Page 14 - Shimadzu AIRsight

AIRsight
Infrared Spectroscopy and
Raman Spectroscopy
Differences between Infrared Spectroscopy and
Raman Spectroscopy
Infrared Spectroscopy
Samples are irradiated with infrared
light to measure how much light is
transmitted through the sample and
how much is reflected.
Molecules are identified based on
the wavelength (or wavenumber) of
absorbed infrared light.
Ground state
Enables Acquisition of Mutually
Complementary Molecular Information
Infrared and Raman Spectra of Polyester
(Laser Wavelength: 532 nm)
C=O C=C
C-O-C
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Applicable components: Applicable components:
Plastics, organic food components, and some inorganic Carbon materials (CNT, DLC, diamond, etc.), pigments,
components additives and other inorganic substances, and some organic
Raman Spectroscopy substances
Samples are irradiated with laser Features Features
light to measure the amount of
Raman scattering that occurs • Extensive spectral libraries available • Especially well-suited for analyzing carbon materials
from the sample. (carbon nanotubes, diamond, etc.)
• Widely used, resulting in plentiful application
examples • Enables analysis in the depth direction
• Rarely damages samples
• Transparent materials (glass, etc.) do not absorb
• ATR (optional), transmission, or reflection methods visible laser light, so samples can be measured
Molecules are identified based on can be selected depending on the sample directly in containers
the difference between the
wavelength of the irradiated laser • High spatial resolution (extremely small areas can be
light and the wavelength of the targeted)
Raman scattered light (Raman shift).
Examples of Problems Solved
Contaminant components cannot be Measuring the same sample location with
identified with an infrared microscope alone. both infrared and Raman is desired.
The infrared and Raman microscope enabled
Polar bonds Non-polar bonds Contaminant was identified based on both the same location to be quickly measured
O-H, N-H, C=O, C-O-C C=C, S-S, C-S infrared and Raman measurement results. without moving the sample.
– Infrared spectrum
– Raman spectrum The target area is too small to be measured Detailed analysis of both organic and
C-O-C with an infrared microscope. inorganic components is desired.
Combining infrared and Raman spectroscopy
The infrared and Raman microscope enabled enabled material analysis.
even smaller areas to be targeted and
1250 1000 750 measured.
cm -1
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