paper chromatography (2)

GROUP 5BS MLS 2-D

Date Performed: November 10, 2012Date Submitted: November 16, 2012

Experiment No. 1Paper Chromatography

I. Objectives

1. To apply the principles involved in chromatography

2. To practice chromatography in determining the solubility of an organic solute in different.

II. Flow Diagram of the ProcedureCut 3 oslo

paperGrid, Add Alcohol, Extract

the Leaves

Spot on the oslo paper, let

it dryPrepare the

Set-Up3 test tubes with solvent

mixed with H2O (Ether, Toluene,

Isopropyl alcohol Transfer the 3

oslo paper on each test tube

Observe

Marked the solvent reached

Cutting of Oslo Paper

Discussing what should be done

Materials and Reagents

Grinding, Adding alcohol, Extracting of Leaves

Transferring of Extract on the beaker

Spot on the oslo paper

Preparing the set-upSet-up w/ each

Oslo paper

Observing

Finding the height of the solute and solvent

Returning the equipment

Chromatography is a technique that is used to separate and to identify components of a mixture.

In this lab experiment, we prepared 3 cut pieces of Oslo paper, leaf extract and the set up place wherein there should be ether with water on the 1st test tube, toluene with water on the 2nd and isopropyl alcohol with water on the 3rd test tube. We have spotted the extract on the Oslo and place each inside the test tube then we observed.

III. Results and Observation 1st Trial

2nd Trial

SOLVENT Maximum height of

solute

Maximum height of solvent

Rf Value

Ether 7.1 cm 7.1 cm 1

Toluene 7.2 cm 7.2 cm 1

Isopropyl Alcohol

1.9 cm 3 cm 0.63

SOLVENT

Maximum height of

solute

Maximum height of solvent

Rf Value

Ether 5.5 cm 5.6 cm 0.98

Toluene 5.4 cm 5.4 cm 1

Isopropyl Alcohol

1.5 cm 1.6 cm 0.94

GUIDE QUESTIONS:1. Which solvent yields the highest Rf value? What does it indicate?

This indicates that the spot is more strongly attracted to toluene than that of the paper. The solute is reabsorbed and displaced by the solvent, the higher the Rf value.

2. Can Rf value be used to identify a substance in the mixture? Why?

Yes. Because the movement of any spot on the paper can be qualified by calculating the Rf value . For this reason, substance in the mixture can be recognized and identified. Rf value is useful mainly for expressing the relative mobility of two or more solutes in a particular chromatography system.

3. How are the components of a sample mixture separated and identified in paper chromatography?

Components of a sample are separated by passing them, through sheets of absorbent material. The key to the separation is that the different components of the mixture in each spot will rise at different rates, and so will be found to have reach different height on the paper.

IV. Learnings

A.Values1. Teamwork must always be observed during the

experiment.

2. Selection of the right solvent combination for chromatography is the very important. It's also the most time consuming part of the process, so we must be patient.

3. Keeping records will help you organize your data.

IV. LearningsB. Concepts

• One of the most effective technique for both identifying and separating mixtures is chromatography. Chromatography literally means “color writing”. Chromatography typically involves two “phases” one moving phase (the mobile phase) through or the past, the other is the stationary phase. The technique takes advantage of the fact that different components of the mixture interact differently with two phases. Some will be strongly attracted to (adsorbed onto) the stationary phase, while others will be more attracted (soluble in) to the mobile phase. As the mobile phase moves through the stationary phase, the components more strongly adsorbed to the stationary phase will lag behind their more mobile counterparts, thereby effecting a separation.

Chromatography of leavesMost leaves are green due to chlorophyll. This substance is

important in photosynthesis(the process by which plants make their food). In this experiment,

the different pigments present in a leaf are separated using paper chromatography.

TEST TUBE

STRIP OF CHROMATOGRAPHY PAPER

SPOT OF PIGMENTSOLVENT

(ETHER, ISOPROPHYL ALCOHOL, TOLUENE)

Performing a chromatographic experiment is basically a three-step process: 1)application of the sample, 2) "developing" the chromatogram by allowing the mobile phase to move up the

paper, and 3) calculating Rf values and making conclusions.

In order to obtain a measure of the extent of movement of a component in a paperchromatography experiment, we can calculate an "Rf value" for each separatedcomponent in the developed chromatogram. An Rf value is a number that is defined

as:

maximum height reached by the leaf extract maximum height reached by the solventRf =

The distance traveled by the spot is measured to the MIDDLE of the spot.

Max. height solvent reached

ABRf= A/B

V. Application to Medical Field

As a medical technologists, we can use chromatography to :

analyse drugs and also test blood and urine samples

use it to separate and purify different substances

chromatography can detect the presence of drugs in a person's blood

used as a technique to separate the additives, vitamins, preservatives, proteins and amino acids

Prepared by:

Mejia, May Kimberly Group Leader

Members:

Mendoza, SyrahMercado, Judy AnnOrtega, Jenny RoseOrtiz, Collen MayPanganiban, KathleenPanopio, Gabrielli

THANK YOU