Thin Layer Chromatography for Plant Pigments

Student Sheet 10

www.saps.org.uk

Thin Layer Chromatography for Plant Pigments

Technical and teaching notes

Apparatus

· 2 or 3 young wheat plants (grown for 2 weeks under a light bank) or grass.

· 2 glass microscope slides

· 1 glass teat pipette

· 10 cm3 propanone

· 1 small watch glass or translucent Fuji film can lid

· 1 electric hair drier

· 1 very fine paintbrush

· 1 or more TLC chromatography strips*, (1.25 cm x 6.7 cm)

· 1 glass specimen tube, (2 cm x 7.5 cm)

· 1 cork to fit the tube, with a horizontal V-slit

· 7 cm3 chromatography running solvent per tube**

· 1 marker pen

Suppliers

TLC chromatography strips available from Camlab House, Norman Way Industrial Estate, Over, Cambridge CB24 5WE (formerly CB4 5WE), United Kingdom. Tel: 01954 233 110 Email:

Order: Precoated plastic sheets Polygram SIL G 5 x 20 cm MN/805 012

Preparation of materials

Running solvent

· 5 parts of cyclohexane

· 3 parts of propanone

· 2 parts of petroleum ether (40 - 60°C)

Different running solvents often produce different Rf values.

For this running solvent typical Rf values are as follows:

· Chlorophyll a 0.60

· Chlorophyll b 0.50

· Carotene 0.95

· Xanthophyll 0.35

· Phaeophytin 0.80 (a breakdown product)

Reference

Tomkins, S. P. and Miller, M. B. (1994), A rapid extraction and fast separation of leaf pigments using thin layer chromatography. School Science review 75 (273), 69 - 72. (Available from the SAPS website)

Acknowledgements

Stephen Tomkins, Homerton College, Cambridge, and Barry Miller, Douglas Ewart High School, Newton Stewart.