The Milestone NEOS performs solvent-free microwave extraction at atmospheric pressure of essential oil in plant material.

The method involves placing the sample in the microwave reactor, without any added solvent or water. The internal heating of the water within the sample distends its cells and leads to rupture of the glands and oleiferous receptacles.

This process thus frees essential oil, which is evaporated by the in-situ water of the plant material. A cooling system outside the microwave oven continuously condenses the vapours which are collected on specific glassware. The excess of water is refluxed back to the extraction vessel in order to restore the in-situ water to the sample.

Once the essential oils have been extracted they can be analyzed directly by GC-MS without any preliminary clean-up
or solvent exchange steps.