Determination of sixteen pesticide residues in leek by solid phase extraction and gas chromatography with mass spectrum

A rapid and effective method was developed for the determination of sixteen pesticides in leek.Leek samples were heated by microwave,extracted by acetonitrile,cleaned up with Cleanert TPT SPE column and detected by GC-MS under SIM mode.The results showed that it was effective to remove the interferences with the microwave treatment and SPE cleanup.The linearity of sixteen pesticides was satisfied between 0.02 and 2 mg/L.The average recoveries fortified at 0.01 and 0.5 mg/kg were 85%-124% and 92%-98%,respectively,with both relative standard deviations of less than 20%.The limits of detection ranged from 1-6 μ g/kg.