Vsebnost Cu, Mn, Zn, Cd, Cr in Pb v različnih stopnjah pridelave vina

In samples taken during different stages of winemaking process (from grapes, crushed grapes, pressed pomace, must deposit, deposit of lees, must before and after clarification and wine) the Cu, Mn and Zn contents were determined by flame atomic absorption spectrometry (FAAS) and the Cd, Pb and Cr contents were determined by electrothermal atomic absorption spectrometry (ETAAS). Grapes, crushed grapes, pressed pomace, must deposit and deposit of lees were microwave digested with nitric acid, hydrofluoric acid and hydrogen peroxide solution, while for must and wine no special treatments were necessary. The highest contents of Cu, Mn, Zn, Pb, Cd and Cr were determined in the pressed pomace, lees, and in white grape varieties also in must deposit. Mean values obtained of dry weight (pressed pomace, lees, must deposit) were 63 mg/kg, 300 mg/kg, 184 mg/kg for Cu, 11 mg/kg, 15 mg/kg, 134 mg/kg for Mn, 14 mg/kg, 35 mg/kg, 17 mg/kg for Zn, 0.3 mg/kg, 0.5 mg/kg, 0.6 mg/kg for Pb, 0.5 mg/kg, 1.0 mg/kg, 1.8 mg/kg for Cr, 15.4 µg/kg, 24.4 µg/kg, 13.0 µg/kg for Cd. The Cu content was decreasing from the grapes to the bottled wine, whereas the Mn, Zn, Cd, Cr and Pb contents in the bottled wine were higher than in musts in all investigated white and red grape varieties. In ten wine samples the following contents were determined: Cumean 0.12 mg/L (range: 0.06-0.30 mg/L), Mnmean 1.04 mg/L (range: 0.60-1.78 mg/L), Znmean 0.50 mg/L (range: 0.13-1.03 mg/L), Cdmean 0.34 µg/L (range: 0.08-1.04 µg/L), Crmean 17.0µg/L (range: 5.2-25.1 µg/L) and Pbmean 25.3 µg/L (range: 16.4-37.8 µg/L).V vzorcih odvzetih v različnih stopnjah predelave grozdja (v grozdju, drozgi, tropinah, usedlini po razsluzu mošta, v drožeh, v moštu pred in po razsluzu in v vinu) smo določili vsebnost Cu, Mn in Zn s plamensko atomsko absorpcijsko spektrometrijo (FAAS) in vsebnost Cd, Pb in Cr z elektrotermično atomsko absorpcijsko spektrometrijo (ETAAS). Vzorce grozdja, drozge, tropin, usedline po razsluzu mošta in droži smo razkrojili v mikrovalovni peči z dušikovo (V) kislino, fluorovodikovo kislino in vodikovim peroksidom. Za mošt in vino predhodna priprava vzorcev ni bila potrebna. Najvišje vsebnosti Cu, Mn, Zn, Pb, Cd in Cr smo določili v tropinah, drožeh in pri belih sortah grozdja tudi v usedlini po razsluzu mošta. Srednje vrednosti preračunane na suho snov (tropin, droži, usedline po razsluzu mošta) so bile 63 mg/kg, 300 mg/kg, 184 mg/kg za Cu, 11 mg/kg, 15 mg/kg, 134 mg/kg za Mn, 14 mg/kg, 35 mg/kg, 17 mg/kg za Zn, 0.3 mg/kg, 0.5 mg/kg, 0.6 mg/kg za Pb, 0.5 mg/kg, 1.0 mg/kg, 1.8 mg/kg za Cr, 15.4 µg/kg, 24.4 µg/kg, 13.0 µg/kg za Cd. Vsebnost Cu je padala od grozdja do stekleničenega vina. Pri vseh analiziranih belih in rdečih sortah so bile vsebnosti Mn, Zn, Cd, Cr in Pb v stekleničenih vinih višje kot v moštih. V desetih vzorcih vina smo določili naslednje vrednosti: Cusrednja vrednost 0.12 mg/L (območje: 0.06-0.30 mg/L), Mnsrednja 1.04 mg/L (območje: 0.06- 1.78 mg/L), Znsrednja 0.50 mg/L (območje: 0.13-1.03 mg/L), Cdsrednja 0.34 µg/L (območje: 0.08-1.04 µg/L), Crsrednja 17.0 µg/L (območje: 5.2-25.1 µg/L), Pb25.3µg/L (območje: 16.4-37.8 µg/L)