Checking the purity of optically active substances

Specific rotation is defined as the angle of rotation in degrees of the plane of polarization of monochromatic light passing through a 100 mm tube containing a solution of an optical active substance with a concentration of 1 g/ml. It is s a substance-specific physical parameter, which can be determined by all the Schmidt + Haensch polarimeters. Depending on the temperature and wavelength of the light, the measuring instruments indicate the specific rotation. For some samples this value depends on the concentration as well, which is why Schmidt + Haensch’s customization of measuring methods will take into account all parameter related to the specific rotation. The specific rotation is an important parameter to check the purity of optically active substances like raw materials for the production of pharmaceutical and cosmetic products, or active pharmaceutical ingredients (API’s) .