a day in the life... Stuart Walker
Studying for a PHD in Chemistry at the University of York
Featuring: Laura Brown (14) and Louise Middleton Booth (14)
10.20
The first thing Stuart did was take us to the coffee portakabin to have coffee and chocolate fingers - " just softening them up for the dreaded lab coats and lab specs, sorry ladies!"
Louise grabbed a handful of the raw ingredient of today's experiment - Household spinach!
And another ingredient you'd find in your kitchen - Icing Sugar. It packs into the large tube nicely and makes the perfect 'assault course' to separate out the various different molecules that make up the spinach extract.
11.30
Next in, Hexate - a substance like petrol. This makes the sugar wet without dissolving it.
Stuart's lab is quite small and the room to write up all his work in next door is even smaller. It's shared by the four people who also use the lab. Judging by the wall covered in postcards you get to travel a bit doing science!
11.40
While the hexate was being drawn through the sugar by a vacuum pump attached to the tap, Stuart showed us a couple of things in the lab.
A lot of the analysis that happens in the lab is done by the High Performance Liquid Chromatography Machine or HPLC for short. Here is the computer that does a lot of the analysis and here is Stuart trying to explain the data to us!
We always thought that a lab would be really tidy and neat, but Stuart explained that with all the people who work in it, it stands no chance of being tidy!
It makes it quite colourful though!
When Stuart knew the hexate was half way through the column, he took us to lunch in the canteen with his labmates. We had a right laugh and they asked us all about school and what we wanted to do afterwards and told us about their work.
12.45
They are Alex Wedgbury, Deborah Mawson and Angela Squier. Everyone was dead friendly and not at all snobby - not what we thought university would be like at all!
The vacuum was so strong that it sucked out the cotton wool bung at the bottom of the column and all the sugar started to fall out!
Poor Stuart looked, well, quite annoyed. But we had loads of time left in the afternoon, so he just started a new column.
That was brilliant - we would just have given up!
13.30
After lunch Stuart got his spinach extract out and placed it in the column on top of the sugar. Now it was just a question of leaving the vacuum pump on to suck the spinach through. Then something really unexpected happened.
14.00
We watched the spinach separate out.
14.40
You can see the different types of chlorophyll coming out of the column - the greeny blue is the chlorophyll A Stuart wants and the paler khaki green is chlorophyll B. It separated because the different molecules 'catch' on the sugar particles at a different speed.
15.00
Here is pure chlorophyll A or C55H72N4O5Mg! and here are we with the beginning and the end of the chromatography process.
It's amazing what you can do with a handful of spinach. Thanks for a great day Stuart.
To find out more about Stuart visit the www.noisenet.ws site.
Spinach
Apparently you can buy Pure Chlorophyll A from the chemistry supplies catalogue but it's VERY expensive so Stuart extracts his own from spinach using chromatography. Cheaper and much more interesting!
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Stuart's Lab
Stuart's PhD is to study how chlorophyll A degrades in the environment, which is important to know, as there's a lot of carbon in chlorophyll, and what happens to it needs to be worked out for the carbon budget and added to what we already know about global warming.
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