Photo Degradation Of Clodinafop-propargyl In Water

The effects of different types of water、light sources、pH, and through N2off02on the photo degradation of Clodinafop-Propargyl in aqueous solution were studied. By LC/Q-TOF-MS, the photo products and hydrolyzes of Clodinafop-Propargyl was detected in distill water. The pathway of Clodinafop-Propargyl photo degradation in water was proposed.1.The photo degradation rate of Clodinafop-Propargyl in aqueous solution by HPLM was quicker, the half-life was0.3655h. however it slowly under sunlight and xenon lamp irradiation, the half-life was53.30h and40.52h. the photolysis follow the first order kinetics.2.In strong basic solution, Clodinafop-Propargyl hydrolyzed rapidly to24.5%in pH=9within48h at room temperature, Clodinafop-Propargyl was stable in acidic solution within48h at room temperature, Clodinafop-Propargyl hydrolyzed to83.6%in pH=7; Under HPML, the pH value has significant effect on Clodinafop-Propargyl photolysis. The result showed the photolysis rates increased with the increase of pH value.3. The photolytic rates of Clodinafop-Propargyl in4types of water ranged as: tapped water> distilled water> reservoir water> ChaoHu Lake water. The half-life of Clodinafop-Propargyl is15.29min in tapped water,17.24min in distilled water,22.24min in reservoir water,23.26min in ChaoHu lake water.4. The photolytic rates of Clodinafop-Propargyl is also affected by its concentration in aqueous solution. In the test, with the increasing concentration of l.Omg/L,3.0mg/L,5.0mg/L. Clodinafop-Propargyl has half-life of16.42min,17.68min,19.58min, respectively.5. Under HPML, filled with N2and air of Clodinafop-Propargyl aqueous photochemical degradation has certain difference. Filling N2Clodinafop-Propargyl photolysis rate decreased. The half-life of Clodinafop-Propargyl is17.02min within N2, filled with air for the14.58min.6. Q-TOFLC/MS analysis, there three distinct product structure respectively:(R)-prop-2-ynyl2-(4-(3-fluoropyridin-2-yloxy)phenoxy)propanoate;2-(4-(5-chloro-3-fluoro-1,6-dihydropyridin-2-yloxy)phenoxy)ethenone and (L)-prop-2-ynyl2-(4-(5 -chloro-3-fluoropyridin-2-yloxy)phenoxy)propanoate hydrolysis productsrespectivel y:(R)-prop-2-ynyl2-(4-(3-fluoropyridin-2-yloxy)phenoxy)propanoate;(L)-prop-2-yny12-(4-(5-chloro-3-fluoropyridin-2-yloxy)phenoxy)propanoate and (R)-methyl2-(4-(5-chloro-3-fluoropyridin-2-yloxy)phenoxy)propanoate...