ELEMENTAL CONTENT AND LEAD-STRONTIUM ISOTOPE CHARACTERIZATION OF WINE

Abstract

The ICP-MS technique was used to determine elemental composition (Pb, Sr, Cd, Ni, Co, Cu, Ni, Hg, As, Cr) of wines (Muscat Ottonel, Fetească Albă, Fetească Regală, Fetească Neagră, Merlot and Cabernet Sauvignon) produced during three consecutive years (2014-2016) in Dealu Bujorului Vineyard. The determination of ²⁰⁶Pb/²⁰⁷Pb, ²⁰⁸Pb/²⁰⁶Pb, ²⁰⁶Pb/²⁰⁷Pb and ⁸⁷Sr/⁸⁶Sr isotopes from wines was performed for establishing reliable markers for the wine geographical origin. For all tested wine samples, the toxic metals contents were found in quantities below the limits imposed by legislation. The highest concentration of heavy metals (Cd and Pb) was found in red wine Cabernet Sauvignon [Cd (0.14±0.01 µg/L) (2013)], followed by the same variety of wine from 2012 [Cd (0.14±0.03 µg/L)], in case of Pb the highest concentration was recorded by Merlot [Pb (54.33±1.00 µg/L) (2011)] followed by the same variety of wine but from 2012 [Cd (51.20±1.19 µg/L). Concerning the concentration of the elements in the white wine, it can be noticed that they recorded close concentration as red wine, Muscat Ottonel [Cd (0.12±0.01 µg/L) (2011)], Feteasca Alba [Cd (0.12±0.01 µg/L) (2012)], in case of Pb from white wines the highest concentration was recorded by Feteasca Alba [Pb (52.07±0.50 µg/L) (2012)], Feteasca Regala [Cd (52.29±1.00 µg/L) (2012)]. The highest mean of ⁸⁷Sr/⁸⁶Sr isotopic ratio was obtained at Feteasca Neagra variety [0.726±0.004 (0.575%, 2014)] and Muscat Ottonel variety [0.723±0.003 (0.416 % 2016)]. A possible explanation for the higher mean of ⁸⁷Sr/⁸⁶Sr isotopic ration for wine can be the mineral consistency of the vineyard soil and its different eco-climatic conditions. ²⁰⁶Pb/²⁰⁷Pb isotopic ratios in the analyzed wine samples indicated traces of pollution originated in automobile emissions. (²⁰⁶Pb/²⁰⁷Pb=1.1000-1.1400). The lowest mean ²⁰⁸Pb/²⁰⁶Pb and ²⁰⁶Pb/²⁰⁴Pb isotopic ratios was obtained at Muscat Ottonel variety [2.141±0.007 (0.346% 2015) and 17.469±0.016 (0.094 % 2014)]. The results confirm that the elemental profile and ²⁰⁷Pb/²⁰⁶Pb, ²⁰⁸Pb/²⁰⁶Pb, ²⁰⁴Pb/²⁰⁶Pb, ⁸⁷Sr/⁸⁶Sr isotope ratio can be used to track the geographical origin of wine, discriminate between wine production regions, and can be used to characterize wine terroirs for forensic purpose.