典型高沸点可燃液体火灾物证的裂解气相色谱-质谱分析

Analysis of Fire Physical Evidence of Typical High Boiling Point Flammable Liquids by Pyrolysis Gas Chromatography Mass Spectrometry

目的导热油、机油、润滑油等高沸点可燃液体的燃烧产物与汽油、柴油等助燃剂的燃烧产物在组分和含量上具有很高的相似性。通过对典型高沸点可燃液体进行裂解分析,建立一种适用此类燃烧残留物的火灾物证鉴定方法,避免物证鉴定结果误判的情况发生。方法以美孚603-天然型导热油为例,应用热分析技术优化了裂解条件,并对样品原样和燃烧产物进行了裂解分析。结果导热油原样的裂解产物中,含有较多的C8~C18的单烯烃及其同分异构体,其中直链端烯烃含量最多。在导热油燃烧烟尘的裂解产物中检测到了C10~C17的直链端烯烃和少量对应碳数的同分异构体,且裂解产物中烯烃含量下降明显。结论裂解气相色谱-质谱技术检测精度高,可用于实际火场中高沸点可燃液体火灾物证的检测,有效地丰富和充实了现代火灾物证鉴定技术,使鉴定结论更加准确、可靠。

Objective Combustion products of high boiling point combustible liquids such as heat transfer oil,engine oil,and lubricating oil are highly similar in composition and content to those of combustion products such as gasoline and diesel.The typical high-boiling-point combustible liquids was analyzed by pyrolysis method.A fire evidence identification method applicable to such combustion residues was developed to avoid misjudgment of the result of material evidence identification.Method Taking Mobil 603-natural heat transfer oil as an example,thermal analysis technology should be used to optimize the pyrolysis conditions.The original samples and combustion products were analyzed.Results The original pyrolysis oil-containing pyrolysis products contained more C8 to C18 monoolefins and isomers,among which the linear end olefin content was the most.C10 toC17 linear terminal olefins and a small number of isomers with corresponding carbon numbers were detected in the pyrolysis products of thermal oil combustion soot,and the olefin content in the pyrolysis products decreased significantly.Conclusion Pyrolysis gas chromatography-mass spectrometry technology has high detection accuracy and can be used for the detection of high-boiling-point flammable liquid fire evidence in actual fires.It effectively enriches modern fire evidence identification technology and makes the identification conclusions more accurate and reliable.