Search results for "solubility"
showing 10 items of 681 documents
Response of Chlamydomonas reinhardtii to Herbicides: Negative Relationship Between Toxicity and Water Solubility Across Several Herbicide Families
2002
International audience
Laboratory leaching studies of oryzalin and diuron through three undisturbed vineyard soil columns
2004
Article de revue (Article scientifique dans une revue à comité de lecture); International audience; The leaching of diuron and oryzalin through undisturbed soil columns was studied in the laboratory using three vineyard soils from Vosne-Romanée (Burgundy): a rendosol, a calcosol and a vegetated calcosol. After 845 mm of simulated rainfall in 15 days, soil leachates contained higher amounts of diuron (3.2%, 11.8% and 18.8% of applied diuron, respectively) than oryzalin (0.2%, 4.9%, 3.7%, respectively). A greater proportion of soil extractable residues was obtained for diuron (42.5%, 26.8% and 32.2%, respectively) than for oryzalin (14.7%, 12% and 15.5%, respectively). The greater mobility of…
Assessing the transfer of pentachlorophenol through soil columns using 13[C]isotope
2002
Abstract The transfer of organic pollutants was studied through soil columns using 13 [C]-labelled pentachlorophenol (PCP) as a model compound. The organic carbon content and the 13 [C]/ 12 [C] ratio were measured in two soil sections, 0–3 cm and 3–6 cm, and in percolated water using an Elemental Analyser coupled with a Magnetic Mass Sector. The mass balance of carbon was evaluated and the amount of PCP was calculated in each compartment of the soil–water systems. The results show that more than 80% of the PCP-derived 13 [C] remained in the upper layer of the soil column. Approximately 20% was transferred to the lower soil layer, and less than 1% was found in the water leachates. The 13 [C]…
Determination of taste-active compounds of a bitter camembert cheese by omission tests
2001
The taste-active compounds of a Camembert cheese selected for its intense bitterness defect were investigated. The water-soluble fraction (WSE) was extracted with pure water and fractionated by successive tangential ultrafiltrations and nanofiltration. The physicochemical assessment of these fractions led to the construction of a model WSE which was compared by sensory evaluation to the crude water-soluble extract, using a panel of 16 trained tasters. As no significant difference was perceived, this model WSE was then used directly or mixed with other cheese components for omission tests. Among the main taste characteristics of the WSE (salty, sour, umami and bitter), bitterness was found t…
Ultrasound assisted method to increase soluble chemical oxygen demand (SCOD) of sewage sludge for digestion
2004
The aim of this study was to clarify the possibilities to increase the amount of soluble chemical oxygen demand (SCOD) and methane production of sludge using ultrasound technologies with and without oxidising agents. The study was done using multivariate data analyses. The most important factors affected were discovered. Ultrasonically assisted disintegration increased clearly the amount of SCOD of sludge. Also more methane was produced from treated sludge in anaerobic batch assays compared to the sludge with no ultrasonic treatment. Multivariate data analysis showed that ultrasonic power, dry solid content of sludge (DS), sludge temperature and ultrasonic treatment time have the most signi…
Temperature effect on solubility of aroma compounds in various aqueous solutions
2005
International audience; Solubility of nine aroma compounds (methyl ketones, ethyl esters, aldehyde and alcohol) in various aqueous solutions was measured by the mutual solubility method from -10 to +10degreesC. Influence of both, the nature (carbohydrates and polyols) and the substrate concentration (from 0 to 57.5g/100g) on aroma solubility in aqueous solutions was studied. Aroma solubility in water decreased when aroma hydrophobicity increased. Aroma solubility in various aqueous solutions decreased when substrate concentration increased; their solubility was higher in polyols solutions than in polysaccharides ones. Temperature effect on aroma solubility showed a noncontinuous evolution f…
Atrazine uptake, elimination, and bioconcentration by periphyton communities and Daphnia magna: effects of dissolved organic carbon.
2001
The bioconcentration and toxicokinetics of atrazine in three different periphyton communities and in laboratory reared Daphnia magna were studied in natural and artificial waters with different dissolved organic carbon (DOC) concentrations and qualities. The exposure concentrations were similar to those short-lived peak concentrations found in contaminated waters. Atrazine uptake and elimination were very fast, and the bioconcentration was low both in periphyton and D. magna. The bioconcentration factors in D. magna were approx. 16% of those in periphyton. The uptake and elimination rates were also higher in periphyton than in Daphnia. The periphyton properties affected the bioconcentration…
Tetra-urea calix[4]arenes 1,3-bridged at the narrow rim.
2009
The synthesis of special tetra-urea calix[4]arene derivatives is described. Two propyl ether groups in 1,3-position and a 5-iodo-isophthalamide bridge connecting two aminopropylether residues in 2,4-position at the narrow rim keep the molecule fixed in the cone conformation. The aryl urea residues are substituted by decyloxy groups in p-position to increase the solubility in apolar solvents, while the iodo substituent allows further functionalization. Two single crystal X-ray structures of 3 and 4 show a strongly pinched cone conformation in which the bridged phenol units are bent outwards, while the phenol units bearing the propyl ether groups are nearly parallel. The molecules are flexibl…
Quinazoline antifolate thymidylate synthase inhibitors: replacement of glutamic acid by aminophosphonic acids
2003
The synthesis of six analogues of the potent thymidylate synthase (TS) inhibitor N -[4-[ N -[(3,4-dihydro-2-methyl-4-oxo-6-quinazolinoyl)-methyl]- N -prop-2-ynylamino]benzoyl]- L -glutamic acid 2 is described in which the glutamic acid residue has been replaced by DL -aminophosphonic acids. New antifolates were tested as inhibitors of TS isolated from mouse L1210 leukemic cells as well as inhibitors of growth mouse leukemic L5178Y cells. In general these modifications result in compounds that are considerably less potent than 2 as TS inhibitors with K i 's 0.17-1.10 w M. Very poor solubility in water limited their proper assay of growth cells inhibition.
Removal of Pesticide Oxadixyl from an Aqueous Solution
2007
ABSTRACT The mycelium of Phomopsis helianthi (Ascomycete) was hydrolyzed with boiling NaOH to give an insoluble fraction composed of chitosan and glucans. The biomass obtained was tested as an agent for the removal of pesticides from an aqueous solution. Oxadixyl, which has a solubility in water of 3400 mg L−1, has been chosen as a hydrophilic organic contaminant model. The new, cheap material was demonstrated to recover up to 6 mg of oxadixyl per gram of adsorbent. The experimental data show an excellent correlation with the Langmuir isotherm model.