SXR375 - Day 2

Day two. A patchy breakfast, fried egg or scrambled, sausage and tomatoes. I was reliably informed by others on the table that they doubted anything organic went into the scrambled egg, so my choice of fried seemed good. Still cereal and toast is ok, and coffee was welcome.

Off to the lab, and our first task was to grind up some leaves. We chose petunia leaves, other groups did tobacco, pak choi, coleus and others. We then extracted the pigments in acetone and diethyl ether. Then we did some thin layer chromatography, try to separate out the pigments such as chlorophylls, lutein, violaxanthin and neoxanthin. Some nice bands separated.

We then tried to take some of the bands - and analyse them in spectrophotometer. FIrst time it didn't work - we had the tube the wrong way round. Second time looked better, but one of the peaks was in the wrong place.

Then just time to put some flowers in to stew in HCl before a break for lunch.

After lunch, we came back and did similar procedures with the extract from flowers. We were looking for flavones and anthocyanins, using similar techniques. We had a hitch when we put our first TLC papers in the solvent, which turned out to have too much acid in, and they all dissolved into mush! Anyway - after coffee break we redid things, and they worked much better.

More chromatography, and some absorption spectra helped us isolate pigments from the various plants we'd looked at. We collated the data - wrote it all down and then went to tea (roast beef and yorkshire pudding).

After that I attended a tutorial on photosynthesis and plant pigments, and another on giving presentations.

Then - to the bar!

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