Aqueous Photolysis of Benzobicyclon Hydrolysate

作者：Williams Katryn L^*; Kaur Richie; McFall Alexander S; Kalbfleisch Jacob; Gladfelder Joshua J; Ball David B; Anastasio Cort; Tjeerdema Ronald S

来源：Journal of Agricultural and Food Chemistry, 2018, 66(22): 5462-5472.

DOI：10.1021/acs.jafc.8b01012

• photolysis
• herbicide
• benzobicyclon
• benzobicyclon hydrolysate
• rice
• PFAM

Benzobicyclon [3-(2-chloro-4-(methylsulfonyl)benzoyl)-2-phenylthiobicyclo[3.2.1]oct-2-en-4-one] is a proherbicide used against resistant weeds in California rice fields. Persistence of its active product, benzobicyclon hydrolysate, is of concern. As an acidic herbicide, the neutral species photolyzed faster than the more predominant anionic species (t(1/2) = 1 and 320 h, respectively; natural sunlight), from a >10-fold difference in the quantum yield. Dissolved organic matter in natural waters reduced direct photolysis and increased indirect photolysis compared to high-purity water. Light attenuation appears significant in rice field water and can slow photolysis. These results, used in the pesticides in flooded applications model with other experimental properties, indicate that a floodwater hold time of 20 days could be sufficient for dissipation of the majority of initial aqueous benzobicyclon hydrolysate prior to release. However, soil recalcitrance of both compounds will keep aqueous benzobicyclon hydrolysate levels constant months after benzobicyclon application.

• 出版日期2018-6-6