Raman spectroscopy (Raman spectra), is a scattering spectrum. Raman spectroscopy is based on the Indian scientist CV Raman (Raman) found Raman scattering effect, and the light frequency of the different scattering analysis to obtain the molecular vibration, rotation of information, and applied to the study of molecular structure an analytical method.
Raman spectroscopy can provide rapid, simple, repeatable, and more importantly, qualitative and quantitative analysis of non-invasive, Zinc oxide it does not require sample preparation, sample through the fiber optic probe directly or through glass, quartz, and optical measurements. In addition, the following features:
1 As the water is very weak Raman scattering, Raman spectroscopy is the study of biological samples in aqueous solutions and chemical compounds ideal.
2 one can simultaneously cover 50-4000 Raman wave-number range, organic and inorganic substances can be analyzed. On the contrary, if the infrared spectrum to cover the same range you must change the grating, beam splitters, filters and detectors.
3 Raman spectra clearly sharp, more suitable for quantitative research, database search, and the use of variance analysis for qualitative research. In the chemical structure analysis, the independent Raman intensity range and the functional groups can be related to the number.
4 Because the diameter of the laser beam focus position in its usually only 0.2 - 2 mm, Titanium dioxide conventional Raman spectroscopy requires only a small amount of sample you can get. This is a relatively conventional infrared Raman spectroscopy a great advantage. Moreover, the Raman microscope objective can further focus the laser beam to 20 microns or smaller, can be analyzed a smaller sample size.
5 Resonance Raman effect can be used to selectively enhance features a large biological molecules the chromophore vibration, these Raman chromophore can be selectively enhanced light intensity 1,000 to 10,000 times.
Application of a Raman spectrum of applications in archaeological research
Archaeologists using portable Raman system and the tomb of the ancient rock paintings to detect, analyze the
The chemical composition of pigments. As non-destructive nature of Raman spectroscopy, Magnesia do not worry the destruction of precious historical relics. In addition, many graves or coffins are buried next to, the use of Raman spectroscopy for probing some of the ceramic, to get the enamel, structure and other important information to help determine the age of the tomb.
Although Raman is also difficult to apply to most of the detection of pure metals and alloys, but the metal arts
Corrosion product on the floor, Pseudomonas layer can make a better identification. Nickel oxide Through such identification, archaeologists can infer changes in the environment in which art has been buried conditions and historical eras and other important information. Today, he used to make textiles, woven goods, the Raman spectra of various plant fibers have also been edited directory, and a variety of biological fur, teeth, bones, etc. Raman spectra are also being gradually included to help archaeologists from these sites to find clues to the history.
Application 2 Raman spectra in the pharmaceutical and Identification of dangerous goods
Department of Chemistry, Neodymium fluoride Boston University and the optical center (Department of Chemistry and Photonics Center, Boston University) of the RH Clarke, S. Londhe, who will be the PeakSeaker Ocean Optics Raman system used in drugs and contraband on-site inspection and has been successful. PeakSeaker using 785nm semiconductor laser light source, USB2000 + as a probe. USB2000 + uses the non-cooled 2048 pixel linear CCD, measuring range 0 - 2700cm-1, the internal use of 1200 lines and 50 micron slit grating, resolution of about 30cm-1.
Respectively, using the system in the amber bottle hydrocodone, plastic bottle of aspirin and ibuprofen capsules sugar detection, the results shown in Figure 1, the same two drugs lines almost overlap. Thus, even if the resolution is only 30cm-1 in the case of Raman system can still easily identify the composition of drugs, and no sample preparation is very convenient. Source:www.mhcocm.com