Welcome to the MSPMLC Learning Center's
Virtual Boot Camp
STEM Challenge #7:
Chromatography
Chromatography is a technique used to separate different components (parts) of a solution or mixture.
It is used in forensics to identify bomb powders, chemical components in drugs, and other substances. For example, a red substance is found at a crime scene. Is it blood, paint, dye, ketchup, or something else? State Police Chemists conduct chromatography tests to identify what the substance is.
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Your challenge is to separate the pigments in black markers. Is the ink in each marker made up of the same pigments? Then, experiment with other colors of markers!
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Materials needed:
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2-3 washable black markers
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Coffee filters, paper towels
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2-3 clear cups of water in a bowl or cup
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Procedure 1:
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Cut or tear a piece of paper towel into a 4-inch strip.
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Draw an M&M sized circle with each black marker, spaced apart about 1-inch from the bottom of the paper towel.
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Add 2-3 tablespoons of water to the bowl or cup. It should only be just enough for the tip of the paper towel to rest in. Place the paper towel in the bowl or cup just touching the water.
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Watch for changes and record your observations. How are the markers different?
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Procedure 2:
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Draw a thick circle on each of the coffee filters. Use a different marker on each filter.
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Fold each coffee filter into fourths.
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Follow steps 3 and 4 from Procedure 1 above.
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Procedure 3:
Try the experiments using other colors of washable markers.
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