Monitoring of Cd, Cr, Cu, Fe, Mn, Pb and Zn in fine Uruguayan wines by atomic absorption spectroscopy

Metals in wine occur at the mg/L level or even less and, though not directly related to the taste of the final product, their content should be determined because excess is undesirable and in some cases restricted by legislation to guarantee consumer health protection. Seven elements were determined in 14 white and 33 red wines from nine Uniguayan wineries. Several techniques have been approved for the determination of metallic ions in wine, but the most sensitive and rapid is atomic absorption spectroscopy. In the present work, flame atomic absorption spectrometry (FAAS) was employed for the determination of Cu, Fe, Mn, and Zn, and graphite furnace-atomic absorption spectrometry (GFAAS) was used for Cd, Cr, and Pb determination. The following concentration (mg/L) ranges were obtained for Cd (0.002-0.003), Cr (0.004-0.052), Pb (0.006-0.057), Cu (0.034-0.65), Fe (0.73-4.6), Mn (0.74-2.2), and Zn (0.49-2.2). Mean recoveries of elements from fortified wines were: 98.3 +/- 2.6% for Cd, 101.5 +/- 1.7% for Cr, 99.1 +/- 2.7% for Pb, 96.9 +/- 1.4% for Cu, 97.3 +/- 3.1% for Fe, 98.1 +/- 1.9% for Mn and 95.7 +/- 3.8% for Zn. The detection limits (mg/L) were: 0.0005 for Cd, 0.001 for Cr, 0.003 for Pb, 0.006 for Cu, 0.020 for Fe, 0.008 for Mn and 0.007 for Zn. The concentrations of all the metal ions analyzed in wines fall within the range typical of wines from around the world and none of them is above the limits established by the Office International de la Vigne et du Vin (OIV).