[Application of IR in the Field of Evidence Identification]

In the process of evidence identification, detecting chemical composition of evidence with instrumental analysis techniques will help get more information relevant to the case quickly and accurately, while the commonly used techniques are chromatography, mass spectrometry and spectroscopy techniques. Forensic science laboratory relates to the identification of evidence from a wide range of complex situations, we need to decide what kind of analytical methods according to the type of physical evidence and instrument characteristics. For example, with the advantages of high resolution, high sensitivity, and strong ability to analysis; gas chromatography-mass spectrometry is often used to detect evidence of fire scene such as flammable liquids. The more common scenarios of the application in forensic science laboratory is related to the case of various organic certificate (ink, paint, plastic, etc.) and inorganic (mineral, inorganic fillers, etc.) for quick and efficient analysis. Infrared spectroscopy is one of the most effective conventional analysis methods to identify and determine the molecular structure of the compound, whihc is especially widely used in the field of forensic science evidence identification. The infrared spectroscopy technique can be used to determine the type of evidence, which also serves as an effective means of test; the test results can offer evidence to the court to settle a lawsuit. This paper reviewed the application status and latest research advances of infrared spectroscopy technique in forensic document examination, oil test, plastic test, paint inspection, fiber inspection, common areas of drugs and other evidence examination, and prospected infrared spectroscopy technology in the field of evidence identification, from a practical point of view to provide infrared spectroscopy research profile for the scientific research personnel.