UNIT 2C
Undertake chromatographic techniques to
identify components in mixtures
P6 – EXPLAIN THE USE OF
CHROMATOGRAPHIC TECHNIQUES
TO SEPARATE MIXTURES
Introduction (what is chromatography?)
When scientists want to use their analyze a mixture it is necessary for that
mixture to undergo chromatography in order to separate the mixture into it’s
different substance. A mixture will contain more than one substance
therefore in order to analyses the mixture it would be needed to analyze the
separate substances within the mixture. This process is known as
chromatography and can be done on a variety of mixtures. For instance in
this unit it was required of me to undergo a variety of chromatographic
experiments. These experiments are as follows ; the paper chromatography
of plant pigments, the TLC chromatography of plant pigments,
chromatography of amino acids. Chromatography can be carried out using a
range of chromatograms such as thin layer chromatogram and paper
chromatography. However each chromatogram it’s own suitability and
advantage over the other. Below will be a discussion of two types of
chromatograms which are paper chromatography and thin layer
chromatography including their suitability (advantages, disadvantages) as
well as chromatographic techniques.
, Paper chromatography
Paper chromatography is a technique used for separating dissolved
chemicals/mixtures into it’s different parts, in other words “substances” the
different substances move across the paper chromatogram at different rates,
this particular feature is why the separation of the mixture occurs. In this
certain chromatographic technique the non stationary phase is considered to
be the solvent wether that is aqueous or non aqueous and in contrast to the
stationary phase the non stationary phase is considered to be the paper
chromatogram. Paper chromatography can be suitable when you want to
perform chromatography in a more cheaper and Less time consuming
method as paper chromatography has these particular advantages. However
this technique is only suitable for certain procedures. It is suitable to undergo
paper chromatography when the mixture being separated is amino acids,
carbohydrates, plant pigments and dyes including many more. However
when substances such as fatty acids and hydrocarbons need to be separated
paper chromatography is not a suitable selection for this and instead another
technique should be opted for.
Thin layer chromatography
Additionally another chromatographic technique is known as thin layer
chromatography. In contrast to paper chromatography this particular
chromatogram material is much thinner and in cases there is a coating of
silica gel present, this is again known as the stationary phase highlighting
that the stationary phase is thinner in thin layer chromatography in
comparison to paper chromatography. This technique is suitable for the
separation of dyes, inks and paints for analysis. Thin layer chromatography
has additional suitabilities/advantages such suitabilities include the mobile
phase being able to move more evenly and quicker. This technique is much
more superior compared to the use of paper chromatography since thin
layer chromatography produce chromatograms where separation of the
mixture into separate components are shown more visibly which confirms
that TLC is able to separate the chosen mixture much better than paper
chromatography
2
Undertake chromatographic techniques to
identify components in mixtures
P6 – EXPLAIN THE USE OF
CHROMATOGRAPHIC TECHNIQUES
TO SEPARATE MIXTURES
Introduction (what is chromatography?)
When scientists want to use their analyze a mixture it is necessary for that
mixture to undergo chromatography in order to separate the mixture into it’s
different substance. A mixture will contain more than one substance
therefore in order to analyses the mixture it would be needed to analyze the
separate substances within the mixture. This process is known as
chromatography and can be done on a variety of mixtures. For instance in
this unit it was required of me to undergo a variety of chromatographic
experiments. These experiments are as follows ; the paper chromatography
of plant pigments, the TLC chromatography of plant pigments,
chromatography of amino acids. Chromatography can be carried out using a
range of chromatograms such as thin layer chromatogram and paper
chromatography. However each chromatogram it’s own suitability and
advantage over the other. Below will be a discussion of two types of
chromatograms which are paper chromatography and thin layer
chromatography including their suitability (advantages, disadvantages) as
well as chromatographic techniques.
, Paper chromatography
Paper chromatography is a technique used for separating dissolved
chemicals/mixtures into it’s different parts, in other words “substances” the
different substances move across the paper chromatogram at different rates,
this particular feature is why the separation of the mixture occurs. In this
certain chromatographic technique the non stationary phase is considered to
be the solvent wether that is aqueous or non aqueous and in contrast to the
stationary phase the non stationary phase is considered to be the paper
chromatogram. Paper chromatography can be suitable when you want to
perform chromatography in a more cheaper and Less time consuming
method as paper chromatography has these particular advantages. However
this technique is only suitable for certain procedures. It is suitable to undergo
paper chromatography when the mixture being separated is amino acids,
carbohydrates, plant pigments and dyes including many more. However
when substances such as fatty acids and hydrocarbons need to be separated
paper chromatography is not a suitable selection for this and instead another
technique should be opted for.
Thin layer chromatography
Additionally another chromatographic technique is known as thin layer
chromatography. In contrast to paper chromatography this particular
chromatogram material is much thinner and in cases there is a coating of
silica gel present, this is again known as the stationary phase highlighting
that the stationary phase is thinner in thin layer chromatography in
comparison to paper chromatography. This technique is suitable for the
separation of dyes, inks and paints for analysis. Thin layer chromatography
has additional suitabilities/advantages such suitabilities include the mobile
phase being able to move more evenly and quicker. This technique is much
more superior compared to the use of paper chromatography since thin
layer chromatography produce chromatograms where separation of the
mixture into separate components are shown more visibly which confirms
that TLC is able to separate the chosen mixture much better than paper
chromatography
2
