Dissipation of oxaziclomefone and residue analysis in rice, soil and water under field conditions.

The analytical method for the residue analysis of a novel herbicide, oxaziclomefone, and its dissipation in soil, water, rice plants and husked rice in rice fields at GAP (Good Agricultural Practices) conditions were studied. Oxaziclomefone residues were determined by GC-NPD. Mean recoveries ranged from 84.4 to 108.2% with relative standard deviations (RSDs) of 2.4 to 17.2% at three different spiking levels for each different matrix. The limits of quantification (LOQ) were found to be 0.01 mg/kg in soil, water, rice plants and husked rice and 0.02 mg/kg in rice hull. The mean half-lives of oxaziclomefone residues in water, soil and rice plants were 11.3, 37 and 4.4 days, respectively. At harvest, soil, straw, rice hull and husked rice samples were found to contain oxaziclomefone below the maximum residue level (0.1 mg/kg) set by Japan and Korea. Following the recommended application method, this herbicide is therefore safe to apply to rice fields.