Unit 2C | Separate to Identify | RESUB Practical date: 7/12/23
Thin Layer Chromatography of Plant Pigments
Identification of Plant Pigments, Practical 2
Aims:
The aim of this practical was to investigate the different pigments present in
leaves using TLC.
Introduction
(Background information of chromatography mentioned in the last practical report)
TLC is similar to paper chromatography but in that, the stationary phase is a thin
layer of an inert substance (e.g., silica) which is supported on a flat, unreactive
surface (e.g., a glass plate). There are certain advantages to using TLC over paper
chromatography. (BBC Bitesize, 2019) The silica’s polarity is very high due to it containing
OH groups. It attracts molecules through hydrogen bonding. The strength of the
adherence of the substance to the stationary phase is depended on this
attraction. The compounds that have a higher adsorption stick closer to the origin
line as they do not travel much distance on the paper in the mobile phase. The
compounds with a lower adsorption are able to travel more distance as they are
more free in the mobile phase. This shows that the properties of silica play a role
in the identification of the different compounds.
Why use thin layer chromatography over paper chromatography?
▪ The mobile phase moves faster through the stationary phase.
▪ The mobile phase moves through the stationary phase more evenly.
▪ The stationary phase has a variety of absorbencies. (BBC Bitesize, 2019b)
TLC produces more useful chromatograms than paper chromatography, which
have larger separations between the substances. As a result of this, it makes it
easier to identify the various pigments found.
, Unit 2C | Separate to Identify | RESUB Practical date: 7/12/23
Uses of thin layer chromatography:
TLC can be used for both qualitative and quantitative sample analysis. It is used by
multiple scientists in fields of research and in many industries. (Santiago and Strobel, 2013)
▪ Pharmaceutical Production ▪ Water
▪ Industrial Chemistry ▪ Plant pigments
▪ Food Chemistry ▪ Herbal Analysis
Thin Layer Chromatography of Plant Pigments
Identification of Plant Pigments, Practical 2
Aims:
The aim of this practical was to investigate the different pigments present in
leaves using TLC.
Introduction
(Background information of chromatography mentioned in the last practical report)
TLC is similar to paper chromatography but in that, the stationary phase is a thin
layer of an inert substance (e.g., silica) which is supported on a flat, unreactive
surface (e.g., a glass plate). There are certain advantages to using TLC over paper
chromatography. (BBC Bitesize, 2019) The silica’s polarity is very high due to it containing
OH groups. It attracts molecules through hydrogen bonding. The strength of the
adherence of the substance to the stationary phase is depended on this
attraction. The compounds that have a higher adsorption stick closer to the origin
line as they do not travel much distance on the paper in the mobile phase. The
compounds with a lower adsorption are able to travel more distance as they are
more free in the mobile phase. This shows that the properties of silica play a role
in the identification of the different compounds.
Why use thin layer chromatography over paper chromatography?
▪ The mobile phase moves faster through the stationary phase.
▪ The mobile phase moves through the stationary phase more evenly.
▪ The stationary phase has a variety of absorbencies. (BBC Bitesize, 2019b)
TLC produces more useful chromatograms than paper chromatography, which
have larger separations between the substances. As a result of this, it makes it
easier to identify the various pigments found.
, Unit 2C | Separate to Identify | RESUB Practical date: 7/12/23
Uses of thin layer chromatography:
TLC can be used for both qualitative and quantitative sample analysis. It is used by
multiple scientists in fields of research and in many industries. (Santiago and Strobel, 2013)
▪ Pharmaceutical Production ▪ Water
▪ Industrial Chemistry ▪ Plant pigments
▪ Food Chemistry ▪ Herbal Analysis
