Advantages and disadvantages
Raman spectroscopy has a number of advantages over other analysis techniques.
- Can be used with solids, liquids or gases.
- No sample preparation needed. For infrared spectroscopy solids must be ground into KBr pellets or with nujol to form a mull.
- No vacuum needed unlike some techniques, which saves on expensive vacuum equipment.
- Short time scale. Raman spectra can be acquired quickly.
- Can work with aqueous solutions (infrared spectroscopy has trouble with aqueous solutions because the water interferes strongly with the wavelengths used)
- Glass vials can be used (unlike in infrared spectroscopy, where the glass causes interference)
- Can use down fibre optic cables for remote sampling.
- Cannot be used for metals or alloys.
- The Raman effect is very weak, which leads to low sensitivity, making it difficult to measure low concentrations of a substance. This can be countered by using one of the alternative techniques (e.g. Resonance Raman) which increases the effect.
- Can be swamped by fluorescence from some materials.