Thin Layer Chromatography Investigations Leighton Dann and Paul Beaumont Science & Plants for Schools

TLC One of a number of types of chromatography: gas/liquid affinity paper

TLC Separation of complex mixtures between two phases: -a stationary phase -and a mobile phase

TLC Phases the stationary phase is a thin layer of absorbent particles, in this case silica gel the mobile phase is the solvent

Fisher Scientific UK. Tel: Cat No: TLC X

Thin Layer Chromatography Separation of: photosynthetic pigments in leaves anthocyanins in leaves, flowers, fruit and vegetables

Method Place ca. 3 cm 2 leaf in mortar [If tissue is coarse, silver sand may be added] Grind until all tissue broken up Add ca. 750  l propanone Pour off supernatant into a container and seal

Method Supernatant and residue from grinding leaf in propanone

Method Mark (with a pencil) a plate 1.5 cm up from the base on the edge of both sides Use a ruler across these marks to mark two spots 2 cm apart in the middle of the plate

Method Use Pasteur pipette to place small drops of supernatant Dry off before adding another lot of drops Continue until there is a concentrated line of colour

Method Repeat process until a second line is produced (or one line across the whole plate)

Method Plate into a 600 cm 3 beaker, replace foil Remove plate when solvent nearly at top Immediately mark solvent front

Solvent system Cyclohexane : propanone : petroleum ether (low boiling point) 5 : 3 : 2

PigmentColourR F value caroteneyellow-orange0.91 pheophytin agrey0.75 pheophytin blight grey chlorophyll ablue green0.63 chlorophyll bgreen0.58 xanthophyllsyellow0.53 xanthophyllsyellow0.47 xanthophyllsyellow0.32

Coleus

Anthocyanin results