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FUNGICIDES AND HEAVY METALS IN WINE SAMPLES PRODUCED FROM EXPERIMENTAL
GRAPES SUBJECTED TO DIFFERENT PESTICIDES TREATMENTS
Salvo Francesco, Saitta Marcello, Di Bella Giuseppa, La Pera Lara, Dugo Giacomo
Dipartimento di Chmica Organica e Biologica Università di Messina Salita Sperone, 3190166 S. Agata -Messina
Wine is a wildely consumed beverage with thousand years traditions, so an accurate quantitative knowledge of
the presence of toxic elements as pesticides and heavy metals, is very important from both toxicological and enological
point of view. The use of pesticides is closely associated with viticulture (1). Many factors influence the presence of
heavy metals in wine: type of soil, wine-processing equipment, vinification methods (2). The purposes of this work are
both to quantify pesticides residues and trace metals in samples of Italian wines, and to study the possible correlation
between the presence these contaminants (3).
Wine farms that comply with the Rule Cee 2078/92 for wine grape defense, have to respect all the provided
restrictions regarding to the use of pesticides.
To control the growth of powdery mildew (Uncinula necator), the use of sulfur, azoxystrobin, dinocap,
fenarimol, penconazole, quinoxyfen, is allowed. Mildew epidemic weakens the vines, causing huge production losses
and negatively influencing the quality of wines. Also an incorrect use of fungicide and frequency of their applications,
maight alter the quality of the final product.
The determination of fungicide residues in wine is well documented, even if the reported extraction procedures
are complex and expensive; meanwhile there is a lack of available data regarding to the extraction of dinocap residue.
In this work a quick chromatographic method for the simultaneous extraction of azoxystrobin, dinocap, fenarimol,
penconazole, quinoxyfen residues in wine samples is described (4).
The same samples of wine were subjected to trace metal determination as Cd (II), Cu (II), Pb (II) and Zn (II).
Heavy metals dosage was carried out by derivative potentiometric stripping analysis (3), which allowed to execute the
determinations in a short time directly on the wine sample appropriately acidified. The presence of Cd (II), Cu (II), Pb
(II) and Zn (II) in white and red wine sample, was correlated to the treatments applied on grapes.
Samples description
All the samples of white and red wine were produced in the crop year 2000-2001.White wines came from Sicily
and Campania red wine from Tuscany. Sicilian wines were produced from Inzolia and Carricante grape variety; wines
from Campania were produced Fiano d’Avellino grape variety. Red wines from Tuscany were vinified from Sangiovese
grape variety, Morellino clone.
The fungicide treatments were carried out on the end of blossoming and maturation; they were used at the doses
recommended by the manufacturers and were sprayed with a manual sprayer every 7-12 days (9 treatments) The last
treatments was executed about 28 days before the grape harvest. Only dinocap, which is generally used to start the
defence strategy, was applied 3 times. A random-block scheme was used with four replications for each test, and each
block contained 60 plants.
HRGC analysis
A HRGC 5300 mega Series Carlo Erba Instruments gas chromatograph was used for determination of five
fungicides. It was fitted with an electron-capture detection (ECD) system and split-splitless injector, connected to a
Hewlett Packard 3394 A reporting integrator.
A SPB-5 fused – silica column (30 m x 0.25 mm i.d.) was employed, with 5% diphenyl 95% dimethyl siloxane
as liquid phase (film thickness 0.25 µm) (Supelco). The injector and detector were operated at 250° C and 280°C,
respectively.
The sample (1 µL) was injected in the split mode (1:3), and the oven temperature was programmed as follows:
200°C (1 min) raised to 270°C (5°C/min), held for 20 min. Helium was the carrier gas and nitrogen the make-up gas
both at 150 Kpa.
Ten grams of wine was collected in an Erlenmeyer flask with a teflon-lined screw-cap. A 20 mL volume of
hexane-ethyl acetate (9:1, v/v) was added, and the mixture was put in a sonicator (Transsonic T420, Elma) for 30 min.
A 2 mL volume of supernatant was evaporated under nitrogen flow; 0.2 mL of the internal standard solution
(bromophos-methyl 1.00 mg/L) was added, and the mixture was directly analyzed by gas chromatography. No clean-up
was necessary because there were no interference in the chromatogram.
Previously, a blank assay was employed to check for the absence of residuals in wine. Untreated samples of wine
were fortified with 0.01, 0.1 and 1.0 mg/Kg of fungicides. The samples were allowed to equilibrate for 60 min prior to
extraction, and were processed according to the above procedure. The recovery assays were replicated 3 times:
recoveries ranged fro 75.9 to 121.5 %. The detection limits were evaluated as the peak height that is two times respect
to the bottom noise. For azoxystrobin, fenarimol, penconazole and quinoxyfen the calculated detection limit is 5 pg/µL;
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