Search results for "Nonylphenol"
showing 10 items of 13 documents
Micellar fluorescence enhancement of carbamate pesticides
1990
Abstract Different studies have been carried out on the interaction of carbamate pesticides, such as carbofuran and carbaryl, with nonionic and anionic surfactants. Micellar fluorescence enhancements (MEF) of 15–20 for carbofuran in the presence of fatty alcohol ethylene oxide condensates, and of 3.7–8.6 in the presence of anionic surfactants at neutral pH have been obtained. Carbaryl does not interact with surfactants, but when it is hydrolysed to 1-naphthol, MEF values of the order of 2 are obtained in the presence of nonylphenol ethylene oxide condensates. The experimental parameters have been optimized in order to obtain maximum fluorescence. The mechanisms involved in the fluorescence …
Quantitative determination of octylphenol, nonylphenol, alkylphenol ethoxylates and alcohol ethoxylates by pressurized liquid extraction and liquid c…
2007
6 páginas, 1 figura, 2 tablas.
Passive sampling in monitoring of nonylphenol ethoxylates and nonylphenol in aquatic environments
2012
The present practices for determining the concentration levels of various pollutants are in many respects insufficient and for this reason, there is an urgent need especially to develop more cost-effective sampling methods. In this study, a novel passive sampling tool (the Chemcatcher®) for monitoring nonylphenol ethoxylates (NPEOs) and nonylphenol (NP) in aqueous media was tested. These environmentally harmful substances have been widely used in different household and industrial applications and they affect aquatic ecosystems, for example, by acting as endocrine disrupting compounds. The highest accumulation of NPEOs and NP in laboratory-scale tests was obtained when using an SDB-XC (stan…
Guidelines for alkylphenols estimation as alkylphenol polyethoxylates pollution indicator in wastewater treatment plant effluents
2013
A solid-phase microextraction coupled with a gas chromatography-mass spectrometry method has been developed for the estimation of technical nonylphenol in the presence of other endocrine disruptors, belonging to different chemical families. The profile of the technical nonylphenol found in real samples was tested, and, given that it was similar to that provided for the standard used, reliable results were obtainable. Endocrine disruptors such as 4-n-nonylphenol, bisphenol A and 4-tert-octylphenol were simultaneously analysed. The best conditions achieved enabled the analysis of all analytes using a sample volume of 15 mL or even only 300 μL. Using such a low sample volume reduced the filtra…
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…
The use of mathematical models in the characterization of ethylene oxide condensate Surfactants by infrared and ultraviolet spectroscopy
1986
A topological treatment of the surfactant molecules (DARC system) and a group contribution model were applied to study the correlation between structures of ethylene oxide condensates with nonylsphenol and tert-octylphenol and their spectral characteristics such as extinction coefficient of the molecular absortion band. Using the experimental values of the spectral characteristics of an unknown smaple of an ethylene oxide condensate surfactant and the information parameters, previously determined by the mathematical treatment of a key population, it is possible to obtain their average condensation degree.
Fluorimetric determination of binding constants between micelles and chemical systems
1991
Abstract A fluorimetric method is adapted to determine the binding constants (K) between different systems and micelles. The method is based on the variation of the fluorescence of the system in the presence of increasing amounts of a surfactant agent. This method permits the determination of binding constants in strong acid or alkaline media. The binding constants of 1-naphthol and 2-(4-alkylamino-2 hydroxyphenyl)benzo-X azoles (X being an O or an S atom, PAS-O and PAS-S) with cationic, anionic, and nonionic surfactants have been determined by the proposed method. Values from 49,100 M−1 for the interaction between PAS-S and CTAB in basic medium to 10 M−1 for the interaction of 1-naphthol w…
Simultaneous determination of bisphenol A, octylphenol, and nonylphenol by pressurised liquid extraction and liquid chromatography–tandem mass spectr…
2011
Abstract A new analytical method, using pressurised liquid extraction (PLE) and liquid chromatography–tandem mass spectrometry (LC–MS/MS), was developed for the simultaneous determination of bisphenol A (BPA), octylphenol (OP) and nonylphenol (NP) in powdered infant formulas (IF) and powdered skimmed milk (PM). The analytes were extracted by PLE, using this optimised conditions: ethyl acetate as solvent, 70 °C of temperature, reversed-phase silica C18 as dispersing agent and three cycles of extraction. The extracts were then injected in LC–MS/MS using a Gemini C18 column and a mixture of 5% water and 95% methanol/acetonitrile, both with 0.1% ammonia, as a mobile phase. Recoveries at differe…
Micropollutants removal in an anaerobic membrane bioreactor and in an aerobic conventional treatment plant
2012
The paper expresses an attempt to tackle the problem due to the presence of micropollutants in wastewater which may be able to disrupt the endocrine system of some organisms. These kinds of compounds are ubiquitously present in municipal wastewater treatment plant (WWTP) effluents. The aim of this paper is to compare the fate of the alkylphenols-APs (4-(tert-octyl)) phenol, t-nonylphenol and 4-p-nonylphenol and the hormones (estrone, 17ß-estradiol and 17¿-ethinylestradiol) in a submerged anaerobic membrane bioreactor (SAMBR) pilot plant and in a conventional activated sludge wastewater treatment plant (CTP). The obtained results are also compared with the results obtained in a previous stud…
The use of utraviolet-visible spectrophotometry in the determination of average properties of nonylphenol ethylene oxide condensates
1983
Ultraviolet spectrophotometry is usd in the determination of average molecular weight (M), average degree of polymerization (X), the hydrophilic-lipophilic balance (HLB) and ethylene oxide percentage of nonylphenol ethylene oxide condensates. The method is based on determination of the absorptivity a, expressed in g lt-1 cm−1, from the absorbances measured at 275 nm for a series of dilutions of an aqeuous ethanolic solution (60:40, v/v/) of a given product, followed by numerical interpolation of this value in the expression a = f(HLB), log a = f(log M), and log a = f(log X). These expressions are obtained from reference samples or samples previously analyzed. The proposed method gives relat…