Monday, October 6, 2014

Perfecting Leaf Chromotography

I decided to test to see if rubbing alcohol or nail polish remover(acetone) would create the best leaf chromatography.  After trying leaf chromatography recently with dismal results this worked much

Flat Coffee Filter
Spinach Leaf
Small Mason Jar
50% Isopropyl Rubbing Alcohol
Safety Goggles


1.  Cut the filter paper into a rectangle with a point like shown. 

2.  Place the spinach leaf on top of the filter paper.  Roll the quarter over the spinach leaf to press a green line into the filter paper just above the point.  It is a good idea to let it dry about 15 minutes.

3.  Attach the top of the filter paper to the pencil using tape.

4.  Pour about an inch of acetone into the mason jar. 

5.  Place the tip of the filter paper into the jar.  Make sure just the tip of the filter paper touches the acetone.  The pencil will help balance the paper.

6.  Observe the acetone traveling up the filter paper and carrying pigments along with it.

7.  When the acetone almost reaches the pencil take it out of the jar.

8.  Follow steps 1-7 for 50%Isopropyl Alcohol

My students enjoyed the leaf chromatography.  They did find that the colors fade rather quickly on the filter paper.  Below are pictures of the acetone being used.  We have green, bluish green, and yellow.  The acetone has more fumes.  We tented some aluminum foil over the top and that helped.  It is also good to have an open window. 

Here is a comparison of 50% isopropyl alcohol and acetone.  You can see that the alcohol on the left did not have much color separation. 

This would work well as a science project.  There are many other changes that can be made.  Isopropyl alcohol comes in different strengths.  The are many different types of filter paper.  Think of all of the leaves you could test.  Just remember to practice good lab practices and be safe with any chemicals used.

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