Search results for "linear alkylbenzene"
showing 7 items of 7 documents
Analysis of linear alkylbenzene samples with a camera-based equipment
2017
Nestemäisiä tuikeaineita hyödyntävät ilmaisimet ovat saaneet jalansijaa neutriinofysiikassa viime vuosikymmeninä. Perinteisiin Cherenkovin ilmaisimiin niiden etu on suurempi hiukkasten vuorovaikutuksesta aiheutuvan valon tuotto. Lisäksi edullisten, suhteellisen ympäristöystävällisten ja optisesti kirkkaiden tuikeaineyhdisteiden (bentseenin alkyylijohdannaiset) saatavuus mahdollistaa yhä suurempien ilmaisimien rakennuksen. Nestemäisten tuikeaineiden ongelmana on kuitenkin niiden taipumus kerätä epäpuhtauksia itseensä ja niiden muutosalttius UV-säteilyn ja korkeiden lämpötilojen vaikutuksesta. Muutokset heikentävät tuikeaineiden valon tuottoa, ja siksi nestemäisten tuikeaineiden puhdistusta j…
Separation and determination of homologues of linear alkylbenzenesulfonates by nonaqueous capillary zone electrophoresis using alkylammonium salts in…
2001
The separation of linear alkylbenzene sulfonates (LAS) by nonaqueous capillary electrophoresis (NACE) using negative polarity, and a buffer containing acetic acid and an alkylamine in nonaqueous ethanol, has been investigated. Several primary, secondary, and tertiary alkylamines with alkyl chains of different length were compared. The solutes travelled against the electroosmotic flow (EOF), and at the same time were braked by association with the alkylamine molecules or with the alkylammonium ions. The best resolution between adjacent LAS homologues (R approximately 2.1), partial isomer resolution in two peaks, and at the same time an excellent repeatability, was obtained with a small dipen…
Determination of non-ionic and anionic surfactants in industrial products by separation on a weak ion-exchanger, derivatization and liquid chromatogr…
2013
Abstract A method for the determination of priority surfactants, including fatty alcohol ethoxylates (FAE), alkylether sulfates (AES) and linear alkylbenzene sulfonates (LAS) is described. The samples were diluted with 50% methanol at pH 4 prior to solid-phase extraction on a weak anionic exchanger (WAX). The AES and LAS surfactant classes were retained, whereas the non-ionic components, including most FAE oligomers were eluted. After washing the WAX cartridge to remove cations, the remaining hydrophobic FAE oligomers were eluted using hot 80% methanol at pH 4 (at ca. 50 °C). These two eluates were combined to constitute the non-ionic fraction. Then, AES and LAS were eluted using 80% MeOH w…
Fate of organic pollutants after sewage sludge spreading on agricultural soils: a 30-years field-scale recording
2006
Le DOI mentionné dans l'article 10.2166/WPT.2007.008 ne fonctionne pas; International audience; Toxic organic compounds, such as the surfactants linear alkylbenzene sulfonates (LAS) and nonylphenol polyethoxylates (NPE), Polycyclic aromatic hydrocarbons (PAH) and residues derived from plastics (PAE-phthalates) end up in sewage sludge. In order to evaluate and quantify the potential environmental risks associated with the xenobiotic introduction into biological life cycle, the EU BIOWASTE project (QLK5-CT-2002-01138) devotes one task to the study of the fate of xenobiotic in a sandy soil after sludge spreading on a 30-year field-scale record experiment. Experimental maize crop fields from Bo…
Liquid Phase Micro-Extraction of Linear Alkylbenzene Sulfonate Anionic Surfactants in Aqueous Samples
2011
Hollow fiber liquid phase micro-extraction (LPME) of linear alkylbenzene sulfonates (LAS) from aqueous samples was studied. Ion pair extraction of C10, C11, C12 and C13 homologues was facilitated with trihexylamine as ion-pairing agent, using di-n-hexylether as solvent for the supported liquid membrane (SLM). Effects of extraction time, acceptor buffer concentration, stirring speed, sample volume, NaCl and humic acids were studied. At 10–50 µg L−1 linear R2-coefficients were 0.99 for C10 and C11 and 0.96 for C12. RSD was typically ~15%. Three observations were especially made. Firstly, LPME for these analytes was unusually slow with maximum enrichment observed after 15–24 h (depending on sa…
Determination of alkylphenol ethoxylates by micellar electrokinetic chromatography with bile salts
2001
Octyl- and nonylphenol ethoxylates (OPEs and NPEs) with different numbers of ethoxy units (average values: n = 10 and N = 40 for OPEs, and n = 10 for NPEs) were separated by micellar electrokinetic chromatography under positive polarity using an 80 mM borate buffer of pH 8.5 containing sodium deoxycholate (SDC) or sodium cholate (SC). When sodium dodecyl sulfate (SDS) was added to the background electrolyte (BGE) in the absence of the bile salt, a single peak at a migration time longer than that of the EOF was obtained. Substituting the SDS by a bile salt, the homologues were resolved. At the same bile salt concentration, resolution between the homologues was higher with SDC than using SC. …
Effect of temperature and organic nutrients on the biodegradation of linear alkylbenzene sulfonate (LAS) during the composting of anaerobically diges…
2004
Limits on the application of biosolids (anaerobically processed sludges from wastewater treatment plants) as fertilizers for the amendment of soil are becoming greater because of the accumulation of recalcitrant substances, making necessary the use of techniques that bring the concentration of xenobiotics to lower concentrations than those permitted. In general, the biosolids composting process is sufficient to reduce the usual concentration of linear alkylbenzene sulfonates (LAS) to low levels. In this work, an assessment is made on the effect of temperature in the capacity of enriched bacterial populations to biodegrade LAS, together with the influence that the available nutrients may hav…