Degradation Characteris Of Saflufenacil

A method for residue determination of saflufenacil, an unselective hebicide in environmental samples was developed. Via this method, environmental behavior of saflufenacil was studied, such as photolysis, hydrolysis and soil degradation.A rapid, accuracy, sensitive method for residue determination of saflufenacil in soil and water was developed using UPLC-ESI-MS/MS. The recoveries of saflufenacil in soil and water ranged from 72.6 to 104.6%, and the RSDs ranged from 0.7 to 9.6%. LOQs were 0.005 and 0.001mg/kg respectively, and LOD was 2.5×10-12 g.Hydrolysis half lives of saflufenacil in different buffer solutions with pH values of 4, 5 and 6 were more than 180 d, and with pH values of 7,8,9 were 10.0d,37.9h and 5.4h, respectively. Hydrolysis velocity in alkaline condition was larger than in acid and neutral condition. Temperature had a significant effect on saflufenacil's hydrolysis, which was increased with temperature increasing. Saflufenacil was photodegradated to M800HA, M800HB and M800HC.Photolysis half lives treated with Xe-lamp with light intension of 12300 and 4000 Lux were 3.5h and 16.7h. Light intension had a significant effect on saflufenacil's photolysis, which was increased with the light intension.Half lives in moisture soil, yellow/red loam and yellow/brown loam were 52.1,121.6 and 223.6 d, respectively. saflufenacil had medium dissipation rate in moisture soil, slightly low dissipation rate in yellow/red loam, but low dissipation rate in yellow/brown loam. The degradation rate had a good negative correlation with the initial concentration. It indicated that soil microorganisms had a significant effect on the degradation of saflufenacil in soil, which the aerobic microorganisms had played a dominant role. In field experiments, half lives in red/yellow loam, red loam, silty loam were/,17.4,47.2d respectively in 2008 and 33.6,19.7,24.3 d in 2009. Under field environment, x's dissipation was faster than that in laboratory.