The document summarizes a chromatography experiment performed by a group to separate and identify pigments in leaf extracts. The group used paper chromatography with three different solvent systems (ether, toluene, isopropyl alcohol). They calculated Rf values from the results and observed that toluene yielded the highest Rf values, indicating the solute was more strongly attracted to toluene. The group learned that chromatography is an effective technique for separating mixtures and that selecting the proper solvent combination is important. As medical technologists, chromatography can be used to analyze drugs and body fluids.
1. GROUP 5
BS MLS 2-D
Date Performed: November 10, 2012
Date Submitted: November 16, 2012
2. Experiment No. 1
Paper 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.
11. 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.
12. III. Results and Observation
1st Trial
SOLVENT Maximum height Maximum height Rf Value
of solute of solvent
Ether 7.1 cm 7.1 cm 1
Toluene 7.2 cm 7.2 cm 1
Isopropyl 1.9 cm 3 cm 0.63
Alcohol
2nd Trial
SOLVENT Maximum height Maximum height Rf Value
of solute of solvent
Ether 5.5 cm 5.6 cm 0.98
Toluene 5.4 cm 5.4 cm 1
Isopropyl 1.5 cm 1.6 cm 0.94
Alcohol
13. 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.
14. IV. Learnings
A.Values
1. 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.
15. IV. Learnings
B. 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.
16. Chromatography of leaves
Most 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 PIGMENT
SOLVENT
(ETHER, ISOPROPHYL ALCOHOL, TOLUENE)
17. 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 paper
chromatography experiment, we can calculate an "Rf value" for each separated
component 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 solvent
18. The distance traveled by the spot is measured
to the MIDDLE of the spot.
Max. height solvent reached
19. 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
20. Prepared by:
Mejia, May Kimberly
Group Leader
Members:
Mendoza, Syrah
Mercado, Judy Ann
Ortega, Jenny Rose
Ortiz, Collen May
Panganiban, Kathleen
Panopio, Gabrielli