paper chromatography

PAPER CHROMATOGRAPHY

DEFINITION

A chromatographic analytical separation technique for complex mixtures involving the progressive adsorption of the dissolved component onto a special grade of paper.

PRINCIPLE

• The certain solvent are used to separate a mixture ex: water, alcohol.

• With capillary action the solvent will move up to filter paper.

• Movement of a solvent will bring together component that are separated from the mixture.

• Every component that are separated will move to several velocity

The moving components are depend on : a. Solubility solute in solvent b. Intermolecule forces c. Pore size of filter paper d. Size of solute

At the end of process, components that are separated will emerge to different distance on filter paper.

Rf values are used to identification of each the component.

• The retention factor, or Rf, is defined as the distance traveled by the compound divided by the distance traveled by the solvent

For example, if a compound travels 2.1 cm and the solvent front travels 2.8 cm, the Rf is 0.75:

• Beakers or jars • Covers or lids • Solvent (Distilled H2O,

Isopropanol) • Graduated cylinder • Filter paper • Sampel (Different colors

of pens, plant extract) • Pencil • Ruler • Scissors • Tape

Materials List

• Prepare the solvent solution in various concentration:

- 0%, 5%, 10%, 20%, 50%, and 100%

Preparing the solvent solution

Preparing the Chromatography Strips

1. Cut filter paper

2. Draw a line 1 cm above the bottom edge of the strip with the pencil

3. Label each strip with its corresponding solution

4. Place a spot from each pen on your starting line

Developing the Chromatograms

1. Place the strips in the beakers 2. Make sure the solution does not

come above your start line 3. Keep the beakers covered 4. Let strips develop until the

ascending solution front is about 2 cm from the top of the strip

5. Remove the strips and let them dry

Developing the Chromatograms

Spot Detection

- Color spot observed by naked eye

- Non – color spot color reagent will give specific colors for different compound.

Example :

Ninhydrin – a.amino

Iodin dalam etanol –bes (termasuk alkaloid)

AgNO3 berammonia - Karbohidrat

USES OF PAPER CHROMATOGRAPHY

1. Separation of ink dyes

- To compare ink dyes use in any company.

2. Food coloring

- To differentiate coloring agent used in food product such as : M&M, Smarties dan Reese candies.

3. Botanist/herbalist

- To isolate plant pigment from root and leaves