Residual Dynamics of Rotenone in Greengrocery by Solid-phase Extraction-High Performance Liquid Chromatography-UV Detection

[Aims] An analytical method for residual dynamics of rotenone in greengrocery by solid-phase extraction(SPE) and high performance liquid chromatography(HPLC)-UV detection was described.[Methods] The sample was extracted by acetonitrile,salted out by adding sodium chloride,and cleaned with Florisil SPE using n-hexane-ethyl ether(3∶7,by vol) as eluents to provide adequate recovery of rotenone.The detection of rotenone was then carried out by HPLC-UV at 290 nm with acetonitrile and water(6∶4,by vol) as the mobile phase.[Results] The method was accurate,specific and sensitive,and had good linear correlations at the concentration range of 0.05-10 mg/L.The average recoveries and the relative standard deviation ranged from 85.9-86.3% at concentration range of 0.5-5 mg/kg.The limits of detection(LOD) of rotenone were 0.05 mg/kg.When greengrocery was treated with rotenone 2.5% EC at recommended dose and 2 times recommended dose,the original residues rotenone in greengrocery were 6.26 and 18.34 mg/kg.[Conclusions] The compound degraded fast in the field.The half-life of rotenone in greengrocery was 11.2 and 11.1 h.