Can Raman be used for macro-bulk analysis?

Macro and bulk analysis is relatively straight forward with Raman. Aqueous solutions will work well and require typically just a simple cuvette cell holder and collection/focusing optics.

Gas samples are more difficult and the success generally will depend on the type of gaseous sample under investigation and its pressure. (trace analysis is far less suited to Raman). Examples of gas measurements include gaseous inclusions within minerals, and headspace analysis in pharmaceutical vials.

Fibre probes can be used for remote sampling whereby optical fibres connect the sampling head to the laser source and to the spectrometer system.

Macro Solid samples can also be analyzed but attention to the focus of the laser is generally more important in this sample type.

Backscattering is the most common sampling arrangement used (the same lens is used to illuminate the sample and to collect the Raman scatter) however, 90o and grazing angle sampling geometries can also be used as Raman scattering will occur at all angles from the sample and not just incident.

Specialized sample cells can also be used with Raman to enable measurements at controlled temperatures, pressures and humidity.