Analysis Of Characteristic Components Of Gasoline And Combustion Residues Based On Comprehensive Two Dimensional Gas Chromatography-Mass Spectrometry

Arson is a kind of serious criminal crime.Arson is one of the eight severe crimes stipulated in the criminal law of the People's Republic of China,which seriously endangers the safety of people's lives and property,disturbs social order,and causes huge losses to economic and social development.In the investigation of arson cases,the investigators should first analyze the causes of the fire and determine the nature of the case.Because of the high temperature environment of the fire site,the evidence value of biological evidence is usually lost.The detection of ignitable liquid residues is the key link to decide whether the fire is caused by human deliberately.In order to better understand the gasoline,the most common ignitable liquid in arson cases,and the interference of combustion materials on the fire site on the inspection of gasoline samples,the inspection method of gasoline samples was optimized by using comprehensive two-dimensional gas chromatography-mass spectrometry,the components of Jilin petrochemical gasoline samples were analyzed in detail,attempting to use chemometrics methods to perform hierarchical clustering and Fisher's discriminant analysis on 50 gasoline samples collected from 22 petrochemical refineries in China,eight kind of common materials' combustion residues were also inspected,and analyzed it's influences on the detection of gasoline samples in the paper.(1)In this paper,the inspection methods of gasoline samples were established,taking 92 #,95 #,98 # gasoline samples produced by Jilin Petrochemical Plant as examples,using the quantitative analysis method of the standard samples combined with library search factors and reserve library search factors and quantitative analysis method of the correcting relative response factors,by observing the composition changes of C7 ~ C12 alkylbenzenes,indene and naphthalene series,the gasoline samples of different labels produced in the same Petrochemical Plant were identified,better analysis results were achieved.(2)Matrix interference is one of the important factors affecting the accuracy of gasoline residues identification on fire site.Through the control conditions combustion experiments of 8 kinds of common burning materials,such as non-slip floor mat,wooden chair,blended carpet,sofa sponge,newspapers,used clothing,magazines and curtains,main components of their combustion residues were summarized,and its interference to gasoline residues detection was evaluated.It is verified that these 8 kinds of materials,especially the other 6 kinds of materials except the non-slip floor mat and blended carpet,have slightly interference on the detection of gasoline in combustion residues.(3)Chemometrics has been applied in the field of combustion residues detection on fire site to a certain extent,cluster analysis and discriminant analysis are two commonly used analytical methods.The results of hierarchical clustering analysis show that Ward method is better than the shortest distance clustering method and the inter-group connection clustering method.Fisher's discriminant method is more accurate than PCA-Fisher's combined discriminant method in discriminating gasoline samples from different production areas(82% > 72%).The established Fisher discriminant function has certain application value.In this paper,the detection method of gasoline samples by using comprehensive twodimensional gas chromatography-mass spectrometry,the identification of combustion products of common substrate materials,and the clustering and discriminant analysis of gasoline samples were discussed,so as to provide reference for the related research on the inspection of combustion residues on the fire site.