顶空进样-气相色谱-串联质谱法快速测定膨化食品中的环氧乙烷残留量

Rapid Determination of Ehylene Oxide Residual in Puffed Food by Headspace Injection Combined with Gas Chromatography-Tandem Mass Spectrometry

建立了以顶空进样技术为前处理手段,结合气相色谱-串联质谱(Gas chromatography-tandem mass spectrometry,GC-MS/MS)测定膨化食品中环氧乙烷的快速分析方法。样品经水浸泡后,于80℃条件下进行气液平衡30 min,通过顶空方式进样,安捷伦PLOT-Q石英毛细柱(30 m×0.32 mm,20μm)进行分离,以电子轰击离子源(Electron impact ion source,EI)进行电离,通过筛选二级子离子进行定性定量。环氧乙烷的测得值由其对应的基质曲线进行定量校正,饼干、薯片和方便面3种基质的基质曲线在50~2000μg/L范围内呈良好线性关系,相关系数R~2均大于0.999,在定量限的1倍、2倍和5倍水平下加标,平均回收率为86.4%~99.4%,相对标准偏差(RSD)为3.56%~8.89%。方法检出限(Limits of detection,LOD)均为0.2 mg/kg,方法定量限均为0.5 mg/kg。该方法操作简单、无有毒溶剂,同时分析时间短、回收率好、灵敏度高、精密度高,可满足膨化食品中环氧乙烷的快速测定要求。

A rapid analytical method has been established for the determination of ethylene oxide in puffed food using headspace sampling technology as a preprocessing method combined with gas chromatography-tandem mass spectrometry(GC-MS/MS).After the sample was soaked in water,vapor-liquid equilibrium was carried out at 80℃condition for 30 min,and then injected by headspace and separated by Agilent PLOT-Q quartz capillary column(30 m×0.32 mm,20μm).Finally ionized at an electron impact ion source(EI)for qualitative and quantitative analysis by screening secondary ions.The measured values of ethylene oxide were quantitatively corrected by their corresponding matrix curves.The matrix curves of biscuits,potato chips,and instant noodles had good linear relationship within the range of 50~2000μg/L,with correlation coefficients R2 were both greater than 0.999.The average recovery rate ranged from 86.4%to 99.4%,while the relative standard deviation(RSD)were in the range of 3.56%to 8.89%when spiked at the levels of 1,2,and 5 times of the limit of quantitation.The limits of detection(LOD)of the method were all 0.2 mg/kg and the quantitative limits of the method were all 0.5 mg/kg.This method was simple to operate,did not contain toxic solvents with short analysis time,good recovery rates,high sensitivity and high precision.It was indicated that this method can meet the requirements for rapid determination of ethylene oxide in puffed food.