Modern teaching in Synthetic chemistry & extraction using microwave technology

The Chemistry Department at the University of Montpellier is able to apply microwave technology to a range of different applications in chemical synthesis or extraction processes. Microwave-activated reactions have been developed in research laboratories for over 25 years with ever increasing demands for industrial applications. The latest generation of microwave instruments have demonstrated to be irreplaceable tools in modern chemistry for their unique versatility to carry out new experiments in a wide range of operating conditions.

The departmental procedure for extraction of flavors and fragrances from plants or spices includes two steps: extraction using a hydrodistillation method plus analysis by GC or GCMS. The extraction step with conventional techniques, is time consuming and lead to degradation of the extracts. The department is committed to teaching students about advanced synthetic and extraction techniques that includes microwave-enhanced processes. Microwave systems enable syntheses for both organic and inorganic chemistry and can perform solvothermal, hydrothermal, and solid phase syntheses plus associated reactions. The technique is also efficient for extracting essential oils from natural products. With the implementation of the ETHOS X microwave extraction system, researchers at University of Montpellier had the opportunity to obtain more efficient and faster extractions compared to traditional thermal heating methods.

ETHOS X utilizes a unique microwave selective heating mechanism where the in-situ water within the plant material is evaporated to quickly extract the desired oils. The water within the sample glands and oleiferous receptacles absorbs microwaves and heats up distending the sample’s cells that ruptures them and releases the oil. “In general, hydrodistillation of pink berries takes about 4 hours. The use of microwaves however reduced the extraction time to 15 minutes delivering a product with higher purity compared to traditional methods based on the use of organic solvents. Moreover, the presence of by-products in the essential oil is greatly reduced and no organic solvents are needed to isolate it.”
An additional benefit of the ETHOS X process is the ability to obtain a higher purity of product without any post-treatment such as purification by liquid chromatography usually carried out after a liquid-liquid extraction. By using microwaves, only water is added to the fresh product and the distillate contains the essential oil that is used afterwards to create flavors. Within minutes, the system’s accelerated heating and water-cooling process enables the first drops of essential oils and water to condense in the fragrances glassware vessel, the glassware is also available in stainless steel and is designed to restore the sample’s in-site water whilst separately collecting the essential oil. Moreover, the system’s fast process avoids thermal degradation as the sample and the essential oil are exposed to heat for only a few minutes.