AN9009: Determination of dn/dc with an Optilab

The term dn/dc, also called the “specific refractive index increment”, represents the change in the refractive index (dn) of a solution with respect to a change in its solute concentration (dc). The measurement of dn/dc is an essential parameter required to analyze multi-angle light scattering for the absolute characterization of molar mass. The dn/dc value is unique for each combination of solute, solvent, wavelength and temperature, so it is vital to measure it at the same wavelength as the light scattering apparatus and experimental conditions.