Determination of Difenoconazole Residue in Foods by Gas Chromatography-Negative Chemical Ionization Mass Spectrometry
气相色谱-负化学离子源质谱法检测食品中苯醚甲环唑的残留量

A method is presented for the determination of difenoconazole residue in all kinds of foods by solid phase extraction-gas chromatography-negative chemical ionization mass spectrometry(SPE-GC-MS/NCI).Difenoconazole residue was extracted with ethyl acetate from different samples,such as perilla leaves,carrots,spinach powder,rice,gram,jasmine flower tea,oolong tea,strawberries,sauce,bee honey,beef,chicken and eels,etc.The extracts were cleaned-up by active carbon SPE column connected to alumina neutral SPE column or Florisil SPE column only.Analytical screening was determined by the technique of GC-MS/NCI on selected ion monitoring mode.The recoveries of difenoconazole in most samples were in the range from 70% to 120% at three spiked levels,0.01 mg/kg,0.04 mg/kg and 0.10 mg/kg,and the relative standard deviations(RSDs) were below 9.5%.The linearity of the method is good from 0.02 to 1.00 mg/L,and limit of detection(LOD) was 0.000 5 or 0.001 0 mg/kg for different type samples.The method is selective without interference and is suitable for determination and conformation of difenoconazole residue in all kinds of foods.