Global InformationSpatially offset Raman spectroscopy information
Spatially offset Raman spectroscopy (SORS)[1] is a variant of Raman spectroscopy that allows highly accurate chemical analysis of objects beneath obscuring surfaces, such as tissue, coatings and bottles. Examples of uses include analysis of: bone beneath skin,[2] tablets inside plastic bottles,[3] explosives inside containers[4] and counterfeit tablets inside blister packs. There have also been advancements in the development of deep non-invasive medical diagnosis using SORS with the hopes of being able to detect breast tumors.
Raman spectroscopy relies on inelastic scattering events of monochromatic light to produce a spectrum characteristic of a sample. The technique usually uses the red-shifted photons produced by monochromatic light losing energy to a vibrational motion within a molecule. The shift in colour and the probability of inelastic scatter is characteristic of the molecule that scatters the photon. A molecule may produce over 10 to 20 major lines, though this is restricted only by the number of bonds and symmetry constraints. Importantly, the spectrum produced by a mixture forms a linear combination of the component spectra, enabling relative chemical content to be determined in a simple spectroscopic measurement using chemometric analysis.
- ^ P Matousek; IP Clark; ERC Draper; MD Morris; et al. (Apr 2005). "Subsurface probing in diffusely scattering media using spatially offset Raman spectroscopy". Applied Spectroscopy. 59 (4): 393–400. Bibcode:2005ApSpe..59..393M. doi:10.1366/0003702053641450. PMID 15901323.
- ^ M. V. Schulmerich; K. A. Dooley; M. D. Morris; T. M. Vanasse; et al. (2006). "Transcutaneous fiber optic Raman spectroscopy of bone using annular illumination and a circular array of collection fibers". Journal of Biomedical Optics. 11 (6): 060502. doi:10.1117/1.2400233. PMID 17212521.
- ^ C. Eliasson; P. Matousek (2007). "Non-Invasive Authentication of Pharmaceutical Products through Packaging using Spatially Offset Raman Spectroscopy". Analytical Chemistry. 79 (4): 1696–701. doi:10.1021/ac062223z. PMID 17297975.
- ^ C. Eliasson; N.A. Macleod & P. Matousek (2007). "Non-invasive Detection of Concealed Liquid Explosives using Laser Spectroscopy". Analytical Chemistry. 79 (21): 8185–8189. doi:10.1021/ac071383n. PMID 17880183.