Day: November 9, 2018

Fun With Photosynthetic Pigments

One of the student lab exercises the human female has to support addresses that all-important biological process, photosynthesis.  One of the activities involves poking test tubes of various photosynthetic pigments into a spectrophotosomethingorother and seeing what wavelengths of light they absorb.  It’s actually rather cool.

But the best part is that these pigments have to be extracted from plants.  One cannot just waltz down to Pigments R’ Us.  The protocol is very long and very finicky, and it involves all SORTS of nasty organic solvents.  It takes all day, and it’s about as close to alchemy as it gets.  At every step, something could go wrong, necessitating starting all over.  Sooo much opportunity for mischief!!

The human female and one of her Tech II’s are attempting the process today.  They’ve whooshed up the spinach and a bit of yellow squash peel (for extra xanthophyll) in a blender full of acetone with some calcium carbonate. (I stayed FAR AWAY from this step!!)

Then they pulled the resulting slop through a Buchner funnel with a vaccum, and the resulting lovely green liquid has been “washed” with water.  That is a very fiddly step, because it takes one person to pour the water s l o w l y into the separatory funnel while someone else gently rocks it and “burps” it periodically to vent the gas it gives off.  I got to help with that this time, because burps are always funny.

They’ve reached the point, about an hour into the process, where the separatory funnel is placed in the hood and the layers are allowed to settle out for about forty minutes.  What they should have is a nice bilayer, with clear water and waste on the bottom and the chlorophyll and other pigments in a nice, dark green layer on the top, all ready to be decanted for the next step.

Let’s have a look!


Norns’ nighties!  That is not at all how things should look.  At this point, there’s nothing to be done except start over.  Perhaps the human female was holding her ugly face the wrong way…

More spinach, more squash peel, more calcium carbonate, more acetone, more getting very much out of the way!, more water, and more rocking and burping.  Surely this time…


Ehehehehe!  And we haven’t even gotten to the petroleum ether part, let alone the rest of the separatory steps!

We could be here all day, folks.

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