Study on the interference of solvent based neoprene and its combustion residues on gasoline identification

In this paper, the interference of solvent-based neoprene and its combustion residues on the identification of gasoline was studied. The colloidal samples of neoprene were analyzed by thermogravimetric analysis (TG-DTG) and pyrolysis gas chromatography (PyGC-MS). The solvent samples and combustion residues of neoprene were analyzed by gas chromatography-mass spectrometry (GC-MS). The spectra of neoprene combustion residues and gasoline combustion residues were compared, and a comprehensive identification method of solvent-based neoprene was systematically summarized. The results showed that the pyrolysis effect of neoprene colloid was the best at $500^{\circ }\text{C}$.25 kinds of pyrolysis products were detected in neoprene colloid, of which 6 components were stable and could be used to identify neoprene colloid as characteristic products. The contents of cycloalkanes, aromatic hydrocarbons and phenols in the solvent samples of neoprene are relatively high, while the contents of straight-chain alkanes and polycyclic aromatic hydrocarbons are relatively low, and there is a certain similarity between the whole components and gasoline components. Neoprene and gasoline can be distinguished by phenolic components. Chloroprene rubber has high similarity with gasoline combustion residue, but it can still eliminate the interference of neoprene on gasoline identification by 1-Magneoprene,7-trimethylnaphthalene,2,5-dimethyl indene,4,7-dimethylindenium and 7 kinds of phenolic characteristic components. The results show that neoprene has a high similarity with gasoline combustion residue, but neoprene can still eliminate the interference of neoprene on gasoline identification. The experimental results can provide reference for the fire evidence identification of solvent-based neoprene adhesive and other adhesives.