固相微萃取-气相色谱-质谱联用法鉴定火场残留物中乙醇、乙醚、丙酮等易燃液体

Identification of Inflammable Liquids (Ethanol,Ether and Acetone) in Debris of Fire Scene by Hyphenated GC-MS with SPME

将从火场残留物中所取得的样品置于密封的金属罐或塑料袋中,置于烘箱中在80℃加热20～30 min,在固体微萃取装置中用聚丙烯酸酯纤维通过针头将密封容器中的易燃液体(此时已成气态)吸附,吸附时间为5～10 min,然后将易燃液体从纤维上解吸并进样于气相色谱仪器中,按预定的条件进行气相色谱-质谱分析。对色谱图上所得的主峰进行分析,并提取此纯化合物的质谱图以及相关信息,从图谱库中进行检索并与标准谱图作比较,从而对相应的易燃液体作出鉴定。

Sample of debris collected from fire scene was sealed in a metal vessel or plastic bag, and heated at 80 ℃ for 20-30 min. Inflammable liquid （in vapor state） in the vessel or bag was adsorbed on the PA （ester of polypropenoic acid） fibre through syringe needle of the SPME installation for 5- 10 min. Inflammable liquid was desorbed and introduced into the GC instrument and determined under the prescribed conditions of GC-MS analysis. By analyzing the principal peak observed in the chromatograph, abstracting the mass spectrum of this pure compound as well as its related information, and finally retrieving and comparing with the standard reference spectra in the database, the respective inflammable liquid was identrified.