Impact of Simulated California Rice-Growing Conditions on Chlorantraniliprole Partitioning

摘要

Chlorantraniliprole (3-bromo-N-[4-chloro-2-methy1-6-(methylcarbamoyl)pheny1]-1-(3-chloro-2-pyridine-2-y1)1H-pyrazole-5-carboxamide, CAP; water solubility 1.023 mg.L-1) was recently registered for application on California rice fields. Air and soil water partitioning of CAP were investigated under simulated California rice field conditions through calculation of K-H and Delta H-aw and a batch equilibrium method following OECD 106 guidelines, respectively. K-H and Delta H-aw were determined to be 1.69 X 10(-16) 2.81 X 10(-15) atm.m(3).mol(-1) (15-35 degrees C) and 103.68 kj.mol(-1), respectively. Log(K-oc) ranged from 2.59 to 2.96 across all soil and temperature treatments. Log(K-F) ranged from 0.61 to 1.14 across all soil, temperature, and salinity treatments. Temperature and salinity increased sorption significantly at 35 degrees C (P 0.05) and 0.2 M (P 0.0001), respectively, while soil properties impacted sorption across all treatments. Overall results, corroborated using the Pesticides in Flooded Applications Model, indicate that volatilization of CAP is not a major route of dissipation and sorption of CAP to California rice field soils is moderately weak and reversible.