Procedures and Techniques.
Part C: undertake chromatographic techniques to
identify components in mixtures.
Assignment title: Separate to identify.
Scenario
I’m a newly appointed technical assistant at a large chemical plant,
Chemcalequip. As part of my induction period and to progress in my role, I
have to demonstrate skills in a range of practical procedures and techniques.
I need to demonstrate that I can carry out Chromatographic techniques to
separate and identify components in mixtures.
Paper chromatography introduction
Paper chromatography is an analytical method used to separate coloured
chemicals or substances. It is primarily used as a teaching tool, having been
replaced by other chromatography methods, such as thin-layer
chromatography. A paper chromatography variant, two-dimensional
chromatography involves using two solvents and rotating the paper 90° in
between. This is useful for separating complex mixtures of compounds having
similar polarity, for example, amino acids. The setup has three components.
The mobile phase is a solution that travels up the stationary phase, due to
capillary action. The mobile phase is generally mixture of polar organic solvent
with water, while the stationary phase is water. Paper is used to support
stationary phase (water). Difference between TLC and paper chromatography
is that stationary phase in TLC is a layer of adsorbent (usually silica gel, or
aluminium oxide), and stationary phase in paper chromatography is water.
hypothesis test
The polar components of the analyte will adhere to the silica tightly and thus
travel slowly up the plate, while the less polar or non-polar components will
not adhere that strongly to the silica and travel up the plate relatively fast with
the solvent.
Introduction
,Paper chromatography is a process that uses special filter paper to identify the
different substances in a mixture. The substances in the mixture dissolve in the
alcohol and move up the paper. The heavier substances move up the paper
more slowly. The lighter substances move up the paper faster. The enable the
heavy and light substances to be separated from one another.
Aim: To find out the colours or pigments presents in spinach leaves by paper
chromatography.
Apparatus
Isopropyl alcohol and acetone mixture
Spinach leaves
Chromatography paper
Pestle and motor
Beaker
Ruler
Scissors
Pencil measuring cylinder
Wooden splint
Hypothesis
Paper can be used to separate mixed chemicals.
Risk assessment
RISK ASSESSMENT FORM
Name of assessor: Priya Gururajan
Date: 19/12/2018
Activity: -
To find out the colours or pigments presents in spinach leaves by paper
chromatography.
Hazards
, ACETONE is an irritant and highly flammable substance.
Risk
Isopropyl alcohol: Flammable. May be harmful by inhalation,
ingestion or skin absorption. May act as an irritant.
Scissors: they can cut anyone’s finger by mistake and cause
injuries.
Beaker: may get broken as it is made of glass.
Those who are at risk
- Students, technician and teacher can be affected.
Control measures/Safety precaution: -
The solvents used to extract the pigments from the leaves and run
the chromatogram are highly flammable. Ensure that there are no
naked flames or other sources of ignition in the laboratory.
Wear eye protection when using the solvent.
Ensure laboratory is well-ventilated.
Wear plastic gloves
Training
Before we start the experiment, the teacher went through all the
dangerous with us the class.
Emergency action
Inhalation: Remove from source of exposure. If breathing stops or
shows signs of failing apply artificial respiration. Use oxygen if
breathing is laboured. Obtain medical help.
Skin Contact: Remove contaminated clothing and flush affected
area with water for at least 15 minutes. Treat patient as for
inhalation. Obtain medical help.
Eyes: Flood with eyewash or water for at least 15 minutes. Obtain