| A head space/gas chromatography-mass spectrometric(HS/GC-MS) method was established for the determination of 5-ethylidene-2-norbornene migration in food packaging materials.Water,4% aqueous acetic acid solution,50% aqueous ethanol solution and olive oil were chosen as food stimulant.Samples were soaked with the food stimulant,followed by injection after gas-liquid equilibrium and separation with a DB-5 MS capillary(30 m×0.25 mm×0.25 μm) column.The target was determined in selective ion mode and quantified by external standard method.The pretreatment methods(solvent extraction-direct injection and gas-liquid balance head space injection),headspace balance temperature,and headspace balance time were optimized.Under the optimal conditions,there was a good linearity for 5 ethylidene 2-norbornene between its peak areas and concentrations in the range of 0.1-10 mg/L with correlation coefficients(r) more than 0.999.The spiked recoveries for 5-ethylidene-2-norbornene in fruits at three spiked levels of 0.1,1.0,10 mg/L ranged from 92.0% to 108%,with relative standard deviations(RSDs,n=5) of 0.9%-4.0%.The limits of detection(LOD) of this method were 0.01 mg/kg,and the limits of quantitation(LOQ) were 0.03 mg/kg.With the advantages of accuracy,reliability and high sensitivity,this method was suitable for the determination of 5 ethylidene 2-norbornene migration in food packaging materials. |