Pollutant binding to environmental interfaces studied by second harmonic generation

GEOC 69

Amanda L. Mifflin1, Hind A. Al-Abadleh, halabadl@chem.northwestern.edu2, Christopher T. Konek2, Andrea B. Voges, voges@northwestern.edu2, and Franz M. Geiger, f-geiger@northwestern.edu2. (1) Department of Chemistry, Bowdoin College, Brunswick, ME 04011, (2) Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208
The agricultural non-therapeutic use of antibiotics can have a significant impact on antibiotic effectiveness in humans. While many studies have established a direct link between antibiotic use on farms and antibiotic resistance in bacteria, the fate and transport of antibiotics in the environment is still not well understood. A detailed understanding of the binding of antibiotics to soil surfaces is needed for predicting their transport in the environment and assessing the impact of mobility on the emerging threat of antibiotic resistance. In this work, second harmonic generation is used to investigate the binding of oxytetracycline (OTC) to organically-functionalized mineral/oxide water interfaces. Direct surface-specific measurements suggest that OTC binding appears to be highly pH dependent and enhanced by the combination of hydrogen bonding and hydrophobic interactions. These studies allow us to calculate surface-specific partition coefficients for use in predicting OTC transport for a variety of soil compositions.
 

Physical Chemistry of Soil and Aquifer Systems: A Symposium in Honor of Garrison Sposito
8:15 AM-11:55 AM, Monday, 11 September 2006 Moscone Center -- Room 256, Oral

Sci-Mix
8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Geochemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006