Geana et al, 2016), Portuguese PDO, where soils were developed on different geological formations (Martins et al, 2014;Catarino et al, 2016). The use of this parameter as a marker of wine geographical origin is based on the assumption that a relation between soil, plants and wine exists.…”

“…The 87 Sr is radiogenic and therefore the 87 Sr content increases with time due to radioactive decay of 87 Rb (Geana et al, 2016). Since the content of 87 Sr in soil varies with geological age and geographical location, the 87 Sr/ 86 Sr isotopic ratio can be used as a tracer for determining the geographical origin of wine (Vorster et al, 2010).…”

“…This can lead to actions that may have negative economic impact to wine industry (Geana et al, 2016).…”

“…The most used chemical parameters for discriminating the geographical origin of wine are the stable isotope ration of oxygen, carbon and hydrogen (Dordevic et al, 2012;Raco et al, 2015;Geana et al, 2016) and also the elemental composition (Fabani et al, 2010;Selih et al, 2014) including rare elements (Gonzálvez et al, 2009) Sr isotope ratio (Durante et al, 2013;Marchionni et al, 2013;Geana et al, 2016) or a combination of them (Dutra et al, 2011). The ability to differentiate wines by regions through their elemental patterns suggests that elements are mainly regulated by their migration from rock to soil and from vineyard soil to grapes.…”