Paper Chromatography Lab Technique

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Paper ChromatographyLab Technique
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Materials

• Whats Needed
• Chromatography Paper
• Solvent (Petroleum Ether / Acetone)
• Substance (concentrated solution)
• Closed container

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http//en.wikipedia.org/wiki/Paper_chromatography
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Background Info.

• A concentrated solution is applied to an area on
  the chromo paper.
• Chromo Paper is dipped in a solvent.
• Solvent moves up the paper via capillary action
  (ability of a substance to draw another substance
  to it i.e. adhesion/cohesion of H2O).
• This is due to the solvent molecules attraction
  to the chromo paper.

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• As the solvent meets the concentrated solution it
  dissolves it.
• The solvent and now dissolved solution move up
  the paper.
• Different substances in the solution travel up
  the paper at different rates.
• This is due to differences in solubility in the
  solvent.
• Also due to differences in attraction to the
  paper fibers.

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Time / Results

• Time Takes minutes to hours depending on the
  substance.
• Results We are looking for 4 pigment molecules
• Chlorophyll a, chlorophyll b, xanthophyll,
  carotene.

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More Results / Data

• Looking for pigment distance traveled.
• Can calculate Rf (Retention factor).
• Rf Distance traveled by pigment / distance
  traveled by solvent.