Isolation of Essential Oils
Isolation of Essential Oils by Steam Distillation
Procedure
Part A
Apparatus
1.) Using a 20- or 25-mL round-bottom flask (for distillation) and a 10-mL round-bottom flask (for collection) assemble a distillation apparatus
2.) Use an aluminum block to heat and insert a water condenser
3.) The collection flask may be immersed in ice to ensure condensation of the distillate
Preparing the Spice
1.) Weigh approximately 1.0 g of your spice or herb onto a piece of weighing paper and record the exact weight
2.) Mix the spice or herb with 12–15 mL of water in the 20-mL round- bottom flask and add a magnetic stirring bar or boiling stone.
3.) Attach the round-bottom flask to an aspirator or vacuum source.
4.) As the solution begins to foam, reduce the vacuum so that the bubbles recede into the flask. 5.)Repeat this process until foaming action subsides or until 15 minutes have passed, whichever is longer.
6.) Disconnect the vacuum and attach the flask to the distillation apparatus.
Steam Distillation
1.) Turn on the cooling water in the condenser, begin stirring and heating
2.) Collect 1 drop of liquid every 2–5 seconds.
3.) Continue distillation until at least 5 mL of distillate has been collected.
Extraction of the Essential Oil
1.) Transfer the distillate to a 15-mL screw-cap centrifuge tube and add 1.0 mL of methylene chloride 2.) Cap the tube securely and shake it vigorously, venting frequently
3.) Allow the layers to separate
4.) If the layers do not separate well, the mixture may be spun in a centrifuge.
Or stir with a spatula or add about 1 mL of a saturated sodium chloride solution
5.) Using a Pasteur pipette, transfer the lower methylene chloride layer to a clean, dry, 5-mL conical vial.
6.) Repeat this extraction procedure two more times with fresh 1.0-mL portions of methylene chloride and place them in the same 5-mL conical vial
7.) If there are visible drops of water, you need to transfer the methylene chloride solution with a dry Pasteur pipette
Procedure
Part A
Apparatus
1.) Using a 20- or 25-mL round-bottom flask (for distillation) and a 10-mL round-bottom flask (for collection) assemble a distillation apparatus
2.) Use an aluminum block to heat and insert a water condenser
3.) The collection flask may be immersed in ice to ensure condensation of the distillate
Preparing the Spice
1.) Weigh approximately 1.0 g of your spice or herb onto a piece of weighing paper and record the exact weight
2.) Mix the spice or herb with 12–15 mL of water in the 20-mL round- bottom flask and add a magnetic stirring bar or boiling stone.
3.) Attach the round-bottom flask to an aspirator or vacuum source.
4.) As the solution begins to foam, reduce the vacuum so that the bubbles recede into the flask. 5.)Repeat this process until foaming action subsides or until 15 minutes have passed, whichever is longer.
6.) Disconnect the vacuum and attach the flask to the distillation apparatus.
Steam Distillation
1.) Turn on the cooling water in the condenser, begin stirring and heating
2.) Collect 1 drop of liquid every 2–5 seconds.
3.) Continue distillation until at least 5 mL of distillate has been collected.
Extraction of the Essential Oil
1.) Transfer the distillate to a 15-mL screw-cap centrifuge tube and add 1.0 mL of methylene chloride 2.) Cap the tube securely and shake it vigorously, venting frequently
3.) Allow the layers to separate
4.) If the layers do not separate well, the mixture may be spun in a centrifuge.
Or stir with a spatula or add about 1 mL of a saturated sodium chloride solution
5.) Using a Pasteur pipette, transfer the lower methylene chloride layer to a clean, dry, 5-mL conical vial.
6.) Repeat this extraction procedure two more times with fresh 1.0-mL portions of methylene chloride and place them in the same 5-mL conical vial
7.) If there are visible drops of water, you need to transfer the methylene chloride solution with a dry Pasteur pipette