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A new sampling system has been developed for the measurement of time-averaged concentrations of organic micropollutants in aquatic environments. The system is based on the diffusion of targeted organic compounds through a rate-limiting membrane and the subsequent accumulation of these species in a bound, hydrophobic, solid-phase material. It provides a(More)
Marine mussels are useful, robust model organisms that have been widely used as biomonitors. In the natural environment they can be subjected simultaneously to a mixture of environmental stresses (hypoxia, starvation) and to pollutants. In this study Mytilus edulis was used to investigate the effects of two pesticides, atrazine and lindane, which have(More)
We previously identified vitamin B6 deficiency in a child presenting with seizures whose primary diagnosis was the inherited disorder hyperprolinemia type II. This is an unrecognized association, which was not explained by diet or medication. We hypothesized that pyridoxal phosphate (vitamin B6 coenzyme) was de-activated by L-Delta(1)-pyrroline-5-carboxylic(More)
Until now, water quality monitoring has relied heavily on spot sampling followed by instrumental analytical measurements to determine pollutant concentrations. Despite a number of advantages, this procedure has considerable limitations in terms of (i) temporal and spatial resolution that may be achieved at reasonable cost, and (ii) the information on(More)
Severe birth asphyxia leads to a transient organic aciduria and increased hypoxanthine excretion. To investigate its origin and timing, we analyzed urine from 12 late gestation fetal sheep in utero subjected to moderately severe isocapnic hypoxia for 1 h. In six fetuses the carotid sinus nerves were cut to determine whether reflex peripheral(More)
The performance of seven passive sampling devices for the monitoring of dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), hexachlorobenzene, and p,p'-DDE was evaluated through simultaneous field exposures of 7-28 days in the River Meuse (The Netherlands). Data from the Chemcatcher, low density(More)
Volatile compounds contribute substantially to the metabolic pool in man. Their analysis in body fluids is problematic. We investigated headspace solid-phase microextraction (HS-SPME) with Carboxen-polydimethylsiloxane fibres and gas chromatography-mass spectrometry for profiling urinary volatile components. These fibres were more sensitive for very(More)
This work aimed to evaluate whether the performance of passive sampling devices in measuring time-weighted average (TWA) concentrations supports their application in regulatory monitoring of trace metals in surface waters, such as for the European Union's Water Framework Directive (WFD). The ability of the Chemcatcher and the diffusive gradient in thin film(More)