[Study on the determination of metsulfuron-methyl and its adsorption behavior on typical soils and minerals]

Adsorption behavior of metsulfuron-methyl on soils and minerals was investigated using batch experiment. The concentration of metsulfuron-methyl in supernatant was analyzed by capillary electrophoresis (CE) method. Metsulfuron-methyl, whose peak centered at 4.6 min in capillary electrophoresis chromatogram, was well separated from impurities in soil slurry. CE was shown to be fast with low operating cost in the routine determination of the herbicide, which was further confirmed by high performance liquid chromatograph (HPLC). Sorption isotherms were fitted to the Freundlich equation, where the parameter Kf was in the range of 0.82-199.69 for minerals and 1.97-10.48 for soils, respectively. Among the various factors influencing the sorption behavior of metsulfuron-methyl, soil pH appeared to be the most important one. The electrostatic interaction mechanism was applied in the explanation of the sorption behavior of metsulfuron-methyl.