Identification of fibers using Raman microscopy: a case study
Description:
Raman microscopy is very applicable in the field of forensics. It uses a technique that offers a non-destructive and non-contact method of analysis. Only a small amount of sample is required, and little or no sample preparation is necessary. It allows for trace analysis, whereas sampling can be done directly through transparent evidence bags and packaging, such as glass and plastics. It covers a wide spectral range from 10 cm-1 to 4000 cm-1, making the technique ideal for identifying organic and inorganic substances, including fibers, drugs, pharmaceuticals, explosives, inks, paint, etc. Raman microscopy also allows identifying the components of inhomogeneous samples and obtaining automated high-definition Raman mapped images.
To aid law enforcement personnel and the public at large, investigations have been geared toward the ability of Raman microscopy to identify a variety of polymers used in fibers. This is very important, as the presence of fibers at a crime scene has often been instrumental in the process of solving crime. “Fingerprints” of nylon 6, Kevlar, polystyrene, PET, polypropylene, and some other fibers along with different types of nylon (nylon 6, nylon 6/6, nylon 12, and others) will be highlighted in the presentation, as well as the ability to identify fiber mounted on a substrate. The capability of Raman spectroscopy to differentiate between fibers of similar chemical structures will be demonstrated.
Spectral data of the fibers were collected using 532 nm, 633 nm, and 785 nm laser excitations. A comparison of the Raman spectra of the fibers taken with different excitation wavelengths will be discussed. It will be shown that search can quickly identify materials whose spectra have been collected in a library or matched to suspect material samples.
Speaker: Sergey Mamedov - HORIBA Scientific
Co-Authors
Identification of fibers using Raman microscopy: a case study
Category
2023 Call for Oral Abstracts
Description
Session Number: C44-05
Session Type:
Session Date: Tuesday 3/21/2023
Session Time: 1:30 PM - 4:25 PM
Room Number: 115C
Track: Forensics & Toxicology
Category: Forensics, Polymers/Plastics, Vibrational Spectroscopy
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