Organic Geochemistry Research Laboratory

Geochemical Process Studies

Studies and accomplishments include work on the formation and transport of herbicides and their degradation products in the soil and vadose zone, dissipation of encapsulated herbicides, understanding the regional transport of herbicides and their degradation producs in surface water, and herbicide degradation products as indicators of surface and ground-water interaction.

Background and Facilities

• Central Region, of USGS for coordination with Midwest Studies, Bill Battaglin, Denver, Colorado
• Geology, J.F. Devlin, University of Kansas, Lawrence, Kansas
• Toxic Substances Hydrology Program, Herbert Buxton and Michael Focazio, Headquarters, Reston, Virginia

Examples of Geochemical Studies

• Metabolism of herbicides
• Transport, sorption, and degradation of hydrologic tracers
• Fate and transport modelling
• Variations in toxicity of surface-water samples

Geochemical process work include the following:

• Formation and transport of deethylatrazine in the soil and vadose zone
• Dissipation of encapsulated herbicides
• Regional transport of herbicides, antibiotics and their degradation products in surface water using immunoassay, GC/MS, LC/MS, and LC/MS/MS
• Herbicide degradation products as indicators of surface- and ground-water interaction
• Modeling water-quality data using attenuation factors

Selected Geochemical Process References

1. Adams, C.D. and Thurman, E.M., 1991, Formation and Transport of Deethylatrazine in the Soil and Vadose Zone: Journal of Environmental Quality, v. 20, no. 3, p. 540-547.

2. Aga, D.S., and Thurman, E.M., 2001, Formation and Transport of the Sulfonic Acid Metabolites of Alachlor and Metolachlor in Soil: Environmental Science and Technology, v. 34, no. 13, p. 2455-2460.

3. Kolpin, D.W., Thurman, E.M., Linhart, S.M., 1998, The Environmental Occurrence of Herbicides: The Importance of Degradates in Ground Water: Archives of Environmental Contamination and Toxicology, v. 35, p. 385-390.

4. Lerch, R.N., Blanchard, P.E., and Thurman, E.M. 1998, Contribution of Hydroxylated Atrazine Degradation Products to the Total Atrazine Load in Midwestern Streams: Environmental Science and Technology, v. 32, p. 40-48.

5. Meyer, M.T., Thurman, E.M., and Goolsby, D.A., 2001, Differentiating Nonpoint Sources of Deisopropylatrazine in Surface Water using Discrimination Diagrams, Journal of Environmental Quality, v. 30, p. 1836-1843.

6. Mills, M.S. and Thurman, E.M., 1994, Preferential Dealkylation Reactions of S-Triazine Herbicides in the Unsaturated Zone: Environmental Science and Technology, v. 28, no. 4, p. 600-605.

7. Thurman, E.M., Meyer, M.T., Mills, M.S., Zimmerman, L.R., Perry, C.A., and Goolsby, D.A., 1994, Formation and Transport of Deethylatrazine and Deisopropylatrazine in Surface Water: Environmental Science and Technology, v. 28, no. 13, p. 2267-2277.

8. Thurman, E.M. and Fallon, J.D., 1996, The Deethylatrazine/Atrazine Ratio as an Indicator of the Onset of the Spring Flush of Herbicides into Surface Water of the Midwestern United States: International Journal of Environmental Analytical Chemistry, v. 65, p. 203-214.

9. Thurman, E.M., Meyer, M.T., Mills, M.S., Zimmerman, L.R., Perry, C.A., and Goolsby, D.A., 1994, Formation and Transport of Deethylatrazine and Deisopropylatrazine in Surface Water: Environmental Science and Technology, v. 28, no. 13, p. 2267-2277.