Comprehensive Analysis Of Pyrotechnics And Explosive Residues Based On The Physicochemical Research Platform Of CID

Explosion case is serious violent crime.Due to the strict control and management of military explosives and the developed fireworks industry,most of the explosives used in explosion cases are pyrotechnic compositions.At present,the Forensic Department of the public security organs has a variety of technical means for the inspection of pyrotechnic explosive residues.Various inspection methods for the qualitative and quantitative analysis of explosive residues collected from crime scenes are comprehensive,pyrotechnic explosive components can be effectively identified.However,most of the methods focus on the inspection of inorganic components,the research on correlative judgement and traceability of pyrotechnic composition through comprehensive examination of inorganic and organic components is still in the blank stage.In this paper,based on the needs of investigation and case solving,we have conducted studies on multi project detection respectively by creatively using effective separation and extraction of inorganic and organic components on the premise of adequate investigation on the current situation of fireworks industry and in-depth understanding of the production process and formula of pyrotechnic composition.Scanning electron microscope / Energy dispersive spectroscopy(SEM / EDS)was used to analyze the micro morphological differences of different pyrotechnic compositions and the changes of elements before and after explosion.Raman Spectrum was used to analyze the water-soluble inorganic salt composition of pyrotechnic composition.Ion chromatography(IC)was used to analyze the changes of anions and cations in pyrotechnic compositions and explosive residues before and after explosion.Fourier transform infrared spectroscopy(FT-IR)was used to analyze the types of organic binders in pyrotechnic compositions,Gas chromatography-mass spectrometry(GC / MS)was used to detect the sulfur components in pyrotechnic compositions and explosive residues,and the alcohol soluble impurities in binders could also be detected by gas chromatography-mass spectrometry.Through the comprehensive inspections of the pyrotechnic raw materials,semi-finished products,finished products and simulated explosive residues,we have established a comprehensive analysis method for pyrotechnic compositions and explosive residues with higher accuracy and less sample consumption.The comprehensive analysis method established in this paper can realize the accurate qualitative analysis of pyrotechnic explosive residues,and also can identify the differences between pyrotechnic production processes,formulas and raw material characteristics through comprehensive inspection data.The correlation identification and traceability of pyrotechnic explosive realized by comparison method、scientific detection method and comprehensive evaluation method,can provide strong technical support for the actual needs of criminal investigation.