RP7-chromatography of photosynthetic pigments

Question 1

what is the purpose of chromatography

Answer 1

to separate out different components of a sample

Question 2

state the factors affecting the rate of migration of different pigments

Answer 2

-solubility
-mass
-affinity to a paper

Question 3

what is the purpose of finding an experimental Rf value

Answer 3

-can be compared to a standard value in Rf database to identify the pigment
-standard value should be done with the same solvent and paper

Question 4

outline the procedure for using chromatography to separate photosynthetic pigments

Answer 4

-draw a horizontal pencil line around 1cm the paper
-add some acetone to a pestle and mortar and grind up leaf sample
-use capillary tube to transfer pigments onto pencil line
-suspend the paper in the solvent so that the level of liquid does not rise above the pencil line
-leave the paper until the solvent has run up the paper near to the top
-remove the paper from the solvent and draw a pencil line to mark the solvent front
-calculate Rf value for each spot

Question 5

What are the hazards and precautions associated

Answer 5

-solvents are irritants and flammable, keep away from naked flames, wear goggles and avoid skin contact
-leaf extract may be biohazard, handle with care and wash hands after use