Example Of Field Results And Future Work

So far, the ceramic dosimeter has been employed in the field for sampling a number of organic chemicals under various sampling conditions with a main focus on groundwater. Figures 12.6 and 12.7 are taken from Bopp et al. [2] where groundwater boreholes at a former gas works site were sampled for PAHs over the course of 1 year. They illustrate the sampling behavior of Amberlite IRA-743-filled ceramic dosimeters in a harsh environment: the borehole was found to contain an unexpected tar oil phase.

Because of its robustness and flexibility, many different sampling applications for the ceramic dosimeter can be envisaged. The robustness stems from the ceramic membrane. The flexibility is due to the possibility of filling the ceramic tube with any sorbent material to accumulate a chemical or chemical group of choice. Along these lines, extensive research was performed by Martin [14] in order to identify suitable sorbents and extraction methods for anions (nitrate) and cations (Cu, Zn). Additionally, applications for sampling different

Fig. 12.7. Comparison of accumulated PAH masses collected over the whole exposure period in 12 months exposed ceramic dosimeters and the sum of accumulated masses in samplers exposed for the first (month 0-6) and the second 6 months (months 7-12) of a 1-year sampling campaign. Reprinted from Bopp et al. [2] with permission from Elsevier.

Fig. 12.7. Comparison of accumulated PAH masses collected over the whole exposure period in 12 months exposed ceramic dosimeters and the sum of accumulated masses in samplers exposed for the first (month 0-6) and the second 6 months (months 7-12) of a 1-year sampling campaign. Reprinted from Bopp et al. [2] with permission from Elsevier.

pharmaceuticals are also underway. The link of ceramic dosimeter derived samples to bioassay analysis, as initiated with the development of the Toximeter (see Chapter 18), is of particular value if the presence of toxicologically relevant chemical contaminants is unknown.

Taken together, any chemical can be collected in any aqueous environment by means of the ceramic dosimeter as long as a solid receiving phase with a high affinity and capacity for the chemical of concern can be found. Therefore, further research is also undertaken to explore the use of ceramic dosimeters as a monitoring instrument in surface waters (rivers, lakes) and sediments. One vision is to provide to authorities the ceramic dosimeters in a sealed cage for time-integrated monitoring at industrial sites with potentially problematic discharges into a river or lake. In principle, even single, temporary events can be detected by the dosimeters because of the long-term stability of once trapped compounds (see Section 12.3.4). Likewise, industrial chemical site owners could use the device as a reassurance that they release only wastewaters according to the quality required by law.

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