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Homework Help: Standard Rf Values - Biology (Photosynthesis)

  1. Mar 23, 2006 #1
    Would anyone happen to know where I could find the standard Rf values (for Chlorophyll a, Chlorophyll b, Xanthophyll, and Carotene) if varsol is the solvent? I'm trying to identify those plant pigments via Paper Chromatography, and I'd like to compare my results to the standards. The problem is, I've been looking and can't find it.
  2. jcsd
  3. Mar 30, 2007 #2
    This is what you can use:

    "Rf values will be unique for each solvent. However, the general order of the Rf values should be the same because the more nonpolar pigments move farther in nonpolar organic solvents.
    A recent plant physiology manual (Reiss 1994) identifies six pigments from spinach leaves extracted with hexane and chromatographed with petroleum ether-acetone-chloroform (3:1:1) on silica-gl chromatography. The pigments and their Rf's were:
    carotene - 0.98
    chlorophyll a - 0.59
    chlorophyll b - 0.42
    pheophytin - 0.81
    xanthophyll 1 - 0.28
    xanthophyll 2 - 0.15
    The color of the bands can be a general guide to identify the pigments. Carotene is orange. Chorophylls are green. Chlorophyll a is a blue-green. Chlorophyll b is a yellow-green. Xanthophylls are yellow. Phaeophytin is chlorophyll lacking the central magnesium ion. Pheophytin is an olive-green."

    Source: http://madsci.org/posts/archives/2001-12/1008377272.Bt.r.html
    (Original source cited: Reiss, Carol 1994. Experiments in Plant Physiology. Englewood Cliffs, NJ: Prentice Hall.)
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