HPLC Determination of Residual Amount of Phoxim in Feed

HPLC was applied to the determination of residual amount of phoxim in feed. The sample was extracted with ethyl acetate and purified by passing through NH2-solid phase extraction column. Reverse C18 chromatographic column was used as stationary phase, and a mixed solution of acetonitrile and water (65+35) was used as mobile phase. UV-detection at 280 nm was adopted in the determination. Linear relationship between values of peak area and mass concentration of phoxim was obtained in the range of 0.10-0.50 mg·L-1, with detection limit of 0.10 mg·kg-1. Values of recovery found by standard addition method were in the range of 80.0%-88.2%, and values of RSD′s (n=5) in the range of 1.6%-6.5%.