Steam Distillation of an Essential Oil

Distillation is a useful method for isolating volatile compounds. Not always mentioned is this: nearly all compounds chemically decompose when heated so distillation is useful only if a compound’s boiling temperature is than its decomposition temperature.

In the days before high vacuum pumps, “steam distillation” (the co-distillation of an organic substance with water) provided a simple means for distilling temperature-sensitive compounds. In this experiment, you will use steam distillation to obtain the “essential oil” of cloves, a typical kitchen spice. You will also experiment with thin-layer chromatography as a means for analyzing clove oil, and dry column flash chromatography as a means for isolating the different components of clove oil.

Time required: 2 laboratory sessions