The use of passive sampling techniques to monitor water quality offers a number of advantages over conventional grab or spot sampling methods. Recently, a passive sampling device - Chemcatcher - has been developed for the measurement of a broad range of priority organic and inorganic pollutants. The device uses a common design with interchangeable receiving phases and membranes, depending upon application. There are two designs of housing available for the Chemcatcher. The samplers were deployed at two sites in Portsmouth Harbour (Portsmouth, UK) for several 14-day periods. Three replicates of the Chemcatcher sampler were deployed at each site. Two different designs of sampler housing were used and compared in the trial. During the whole exposure time the water chemistry was carefully monitored. Spot samples were collected regularly during the deployment period and the uptake of selected organic priority pollutants in the passive samplers was compared to the levels found in the spot samples. The samplers provided time-weighted average concentrations of the bioavailable (truly dissolved) fraction of monitored pollutants. Sampling rates at Site 1 (outside the harbour basin) were are almost three times higher than those at Site 2, which was probably caused by the more intense turbulence of water. In comparison with the concentrations of truly dissolved analytes measured by passive samplers, higher concentrations of pollutants were determined in filtered spot water samples. The difference was likely caused by the elevated content of colloidally bound contaminants present in water samples. In contrast, passive samplers measure the concentrations of truly dissolved fractions. Concentrations of pollutants at Site 1 determined in passive samplers were lower compared to Site 2. Concentrations in water samples at the two sites did not differ significantly, although slightly higher PAH concentrations were determined at Site 1.
|Number of pages||14|
|Journal||Acta Chimica Slovaca|
|Publication status||Published - 2010|