Passivsammler für die zeitintegrierte chemische und toxikologische Überwachung des Schadstoffgehaltes in Grund- und Oberflächenwasser

The availability of high-quality water plays a pivotal role for the protection of the ecosystem and the quality of human life. An important step in assessing ground and surface water quality is sampling. The time-integrated accumulation of environmental contaminants by passive sampling is an attractive alternative to conventional snap-shot sampling. Thein situ accumulation during passive sampling allows the detection of even lowconcentrated contaminants and reduces cost and time for continuous monitoring. Passive sampling provides information on the whole sampling period and avoids the transport and storage of large sample volumes. Matrix effects are reduced due to the selective enrichment. Various passive samplers have been developed for sampling in aqueous media. Early developments used water filled dialysis tubes for the sampling of trace elements. Later on, solvent filled devices and triolein-filled semipermeable membrane devices (SPMDs) were deployed. More recent developments use a solid rather than a liquid sorbent as the receiving phase. Examples of this are the solid phase microextraction (SPME) and the membrane enclosed sorptive coating (MESCO). In addition to comprising miniature devices, SPMEs as well as MESCO are thermodesorbable and, as such, no longer require solvent extraction. Conventionally the sampled contaminants are removed from the passive sampling devices by solvent extraction or thermodesorption in order to be analyzed chemically. For an in-depth analysis of sampled analytes, however, it would be advantageous to modify passive sampling such that sampled contaminants can also be analyzed biologically. Thus, it is our goal to construct a passive sampling device that serves both as a sampling device as well as an exposure chamber for toxicity testing. The principle underlying this technology is the bioavailability of sorbed contaminants, thereby eliminating the need for solvent extraction.