Advantages of Raman

Raman Spectroscopy combines the finger-printing advantage of mid-IR spectroscopy with the ease of use and remote, non-invasive capability of near-IR spectroscopy, to make it a very versatile tool for quantitative or qualitative analysis.

  Raman Spectroscopy Mid-IR Spectroscopy Near-IR Spectroscopy
Phenomenon Scattering Absorption Absorption
Information Fundamental vibrational bands (fingerprint region) Fundamental vibrational bands (fingerprint region) Overtone and Combination bands
Type of samples analyzed Ideal for organics, inorganics, metals Ideal for organics, inorganics, metals Does not work for metals and inorganics
Sampling Issues
Sample preparation None (point and click method) Often KBr pellet None (point and click method)
Sample state Solid, liquid, powder, tablet, slurry, gel, suspension etc. Solid samples need to be ground into KBr pellets Solid, liquid, powder, tablet, slurry, gel, suspension etc.
Glass vials Not a problem, sampling through glass vials possible nterference from glass Not a problem, sampling through glass vials possible
Water Not a problem, aqueous solutions can be analyzed Interference from water Not a problem, aqueous samples can be analyzed
Remote sampling Up to 200 meters Not possible, IR light loss in optical fibers Up to 200 meters
Libraries and Models
Spectral interpretation Easy Easy Difficult, often not very informative
Building libraries Easy and quick (commercial libraries available) Easy and quick (IR-tables available) Commercial libraries cannot be built, because its not a fundamental technique
Quantitative analysis Easy Easy Requires elaborate calibration set
Calibration transfer Easy Easy Possible but involved
Applications
Most common applications Industry (material-ID, quantitative analysis, process monitoring, R&D) and Academia (fingerprinting) Mostly academia and R&D (fingerprinting) Industry (raw material ID, quantitative analysis and process control)
Instrumentation Portable and inexpensive miniature systems available for field deployment Often a bench top or laboratory setup Portable systems available, but expensive (upward of $40,000)