► Ninety-two water samples from vulnerable sites along a vineyard area were evaluated. ► A LC–MS method and SPE procedure were optimised to analyze 58 pesticides. ► More than 90% of the 40 pesticides ...detected were at level higher than 0.1μgL−1. ► The sum of pesticides was higher than 0.5μgL−1 in 64% of groundwaters and 62% of surface waters. ► Water pollution by pesticides was derived from its widespread use in agricultural activities.
A multi-residual analytical method based on solid phase extraction (SPE) followed by liquid chromatography–electrospray ionisation–mass spectrometry (LC–MS) was developed to monitor pesticides in natural waters. Fifty-eight compounds, including herbicides, fungicides, insecticides and some of their degradation products, were surveyed to evaluate the quality of natural waters throughout the wine-growing region of La Rioja (Rioja DOCa). Ninety-two sampling points were selected, including surface and ground waters that could be affected by agricultural activities covering the region’s three sub-areas. Different parameters that may affect the efficiency of the SPE procedure were optimised (sorbent type, elution solvent and sample volume), and matrix-matched standards were used to eliminate the variable matrix effect and ensure good quantification. The developed method allows the determination of target compounds below the level established by the European Union for waters for human use with suitable precision (relative standard deviations lower than 18%) and accuracy (with recoveries over 61%). Forty compounds included in this study (six insecticides, 12 herbicides, 16 fungicides and six degradation products) were detected in one or more samples. The herbicides terbuthylazine, its metabolite desethyl terbuthylazine, fluometuron and ethofumesate and the fungicides pyrimethanil and tebuconazole were the compounds most frequently detected in water samples (present in more than 60% of the samples). Concentrations above 0.1μgL−1 were detected for 37 of the compounds studied, and in several cases recorded values of over 18μgL−1. The results reveal the presence of pesticides in most of the samples investigated. In 64% of groundwaters and 62% of surface waters, the sum of compounds detected was higher than 0.5μgL−1 (the limit established by EU legislation for the sum of all pesticides detected in waters for human use).
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•Tetraconazole promotes a significant decrease in the sugars-to-ethanol yield.•Methionol content decreased around 24% in the presence of Tetra Form.•The most significant increases ...were for fatty acids and ethyl esters (>23%).•Tetraconazole exerts effects on methionine and ergosterol biosynthesis pathways.•Coadyuvants of Tetra Form could have an essential impact on volatile biosynthesis.
The influence of antifungal tetraconazole residues (either as an active substance or as a commercial formulation product) on the fermentative activity of Saccharomyces cerevisiae yeast was evaluated in pasteurized Garnacha red must by using laboratory-scale fermentation assays. The presence of this fungicide promoted a slight decrease in glucose consumption. Volatile fermentative-derived compounds were evaluated in deep. Statistically significant changes were found in methionol (with a mean decrease of around 24%), fatty acids (with increments ranged from 23% to 66%), and ethyl esters (with increases ranged from 23% to 145%) contents when grape musts were enriched with the commercial formulation at both contamination levels assayed. Based on protein mass fingerprinting analysis, it was possible to relate these variations on volatiles content with changes in the activity of several enzymes (Met3p, Met14p, Adh2p, Hmg1p, Erg5p, Erg6p, Erg11p, and Erg20p) involved in the secondary metabolism of yeasts.
Mancozeb is a dithiocarbamate non-systemic agricultural fungicide with multi-site, protective action. It helps to control many fungal diseases in a wide range of field crops, fruits, nuts, ...vegetables, and ornamental plants. We have investigated the stability profiles of mancozeb in aqueous solutions to determine the effect of pH, temperature and light on the degradation process of mancozeb. In addition, the toxicological risk for humans associated with the joint intake of mancoze7b and its final degradation product, ethylenethiourea (ETU), was calculated and modelled as a function of the experimental conditions. Stability study results showed a very low stability profile of mancozeb in all the aqueous solutions with rapid degradation that varied with experimental conditions. The process followed first order kinetics. The study of the degradation kinetics showed a significant effect of pH*temperature interaction on the degradation process. The results also expressed that light has a greater impact on the stability of mancozeb and the formation of ETU. The current study concludes that mancozeb is unstable in aqueous solutions, particularly at an acid pH, in addition to presenting both severe light and lower temperature sensitivity. The toxicological risk associated with mancozeb degradation increases with time and temperature, being higher at basic pH and in absence of light.
•Mancozeb hydrolysis follows a first order reaction model.•Mancozeb hydrolysis is controlled by the pH*temperature interaction.•ETU and EBIS were the main hydrolysis products.•Mancozeb conversion to ETU is minimized at pH 2, 25°C in presence of light.•Risk associated with mancozeb degradation is higher at basic pH in absence of light.
The impact of mepanipyrim (Mep) and its corresponding commercial formulation (Mep Form) on Saccharomyces cerevisiae metabolites was assessed, separately, by using laboratory-scale wine fermentation ...assays on pasteurized red must. The presence of Mep did not alter the fermentation course. With regard to volatiles formed at the intracellular level by fermenting yeast cells, Mep residues affected mainly the acetate and ethyl ester biochemical pathways. In particular, the target acetates showed a notorious increment, >90%, in presence of commercial Mep Form at the higher dose assayed. The addition of Mep and Mep Form, at both tested levels, highly increased ethyl caprylate (between 42 and 63%) and ethyl caprate (between 36 and 60%) contents as the same as their respective fatty acid precursors. No important effects were observed on colour and non-volatile pyranoanthocyanins, probably due to the low anthocyanin content characteristic of pasteurized musts.
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•The presence of Mep did not alter the fermentation course.•Mep Form at 2MRL increased the acetate content >90%.•Ethyl caprylate and ethyl caprate were the more affected ethyl esters.
► We study the adsorption of fungicides cyprodinil and fludioxonil in soils. ► We examine the influence of adjuvants present in commercial formulations in the adsorption. ► Adjuvants in the ...commercial formulation induce strong deviations in the adsorption isotherms regarding to experiments using the pure active ingredients.
The objective of this work was to assess the effect of adjuvants in the sorption in soils of the fungicides, cyprodinil and fludioxonil, usually applied together in a mixture commonly called ‘Switch’. Water suspensions of a commercial formulation of Switch were used in phase partition experiments for a set of selected soils from vineyards. A clean-up procedure of the supernatant was developed for the phase separation in presence of the adjuvants prior to quantification of cyprodinil and fludioxonil. The maximum sorption on the solid phase (which includes soil and other solids from the commercial formulation of Switch) was 2000
mg
kg
−1 for fludioxonil and 3000
mg
kg
−1 for cyprodinil after incubation with 800
mg
L
−1 of Switch. However, adsorption to soil particles were lower; fludioxonil concentrations adsorbed in soils range from 50 to 80
mg
kg
−1 of soil and cyprodinil concentrations range from 120 to 260
mg
kg
−1 of soil. Adjuvants increased the solubility of fludioxonil in pure water at 25
°C up to 5 times that of the pure substance (from 1.8 to 9
mg
L
−1 in control samples), and show a strong influence on the adsorption in soil. Soil pH, effective cation exchange capacity and copper content due to past anti fungal copper-based sprays, have also influence on the adsorption of the active ingredients in presence of adjuvants.
The objective of this work was to assess the effect of surfactants and oils of a commercial formulation on the potential mobility of penconazole in agricultural soils that have been subjected to a ...high rate of application of agricultural chemicals. Soil–water partition tests on a commercial water–oil emulsion formulation of penconazole (WOEP) in 0.01
M CaCl
2 containing 35
mg
L
−1 penconazole, incubated for 24
h, showed a maximum retention of approximately 250–300
mg
penconazole
kg
−1 soil. Approximately 70% of the total penconazole retained by the solid phase was sorbed on the soil (175–200
mg
kg
−1). The other 30% was retained by the adjuvants present in the commercial formulation. The formulation also influenced the water–soil partition, increasing the sorption in tests on batch studies using technical-grade penconazole (TGP). Soils with high total copper and organic matter had the greatest affinity for penconazole when added as WOEP. Additionally, adsorption of penconazole followed an S-type isotherm, whose behavior was consistent with the ability of the technical-grade penconazole to form aggregates. In the case of the WOEP, the S-type behavior could be attributed to the surfactant present in the formulation, which could be adsorbed onto soil as hemimicelles, which in turn may facilitate adsorption of penconazole.
The objective of this work is to asses the sorption of metalaxyl applied as a copper oxychloride (CO)-metalaxyl formulation, for a set of selected soils devoted to vineyards. The method involved ...batch incubation of soils suspended with a commercial copper oxychloride–metalaxyl-based fungicide in 0.01
M CaCl
2. Afterwards, the metalaxyl concentration remaining in solution was determined by high-performance liquid chromatography (HPLC). The amount of dissolved metalaxyl in the fungicide suspension depends mainly on the soil pH, its potential acidity, and the cation exchange capacity. Of the approx. 20% metalaxyl retained by the solid colloids, the effect of organic matter colloids in soils (15–20
mg
kg
−1) had a poor contribution (six times lower) than the copper oxychloride colloids (40%, w/w) in the commercial fungicide formulation (100–130
mg
kg
−1). When comparing these retention data with the behaviour of metalaxyl used as a technical grade fungicide of about 100% purity (10–15
mg
kg
−1 in solids), it is clear that the commercial formulation increases a 30% retention of metalaxyl by soil (15–20
mg
kg
−1 in solids). The overall effect of the metalaxyl formulation plus soil show values of 10 times higher retention than technical grade-metalaxyl plus soil. Commercial formulation can decrease the mobility of soluble metalaxyl in agricultural soils with regard to the expected values obtained from batch studies using analytical grade-metalaxyl. Therefore, the effect of surfactants should be considered in the assessment of water contamination by the pesticides used in agriculture.
The disappearance of the fungicides cyprodinil, fludioxonil, procymidone and vinclozoline, which are widely used to control grey mold in vineyards, from commercially sterilized white grape juice was ...studied. Fungicide losses from white grape juice stored at 40
°C were monitored for about 2
months in order to simulate in a fast way the shelf-life of the product at room temperature (about 1
year). The fungicides were determined by using a simple method based on a liquid–liquid extraction (LLE) and gas chromatographic separation, followed by mass spectrometric detection (GC–MSD). Fortified white grape juice subsamples were taken three times a week from the oven and the degradation of the fungicides monitored for 56
days. The half-lives at 40
°C for vinclozoline and procymidone were found to be 11 and 20
days, respectively. Those for the more recently introduced fungicides fludioxonil and cyprodinil were somewhat longer (33 and 44
days, respectively). Based on the first-order rate constants obtained, the fungicides dissipated in the following sequence: vinclozoline (0.062
d
−1)
>
procymidone (0.035
d
−1)
>
fludioxonil (0.021
d
−1)
>
cyprodinil (0.016
d
−1).
The application of different organic residues as a soil amendment is an agricultural practice used to improve soil fertility by increasing the soil organic matter (OM). However, the OM from these ...residues can influence the behavior of pesticides applied jointly to the soil. Modification of the pesticide bioavailability in soils is of special interest since it can affect the activity and/or functioning of soil microbial community. Accordingly, the dissipation kinetics of mesotrione in unamended soil (S) and soils amended with sewage sludge (S+SS), green compost (S+C) and commercial pellets (S+P) and its possible effects on the soil microbial communities were studied. Soil biological parameters were determined as indicators of the soil microbial activity, functioning and structure: microbial biomass, dehydrogenase activity, respiration, and analysis of the phospholipid fatty acid (PLFA) profile extracted from the soil. Dissipation was more rapid in unamended soil than in amended soils and half-life (DT50) values followed the order S+SS > S+C ≥ S+P > S. The biomass values increased in the amended soils with the exception of the P-amended soil. However, mesotrione had different effects on this parameter depending on the soil treatment. In general, dehydrogenase activity was stimulated by the addition of the amendment and herbicide to soil. Initially, respiration was higher in the unamended soil (control and treated soils) than the amended soils and mesotrione did not have any effect on this parameter. PLFAs analysis indicated that the overall structure of active microbial communities as well as the relative abundance of certain groups of microorganisms clearly changed according to the type of amendment and the incubation time, but remained unaffected by the application of mesotrione.
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