TEXTO 70

Material da Profa. Dra. Durvalina Maria Mathias dos Santos. Disciplina de Fisiologia Vegetal, Unesp, Jaboticabal. 2006

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SEPARAÇÃO E IDENTIFICAÇÃO DE PIGMENTOS
FOTOSSINTÉTICOS
CROMATOGRAFIA DE PAPEL

Carotenos

SEPARATION AND IDENT IFICATION OF
PIGMENTS INVOLVED IN
PHOTOSYNTHESIS
(Cambell 6th Ed. 181-183; 7th Ed. 186188)
The three main groups of photosynthetic pigments are the chlorophylls, xanthophylls and carotenoids.
Most photosynthetic pigments are insoluble in water but soluble in nonpolar solvents such as ether, acetone and chloroform. One can therefore make use of this property in resolving a solution of pigments into its individual components. The technique of paper chromatography will be utilized to resolve a chloroplast preparation into its components. Consult the appendix of your lab manual and make sure you have a good knowledge of the principles of chromatography.

Laranja com amarelo forte

Xantofilas
Amarelo
claro

Clorofila a

verde -azulado

Clorofila b verde amarelado

With the aid of a capillary tube carefully spot a tiny droplet of the pigment extract on the paper strip. The spot should be about 1.5 cm from the tip of the paper. Allow the spot to dry and repeat the application 30 to 40 times.
(Be careful to keep the spot as small as possible to facilitate good resolution).
Secure the strip of paper to the stopper provided by means of a paper clip. Place about 3 ml of the solvent (acetone petroleum ether 10:90 v/v) in a test tube. Suspend the paper strip in the test tube making sure it does not touch the solvent or the sides of the tube. This can be achieved by raising the paper clip.
Stopper tightly. After 5 minutes lower the paper clip so that the tip of the paper touches the solvent but the spotted area is well above the solvent.
After about 10-15 minutes, observe the chromatogram. First published Oct 95: Modified Aug 05;
Copyright © Michael Shaw 2005 (Images and Text)

Adaptado e modificado pela Profa. Durvalina Maria (2006)
Disciplina de