Wednesday, September 22, 2010

Chromatography: Spinach

Is spinach colored by purely chlorophyll (green pigment)? Or are there other pigments hiding in there, masked by the presence of chlorophyll?

Before beginning, if you aren't familiar with chromatography, you may want to review the basics, here.  

Use a quarter to rub spinach into a piece of filter paper, a couple of centimeters from the end of the paper. (If you’re doing this at home and don’t have lab grade filter paper, have no worries! A coffee filter works beautifully (that’s actually what I used with my students – why spend the money on expensive filter paper!) and even paper towels can be made to work).

 Put about a centimeter or so of rubbing alcohol in a cup.  Place the filter paper in the cup, so the end is in the alcohol, but the spinach transfer is above the liquid.  Allow it to sit.

Now, here's where it would be nice to have a picture of the finished chromatograph.  But, milk spilled on mine before I snapped a picture and I haven't had the opportunity (or spinach) to recreate it.  It's subtle, but you can find both green and yellow pigments on the paper, if you look carefully. 

Presented at the 2003 New Jersey Science Convention.

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