Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 25, 2003
Publication Date: March 25, 2003
Citation: RICE, P.J., KOSKINEN, W.C., CARRIZOSA, M. CHARACTERIZATION OF SORBED-DESORBED ISOXAFLUTOLE RESIDUES. AMERICAN CHEMICAL SOCIETY. 2003. ABSTRACT FALL. #71. Technical Abstract: Sorption-desorption of isoxaflutole (ISOX) and a diketonitrile degradate (DKN) were characterized in five soils with different clay and organic carbon contents and soil pH. Sorption fit the Freundlich equation with sorption minimally dependent on herbicide concentration. ISOX and DKN sorption was immediate; 95% of the sorption occurred within 2 h. Characterization of the CaCl2 solution revealed ISOX degradation was rapid in the CaCl2/soil systems. Solution phase ISOX and DKN concentrations were similar at 24 h, suggesting the 24-h sorption coefficients (Koc) for 14C-ISOX treated soils are actually a Koc for mixed ISOX residues. For the five soils, Koc of ISOX residues ranged from 24.8 to 85.3 while the Koc for DKN ranged from 8.17 to 22.2. Greatest sorption of ISOX residues and DKN was observed in the soil with the lowest pH (5.69), while the soil with the least sorption had the lowest clay content (12.3%).