火灾过程中易燃液体物证的鉴定方法

Forensic science methods of flammable liquid during fire process

采用相似程度度量的方法,分析简单光谱图和吸收峰的信息,获得充分的内在关系,通过特定分段区间的光谱图数据分析,对比紫外光谱法和气相色谱法分析结果,采用自动直接顶空法和溶剂萃取法进行比较研究。研究结果表明：傅里叶变换红外光谱分析汽油残留物适合谱段为2 700~3 000,1 300~1 600及1 000 cm-1以下的指纹峰;傅里叶变换红外光谱鉴定汽油燃烧残留物的识别率高,达到97.5%;相似度计算可作为判断火场残留物中汽油成分的依据;采用傅里叶变换红外光谱分析火场残留物中汽油成分的研究为放火案件中汽油的鉴定分析提供了一种新的方法。

The similarity measurement method was used to analyze the simple spectra and absorption information of flammable liquid during fire process, and the intrinsic relationship between simple spectra and absorption information was obtained. Through specific sub-interval spectra data analysis, the difference between ultraviolet spectroscopy and gas chromatography was compared, a comparative study of the automatic direct headspace method and solvent extraction method was conducted. The results show that the proper spectral range which can be used for infrared spectroscopy analysis of Fourier transformation is 2 700-3 000, 1 300-1 600 and the peaks below 1 000 cm-1. The identification of gasoline combustion residues has high recognition rate, reaching 97.5%, and similarity calculation can be used to determine the residues of gasoline in fire field basis. Studies using Fourier transform infrared spectroscopy fire residue gasoline components can provide a new method for the identification of arson analysis of gasoline.