The sorption of thiamethoxam in a Brazilian Oxisol was determined in soil samples with and without organic matter for two different dephs (0-0.1 and 0.4-0.7 m). The results indicated a predominant sorption of thiamethoxam on soil without organic matter. The following Kd values of 4.25 mL g-1 (0-0.1 m, r² = 0.8534) and 5.30 mL g-1 (0.4-0.7 m, r² = 0.9884) and Kf values, 7.65 mL g-1 (0-0.1 m, r² = 0.9623) and 7.72 mL g-1 (0.4-0.7 m, r² = 0.9775) were obtained. Those sorption coefficient values indicated a small interaction between thiamethoxam for both original soil and soil without organic matter.
bath experiment; soil organic matter; environmental contamination
