1. Plant Pigment Chromatography
AP Investigation 5: Photosynthesis – Part I

2. Chromatography
Technique used to separate a mixture into its component molecules
The molecules migrate, or move up the paper, at different rates because of differences in solubility, molecular mass, and hydrogen bonding with the paper.

3. Chromatography Set-Up

4. Analyzing the Chromatogram
Migration of pigment relative to migration of solvent is a constant (Rf)
Each pigment has a different Rf (reference front) value

5. Calculating Rf Values

6. Distance pigment migrated (mm) Distance solvent migrated (mm)
Data Table
Band #
Color
Distance pigment migrated (mm)
Distance solvent migrated (mm)
Rf Value 1
“purple”
35 mm
70 mm
0.5 2 3 4 5

7. Known Spinach Pigments & Rf Values
Carotene
Chlorophyll a
Chlorophyll b
Xanthophyll

8. Pigments in Spinach Leaves
Color
Rf Value
Chlorophyll a
Bright green
0.59
Chlorophyll b
Olive, yellow-green
0.42
Carotene
Yellow-orange
0.98
Xanthophyll
Yellow
0.35
Anthocyanin (not visible)
Reddish
Near bottom (0)