MWChromatography

=Leaf Chromatography= In this investigation, students will extract the pigment from leaves and gain a deeper understanding of photosynthesis. They will also learn about why the leaves change color and are shed in the autumn.

Investigation Questions:

 * What pigments are present in leaves?
 * Where does the green pigment go?
 * Where does the red pigment come from?
 * Are all leaves the same?
 * Is there a difference between leaves of different colors from the same species?
 * Is there a difference between species?
 * How do the results compare over time?

Materials:

 * Chromatography Paper[[image:DSCN1327c.jpg width="120" height="85" align="right" caption=""loaded" chromatography paper"]]
 * Leaves
 * Chop Sticks
 * 250 ml beakers
 * Rubbing Alcohol
 * Drying Racks

Procedure:

 * 1) Cut chromatography paper into strips about 20 cm long.
 * 2) Cut a pointed tip on one end of each strip.
 * 3) Mark a 1 cm wide "loading zone" about 1-2 cm from the pointed tip of the strip of chromatography paper.
 * 4) Position leaf over "loading zone" of paper.[[image:DSCN1329c.jpg width="120" height="90" align="right"]]
 * 5) Bruise the leaf with the end of a chop stick to release the juice. Continue until the chromatography paper is saturated with leaf juice in the loading zone.
 * 6) Hang the loaded strips over the edge of the beaker with the pointed tips just touching the bottom of the beaker.
 * 7) Pour enough alcohol into the beaker to just cover the bottom of the beaker to a depth of 1-2 mm.
 * 8) Alcohol will be absorbed by the strips and will act as a solvent on the pigments in the leaf juice.
 * 9) After about 30-60 minutes, the colors should be drawn several centimeters upward along with the alcohol and it should be possible to observe color separation.