Separation of Pigments from the Extract of Spinach Leaves by Paper Chromatography - MeitY OLabs

Summary

This video script outlines a paper chromatography experiment to separate pigments from spinach leaf extract. Using a chromatographic chamber, Whatman filter paper, and a mixture of isopropyl alcohol and water, the procedure involves applying the extract to the paper, suspending it above the solvent, and observing the separation of pigments like carotene, xanthophyll, chlorophyll a, and chlorophyll b. The Rf values of each pigment are calculated to determine their separation.

Takeaways

• 🌿 **Paper Chromatography**: A method to separate colored substances, especially pigments.
• 🧪 **Stationary Phase**: High-quality filter paper serves as the stationary phase in paper chromatography.
• 💧 **Mobile Phase**: The developing solution that moves up the filter paper, carrying the sample.
• 🥬 **Objective**: To separate pigments from spinach leaf extract using paper chromatography.
• 📝 **Materials Needed**: Chromatographic chamber, spinach leaf extract, isopropyl alcohol-water mixture, Whatman filter paper strip, capillary tube, thread, scale, pencil.
• 📏 **Procedure**: Marking lines on the filter paper, applying the extract at the intersection, and suspending the paper in the chamber with solvent.
• 📈 **Observation**: The solvent front's rise and the separation of pigments into distinct spots.
• 🎨 **Pigments Identified**: Carotene, xanthophyll, chlorophyll a, and chlorophyll b can be observed on the filter paper.
• 📏 **Rf Values**: Calculated to quantify the pigment separation, with values provided for each pigment.
• 🧪 **Precautions**: Use a fine capillary tube, keep the chamber undisturbed and covered, and ensure the sample spot is rich.

Q & A

What is paper chromatography?

Paper chromatography is an analytical method used to separate colored substances, particularly pigments, by distributing the sample between a stationary phase (filter paper) and a mobile phase (developing solution).

What are the main components separated from spinach leaf extract using paper chromatography?

The main components separated are carotene, xanthophyll, chlorophyll a, and chlorophyll b.

What materials are required for the paper chromatography experiment described in the script?

The materials required include a chromatographic chamber with a lid, spinach leaf extract, isopropyl alcohol-water mixture, Whatman filter paper strip, fine capillary tube, thread, scale, and a pencil.

How should the Whatman filter paper strip be prepared for the experiment?

The strip should have a line drawn 2cm from one end and another line lengthwise from the center, intersecting at point P where the leaf extract will be applied.

What is the purpose of applying the spinach leaf extract at point P on the filter paper?

Applying the extract at point P allows for the separation of pigments when the mobile phase moves over the stationary phase.

How is the filter paper suspended in the chromatographic chamber?

The filter paper is tied with a thread and suspended vertically in the chamber containing the isopropyl alcohol and distilled water solvent.

Why is it important to keep the pencil line about 1cm above the solvent level?

Keeping the line above the solvent level prevents the sample from being dissolved by the solvent, ensuring clear separation of pigments.

What is the solvent front and how is it marked on the filter paper?

The solvent front is the distance the solvent has risen on the filter paper. It is marked with a pencil after the paper is removed from the chamber.

How are the Rf values of the pigments calculated?

The Rf values are calculated using the formula: Rf = (distance of the spot from the original line) / (distance of the solvent front from the original line).

What are the Rf values for each pigment mentioned in the script?

The Rf values are: carotene 0.94, xanthophyll 0.89, chlorophyll a 0.46, and chlorophyll b 0.22.

What precautions should be taken during the experiment?

Precautions include using a fine capillary tube, keeping the chamber undisturbed and covered, and ensuring the sample spot is rich with the mixture.