Kansas Water Science Center
USGS Water Science Centers are located in each state. ![]() |
A Reconnaissance Study of Herbicides and Their Metabolites in Surface Water of the Midwestern United States Using Immunoassay and Gas Chromatography/Mass SpectrometryBy E.M. Thurman, D.A. Goolsby, M.T. Meyer, and M.S. Mills, M.L. Pomes, and D.W. Kolpin AbstractPreemergent herbicides and their metabolites, particularly atrazine, deethylatrazine, and metolachlor, persisted from 1989 to 1990 in the majority of rivers and streams in the midwestern United States. In spring, after the application of herbicides, the concentrations of atrazine, alachlor, and simazine were frequently 3-10 times greater than the U.S. Environmental Protection Agency maximum contaminant level (MCL). The concentration of herbicides exceeded the MLCs both singly and in combination. Two major degradation products of atrazine (deisopropylatrazine and deethylatrazine) also were found in many of the streams. The order of persistence of the herbicides and their metabolites in surface water was atrazine > deethylatrazine > metolachlor > alachlor > deisopropylatrazine > cyanazine. Storm runoff collected at several sites exceeded the MCL multiple times during the summer months as a function of stream discharge, with increased concentrations during times of increased streamflow. It is proposed that metabolites of atrazine may be used as indicators of surface-water movement into adjacent alluvial aquifers. Additional information about the Organic Geochemistry Research Laboratory can be found at: http://ks.water.usgs.gov/studies/reslab/Thurman, E.M., Goolsby, D.A., Meyer, M.T., Mills, M.S., Pomes, M.L., and Kolpin, D.W, 1992, A reconnaissance study of herbicides and their metabolites in surface water of the midwestern United States using immunoassay and gas chromatography/mass spectrometry [abst.]: Environmental Science & Technology, v. 26, p. 2440-2447. To request a paper copy of this journal article, email: scribner@.usgs.gov |