Steam Distillation of an Essential Oil


We treasure food not only for the fuel it provides, but also for the enjoyment we find in preparing and sharing it, and in eating. Probably every culture claims a signature cuisine based on distinctive herbs and spices that signal “my kind of food” to the consumers of that cuisine.

As chemists we can ask, “What are the chemical substances that create food’s distinctive flavors and odors? Are these substances few in number or many?” These questions have been considered by food chemists for over a century, powerful tools that allow us to break down a complex mixture into individual substances (chromatography) and determine the structures of these substances (NMR, IR spectroscopy and GC-MS) have only become widely available in the last 2-3 decades. With these tools in hand, chemists have determined that some foods like wine and chocolate are flavored by a large number of substances, not all of which have been identified (better tools are needed!), while other flavorings, like vanilla and cloves, owe most of their distinctive properties to just a single compound.

Nature is unpredictable.

In this experiment, you will employ a number of techniques (steam distillation, liquid-liquid extraction, simple distillation, thin layer chromatography, dry column flash chromatography, and IR and NMR spectroscopy) to analyze some of the compounds found in cloves.