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Full-Text Articles in Physical Sciences and Mathematics
Analysis Of Selected Herbicide Metabolites In Surface And Ground Water Of The United States, Elisabeth A. Scribner, E. M. Thurman, Lisa R. Zimmerman
Analysis Of Selected Herbicide Metabolites In Surface And Ground Water Of The United States, Elisabeth A. Scribner, E. M. Thurman, Lisa R. Zimmerman
United States Geological Survey: Staff Publications
One of the primary goals of the US Geological Survey (USGS) Laboratory in Lawrence, Kansas, is to develop analytical methods for the analysis of herbicide metabolites in surface and ground water that are vital to the study of herbicide fate and degradation pathways in the environment. Methods to measure metabolite concentrations from three major classes of herbicides ─ triazine, chloroacetanilide and phenyl-urea ─ have been developed. Methods for triazine metabolite detection cover nine compounds: six compounds are detected by gas chromatography/mass spectrometry; one is detected by high-performance liquid chromatography with diode-array detection; and eight are detected by liquid chromatography/mass spectrometry. …
Effects Of Topography And Soil Properties On Recharge At Two Sites In An Agricultural Field, Geoffrey N. Delin, Richard W. Healy, Matthew K. Landon, John Karl Böhlke
Effects Of Topography And Soil Properties On Recharge At Two Sites In An Agricultural Field, Geoffrey N. Delin, Richard W. Healy, Matthew K. Landon, John Karl Böhlke
United States Geological Survey: Staff Publications
Field experiments were conducted from 1992 to 1995 to estimate ground water recharge rates at two sites located within a 2.7-hectare agricultural field. The field lies in a sand plain setting in central Minnesota and is cropped continuously in field corn. The sites are located at a topographically high (upland) site and a topographically low (lowland) site in an effort to quantify the effects of depression focusing of recharge. Three site-specific methods were used to estimate recharge rates: well hydrograph analysis, chlorofluorocarbon age dating, and an unsaturated zone water balance. All three recharge methods indicated that recharge rates at the …