基于拉曼光谱的口罩物证检验方法研究

Study on Physical Evidence Testing Method of Mask Based on Raman Spectroscopy

为分析口罩材质,建立口罩物证鉴别方法,试验用拉曼光谱仪检测107个口罩纤维样品,研究黑色、粉红色、蓝色染料对口罩纤维拉曼光谱的影响程度,基于主成分分析和相关性检验法对不同品牌、相同品牌不同批次的口罩进行区分,并实现未知品牌口罩的预测。研究表明,在拉曼特征峰相同的条件下,通过分析口罩纤维拉曼强度的差异和主成分得分图可快速找到与未知品牌相关性最强的口罩。在犯罪现场模拟试验中,未知品牌与相似品牌在主成分得分图中显示的距离最近,Pearson、Kendall Rank和Spearman 3种相关系数最大分别为0.932、0.799、0.942,据此找到了与未知品牌相似度较高的口罩。该方法缩小了物证搜查范围,可为公安办案寻找线索提供依据。

In order to analyze the mask material and establish the identification method of mask material evidence,107mask fiber samples were detected using Raman spectrometer for the study of the influence of black,pink and blue dyes on the Raman spectrum of mask fiber.Based on principal component analysis and correlation test,masks of different brands and batches of the same brand were distinguished,and the prediction of unknown brand mask was realized.The results show that under the condition of the same Raman characteristic peak,the mask with the strongest correlation with unknown brand can be quickly found by analyzing the difference of Raman intensity of mask fiber and the score chart of principal component.In the crime scene simulation experiment,the distance between unknown brand and similar brand is the closest in the principal component score graph,and the correlation coefficients of Pearson,Kendall rank and Spearman are the largest,which are 0.932,0.799 and 0.942,respectively.Based on this,the mask with high similarity to unknown brand is found.This method reduces the scope of material evidence search,which can provide the basis for public security to find clues.