Toxic trace metals in food. II. A comparative study of the levels of toxic trace metals in wine by differential pulse anodic stripping voltammetry and electrothermal atomic absorption spectrometry

Direct Determination of Zn, Cd, Pb and Cu in Wine by Differential Pulse Anodic Stripping Voltammetry

Metals in wine can originate from natural and anthropogenic sources and their concentrations have significant effects on wine proprieties as well in its conservation. In this work, direct and simultaneous determinations of Zn, Cd, Pb and Cu in wine samples were carried out by differential pulse anodic stripping voltammetry without any steps of previous pretreatment. The samples analyzed presented concentration levels from 4.64 to 69.3 µg L−1 of Zn, from 1.74 to 5.25 µg L−1 of Cd, from 4.57 to 17.9 µg L−1 of Pb and from 1.0 to 10.3 µg L−1 of Cu. Accuracy was evaluated with the standard addition method and recoveries ranged from 82.5 and 130.8% for Zn, from 85.7 to 107.0% for Cd, from 89.7 to 101.0% for Pb and from 81.4 to 105.9% for Cu. With the application of this method, it was possible to quantify the metals in a simple and easy way not requiring sample preparation or other approaches for the destruction of organic substances.

Statistical study of the influence of fungicide treatments (mancozeb, zoxamide and copper oxychloride) on heavy metal concentrations in Sicilian red wine

The aim was to assess the influence of mancozeb, zoxamide and copper oxychloride fungicide treatments on Mn, Zn, Cu, Cd and Pb concentrations in Sicilian red wines, grapes, marcs and grape stalks. The experimentation was carried out over two crop years: 2003 and 2004. Trace metals analysis was performed by derivative stripping chronopotentiometry, which allowed detection of concentrations lower than 1 ng g(-1). The data obtained gave evidence that the levels of Mn and Zn in wines from plots treated with zoxamide-mancozeb were about threefold higher than those observed in the control. Wines treated with Cu oxychloride had a significant increase in Cu(II) concentrations with respect to the control; in particular, samples from 2004 showed a 50% increase in Cu levels. Furthermore, as shown in a previous paper, the fungicides treatments studied led to a moderate increase in Pb(II) and Cd(II) levels in treated samples with respect to the control. Wines from 2004 had higher Cu and Pb amounts than wines from 2003; but the concentrations of all the other metals were similar. Statistical analysis of the data by linear discriminant analysis (LDA) and the Kruskal-Wallis test confirmed that both zoxamide-mancozeb treatments and copper oxychloride treatments exerted a significant influence on Mn(II), Zn(II) Cu(II), Pb(II) and Cd(II) concentrations in wines, grapes, marcs and grape stalks samples from both the studied vintages.

Main targets of tetraaza macrocyclic copper complex on L1210 murine leukemia cells

Several metal complex agents have already been introduced into clinical tumor therapy and others are subject of antitumor studies. In this study we focused on the tetraaza macrocyclic copper complex (Cu(TAAB)Cl(2)). We studied the influence of the substance on cell growth, cell cycle, membrane integrity, necrosis, apotosis and glutathione level on the leukemic cell line L1210 in 1-day (22 h) and 3-day (72 h) experiments. The metal complex shows a dose-dependent antiproliferative effect, without affecting cell cycle phases. The present results confirm that copper complex can damage plasmatic membranes and trigger apoptosis, and that after treatment of leukemic cells with the copper complex, glutathione levels were increased.

Influence of hexacyanoferrate (II) based treatments upon the elimination of heavy metal traces in wine. II. The case of cadmium

The present study has shown that the cadmium content of wine can be greatly reduced by two treatments normally associated with the removal of copper and iron from wine. The European treatment requires the addition of tetrapotassium hexacyanoferrate (II), K4[Fe(CN)6] to the wine, whereas in the United States, the FDA-approved method, involves the use of a formulation known as the Fessler's compound, which contains the Williamson salt i.e. iron (II) potassium hexacyanoferrate (II), K2Fe[Fe(CN)6]. For a test wine very lightly loaded with iron and consequently requiring the addition of only a very small quantity of iron remover, 72-82% of the cadmium can be eliminated. At higher iron concentrations where the amount of reagent added is increased, the removal of cadmium from the same wine can be as great as 95%.