Search results for "PES"
showing 10 items of 5212 documents
Dependence of accelerated degradation of atrazine on soil pH in French and Canadian soils
2000
Abstract A series of agricultural soils varying in their atrazine treatment history were sampled from 12 sites in France and two sites in Canada. The soils varied widely with respect to soil chemical, physical and microbiological (total microbial biomass, kinetics of C and N mineralization) properties. Soils treated with as few as two successive atrazine field applications mineralized [U- ring - 14 C]atrazine significantly more rapidly in 35 d laboratory incubations than did soils which had never received atrazine. Longer treatment history tended to favour more rapid mineralization in the so-called “adapted” soils. Up to 80% of the initially applied 14 C-atrazine was mineralized at the end …
Application of solid-phase microextraction for determining phenylurea herbicides and their homologous anilines from vegetables.
2004
Abstract Residues of metobromuron, monolinuron and linuron herbicides and their aniline homologous were analyzed in carrots, onions and potatoes by solid-phase microextraction (SPME) performed with a polyacrylate fiber. A juice was obtained from food samples that were further diluted, and an aliquot was extracted after sodium chloride (14%) addition and pH control. At pH 4 only the phenylureas were extracted. A new extraction at pH 11 allowed the extraction of phenylureas plus homologous aniline metabolites. Determination was carried out by gas chromatography with nitrogen–phosporus detection (NPD) the identity of the determined compounds was studied by gas chromatography–mass spectrometry.…
Beeswax cleaning by solvent extraction of pesticides
2018
We set out to test if the methodology used to clean sheep wool wax (Lanolin) from pesticides could be used to clean beeswax as well. We first made an aggregate sample of brood comb wax from three different US beekeepers. Sub-samples of these aggregate wax samples were analyzed for pesticide contamination. The remaining wax, was then dissolved into hexane solution and run through four N, N-Dimethylformamide (DMF) washes. During these extractions, the pesticides partitioned into the DMF, and so were removed from the beeswax. Following the solvent extractions, the beeswax was tested again for pesticides. An average of 95% of the pesticide contamination was removed by the chemical wash procedur…
Rearing of Prays citri on callus derived from lemon stigma and style culture
2000
A new method for rearing the citrus flower moth (Prays citri Mill.) (Lepidoptera, Yponomeutidae) on lemon [Citrus limon (L.) Burm.] callus is reported. In the present research callus (an undifferentiated mass of plant cells that can be grown under sterile conditions on an artificial medium in vitro) was induced from lemon stigma and style explants cultured on Murashige and Skoog (MS) medium supplemented with 500 mg l -1 malt extract, 13.3 μM 6-benzylaminopurine, and 146 mM sucrose. Also somatic embryogenesis and plant regeneration were obtained from the cultures of styles and stigmas of lemon. Adults were obtained from larvae on infested flowers collected in the field. Different oviposition…
Current trends in solid-phase-based extraction techniques for the determination of pesticides in food and environment
2006
Solid-phase extraction (SPE) procedures for pesticide residues in food and environment are reviewed and discussed. The use of these procedures, which include several approaches such as: matrix solid-phase dispersion (MSPD), solid-phase micro-extraction (SPME) and stir-bar sorptive extraction (SBSE), represents an opportunity to reduce analysis time, solvent consumption, and overall cost. SPE techniques differ from solvent extraction depending on the interactions between a sorbent and the pesticide. This interaction may be specific for a particular pesticide, as in the interaction with an immunosorbent, or non-specific, as in the way a number of different pesticides are adsorbed on apolar or…
Pesticide analysis in coffee leaves using a quick, easy, cheap, effective, rugged and safe approach and liquid chromatography tandem mass spectrometr…
2017
An analytical method using a quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure for multi-residue determination of 52 pesticides in coffee leaf extractshas been developed and validated according to SANTE/11945/2015 guidelines. Different sorbent combinations for dispersive solid phase extraction (d-SPE) clean-up as well as dispersive liquid-liquid microextraction (DLLME) were tested. The relative standard deviations (RSDs) for the recovery of 87-94% of pesticides added to coffee leaf extracts,was ≤20% for samples spiked at concentrations up to 50ng*g-1 depending on the clean-up procedures. However, samples spiked with a 100ng*g-1 pesticide mixture gave RSDs>20% for most pest…
Selection of sampling adsorbents and optimisation and validation of a GC-MS/MS method for airborne pesticides
2017
ABSTRACTA methodology for the sampling and determination of airborne pesticides has been developed. The trapping efficiency of three adsorbents, namely XAD-2,XAD-4 and a sandwich sorbent (PUF-XAD2-PUF), was tested for 34 pesticides and the latter was selected because it presented the highest retention capacity without breakthrough. Pesticides were determined by gas chromatography coupled to an ion trap mass spectrometer in tandem. The method showed recoveries ranging from 70% to 120% with limits of quantification in the range of 16.1–322.6 pg m−3 when 155 m3 were sampled. This analytical strategy was applied to 10 indoor air samples collected in dwellings from the Valencian Region. Six pest…
Design d'un iprodione-MIP (molecularly imprinted polymer) : application à la pré-concentration des fongicides dans le vin
2014
The aim of this study was the synthesis of a MIP (molecularly imprinted polymer) specific for a fungicide that is found in the majority of the french wine: iprodione. The challenge for extracting iprodione from wine medium was that the hydoralcoholic solution is a dipolar solvent, whereas the interaction between the MIP and iprodione is based on dipolar interactions. The first extraction study of iprodione was made on a MIP synthesized by bulk polymerization using methacrylamide and ethylene glycol dimethacrylate (EGDMA). The MIP was found to be more efficient than the NIP (non-imprinted polymer) in hydroalcoholic solutions which demonstrates that the molecular imprinting was successful. Th…
S. Butler - S. Nooter, eds. Sound and the Ancient Senses (The Senses in Antiquity, vol. 6), London-New York: Routledge, 2019
2021
Review of S. Butler - S. Nooter, eds. Sound and the Ancient Senses (The Senses in Antiquity, vol. 6), London-New York: Routledge, 2019. An essential read for all those interested in the ‘soundscape’ of Antiquity – from rites to the human body, the physiology of hearing, myth, music on the stage, ancient emotions and contemporary attempts in reconstructing ancient sounds –, the volume offers a broad perspective on sounds and hearing in Antiquity by means of its fourteen essays, distributed into three parts (“Ancient soundscapes”, “Theories of sound”, “Philology and sound”).
The evolutionary history of the Arabidopsis arenosa complex: diverse tetraploids mask the Western Carpathian center of species and genetic diversity.
2012
The Arabidopsis arenosa complex is closely related to the model plant Arabidopsis thaliana. Species and subspecies in the complex are mainly biennial, predominantly outcrossing, herbaceous, and with a distribution range covering most parts of latitudes and the eastern reaches of Europe. In this study we present the first comprehensive evolutionary history of the A. arenosa species complex, covering its natural range, by using chromosome counts, nuclear AFLP data, and a maternally inherited marker from the chloroplast genome [trnL intron (trnL) and trnL/F intergenic spacer (trnL/F-IGS) of tRNA(Leu) and tRNA(Phe), respectively]. We unravel the broad-scale cytogeographic and phylogeographic pa…