I encourage my classes to bring their mobile phones to lessons. And I encourage them to make full use of the available technology – taking photos of demonstrations or practical results, looking up answers to esoteric questions, using the timer or the calculator. They know that if they start texting each other then the arrangement comes to a quick and brutal end, but I always feel that if my lessons become so dull that they’re forced to text each other for entertainment, then I kind of deserve it.
Anyway, I got my Year 13s to try something else today – using the time lapse video function to film Thin Layer Chromatography of mint photopigments. Doesn’t need to be phones – the link here was filmed with my i-pad – so if you have a class set of i-pads, you can always use them instead.
(nb WordPress won’t let me add videos without a paid subscription, hence the use of YouTube…)
As you can see, the carotene races beautifully up the strip, the phaeophytin does a great supporting act, but then the chlorophylls and xanthophyll, after a promising start, get a bit bogged down. Though look at that beautiful blue-green of the chlorophyll A!
If anyone has a better recipe for a running solvent I’d love to hear it!
And the relevant practical protocol and questions are here.
chromotography-chlorophyll-2016
I like my last question: Why is butter yellow? It seems to random, after all the carefull rf value calculation and so on, but there are so many good biological synoptic ideas tied up in this.
Have a good weekend!
What solvent are you using, Paul?
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a fragrant cocktail of acetone, diethyl ether and petroleum ether
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