Utilizing Polymer-Coated Vials To Illustrate the Fugacity and Bioavailability of Chlorinated Pesticide Residues in Contaminated Soils
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- 作者：Natasha A. Andrade ; Laura L. McConnell ; Alba Torrents ; Cathleen J. Hapeman
- 刊名：Journal of Chemical Education
- 出版年：2013
- 出版时间：April 9, 2013
- 年：2013
- 卷：90
- 期：4
- 页码：479-482
- 全文大小：194K
- 年卷期：v.90,no.4(April 9, 2013)
- ISSN：1938-1328
文摘
Fugacity and bioavailability can be used to facilitate students鈥?understanding of potential environmental risks associated with toxic chemicals and, therefore, should be incorporated in environmental chemistry and science laboratories. Although the concept of concentration is easy to grasp, fugacity and bioavailability can be challenging topics to communicate effectively in the timeframe of an academic laboratory course setting. In the experiment reported here, students observed the partitioning of chemical residues over time from soil into an artificial biological matrix. The two compounds utilized here as examples are commonly found in historically contaminated agricultural sites: 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane (DDT) and 1,1-bis-(4-chlorophenyl)-2,2-dichloroethane (DDE). A known quantity of the compounds was spiked and mixed into soil, which was then placed in replicate glass vials coated with a thin layer of polymer to mimic contact between soil and an organism. The polymer was then extracted and analyzed by standard gas chromatography鈥搈ass spectrometry (GC鈥揗S). The fugacity gradient across the soil鈥損olymer interface and the hydrophobic nature of the compounds drive the residues into the polymer, illustrating the concept of fugacity. A number of variations of this experiment, such as the comparison of different soils or the use of different contaminants could also be utilized for more advanced laboratory courses.