International Congress BIOLOGICAL PRODUCTS - Gruppo di ...

while for dinocap is 10 pg/µL. For the determination of sulfur residue, a HRGC Dani 86.10, fitted with a FPD Dani
86/70 detector and a Mega 68 fused Silica column, were used; the detection limit was 2 ng/µL.
Derivative potentiometric stropping analysis
For metals determination an ION 3 Steroglass potentiometric stripping analyzer equipped with a conventional
three electrodes cell, was used. The working electrode was a glassy carbon one covered with a thin mercury film.
Before each analysis an appropriate volume of wine was treated with HCl 2M lowering the pH to 2, in order to ensure
that all metals present remain in unbound –free forms. Cd (II), Cu (II) and Pb (II) were determined simultaniously, their
oxidation potential were respectively –590 mV, -185 mV and –400mV. Zn was separately determined, its oxidation
potential was –950 mV. Quantitative analysis was always carried out by the method of standard additions.
RESULTS and CONCLUSION
The residues found in all wines were below the limits that Italian law (D.M. 19 may 2000) provides for grapes
and wines. Particularly no quinoxyfen residues were found in the wines; also in wines originated from treated grapes,
no dinocap residues were found probabily because of an inferior number of tratments applied on vines (table 1).
Maximum accetable levels of Cd (II), Cu (II), Pb (II), and Zn (II) in wines, has been estabilished by the Italian
Republic (5) and by the European Commission (6) respectively at 100
ng L -1 , 1000 ng L -1 , 300 ng L -1 , and 500 ng L -1 . As tables 2 a-c evidence that the metals content of the studied wines was
always under the acceptable levels, particularly Cd was not found in any sample. The content of Cu, determined in
wines coming from the three regions ranged from 10.5 to 415.7 ng mL -1 and was not influenced by fungicides
treatments applied on grapes. The concentration of Pb spanned from 3.6 to 17.4 ng mL -1 and was regularly influenced
by pesticides treatments (fig. 1): the highest amounts were extimated for samples treated only with sulfur and with
azoxystrobin while the lowest were found in wines trated with quinoxyfen and dinocap. The level of Zn was in the range
21.6-263.0 ng mL -1 and showed a regular behaviour respect to the treatments (fig.2) only in white wines: the highest
amounts were extimated for samples treated with fenarimol and azoxystrobin, and as already observed, the lowest in
samples treated with dinocap. For red wines the highest Zn contents were evaluated in samples treated with azoxstrobin
and in the one trated with sulfur, the lowest in the sample treated with fenarimol.
LITERATURE
1. Fernadez-Cornejo, J. Environmental and economic consequences of technology adoption: IPM in
viticulture. Agricultural Economics 1998, 18, 145-155.
2. Golimowsky, J.; Valenta, P.; Wolfgang-Nurnberg, H. 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. Z.Lebensm. Unters. Forsh. 1979 b, 168, 439-443.
3. Salvo, F.; La Pera, L.; Di Bella, G.; Nicotina, M.; Dugo, G.mo. Influence of mineral and organic
pesticides treatments on Cd (II), Cu (II) Pb (II) and Zn (II) content determined by Derivative Potentiometric Stripping
Analysis in Italian Red and white wines. J. Agric. Food Chem. 2003 in press
4. Dugo, G.mo; Visco A.; Saitta M.; Vinci, V.; Di Bella G.Dosaggio di quinoxyfen su prodotti vitivinicoli
siciliani. Vigne vini, 2001, 91, 7-8.
5. Repubblica Italiana; Caratteristiche e Limiti di alcune Sostanze nel Vino. 1986, december D.M. 29.
6. European Commission; 1997 Doc III/5125/95/ Rev.3.
Table 1: Fungicide residues (µg /Kg + s.d.) in wine.
azoxystrobin dinocap fenarimol penconazole quinoxyfen
Sicily 21±6 n.d. 13±2 10±1 n.d.*
Campania 5±1 n.d. 6±2 8±2 n.d.*
Tuscany 12±2 n.d. 70±6 12±1 n.d.*
n.d. < 10 µg /Kg
n.d.* < 5 µg /Kg
PDF creato con FinePrint pdfFactory versione dimostrativa http://www.secom.re.it/fineprint
155