Analyzing purity and composition of essential oils

Essential oils contain many different compounds and almost all of them are optically active. Schmidt + Haensch polarimeters and refractometers are able to detect any change in the composition of essential oils by measuring the refractive index. A consistent quality can also be ensured by measuring the specific gravity using the Schmidt + Haensch VariDens. The density of the oil is measured in comparison to water. Each oil has a known range of specific gravity in which the oil is considered pure.