ENVR 151 |
| We have developed a new preconcentrating minicolumn sensor concept for water monitoring where the column contains tens to hundreds of milligrams of selectively sorbent material and the entire column content is monitored with a radiometric or absorptiometric detector. Compared to thin film sensors with a few micrograms of sorbent, this approach achieves tremendous preconcentration with efficient mass transport via pumping. Furthermore, in an equilibration-based mode of operation, the preconcentration by the sensor is maximized while eliminating the need for consumable reagents to regenerate the column; it can simply be re-equilibrated. Frontal chromatography theory can be used to characterize and design such sensors. We have demonstrated quantification of radionuclides (99-technetium) and metal ions (hexavalent chromium) to trace levels below drinking water standards in an equilibration-based process that produces steady state signals, signal proportional to concentration and easy re-equilibration to new concentration levels. These features are well suited to in situ environmental sensing and monitoring. |
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Sensors for Detection and Quantification of Contaminants in Drinking Water and the Environment
8:30 AM-12:10 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 235, Oral
Division of Environmental Chemistry |