Confused About Procedure for "Column Chromatography: Can you Separate the Dyes in Grape Soda Using Space Sand™?"

[7471c518a6c64d7aa92ec9d151800e2b]

I am in 7th grade, and I am doing the "Column Chromatography: Can you Separate the Dyes in Grape Soda Using Space Sand™?" experiment for my Science Fair Project. Link: https://www.sciencebuddies.org/science- ... da#summary

The objective of this experiment simply says to "Investigate whether a homemade column chromatography setup can be used to separate and isolate the different food colorings that are in grape soda." I don't see how doing all of the steps in the "Procedure" tab will separate the blue and red dyes from the grape soda though. I completed the experiment, but all I ended up with was 6 cups with some clear-colored eluates and some purple-colored eluates.

[cumulonimbus]

Hi,

The procedure is testing whether the nonpolar eluent or the space sand by itself is enough to separate the two nonpolar dyes, Blue 1 and Red 40. In steps 7 and 8, you are testing whether the space sand alone can separate the two nonpolar dyes, since one is slightly more polar than the other. In steps 9 and 10, you are testing whether the assistance of the nonpolar eluent will create enough of a difference so that one dye travels more slowly than another. If you have only purple-colored eluates, it could be that for some of the steps, you are not switching to a new cup when the dye color changes, so if possible, you might want to repeat the procedure again and observe very carefully. It is also possible that neither the space sand nor the eluent is able to separate the nonpolar dyes; the difference in polarity may be too small. I hope this helps!

Elena

[7471c518a6c64d7aa92ec9d151800e2b]

Thanks for the reply. I was planning on doing a redo of the experiment today. The first time I did this experiment, there was no change in color, so I didn't have anything in the 4th Fraction cup. I am using red cups too, so that made it difficult to see the colors of the eluates once they were in the cup. I am going to follow the steps more carefully and try using clear cups too. I procrastinated doing the project until less than a month before my school's science night. Since this is a 9th grade project, I don't know what polar and nonpolar mean. I didn't think it would be important when doing the experiment, but I am going to start learning all the vocab words that the website said were related to the project. I think this will help me understand more about the experiment because I honestly skipped a lot of text when I started reading about tbis experiment. Again, thanks for the clarification and tips.