Joint International Conference on Long-term Experiments ...

we made a deeper vertical sampling to 300 centimetres depth of soil and we separated
10-12 layers in the profiles based on their physical properties.
Pesticide residue analysis: Pesticide residue analysis was made in the Soil and Plant
Conservation Service of Miskolc in 2005 and in the Institute of Food Science, Quality
Assurance and Microbiology in 2006. Sample preparation was carried out as follows:
after milling and drying, 50 g of the soil was accurately weighed and added 7 ml of 0.2
M ammonium-chloride (Sigma). After resting for approximately 15 minutes nhexane:acetone
(1:1) mixture was added, and the solution was shaked for 2 hours in
laboratory shaking machine. The mixture was filtered on Büchner funnel and the
acetone was separated with 700 ml of distilled water. The phase of n-hexane was dried
on sodium-sulphate and concentrated with rotation evaporating machine. The residue
was dissolved in 5 ml n-hexane. The extract was cleaned by column-chromatography,
the column filled with 8 g of Alumina (activity: V.). The evalution was carried out with
n-hexane, finally the solution was evaporated again and dissolved in 1 ml of n-hexane.
During the sample preparation we used organic solvents in the quality of GC-residue
analysis (Scharlau). The detection of the analytes was performed on a Varian CP-3800
gas chromatograph with ECD detector (Nederland). Operating conditions: CP 8907
Factor Four Capillary Column, 15 m * 0.25 mm, temperature program: 50 °C, 1 min;
50-180 °C, 25 °C min-1; 180-250 °C, 4°C min-1; 250°C, 1 min, helium carrier gas (1.0
ml min-1, 6.0 Linde), injected volume: 1 µl, temperature of the detector: 250 °C. The
standard materials and internal standards were prepared from MERCK Chlorinated
Pesticide Mix 40.
Heavy metal content analysis: Determination of heavy metal concentrations was made
in the Institute of Food Science, Quality Assurance and Microbiology. Samples were
dried at 60 o C, ground, sieved through a 2 mm mesh sieve and digested in HNO3-H2O2
according to Hungarian methodological standard procedure: MSZ 21470-50:1998
(Kovács et al., 2000). Merck and BDH standard solutions were used to prepare the
stock-solutions, and REANAL (Budapest, Hungary) solid chemicals were also used.
Ultrapure water was used to prepare the solutions (Millipore, Paris, France). The
determinations were made by a Perkin-Elmer Optima 3300 DV Inductively Coupled
Plasma - Optical Emission Spectrometry (ICP-OES) equipment.
RESULTS AND DISCUSSIONS
In 2005 by the analysis of element composition we found that the examined fields show
significant differences in macro nutrient concentrations (N, P, K, S), but show
surprisingly homogenous distribution in the case of several micro nutrients and toxic
elements (Table 1). We found no significant amount of pesticide residues in the
ploughed upper soil layer (0-20 cm layer), but in the case of maize and winter wheat
fields a small degree of accumulation was observed (Table 2). These results from the
pesticide residue analysis induced us to continue the sampling in wider soil profile.
We found as a result of analysis in 2006 that the bio production field at Látókép
did not contain detectable amounts of pesticide residues. In the case of other sites the
detected amount of pesticide residues was diverse in the case of different chemicals, but
in all case it was under the contamination limit value (A value) of 10/2000. (VI.2.)
KöM-EüM-FVM-KHVM ministry order in the whole soil profile (Figure 1). The peaks
371