基于裂解气质联用技术分析二烯橡胶对火场汽油鉴定的干扰机理  

Analysis of the interference mechanism of diene rubber on gasoline identification by pyrolysis-gas chromatography-mass spectrometry

作　　者：李秋璠梓 张靓婷 李慷旭 金静 邓亮 LI Qiufanzi;ZHANG Liangting;LI Kangxu;JIN Jing;DENG Liang(Graduate Department,China People's Police University,Langfang 065000,China;School of Fire Protection Engineering,China People's Police University,Langfang 065000,China;School of Criminal Investigation,China People's Police University,Langfang 065000,China)

机构地区：[1]中国人民警察大学研究生院,廊坊065000 [2]中国人民警察大学防火工程学院,廊坊065000 [3]中国人民警察大学侦查学院,廊坊065000

出　　处：《分析试验室》2024年第8期1196-1203,共8页Chinese Journal of Analysis Laboratory

基　　金：河北省自然科学基金(E2021507001);中国人民警察大学科研重点专项课题(ZDZX202003)资助。

摘　　要：基质干扰的分析和排除一直是火场燃烧残留物检验鉴定的关键和热点,为验证二烯结构对汽油检验鉴定具有较强干扰这一规律的普适性,探究其干扰机理,首先通过气相色谱-质谱联用技术(GCMS)分析对比了5种典型二烯橡胶的燃烧残留物对火场汽油检验鉴定的干扰性,随后基于裂解气相色谱-质谱联用技术(Py-GC/MS)对裂解产物和裂解过程进行了分析,以推断干扰性产生的原因。结果发现,二烯橡胶样品在高温裂解时会生成具有环状结构和-C=C-结构的典型中间体,其会进一步芳构化生成芳香烃类组分,这是二烯橡胶对火场汽油识别干扰性的重要来源,同时由于中间体所含环状结构和-C=C-结构的位置、含量以及中间体形成的难易程度不同,几种二烯橡胶对火场汽油识别造成的干扰程度存在差异。本研究从化学组成和裂解过程角度解释了二烯橡胶在火场汽油鉴定中干扰性的来源,可为法庭科学物证检验鉴定基质干扰的排除和溯源提供理论依据和参考。The analysis and exclusion of matrix interference have been the key issues in the identification of combustion residues at fire scenes.To verify the universality of the rule that diene structure has strong interference on gasoline inspection and identification,the interference mechanism was explored.This paper first analyzed and compared the interference of combustion residues of five typical diene rubbers on gasoline identification at the five scene by gas chromatography-mass spectrometry(GC-MS).Subsequently,the pyrolysis products and processes were assessed by chromatography-mass spectrometry(Py-GC/MS)to trace the causes of interference.It was found that when diene rubbers cracked at a high temperature,typical intermediates with cyclic structure and-C=C-structure,such as dimethylcyclohexene,4-vinylcyclohexene,and cyclohexene,were generated,which further aromatized to produce aromatic hydrocarbon components.The intermediates were important sources of the interference with gasoline identification at fire scenes.At the same time,due to the locations and contents of the cyclic and-C=C-intermediates,as well as the ease of formation of intermediates,the degree of interference caused by several types of diene rubber to the identification of gasoline at the fire scenes is distinctive.This study explains the source of interference of diene rubber in gasoline identification for fire debris analysis from the perspective of chemical composition and pyrolysis process,which provides a theoretical basis and reference for the exclusion and traceability of matrix interference in practical work.

关 键 词：火场基质干扰 干扰机理 化学结构 裂解过程 二烯橡胶 

分 类 号：O657.7[理学—分析化学]