Leaf Chromatography. Why do leaves change color?

Many deciduous trees have green leaves during the spring and summer, but something magical happens in the fall: the leaves take on shades of red, orange, yellow, brown and purple before falling down on the ground. 

What triggers the change? Where do the colors come from?

Turns out leaves contain different pigments which give them their color: chlorophyll (green,) carotenoids (yellow and orange) and anthocyanins (red.) Chlorophyll helps carry out photosynthesis during warm sunny months. It  masks other pigments and makes leaves appear green. As fall arrives, days get shorter and temperatures drop and green pigment breaks down letting beautiful vibrant colors become more visible.  

With the help of chromatography we can see leaves’ hidden mysteries. 

Chromatography is the process of separating a mixture by passing it through another medium. 

For this experiment you will need 

Leaves 

Glass jars

Coffee filters cut into 1″×5″ strips

Rubbing alcohol

Patience.

Step 1. Sort leaves, too them up in small pieces and place them in the jars. 

Step 2. Pour enough rubbing cool to cover the leaves. Let the mixture sit for couple of hours. 

Step 3. Optional.  Forget about the experiment for 2 days. Now the color of rubbing alcohol is very pronounced.  The same effect is acheived by baking the jars with the mixture at 250°F for 1 hour. MAKE SURE JARS COOL COMPLETELY BEFORE HANDLING THEM. Don’t ask me why I included this tip🔥. 

 Step 4.  Secure one end of coffee filter on the pencil, craft stick or the side of the jar; place the other end of coffee filter in leaf+alcohol mixture, make sure it is narely touchong the liquid. 

Step 5.  This is where we got sidetracked and forgot about the experiment for 3 days, but leaving it overnight would have given us the same great result. 

Step 6. Let the color climb to the top.lf the coffee filter, then dry it. 

Step 7. Observe and analyze the results