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1.
Fenamidone is an imidazolinone fungicide recently introduced in viticulture practices. This work reports the validation and assessment of global uncertainty of a gas chromatographic with mass spectrometry method to analyze fenamidone in grapes and wines. This method consists in a simple and fast liquid-liquid extraction step followed by chromatographic determination. Limits of detection for fenamidone in grapes and wines were, respectively, 0.05 mg/kg and 0.06 mg/L, precision was below 9.4% and average recovery was 89 +/- 5%. In the concentration range from 0.05 to 1.00 mg/kg (or mg/L) of fenamidone, global uncertainty calculated following the EURACHEM/CITAC rules, and also by the Horwitz function, was below 25%. The EURACHEM/CITAC global uncertainty budget used gave lower estimates than those obtained from the Horwitz function.  相似文献   
2.
Chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate) was applied with three different formulations on oranges, peaches, tomatoes, wine and table grapes, and its behaviour was evaluated after field treatment. The formulations applied were emulsifiable concentrates (EC), microencapsulates (ME), and wettable granules (WG). The residues were similar in all crops studied in the EC and WG experiments, except peaches with WG treatment, the residue amount was lower than EC values. Tomatoes which were grown in greenhouse showed similar residues in all treatments just after treatment. Wine and table grapes showed different decline curves in the EC experiments ascribable to the different growing technology. Instrumental limit of determination (LOD) and limit of quantification (LOQ) for all matrices were 0.01, and 0.03 mg kg?1, respectively. Repeated treatments showed that Chlorpyrifos can accumulate leading to residue levels at the preharvest interval (PHI) over the maximum residue level (MRL), especially on oranges and peaches. Among the formulates used ME showed the higher risk of residues over the MRL at harvest.  相似文献   
3.
The degradation of the main azadirachtoids on tomatoes was studied after greenhouse treatment. These experiments were carried out at 1 and 5× the concentration recommended by the manufacturer. In all experiments the deposition of azadirachtin A (AZA-A) was below the maximum residue level (MRL). Even if at the highest dose, AZA-A half-life time calculated as pseudo first order kinetic was 1.2 days in agreement with the recommended preharvest interval (PHI) of 3 days. Experiments with a model system showed that sunlight photodegradation is the main factor influencing the rate of disappearance of AZA-A after greenhouse treatment while tomato epicuticular waxes doubled the photodegradation rate of AZA-A in a commercial formulation.  相似文献   
4.
/ Marginal aquatic systems (wetlands) of the Po River (Italy) have become the target of a renewed interest because of their value for recreation, natural reserves, and deposits of sand. To preserve these sites, wise management must be the objective of local administrations. In this paper a strategy for the sustainable use of 11 wetlands is presented. It uses simple economic analysis and multiple criteria techniques and provides suggestions to promote sustainability in terms of conservation of natural resources, economic self-sufficiency, and minimization of potential conflicts about the use of the wetlands. In the understanding that sustainability is framed in a long-term perspective, stability analysis is also considered and performed by means of loop analysis, a qualitative technique. Conditions for stability are then discussed about management opportunities.  相似文献   
5.
Here we describe a foetus with intrauterine growth retardation (IUGR), cerebral malformations and a 46,XY,der(1),t(1;6)(p36.3;q25.2) karyotype owing to a familial cryptic translocation segregating in three generations. A balanced translocation was present in the mother, the maternal uncle, the aunt and the grandmother. A female first cousin with dysmorphisms, hydrocephalus and mental retardation was a carrier of a partial trisomy 1p and a partial monosomy 6q. Multiple miscarriages were present in the family pedigree. Parents of the foetus had three other pregnancies: a male with a balanced translocation, and two foetuses with 1p36.3–pter monosomy and 6q25.2–qter trisomy. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
6.
Environmental Science and Pollution Research - In recent years, the occurrence of microplastics in the aquatic environment has gathered increasing scientific interest. Several studies have shown...  相似文献   
7.
We evaluated the catalytic activity of a water-soluble iron-porphyrin in an oxidative coupling reaction to form covalent bonds between 2,4-dichlorophenol (2,4-DCP) and humic molecules. The biomimetic catalysis in the presence of H2O2 was tested in the dark and in daylight, and changes in reaction products were revealed by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopy. In all conditions, iron-porphyrin was effective in promoting complete disappearance of 2,4-DCP, although catalyst activity was enhanced in daylight (with a maximum turnover number of 85.13). Further evidence of the occurred covalent coupling between 2,4-DCP and humic molecules was revealed by diffusion-ordered nuclear magnetic resonance (DOSY-NMR) spectroscopy that showed a reduced diffusivity of 2,4-DCP after the catalytic reaction. These findings indicate that iron-porphyrin is an efficient catalyst for the covalent binding of polyhalogenated phenols to humic molecules, thereby suggesting that the copolymerization reactions may become a useful technology to remediate soils and waters contaminated by halogenated phenols and their analogues.  相似文献   
8.
Residues of the pyrimidine fungicide pyrimethanil [N-(4,6-dimethylpyrimidin-2yl)aniline] were determined in table grapes "Italia" by gas chromatography nitrogen-phosphorus detector (GC-NPD). Pesticides were extracted from grapes with ethyl acetate and hexane solution (1:1 v/v), and were analyzed without any further clean up. Pyrimethanil was confirmed by high-performance liquid chromatography (HPLC) fitted with a diode array detector (DAD) and electrospray ionization mass spectrometry (ESI-MS) in the select ion-monitoring mode (SIM). The residue of pyrimethanil was under the legal limit immediately after treatment, and showed a half-life time, calculated as a reaction of pseudo first order, of 12 days, with a regression coefficient of 0.9954. Recoveries from fortified grapes ranged between 90 and 113% with a maximum coefficient of variation (CV) of 11%. The calculated limits of detection and quantitation for pyrimethanil were 0.005 and 0.01 mg/kg, respectively.  相似文献   
9.
Smallholder agriculture in the Central Andes of Peru is based to large extent on rainfed cropping systems, is exposed to climatic risks and is expected to respond sensitively to increasing temperatures and shifts in the precipitation regime. Here, we examine the potential implications of early twenty-first century climate change scenarios for the cultivation of potato, maize, wheat, barley and broad bean, five annual crops that account for 50 % of the cultivated area in the Department of Cusco and Apurímac and provide the dietary backbone for a large share of the local population. The scenarios disclose a regionally coherent increase in temperature of the order of 1 °C but overall only moderate changes in growing season precipitation by 2030. A simple crop model is used to assess the effects of these changes on crop phenology and development. The results show earlier harvest dates, shorter cropping seasons and, in a few cases, a slightly higher risk of planting failure in the near future. This suggests that a better understanding of changes in the precipitation regime at the onset of the cropping season is required to evaluate short-term needs and possibilities for adaptation. However, as the scenarios are highly uncertain, these conclusions should be verified.  相似文献   
10.
The purpose of this work was to investigate the effects of spreading olive oil mill wastewater (OMWW) on soil biochemical parameters and olive production in an organically managed olive orchard. The experiment was carried out with three different doses of OMWW (80, 160 and 500 m3 ha?1) and a control (untreated soil). Three samplings were done at 10, 30 and 90 days after the administration of the byproduct. OMWW application differentially modified the biochemical properties of the soil analyzed. Organic matter, organic carbon, total nitrogen and extractable phosphorus soil contents increased proportionally with each increasing dose. The values of these parameters decreased gradually with time. Total microbial activity was altered and the OMWW 500 m3 ha?1 treatment proved to be the most active when compared with the other applied doses. OMWW agricultural application also modified the structure of soil microbial communities, particularly affecting Gram positive and negative bacteria, while fungal biomass did not show consistent changes. Although there was a salinity increase in the treated soil, especially at the highest dose, the productive parameters analyzed (fruit and oil tree?1) were not affected. In light of the obtained results, we consider that low dose of OMWW could be considered an alternative farming practice for semiarid regions.  相似文献   
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