Refractive Index of Essential Oils

The refractive index of essential oils is a quickly measured, easily generated quality parameter. Moreover, it helps to differentiate between different essential oils.

Easily determine the quality of your essential oil

Essential oils such as lemon or orange oil are also referred to as volatile oils. They are concentrated hydrophobic liquids which obtain essential aroma compounds from plants. These essential oils are often obtained by distillation.

Essential oils consist of many different compounds. Their varying composition allows for them to be characterized by refractive index measurement. These measurements can therefore also provide insight into the quality of essential oils, as any change in their optimal composition will affect the refractive index.

International regulations such as the official AOAC method 920.141 "Refractive Index of Lemon and Orange Oils", the ISO 280 "Essential oils - Determination of Refractive Index" as well as international pharmacopoeias require the measurement of essential oils with a refractometer.

Abbemat refractometer family from Anton Paar

The determination of the refractive index is a simple, accurate and fast method.


  • Peltier temperature control: The refractive index is dependent on the temperature of the sample.The Abbemat offers a precise built-in temperature control with a temperature stability of 0.002 °C.
  • Measurement accuracy: Depending on the chosen Abbemat, a measuring accuracy of 0.0001 nD to 0.00002 nD can be obtained.
  • Data security: Varying degrees of security can be set, which include electronic signature and audit trail (not Abbemat 200).
  • Modularity: The Abbbemat can be combined with an MCP polarimeter or a density meter from Anton Paar.The refractometric analysis of essential oils is further specified in the Application Report "Refractive index of fats, oils and essential oils".

Learn more about Abbbemat Refractometers

Other relevant instruments

The MCP polarimeters from Anton Paar are ideal for determining the optical rotation of optically active essential oils.

Good to know

The refractive index of essential oils can easily be measured with an Abbemat refractometer. It can thus provide insight as to their quality.