DETECTION OF FUNGICIDE RESIDUES IN SOME FRUITS AND VEGETABLES BY CHROMATOGRAPHIC METHODS

The use of pesticides is a common practice in modern agriculture. To increase and to ensure the security in people nutrition, two comparative chromatographic methods (GC-MS and HPLC-DAD) for fungicide residues detection and monitoring in some fruits and vegetables were tested. Some vegetables, eggplants, cucumbers, red potatoes, white potatoes, red peppers and fruits, plums, apples, lemons, grapes, clementines, were analyzed for fungicide residues quantification. The presence of Tebuconazole, Boscalid, Iprodione and Imazalil was followed and quantified in the tested samples. These analyses are important for environment and end-consumers protection. Generaly, both techniques are very sensitive and selective for the analysis of pesticides at low concentrations. GC-MS presents better linearity characteristics for Tebuconazole and Imazalil, but HPLC-DAD was the most rapid method. The tested products do not contain large fungicides quantities.

Post-pruning storage and toasting of vine-shoots decrease fungicide residues

The potential use of vine-shoots as enological additives has been recently demonstrated. They can make a positive contribution to the sensorial profile of wines when they have been stored for 6 months after pruning, granulated, toasted under specific conditions and finally added to wines during winemaking. Since fungicide application is a common practice in vineyards, it is necessary to know the possible presence of such residues. In this study, a liquid chromatography-mass spectrometry analytical technique method for determination in vine-shoots of the main vineyard fungicides was developed, and their dissipation after post-pruning storage and toasting process was demonstrated. It was confirmed that the use of vine-shoots as enological additives will not pose a risk to the consumer, if good agricultural practices are used.

Findings of herbicide and fungicide residues in bee bread

The honey bee is one of the insects that is significantly endangered by the application of pesticides in the cultivation of crops. Not only is acute toxicity dangerous, but the importance of chronic poisoning by low doses of pesticides in hives is growing. The behavior of bees can be affected not only by insecticide residues but also by herbicide and fungicide residues. In 2016–2018, samples of bee bread were analysed for pesticide content at 25 different localities from intensive agricultural production areas of the Czech Republic. Substances were extracted by QuEChERS and determined by liquid chromatography, together with mass spectrometric detection. We detected up to 18 pesticides in one sample. In total, during 2016–2018, we identified 53 active substances. Fifteen substances (31%) were herbicidal, 23 substances (47%) of fungicidal nature and 6 substances (12%) of insecticidal nature. The coefficient of variation showed large differences in the frequency of revealed pesticides between years. For substances sprayed outside period attractive for pollinators (mainly herbicides and some fungicides), the usual methodology cannot reliably determine the degree of contamination, and thus the actual contamination with these substances may be even higher than demonstrated in this study.

Triazole Fungicide Residues and Their Inhibitory Effect on Some Trichothecenes Mycotoxin Excretion in Wheat Grains

Wheat is one of the global strategic crops and ranks third in terms of cereals production. Wheat crops are exposed to many fungal infections during their cultivation stages, some of which have the ability to secrete a number of toxic secondary metabolites that threaten the quality of the grains, consumer health, producer economics, and global trade exchange. Fifty-four random samples were collected from wheat which originated from different countries. The samples included 14 types of soft wheat to study the extent of their contamination with deoxynivalenol (DON) and T-2 toxin by auto-ELISA technology and r-biopharm microtiter plate. All samples were contaminated with DON toxin except one sample, and the values ranged between 40.7 and 1018.8 µg/kg−1. The highest contamination rates were in Lithuanian wheat and the lowest was in Indian wheat. Meanwhile, the highest average level of T-2 toxin contamination was in Lithuanian wheat grains with 377.4 µg/kg−1, and the lowest average was 115.3 µg/kg−1 in Polish wheat. GC-MS/MS and multiple reaction monitoring mode (MRM) were used to detect 15 triazole derivatives in the collected samples, which may be used to combat fungal diseases on wheat during the growing season. Only 9 derivatives were found: simeconazole, penconazole, hexaconazole, cyproconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole. These derivatives varied according to the origin of the wheat samples as well as their concentration, whereas another 6 derivatives were not detected in any samples. A direct inverse relationship was found between the DON concentration in the samples and the residues of simeconazole, penconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole, and the T-2 toxin showed the same relationship except for tebuconazole. The safe and rational use of some triazole derivatives may be a new approach and a promising strategy to not only reduce plant diseases and their problems, but also to get rid of some mycotoxins as grain contaminants.