When should I use Raman spectroscopy?
You can use Raman spectroscopy (RS) whenever you need to use any of its advantages.
Detailed structural information
RS gives more detail on bond vibrations than IR does. Raman bands are narrower and tend not to overlap.
RS can give information on details such as crystal structure, protein folding, and hydrogen bonding.
No sample preparation
You can use RS on solid, liquid, powder, slurry, or gas samples with little or no preparation.
It takes just a few seconds to obtain a good quality spectrum.
RS requires no contact and is non-destructive.
Insensitive to water
You can analyze samples in water, such as suspensions and biological materials.
Choice of sample size
You can use a microscope to get Raman spectra of individual grains and samples that are smaller than 1 µm or up to several centimetres wide.
You can analyze different layers of samples such as tissue on a microscope slide and materials in transparent containers such as vials or capillary tubes.
You can use fibre optics up to hundreds of metres long for remote analyses.
Gives complementary information
Strong Raman absorptions usually appear as weak IR signals and vice versa. So the two spectra give different information on the vibrations.
For example, compare the IR and Raman spectra of styrene butadiene rubber.