Clove water obtained from steam distillation may be further purified using the techniques of extraction, drying and evaporation (which is a variation of simple distillation where the low boiling liquid is not of any value and is not collected).

Extraction is a general procedure used to remove a marginally soluble material from a solvent. In the procedure, a liquid mixture is treated with a second solvent which has certain properties:

• The solute should be more soluble in the second solvent than in the original solvent
• The second solvent should be insoluble in the original solvent
• The second solvent should have a low boiling point

Procedure

Transfer the clove water to a separatory funnel.

Add 5-7 mL methylene chloride to the original clove water flask, swirl the liquid and transfer to the separatory funnel. Extract the clove oil into the methylene chloride and remove the methylene chloride into a clean, dry 18x150mm (standard) test tube. Repeat the procedure, adding the second extract to the original.

Add sodium sulfate drying agent to the extract. After waiting 5 min, filter through a cotton plug in a stemless funnel into a tared 25x100mm test tube with boiling stone. Warm over a steam bath, aspirating methylene chloride from the test tube as described by the instructor. Continue until no methylene chloride vapors are detected from the mouth of the tube.

Dry the tube, obtain the new mass to determine mass of clove oil. Calculate the percentage of clove oil obtained based on the original mass of the spice.