MA6 Environmental Chemistry and Toxicology of Chiral Pollutants
202 Oregon Ballroom
8:00 AM - 12:00 PM, Monday
() Analytical Methods for the Analysis of Chiral and Other Xenobiotic Compounds Within the Rhizosphere and Rhizosphere Associated Plant Materials. Part A.
Eitzer, B.1, Mattina, M.J.1, Isleyen, M.1, Iannucci-Berger, W.1, 1 The Connecticut Agricultural Experiment Station, New Haven, CT, USA
ABSTRACT- It has been suggested that highly hydrophobic (log Kow > 6) xenobiotic compounds such as chlordane and DDE become sequestered within the soil matrix as their residues age. Despite this suggestion, we have found that certain plants such as Cucurbita pepo L. (zucchini) have the ability to release contaminants from the sequestered matrix, transfer the contaminant across the root membrane, and translocate the contaminants to aerial tissue. In order to understand the mechanisms that control this transfer it is necessary to develop analytical methods which will allow for the site-specific analysis of these contaminants within the soil/root/plant system; concomitantly, plant root exudates which may be facilitating this transfer must be determined. Some of our recently developed methods will be discussed in this talk. These include techniques for sampling and analyzing small quantities of rhizosphere soil, soil pore water, and xylem sap for xenobiotic organic compounds, including DDE and chlordane at the sub parts per billion range. The procedures utilize a solid phase microextraction technique followed by chiral thermal desorption gas chromatography/mass spectrometry. The analysis of both chiral and achiral contaminants within a single analysis can help elucidate whether the mechanisms controlling the translocation of the compounds are driven strictly by physico-chemical parameters or involve biotic interaction. We have also developed a derivatization procedure, which allows for the analysis of low molecular weight organic acid root exudates within the same set of samples used for the xenobiotic organic compound analyses.
Key words: spme, chlordane, rhizosphere