Lab #4: Extraction of Trimyristin from Nutmeg

By: Lisa Wu



Before the lab:

- find the MSDS for the following: nutmeg, diethyl ether, acetone, trimyristin

- good idea to watch the Potter videos on reflux, simple distillation, and extraction

- the whole lab consists of extracting trimyristin from nutmeg by means of reflux, and simple distillation





Essentially, the first part of the experiment is refluxing the reagents at a high temperature 30-35 degrees celsius because we want the reaction to go to completion by boiling diether ethyl but not cause an explosive reaction. By allowing the water in the condenser tubes to run in a counter-current flow, this allows the condenser column to be very cold such that any vapours given off are cooled back to liquid, and fall back into the reaction vessel. This is very convenient for the chemist whom want the reaction to be thermically accelerated at a higher temperature without worrying about adding excess reagents (unless needed to). In this lab, a water bath is used heated by a heating mantel since the experiment calls for low temperatures of 30-35 degrees celsius.

To purify the product, separation by simple distillation is used in order to distill most of the diethyl ether off from the filtrate.

Then extraction is used to partition the desired product into a solvent with a better solubility to the desired product than the previous solvent OR it is used to partition the undesired products out of the solvent. This often consists of partitioning products between aqueous and organic solvents or partitioning at a particular temperature. In this lab, the organic solvent of acetone is used to partition the trimyristin out of its original organic solvent, diethyl ether, in order to obtain a more purified crude product using temperature.



k = [solute] in organic solvent/ [solute] in aqueous solvent


In this lab, trimyristin is extracted from ground nutmeg.Occuring in many vegetable oils as well as myristic acid. Trimyristin consists of long saturated hydrocarbon chains and it is relatively nonpolar. Thus using a relatively nonpolar solvent, trimyristin can be easily extracted by the concept of "like dissolves like". Diethyl ether is a relatively organic substance that can easily dissolve trimyristin more so than aqueous solvent. However, acetone is an organic solvent that can more easily dissolve trimyristin at a higher temperature than diethyl ether.



Procedure:

Part A: Reflux

à obtain a heating mantle, 250mL beaker, water, buret clamp, retort stand, thermometer

- set up a water bath by heating water in a 250mL beaker on heating mantle on "LO" settings (before the quiz)
- clamp a thermometer using a buret clamp onto the retort stand with the tip placed into the sand but not touching the sides

- reach a steady temperature of 30-35 degrees celsius

à obtain 5g of ground nutmeg, 50 or 100mL RB flask, 15mL diethyl ether, couple of boiling chips, column condenser + water tubes

- 5g of weighed ground nutmeg, 15mL of diethy ether, and couple of boiling chips were added in 50mL or 100mL RB flask

- set up the vertical water cooler condenser for the reflux process (drying tube on top of the condenser with the water-out tube over the water-in tube; attached to the top of the RB flask)

- place the bottom of the RB flask into the water bath

*NOTE: Clamp the flask, not the condenser!
- stop relfux after 30 min since the solution boils
- turn heat off and allow solution to reach RT of 25 ̊C (~5-10min)


Part B: Gravity Filter

à obtain filter paper, clamps, retort stand, another 50mL RB flask, powder funnel

- clamp the 50mL RB flask onto the retort stand with a funnel on top

- fold the filter paper as shown on Fig. T-1 and place the filter paper in the funnel

- flute the filter paper with diethyl ether

- pour the contents of the RB flask in Part A into the new RB flask



Part C: Simple Distillation

à obtain simple distillation apparatus like the condenser column, water tubes, spout, heating mantle, clamps, 10-25mL graduated cylinder, ice bath

- set up the simple distillatin apparatus as outlined in your lab manual with the water out tubes over the water-in tubes and a thermometer above the condenser column

- turn the heating mantle on "LO" below the RB flask

- reach steady temperature of 35 degrees celsius

- set up the 10-25mL graduated cylinder in an ice bath below the spout of the distillation apparatus

- turn on the water tap and distill most of the diethy ether off from the filtrate

*NOTE: Yellow oil should remain in the RB flask; don't distill to dryness!

- stop the distillation



Part D: Extraction

à obtain 4-5mL of acetone in a graduated cyliner, the RB flask from Part C, hot water bath, stirring rod, 25mL Erlenmeyer flask

- add 4-5mL of acetone to the oil remaining in the RB flask

- warm the RB flask in a hot water bath and then pour the contents into a 25mL E. flask

- cool solution to RT (25 degrees celsius) and let stand for 30 min

- scratch the 25mL E. flask with stirring rod to induce crystal formation



Part E: Vacuum Filtration and % yield

à obtain the 25mL E. flask from Part D, Buchner flask, vacuum tubes, acetone

- set up the vacuum filtration apparatus with the vacuum tubes attached to the vacuum tap and to the Buchner flask

*NOTE: Clamp the Buchner flask to a retort stand! Vacuum filter uses the thick vacuum tubes, not thin ones!

- wet the filter paper with acetone

- open the vacuum tap

- swirl and pour contents in the 25mL E. flask into the Buchner funnel

*NOTE: Do not let filter paper dry out!

- use the mother liquor to remove any trimyristin from the flask

- air dry the crystals

- obtain the solid, weight, and percent recovery of pure product in a plastic bag to be handed in