SEPARATE TO IDENTIFY
INTRODUCTION
Paper chromatography uses strips or papers as the permeable being the stationary phase
through which a solution needs to go pass through.
In each of the practicals, chromatography is used to distinguish a plant's pigment (P.C for
extraction of plants), what the unknown substance contains (P.C of amino acids) and to
determine the purity of a substance (TLC).
Paper chromatography is used on a daily basis by scientists for separating different
constituents of a mixture [1], a useful tool for separating polar and nonpolar solutes. [2]
Although it’s just a paper, it plays a big role in society, to identify forgery by forensic
scientists [3] and analyzing fibres that are found at a crime scene by police enforcement
In this investigation, it is encouraged to only use a chromatogram to separate mixtures to
identify every one of them.
Three sub-practical’s done to separate substances are:
1. Paper chromatography of extracted plant pigments (test tube).
2. Thin layer chromatography (TLC) of extracted plant pigments (expensive one).
3. Paper chromatography of amino acids (the 4 dots).
RISK ASSESSMENT
This is part evidence for P5 and M3 - safe working practices
RISK HAZARD LEVEL PRECAUTION EMERGENCY
Solvent could Inflammation 2 Be very careful Immediately rinse
get into skin with supervision skin with
Wear gloves lukewarm water
Solvent can spill Fire hazard 3 Immediately rinse Make sure to be in
the area an open place
The pin pricking Puncture 3 Wear gloves and Enforce supervision
your fingers be careful and sanitize
, PAPER CHROMATOGRAPHY OF EXTRACTED PLANT PIGMENT
AIM
This is to show hidden colours that are extracted from the plant’s pigment.
SUGGESTED APPARATUS & MATERIALS
Test tube
Test Tube rack
Chromatography paper (6” long and 0.75 wide )
Pencil
mm ruler
Tweezer
Bong
Pin
gloves
PROCEDURE
Take one baby spinach leaf and make a hole with a cork borer.
Grab a chromatography paper and label its paper line (2cm) and solvent line (3.5cm).
Place the cut leaf in the centre of the paper & solvent line and use a glass rod to put
force into it so that there would be a smudge (make sure it’s very prominent).
Grab the test tube and pour 10 ml of acetone into it.
Make sure only the end bit of the chromatography paper is touching the solvent
subtly, if this is not expected then the component would go past the solvent line.
Place a pin through the solvent line and connect it to the inside of the bong.
Tightly close the test tube.
Wait 2 minutes and make an astute observation.
Remove it before it reaches the solvent line.
Calculate its rf value.
PRECAUTIONS
Make sure the tip of the paper is touching the Solvent line.
Wait for the solvent to reach nearly half the chromatography paper.
Never touch the paper with bare hands /gloves, and always use a tweezer to avoid a change
in the results.
HEALTH AND SAFETY
Always wear goggles no matter the environment.
Put (long) hair in a bun.
Wear gloves if necessary (handling dangerous substances).
Wear lab coats.
INTRODUCTION
Paper chromatography uses strips or papers as the permeable being the stationary phase
through which a solution needs to go pass through.
In each of the practicals, chromatography is used to distinguish a plant's pigment (P.C for
extraction of plants), what the unknown substance contains (P.C of amino acids) and to
determine the purity of a substance (TLC).
Paper chromatography is used on a daily basis by scientists for separating different
constituents of a mixture [1], a useful tool for separating polar and nonpolar solutes. [2]
Although it’s just a paper, it plays a big role in society, to identify forgery by forensic
scientists [3] and analyzing fibres that are found at a crime scene by police enforcement
In this investigation, it is encouraged to only use a chromatogram to separate mixtures to
identify every one of them.
Three sub-practical’s done to separate substances are:
1. Paper chromatography of extracted plant pigments (test tube).
2. Thin layer chromatography (TLC) of extracted plant pigments (expensive one).
3. Paper chromatography of amino acids (the 4 dots).
RISK ASSESSMENT
This is part evidence for P5 and M3 - safe working practices
RISK HAZARD LEVEL PRECAUTION EMERGENCY
Solvent could Inflammation 2 Be very careful Immediately rinse
get into skin with supervision skin with
Wear gloves lukewarm water
Solvent can spill Fire hazard 3 Immediately rinse Make sure to be in
the area an open place
The pin pricking Puncture 3 Wear gloves and Enforce supervision
your fingers be careful and sanitize
, PAPER CHROMATOGRAPHY OF EXTRACTED PLANT PIGMENT
AIM
This is to show hidden colours that are extracted from the plant’s pigment.
SUGGESTED APPARATUS & MATERIALS
Test tube
Test Tube rack
Chromatography paper (6” long and 0.75 wide )
Pencil
mm ruler
Tweezer
Bong
Pin
gloves
PROCEDURE
Take one baby spinach leaf and make a hole with a cork borer.
Grab a chromatography paper and label its paper line (2cm) and solvent line (3.5cm).
Place the cut leaf in the centre of the paper & solvent line and use a glass rod to put
force into it so that there would be a smudge (make sure it’s very prominent).
Grab the test tube and pour 10 ml of acetone into it.
Make sure only the end bit of the chromatography paper is touching the solvent
subtly, if this is not expected then the component would go past the solvent line.
Place a pin through the solvent line and connect it to the inside of the bong.
Tightly close the test tube.
Wait 2 minutes and make an astute observation.
Remove it before it reaches the solvent line.
Calculate its rf value.
PRECAUTIONS
Make sure the tip of the paper is touching the Solvent line.
Wait for the solvent to reach nearly half the chromatography paper.
Never touch the paper with bare hands /gloves, and always use a tweezer to avoid a change
in the results.
HEALTH AND SAFETY
Always wear goggles no matter the environment.
Put (long) hair in a bun.
Wear gloves if necessary (handling dangerous substances).
Wear lab coats.
