Degradation Dynamics of Halosulfuron-methyl in Two Textured Soils

A laboratory experiment was conducted to study the degradation dynamics of halosulfuron-methyl residues in sandy loam and clay loam soil. The herbicide formulation was applied at 0.034 and 0.068 mg kg^- 1 equivalent to field application dose of 67.5 and 135 g a.i. ha^- 1 as single and double dose respectively. Soil samples were collected on 0 (1 h), 1, 3, 7, 10, 15, 30 and 45 days after treatments. Extraction was done using modified QuEChERS method. Residues were estimated by UPLC coupled with quadrupole Dalton mass detector. Average recoveries ranged from 85.5% to 94.5% for both soils at different fortification levels of 0.005 to 0.1 mg kg^- 1 with limit of detection (LOD) and limit of quantification (LOQ) as 0.001 and 0.005 mg kg^- 1, respectively. Dissipation followed first order kinetics with half-life of 8.4 to 10.7 days in both soil at two doses. The residues reached below LOQ of 0.005 mg kg^- 1 after 45 days of herbicide application.