Determination of Bispyribac-Sodium Residues in Water,Soil and Rice Tissues by High Performance Liquid Chromatography (HPLC)

An analytical method for determining bispyribac-sodium residues in water, soil, rice plant tissues by HPLC was described. The samples were extracted with 4%NaHCO3 water solution, followed the extract was partitioned with petroleum ether and dichloromethane, respectively. The aqueous phase (containing the final residue) was acidified with 1 moL·L-1hydrochloric acid and re-extracted with ethyl acetate. 20 μL of final solution was injected into a stainless column with 250 mm×4.0 mm ODS for chromatography using mobile phase of methanol +water (75+25,V/V) containing 0.04%H3PO4. The quantification of the herbicide was conducted by using UV detection at 250 nm wavelength. The results showed that the averaged recoveries of the method ranged 81.02%～95.54%,at the fortified levels of 0.01～1.0 mg·kg-1 for the samples, and coefficient of variation was in a rage of 3.89%～8.66%. The minimum detectable limits in water, soil, rice tissues were found to be 0.002 mg·L-1, 0.01 mg·kg-1, 0.01 mg·kg-1 and 0.01 mg·kg-1, respectively.