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Coffee Filter Chromatography

  • Introduction
  • Video
  • Materials
  • Procedure
  • Preparation & Notes
  • Downloadable Files

Chromatography coffeefilter_eye

Chromatography (chroma  means color, graph means write) is a technique that scientists use to separate the components of a mixture.  In this activity, you will use paper chromatography to separate the pigments that are in pens.  Some pens have a pure pigment, one color, but others are a mixture of several dyes.  If the pigments are solublein water, they will move over paper as water is absorbed.   If there is a mixture of pigments in the marker, the colors may separate if they move at different rates across the paper.  The "chromatography eye " to the right is separations from a black Vis-a-Vis pen. The black outlines should be done with a permanent marker, like a Sharpie, otherwise the color will spread when wet.

 

 

Video Demonstrations

1) Creating the Chromatogram

2) Folding into a butterfly.

3) Black vis-à-vis radial chromatography pattern

eye_chroma

 

Materials – Eye pattern & Coffee filter butterfly

  • square of chromatography paper
  • large white circular coffee filters
  • water
  • pipe cleaners
  • scissors
  • plastic pipets or eye droppers
  • cup or bowl to hold the coffee filter horizontal
  • pens (water soluble)
         vis-à-vis acetate markers
         crayola scented markers
  • permanent markers for pictures

Coffee filter butterflies
1.  Take a round coffee filter and make a small dot in the center with the black vis-à-vis pen.  Dot the same spot several times to make it intense, but not large.

2.  Have a friend hold it horizontal or rest the coffee filter on a bowl so that the center doesn’t touch the table.

3.  Place one drop of water on the dot, and watch the water spread.  Add another drop when the water stops spreading.  Repeat until you can see all the pigments that were in the pen.

4.  You can make new dots and repeat the chromatography to make a pretty design.

5.  Let the coffee filter dry.  Then accordian fold it from top to bottom.   This will create the wings of your butterfly. (see video)

6.  Make antenna for the butterfly using the pipe cleaner to tie the center of the butterfly’s body.

 

Eye Chromatography Pattern

  1. Use the square chromatography paper to make a symmetric pattern like an eye.

  2. Repeat the same process. Dot the center of the paper with the black vis-à-vis marker and slowly drip water onto the paper. Let the colors spread before adding another drop.

Notes
 For the best symmetric chromatography patterns, keep the coffee filter perfectly horizontal and avoid puddling of the water.

Avoid washable and permanent markers. 
Black vis-à-vis pens have interesting pigments.

Be creative.  Kids can draw pictures with a permanent marker and then color with the chromatograms of the vis-à-vis markers.