Jane Wissinger (University of Minnesota, USA)
A safe, green, and efficient extraction of eugenol from cloves using liquid carbon dioxide was successfully developed and implemented in our large university organic chemistry teaching laboratories. This small-scale procedure resulted in sufficient quantities of essential oil that could be analyzed directly by H-1 NMR and IR, further purified by acid/base extraction, or hydrogenated in a subsequent experiment. Alternatively, students were divided into groups to observe and compare the efficiency, green benefits, and product purity of extraction by liquid carbon dioxide extraction to that of steam distillation. Students gain an appreciation for the industrial use of carbon dioxide as a green solvent and the poly-functional structure of eugenol provides ample pedagogical learning opportunities.
