SIMULASI EKSTRAKSI CAIR CAIR UNTUK FRAKSINASI

Summary

This video tutorial demonstrates a liquid-liquid extraction process using ethanol extract from Java teak leaves. It explains the use of multiple solvents with different polarities and densities—water, n-hexane, and ethyl acetate—to separate compounds based on their solubility. The process includes dissolving the extract in water, followed by phase separation using a separating funnel, and extracting further with n-hexane and ethyl acetate. Each solvent selectively dissolves different compounds based on their polarity. The outcome is three fractions: aqueous, n-hexane, and ethyl acetate, which will be further analyzed for phytochemical content, followed by column chromatography.

Takeaways

• 😀 The extraction process begins by weighing 2 grams of ethanol extract from teak leaves.
• 😀 The ethanol extract is dissolved in water, and the solution is heated in a water bath to ensure complete dissolution.
• 😀 The dissolved extract is transferred into a separating funnel, where additional water is added to maintain a total volume of 40 mL.
• 😀 A nonpolar solvent, n-hexane, is added to the funnel to help separate compounds based on polarity.
• 😀 The separating funnel is shaken gently to ensure proper mixing of the solvents, which helps partition the substances into two layers.
• 😀 The two layers are separated: the polar compounds remain in the aqueous layer, while nonpolar compounds move into the hexane layer.
• 😀 The aqueous layer is drained from the separating funnel, and the hexane layer is transferred into a new beaker for further analysis.
• 😀 The aqueous layer undergoes a second extraction with 40 mL of ethyl acetate, another nonpolar solvent, to capture more nonpolar compounds.
• 😀 After the second extraction, the layers are separated again, with ethyl acetate forming the upper layer and the aqueous layer forming the bottom.
• 😀 Three fractions are obtained: the aqueous fraction (polar compounds), the n-hexane fraction (nonpolar compounds), and the ethyl acetate fraction (semi-polar compounds).

Q & A

What is the main purpose of the liquid-liquid extraction process described in the script?

The purpose of the liquid-liquid extraction process is to separate and purify compounds from the jati Belanda (guava leaves) extract using solvents with different polarities to selectively dissolve various chemical compounds.

Why is water used as the first solvent in this extraction process?

Water is used as the first solvent because it is a polar solvent, which helps to dissolve polar compounds present in the jati Belanda extract.

What is the role of heating the extract in a water bath?

Heating the extract in a water bath helps to increase the solubility of the compounds, ensuring that the extract dissolves completely in water.

Why is n-hexane chosen as the second solvent in the extraction process?

n-Hexane is a nonpolar solvent with a lower density than water. It is chosen because it selectively dissolves nonpolar compounds from the extract, allowing for phase separation.

How does the polarity of the solvents affect the separation of compounds?

The polarity of the solvents allows for the selective dissolution of compounds. Polar compounds dissolve in the polar solvent (water), while nonpolar compounds dissolve in the nonpolar solvents (n-hexane or ethyl acetate), enabling the separation of different types of compounds.

What happens if the separating funnel is not opened periodically during shaking?

If the separating funnel is not opened periodically, the gas pressure from the generated reaction may build up inside, potentially causing the funnel to burst, which could be dangerous.

What is the purpose of shaking the separating funnel during the extraction process?

Shaking the separating funnel helps to mix the solvents and the extract, improving the extraction of compounds into their respective solvent layers based on their solubility.

Why is ethyl acetate used as a third solvent in the extraction process?

Ethyl acetate is used as the third solvent because it is a nonpolar solvent that further extracts nonpolar compounds from the aqueous layer, which were not extracted by n-hexane.

How are the different layers separated in the extraction process?

After shaking, the solvents separate into layers based on their densities. The aqueous layer, being denser, remains at the bottom, while the nonpolar solvents (n-hexane and ethyl acetate) form the top layers. The layers are separated by opening the valve of the separating funnel and draining the aqueous layer first.

What are the three fractions obtained after the extraction process?

The three fractions obtained are the aqueous fraction (water), the n-hexane fraction (nonpolar compounds), and the ethyl acetate fraction (nonpolar compounds from the aqueous layer).