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E Matthijs

Publications and source records attributed to E Matthijs.

6 recordsLinked to original sources
PubMed2005

Monitoring of environmental fingerprints of alcohol ethoxylates in Europe and Canada.

Recent improvements in methodology for the determination of alcohol ethoxylates (AE) in effluents now enable measurement of the full range of AE components, at ng/L levels, in the same analysis. This approach was deployed in effluent monitoring of biofilm and activated sludge wastewater treatment plants from Europe (n = 12) and Canada (n = 8) receiving predominantly municipal effluent. Individual component or "environmental fingerprint" analyses for alkyl carbon numbers C12-C18 and ethoxylate numbers 0-18 were conducted using a derivatization procedure with liquid chromatography/mass spectrometry determination. The AE results were very similar with an overall mean level of 5.7 microg/L (range 1.0-22.7 microg/L). The major contribution to the total AE content was from fatty alcohol, which constituted, on average, 43% of the total. The exposure data can then be corrected to account for alcohol derived from sources other than AE and for sorption to particulate matter to determine AE concentrations in undiluted effluents. These data can be used with site-specific dilution information to estimate river water exposure in mixing zones and then to determine aquatic risk by integrating normalized AE effect concentrations determined through quantitative structure-activity relationships.

Alcohols↗
PubMed2000

Predictive exposure modelling--a case study with a detergent surfactant.

Environmental exposure estimations are generally based on a knowledge of how and in what quantity a substance enters the environment and how it may subsequently be distributed and transformed. Once present within the environment, biota (including man) may be exposed. This paper outlines the tools commonly used to estimate environmental exposure to ingredients from detergents and other household products. Such products are typically manufactured in large quantities, used by many people, and disposed of after household use into the environment via the sewer. The vast majority of this waste stream is treated via domestic wastewater treatment plants (WWTPs) as documented in the sewage treatment Directive 91/275/EEC. WWTPs significantly reduce the load of chemical substances to the receiving surface waters, and have become an intrinsic part of exposure and risk assessment of household chemicals. WWTP models are generally first-order (e.g. SIMPLETREAT, WWTREAT) or mixed-order (e.g. Monod) kinetics and can exhibit, potentially, very distinct dependencies on the influent concentration. Thus, the correct representation of xenobiotic behaviour in a WWTP and modeling of their fate has a significant impact on exposure assessment. The Environmental Risk Assessment Steering Committee (ERASM) of the Association Internationale de la Savonnerie et la Détergence, et des Produits d'Entretiens (AISE) and the Comité Européen de Agents de Surface et Intermédiares Organiques (CESIO) has commissioned a joint industry Task Force of the Association to develop and apply specific methodology for the environmental monitoring of surfactants, and verification of fate models. The monitoring programmes have been designed to (1) establish the fate, distribution and concentrations of the major surfactants used in detergents-linear alkylbenzene sulfonate (LAS), alcohol ethoxylates (AE), alcohol ethoxylated sulfates (AES) and soap in relevant environmental compartments and (2) to provide the necessary data for checking the applicability of mathematical models to predict their fate and concentrations in these environmental compartments. The case study detailed here, specifically focuses on the refinement of the LAS exposure assessment for surface waters in The Netherlands.

Animals↗
PubMed1977

Antihaemophilic factor A activity, F VIII-related antigen and von Wilebrand factor in hepatic cirrhosis.

F VIII activity, F VIII-related antigen and von Willebrand factor were measured in 46 patients with hepatic cirrhosis and in 30 normal individuals. These parameters were significantly higher in hepatic cirrhosis than in the controls. Linear relationships between F VIII activity and F VIII-related antigen and between F VIII-related antigen and von Willebrand factor were found in patients with hepatic cirrhosis as well as in normal individuals. However, in both groups no relationship between F VIII activity and von Willebrand factor was present. The existence of a low-grade intravascular coagulation in hepatic cirrhosis may be postulated but more information about the metabolism of F VIII protein is needed before such a statement can be proven.

Antigens↗