使用危险化学品实施放火案件的物证检验1例

随着科技的发展,分析仪器在刑事技术领域的应用越来越广泛,有时往往会忽视对传统化学分析方法的应用。作为检验无机粉末的常用仪器,扫描电镜/能谱仪(SEM/EDS)和X射线衍射仪(XRD)受检出限的影响,无法准确分析样品中的低含量组分。本文在一起危险化学品放火案件检验中,为确定样品中含S元素的物质种类,利用化学分析法对其进行沉淀富集,再使用SEM/EDS和XRD检验,确认其中含有KMnO4和KHSO4,推测嫌疑人使用KMnO4和浓H2SO4等危险化学品实施放火,这在日常工作中比较罕见。通过总结相关工作经验,可为类似案事件的预防、物证提取和检验提供新的思路。

Tactful Utilization of Chemical Analysis to Detect Evidential Substances from an Arson Case of Using Hazardous Chemicals

Advanced analytical instruments and methods have been being widely used into criminal investigation,even sometimes causing the traditional chemical analysis to be ignored.Yet,both the scanning electron microscope/energy dispersive spectrometer(SEM/EDS)and X-ray diffractometer(XRD),those commonly-used instruments for testing inorganic powder,are diffi cult to accurately analyze the quantity-low substance when their detection limit is not allowable.In order to determine the substance containing element sulfur(S)for an arson case of using hazardous chemicals,the traditional inorganic chemical analysis was tactfully utilized to have the low-content component enriched so that SEM/EDS and XRD were thereby able to carry out their determination.The result showed that the substance has putatively contained potassium permanganate(KMnO4)and potassium bisulfate(KHSO4),suggesting that the suspect likely set the fire through exploiting hazardous chemical substance including potassium permanganate(KMnO4)and concentrated sulfuric acid(H2SO4),a rare way to commit arson.The jobs done here may provide reference for evidential substance extraction and detection of similar cases.