法庭科学领域中微量物证的显微红外技术鉴定

在法庭科学领域中，由于案件现场提取到的物证通常是极微量的，另外样品形态各异、成分复杂，常规红外光谱分析技术常常无法达到检测要求。显微红外技术是基于傅里叶变换红外光谱技术与显微镜技术的结合发展起来的。与常规红外光谱技术相比，显微红外技术具有检测灵敏度高、微区分析和无损检测等优点，测试时几乎不引入外部干扰，卓有成效地解决了法庭科学领域中微量物证鉴定的难题，可以满足微量物证必须保留以用于法庭作证的特殊需要。通过本实验中心测试的真实案例分析，详细阐述了显微红外技术在法庭科学领域中微量物证鉴定方面的优势。采用显微红外技术，本文分别对油漆物证、塑料物证、橡胶物证、纤维物证、药物和毒物物证进行了红外光谱振动特征的比对分析，为各类刑事案件和交通肇事案件的定性提供有力的谱学依据。实验结果表明，显微红外技术具有常规红外测试技术无法比拟的优势，是法庭科学领域中微量物证鉴定的有效手段。

Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique

In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science.