ICP-MS analysis for the characterization of the origins of wines MASSIMO DI MARTINO1, CIAVARDELLI DOMENICO2, FRANCO DI GIACOMO1, CARLO CIVITARESE1, ANGELO CICHELLI1* Angelo Cichelli *Corresponding Author 1. Università Chieti-Pescara, DEc. Laboratorio di Merceologia, Viale Pindaro 42, Pescara, Italy 2. School of Engineering, Architecture/Motor Science Kore University, Enna, Italy/University Foundation, Centre of Study on Aging (Ce.S.I.), Chieti, Italy KEYWORDS: Wine; metals; inductively coupled plasma mass spectrometry; traceability; origins; Italy; Abruzzo; strontium; rubidium; barium. ABSTRACT: Element profiling might represent a valid too for the determination of the origins of foods. In the present study, we have investigated this issue within the oenological sector on 32 wines produced in Abruzzo, Italy. In order to assess wine element composition, we used inductively coupled plasma mass spectrometry, which can be used to determine the levels of a wide range of metals in a short time and classified wine samples on the basis of their origins and element profiles using discriminant analysis. We determined the levels of the following elements: Li, Be, Na, Mg, Al, Ca, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, Se, Rb, Sr, Cs, Ba and Pb. Our analytical approach provided suitable sensitivity for accurate quantification of these elements in red and white wines. The limit of quantification were between between 0.1 mg L-1 (Co, m/z 59) and 42 mg L-1 (Fe, m/z 57). Precision expressed as relative standard deviation and calculated under repeatability conditions was between 3% (Fe, m/z 57) and 22.53% (Co, m/z 59). Recovery values obtained by spike experiments were between 77±5 (Pb, m/z 206) and 110±6 (Li, m/z 7). As specific markers, we evaluated the concentrations of Sr, Ba and Rb. The classification of wines were 100% accurate in linear discriminant analysis. Overall, this study investigates wines produced in central Italy, and it contributes to their traceability and assessment of their origin. Furthermore, our data are in agreement with previously published data, and will help to contribute towards the creation of a national database to protect the consumer against Food analysis commercial fraud. INTRODUCTION than 300 million euro, which constitutes 28% of the regional gross saleable productionand 7% of the national gross saleable Recently, grapevine (Vitis vinifera) cultivation has spread into production. The most cultivated grapevines are: Montepulciano geographical areas and continents where there was not d’Abruzzo, with an area of about 15,000 Ha; Trebbiano, with previously any tradition in this sector. Therefore, in a more an area of about 13,000 Ha; international grapevines (e.g., globalised market, there is a large presence of wines with Chardonnay, Pinot, Cabernet Sauvignon); and indigenous standardised and homogeneous characteristics of their grapevines (e.g., Pecorino, Cococciola, Passerina, Montonico, composition, which often represent imitations of products coming Malvasia). from local supply chains. The differences in wine composition In 2009, approximately 75,000 hL of Montepulciano D’Abruzzo depends on the cultivars, environment, technologies used and DOP wines were bottled, with 62% of this exported, which operative techniques. All of these factors contribute to the demonstrates its commercial success worldwide (4). It is essential - January/February 2013 Vol. 24(1) quality (physicochemical, sensorial, hygienically safe) and to the for the customers to know the origin of these products, in order excellence of origin according to the introduction of the DOP to keep the customers satisfied and provide the necessary and IGP classifications (1). guarantees of transparency in an ever-more-demanding market. The European Community (EC) understands the importance of the protection of local products. To Industry Hi Tech achieve this, the EC issued Regulation EC 1169/2011(2), OOD according to which it is mandatory to indicate the origin F of many products, including wines, extra virgin olive oil, gro A honey, fruit, tomato sauce, fresh milk, and sheep and pork. The traceability of the origins of these products can be important in order to protect the origins of national and local foods, as well as to confirm that a certain product fulfils the necessary conditions to allow it to be linked to its own territory. This produces two main advantages: first, it gives value to the ‘made in Italy’ brand; and second, it helps small local companies that produce excellent products, but oftentimes are imitated by others that are sold as if they were the originals(3). Vineyard cultivation in Abruzzo (Italy, Figure 1), is spread overan area of approximately 33,000 Ha on the hills of the Provinces of Chieti, Pescara, Teramo and L’Aquila. These grapevines represent the main agricultural sector Figure 1. The provinces of Abruzzo of this region, with a gross saleable productionof more 30 According to the literature, some metals present in wines, Teramo (TE), as 5 red wines and 8 white wines (Table 1). such as strontium (Sr), barium (Ba), rubidium (Rb), aluminium The samples were taken from batches ready for commerce (Al), silicon (Si), boron(Bo) and cobalt (Co), can reflect the and were similar according to type, lot number, and accredited composition of the soil of origin and can therefore be useful to area of origin. Subsequently, these samples were mixed to give indications of the different areas of origin of wines(5-16) produce statistically significant samples of approximately and other foods (17). 1 L each. The wines that were sampled were: red wines The aim of the present study was to define the origins of (Sangiovese IGP, Montepulciano D’Abruzzo DOP and, Merlot wines produced in two different areas of the Abruzzo IGP) and white wines (Malvasia IGP, Pecorino IGP, Trebbiano region, but coming from the same vine, according to metal D’Abruzzo DOP, and Chardonnay IGP). Their areas of origin concentrations. The presence of these metals was determined are at altitudes of between 200 m and 300 m above sea using inductively coupled plasma mass spectrometry (ICP-MS), level, which are characterised by a substratum constituted by a tool that allows a element fingerprint of a product, so that it is sedimentary rock. The emerging soils are represented mostly by possible to have scientific traceability of its origins (18). sandstone and marine clay (12). Sample preparation MATERIALS AND METHODS Standards and reagents Deionised water with a specific resistance of 18.2 MW cm Sampling (Milli-Q system, Millipore, Watford, UK) was used to prepare all ICP-MS analyses were conducted on 32 samples of wine solutions and to dilute the samples. Analytical grade ethanol collected directly from the producers. 19 samples came from and the yttrium (Y) stock solution (10 mg L-1) were purchased municipalities in the Province of Chieti (CH), as 12 red wines from Fluka (Shnelldorf, Germany). Ultrapure nitric acid (HNO3, and 7 white wines, and 13 from municipalities of the Province of 69%, UpA) was purchased from Romil (Cambridge, UK). The tuning solution was prepared from a stock solution containing lithium Food analysis (Li), Y, cerium (Ce), tallium (Tl) (10 -1 mg L , in 2% HNO3) purchased from Agilent Technologies (Palo Alto, CA, USA) and from a magnesium (Mg) standard solution (1000 mg L-1) that was purchased from Romil. Multi-element calibration standard stock solution containing Li, beryllium (Be), sodium (Na), Mg, Al, calcium (Ca), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), Co, A nickel (Ni), copper (Cu), zinc (Zn), gro F gallium (Ga), arsenic (As), selenium OOD (Se), Rb, Sr, silver (Ag), cadmium (Cd), caesium (Cs), Ba, Tl, lead (Pb), Industry Hi Tech and uranium (U) (10 mg L-1, in 2% HNO3) was purchased from Agilent Technologies. - January/February 2013 Vol. 24(1) Inductively coupled plasma mass spectrometry analysis The preparation of the wine samples was performed according to previously published procedures, with some minor modifications (11,19). Briefly, the wine was diluted ten-fold with HNO3 (2%) in polystyrene tubes (15 mL; BD Falcon, BD Biosciences, Franklin Lakes, NJ, USA) and analysed for Li, Be, Na, Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb and U. The ICP-MS analysis was performed with a 7500A ICP mass spectrometer (Agilent Technologies, Tokyo, Japan). A Babington nebuliser with a Scott spray chamber (Agilent Technologies) and shield torch system were used. The following operating conditions were applied: forward power, 1260 W; plasma gas flow rate,15 L min-1; carrier gas, 1.13L min-1; spray chamber temperature, 2°C; sampler and Table 1. Municipalities of origin and details of the wines analysed in this study skimmer cone, Ni, 1.0mm and 31 0.4 mm inside diameter; sample uptake rate, 0.4 mL min-1; of the trace elements (n=3). Matrix-matched calibration sample depth,7 mm; measured m/z,7Li, 9Be, 23Na, 24Mg, 27Al, functions were calculated over two orders of magnitude of 43Ca, 51V, 53Cr, 55Mn, 57Fe, 59Co, 60Ni, 63Cu, 66Zn, 69Ga, 75As, concentration, by analysis of the element standards prepared in 82 85 86 89 107 111 133 137 203 206 Se, Rb, Sr, Y, Ag, Cd, Cs, Ba, Tl, Pb and 2% ethanol/2% HNO3. Furthermore, internal standard correction 235U; sampling period per mass, 0.3 s; number of instrumental was performed for both quantification methods by online replicates, 3. The operating conditions were optimised for the addition in a T-piece of an internal standard solution of Y (50 best sensitivity of 1 µg L-1withMg, Y and Tl, and for the reduction µg L-1). The limit of quantification (LOQ) was calculated from of cerium oxide (140Ce16O+/140Ce+) and doubly charged standard deviations (SD) of the mean blank signals from the (140Ce2+/140Ce+) ion ratios.