关键词: Fisher判别, 气相色谱-质谱, 物证鉴定, 主成分分析, 助燃剂

Abstract:

To find out a more accurate and effective pattern recognition method for the identification of combustion residues of typical combustion improvers, gas chromatography-mass spectrometry (GC-MS) was applied to analyze the combustion residues of seven combustion improvers loaded on different carriers and one submitted sample, and gasoline was identified directly by the GC-MS analysis from the unknown specimen. Two discrimination methods, including Fisher discrimination and PCA (principal component analysis) combined with Fisher discrimination, were used for the data analysis. The results showed that nitro paint thinner was discriminated from the submitted sample by PCA combined with Fisher discrimination, while gasoline was discriminated from unidentified sample by Fisher discrimination, which was in accordance with the direct GC-MS identification result. By comparing the results obtained by these two discrimination methods, Fisher discrimination is believed to be more efficient in classification of combustion residues of the seven combustion improvers and identification of the submitted sample. The results of this study provide a new analytical method for the combustion improvers identification.

Key words: combustion improvers, evidence identification, Fisher discrimination, gas chromatography-mass spectrometry (GC-MS), principal component analysis (PCA)