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In the Netherlands the groundwater-surface water interaction processes vary spatially and temporarily. In this article we present maps of the spatial distribution of monthly water exchange modelled with the National Hydrological Instrument of the Netherlands (NHI) for three years that represent a dry, an average and a wet year. Additionally, for five characteristic regions we present the exchange in more detail, both the temporal variability and the origin of water fluxes. The simulation results provide a better understanding of the hydrogeological system. The Dutch water authorities use the maps in the planning process of measures to fulfil the framework directive of the European Union.

For forensic toxicological investigations only whole blood, but no serum is often available. Pharmacokinetic data are helpful for interpreting the results, but most of these studies indicate serum or plasma concentrations. In order to obtain reliable conversion factors which also take intersubject variability into account, the blood/serum ratios (B/S) of oxycodone, morphine, fentanyl, hydromorphone, zopiclone, MDMA, dexamphetamine, alprazolam, risperidone and 9-hydroxyrisperidone were determined by LC-MS/MS using authentic samples. Blood and corresponding serum samples were obtained from driving studies performed with controlled or known dosages of the above drugs. The analytes were analysed in blood and serum and the following mean B/S ratios (relative standard deviations) were determined: oxycodone 1.48 (8.19 %); morphine 1.03 (3.59 %); fentanyl 0.87 (13.9 %); hydromorphone 1.04 (8.11 %); zopiclone 0.89 (16.1 %); MDMA 1.19 (8.04 %); dexamphetamine 0.89 (10.9 %); alprazolam 0.81 (5.84 %); risperidone 0.65 (7.52 %); 9-hydroxyrisperidone 0.73 (12.3%). These mean values are largely in line with those reported in the literature. The B/S ratios did not appear to depend on partition coefficients, whereas there was strong evidence that B/S ratios decreased with increasing plasma protein binding.