Raman Addition Spectroscopy with a Rotating Cell

A new technique is described for obtaining quantitative relative intensity measurements, in the study of solution equilibria by laser-Raman spectroscopy, without the necessity for adding an internal standard to the sample. A rotating cylindrical double cell with separate compartments for sample and reference is used to superimpose the Raman spectra of sample and reference and hence avoid any uncertainties arising from the displacement of the equilibrium by reference substance addition.