顶空-气相色谱法检测原粮中氯化苦和二溴乙烷的残留

Determination of chloropicrin and 1,2-dibromoethane residues in raw cereal by headspace gas chromatography

建立了同时测定原粮中氯化苦和二溴乙烷残留的顶空气相色谱分析方法。原粮样品经无水乙醇超声提取,过滤后直接采用顶空气相色谱检测残留,采用内标法定量。结果表明,氯化苦和二溴乙烷样品添加回收率分别在83.0%与94.2%和83.6%与96.7%之间;相对标准偏差范围分别在3.0%与9.3%和5.6%与9.4%之间;最小检出量分别为0.02 mg/kg和0.06 mg/kg。同时建立的顶空气相色谱法还具有操作简单、灵敏度高、干扰少等特点。

Headspace gas chromatography（GC） method for determining the fumigants of chloropicrin and 1,2-dibromoethane（EDB） in raw cereal was established.Fumigants residues were ultrasonically extracted by absolute ethyl alcohol,and then filtrated,directly detected by headspace gas chromatography,and quantified by internal standard method.The results showed that recovery of chloropicrin and EDB were 83.0%-94.2% and 83.6%-96.7% respectively.Relative standard deviations（RSD） were 3.0%-9.3% and 5.6%-9.4% respectively.Detection limit of chloropicrin was 0.02 mg/kg and of EDB was 0.06 mg/kg.This method was also proved to be easy in operation,high in sensitivity and effective in purification.