Assignment Title: Separate to Identify
,ABSTRACT: This practical is about using different chromatographic
techniques to separate mixtures of plant pigments and amino acids. The
two chromatographic techniques used during this practical were paper
chromatography and thin layer chromatography. Paper chromatography
was used in the separation of mixtures of plant pigments, and it was not a
suitable technique because not all the colours of the pigments appeared
on the chromatogram produced. It was also used to identify two unknown
amino acids (unknown a and unknown b) and it was a suitable technique
for identifying the amino acids. Unknown a was identified as L-lysine and
unknown b was identified as Threonine. The other chromatography
technique used during the practical was thin layer chromatography. Thin
layer chromatography was used in the separation of plant pigments, and
it was suitable for the separation of the plant pigments because the
chromatogram produced during the practical showed clear separation of
colours and the colours on the chromatogram moved up straight and did not
smear into each other which made it easy to calculate their Rf values and
also identify the pigments using their colours and the Rf values.
Introduction: Chromatography can be defined as a laboratory technique
used for separating solutes from a mixture based on the relative amounts of
each solute spread between the stationary phase (which can be either a
liquid or a solid) and the mobile phase (can either be a gas or liquid). The
main purpose of chromatography is to separate a mixture of compounds into
its individual components. There are different types of chromatographic
technique, and they include: paper chromatography, gas chromatography,
thin layer chromatography, ion chromatography etc.
Paper chromatography: Paper chromatography (PC) can be described as
a type of chromatographic technique that runs on a piece of specialized
paper. It is used to separate mixtures of soluble substances which are mostly
colored substances such as plant pigments, dyes, food coloring or inks.
Advantages and disadvantages of paper chromatography
Advantages Disadvantages
It is less time-consuming and not as This technique is not suitable for the
expensive as other types of separation of volatile substances such
chromatography technique. as hydrocarbons and volatile fatty
acids.
, Requires a very less amount of sample Paper chromatography is prone to
for testing smearing so it easy for the spot to smear
into each other
Can be detected by the naked eye so it Not as accurate as HPLC and TLC.
does not involve the use of any
chemicals to detect the separation of
the mixture
Paper chromatography with plant pigment
Equipment used:
● Spinach leaves
● Pestle and mortar
● Sand
● Propanone
● Pencil and ruler
● Chromatography solvent (9:1 petroleum ether and acetone)
● Glass tube
● Beaker
● Gloves
● Wooden splint
Risk Assessment
Investigation Title: Paper chromatography with plant pigment
Aim of investigation: Using paper chromatography to separate mixtures of
plant pigment
Date of investigation: 07/02/2022
Hazard Risk Level of Likelihood Precaution
seriousness to occur
0=not
0=no
serious,
chance
5=very
, serious 5=very
likely
Propanone Flammable 5 3 If there is
contact with
Irritant
the eye, flood
the eye with
gently running
tap water for
10 minutes
and consult a
medic
If swallowed,
do no more
than wash out
the mouth
with water. Do
not induce
vomiting and
consult a
medic
If clothes
catch fire,
smother
flames on
clothing or the
skin with a fire
blanket or
other
material. Cool
any burnt skin
with gently
running tap
water for 10
minutes.
,ABSTRACT: This practical is about using different chromatographic
techniques to separate mixtures of plant pigments and amino acids. The
two chromatographic techniques used during this practical were paper
chromatography and thin layer chromatography. Paper chromatography
was used in the separation of mixtures of plant pigments, and it was not a
suitable technique because not all the colours of the pigments appeared
on the chromatogram produced. It was also used to identify two unknown
amino acids (unknown a and unknown b) and it was a suitable technique
for identifying the amino acids. Unknown a was identified as L-lysine and
unknown b was identified as Threonine. The other chromatography
technique used during the practical was thin layer chromatography. Thin
layer chromatography was used in the separation of plant pigments, and
it was suitable for the separation of the plant pigments because the
chromatogram produced during the practical showed clear separation of
colours and the colours on the chromatogram moved up straight and did not
smear into each other which made it easy to calculate their Rf values and
also identify the pigments using their colours and the Rf values.
Introduction: Chromatography can be defined as a laboratory technique
used for separating solutes from a mixture based on the relative amounts of
each solute spread between the stationary phase (which can be either a
liquid or a solid) and the mobile phase (can either be a gas or liquid). The
main purpose of chromatography is to separate a mixture of compounds into
its individual components. There are different types of chromatographic
technique, and they include: paper chromatography, gas chromatography,
thin layer chromatography, ion chromatography etc.
Paper chromatography: Paper chromatography (PC) can be described as
a type of chromatographic technique that runs on a piece of specialized
paper. It is used to separate mixtures of soluble substances which are mostly
colored substances such as plant pigments, dyes, food coloring or inks.
Advantages and disadvantages of paper chromatography
Advantages Disadvantages
It is less time-consuming and not as This technique is not suitable for the
expensive as other types of separation of volatile substances such
chromatography technique. as hydrocarbons and volatile fatty
acids.
, Requires a very less amount of sample Paper chromatography is prone to
for testing smearing so it easy for the spot to smear
into each other
Can be detected by the naked eye so it Not as accurate as HPLC and TLC.
does not involve the use of any
chemicals to detect the separation of
the mixture
Paper chromatography with plant pigment
Equipment used:
● Spinach leaves
● Pestle and mortar
● Sand
● Propanone
● Pencil and ruler
● Chromatography solvent (9:1 petroleum ether and acetone)
● Glass tube
● Beaker
● Gloves
● Wooden splint
Risk Assessment
Investigation Title: Paper chromatography with plant pigment
Aim of investigation: Using paper chromatography to separate mixtures of
plant pigment
Date of investigation: 07/02/2022
Hazard Risk Level of Likelihood Precaution
seriousness to occur
0=not
0=no
serious,
chance
5=very
, serious 5=very
likely
Propanone Flammable 5 3 If there is
contact with
Irritant
the eye, flood
the eye with
gently running
tap water for
10 minutes
and consult a
medic
If swallowed,
do no more
than wash out
the mouth
with water. Do
not induce
vomiting and
consult a
medic
If clothes
catch fire,
smother
flames on
clothing or the
skin with a fire
blanket or
other
material. Cool
any burnt skin
with gently
running tap
water for 10
minutes.
