Isolation of Trimyristin from Nutmeg by Soluid-Liquid Extraction PDF

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Lab report for Isolation of Trimyristin from Nutmeg by Soluid-Liquid Extraction...

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Autumn Sturhahn CHEM 2211L TA: Chen Zhao 24 September 2019 Isolation of Trimyristin from Nutmeg by Solid-Liquid Extraction Introduction: Trimyristin makes up 20-25% of the nutmeg seed composition by mass. Solid-liquid extraction is a method that can be used to separate the trimyristin from the rest of the ground nutmeg seed by utilizing the differences in solubility between the pure substance, trimyristin, and the permeable, composite solid, the nutmeg seed. Reflux will be utilized in order to collect solvent vapors and return them to the original mixture in order to prevent solvent loss. Gravity filtration will be used to isolate the trimyristin from the rest of the ground nutmeg seed after reflux. Simple distillation will then be used to remove any remaining solvent from the isolated trimyristin. Suction filtration will then be used to isolate the pure trimyristin crystals. Melting point determination will be used on the pure product to compare the melting point with the literature value. Balanced Equation:

Table of Reagents: Compound Name

Acetone

Structure

Molecular Boiling Weight Point ( ) (g/mol)

Melting Point ( )

Density (g/mL at 25 )

58.08

--------

0.791

56.08

Methylene Chloride (dichloromethane)

84.93

39.75

--------

1.325

Trimyristin

723.18

-------

58.50

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Safety Information: Caution should always be used in a lab setting. Lab coats, gloves, and safety goggles/glasses should be worn at all times in the lab. Boiling chips should be added to any liquid before heating, and closed containers should never be heated. All liquid waste should be safely disposed of in the appropriately labeled bottle in the fume hood. Apparatus should be fully cooled before handling. Acetone and methylene chloride are highly flammable. Avoid flames, sparks, and hot surfaces. Acetone and methylene chloride are toxic and should not be inhaled or come into contact with skin. Methylene chloride is highly carcinogenic. Snorkels should be on and checked to ensure proper function before dispensing liquids. Specific safety precautions for each compound are listed below: Acetone: 1. Causes serious eye irritation 2. Highly flammable liquid and vapor 3. May cause damage to organs through prolonged or repeated exposure 4. May cause drowsiness or dizziness Methylene Chloride 1. Causes serious eye irritation 2. Causes skin irritation 3. Harmful if swallowed 4. May cause drowsiness or dizziness 5. May cause respiratory irritation 6. Suspected of causing cancer Trimyristin 1. N/A Experimental Procedure: Solid-Liquid extraction via Reflux: ● 4.5 g of ground nutmeg is weighed out and placed in a 100mL round-bottom flask with several boiling chips. ● The flask is clamped to a ring stand, and 45mL of methylene chloride is added.

●

A water-cooled condenser is attached to the flask and the apparatus is fitted with a heating mantle. ● The mixture is refluxed for 30 minutes once boiling begins. ● The heating mantle is removed and the apparatus is allowed to cool. The snorkel is positioned over the apparatus as it is disassembled. ● The solution is hot filtered into a second 100 mL round-bottom flask using a short stem funnel and fluted filter paper. ● The original reflux flask is rinsed with 5 mL of methylene chloride and the extra solvent is poured through the filter paper. Simple Distillation and Filtration: ● Several boiling chips are added to a round-bottom flask and a simple distillation apparatus is set up. ● The solvent is distilled and the distillate is caught in a cooled Erlenmeyer flask (flask placed in an ice bath) to prevent vaporization of methylene chloride. ● Once 2-3 mL of liquid remains in the boiling flask, the heating mantle is removed to stop distillation. ● The distillate, methylene chloride, is disposed of in the waste bottle in the fume hood. ● The apparatus is allowed to cool before disassembling. Once at room temperature, the remaining methylene chloride/trimyristin mixture is cooled in an ice-water bath. Trimyristin will crystallize if enough solvent has been removed by distillation. ● 10 mL of acetone is added to the cooled mixture, and the flask is swirled. A stirring rod is used to break up clumps of crystals. ● Suction filtration is used to collect the crystals of trimyristin. ● The crystals are transferred to a new 100mL beaker and washed with an additional 10 mL of acetone. Suction filtration is repeated to collect the crystals. Air is pulled through the Buchner funnel for 5-6 minutes to ensure the crystals have dried. ● The trimyristin crystals are collected and weighed. The melting point is determined, and the percent recovery is calculated. Apparatuses: Reflux:

Autumn Sturhahn CHEM 2211L TA: Chen Zhao 1 October 2019 Isolation of Trimyristin from Nutmeg by Solid-Liquid Extraction: Post Lab Results: Theoretical Yield: Starting Nutmeg Weight * (0.20) = theoretical weight of trimyristin 4.512 g of Nutmeg * 0.200 = 0.9024 g of trimyristin Percent Recovery: (Actual yield/theoretical yield) * 100% (0.721g / 0.9024 g) * 100% = 65.1% recovery Discussion/Conclusion: 65.1% of the expected trimyristin was recovered, a reasonable result as the number is less than 100%. One potential reason for the decreased percent recovery could be loss of nutmeg throughout the transfer of the substances such as from the weigh paper to the round bottom flask. The final white powdery substance, the pure trimyristin, was extracted from the initial rusty red colored powder, the nutmeg. The solution became a yellow liquid after gravity filtration and turned into a cloudy yellow liquid after a short time in the ice bath. The pure methylene chloride, one result of the simple distillation, first began to drip into the recieving flask at 32.7℃ which aligns relatively closely with the literature value of the boiling point of methylene chloride, 39.75℃. The melting point range of the recovered trimyristin product was 55.7℃-56.5℃. The literature value of the melting point of trimyrsitin is 58.5℃, slightly higher than our observed melting point. Typically, the lowering of the melting point of a substance is due to the presence of an impurity, which could be a potential cause of the lowered melting point in the trimyristin. In this case, the impurity could potentially be acetone as that was the liquid used to rinse the trimyristin during suction filtration. If the acetone had not been completely dried out of the final powder, it could have affected the final weight of the trimyristin as well as the melting point of the substance....