Spectrophotometry

Today´s practical was going to be, as I found out on WebCT a while ago, about the thrilling subject of spectrophotometry (whatever.....).
You can imagine how surprised I was when looking through my papers as I found a line about the so called Beer-Lambert-Law. Were we going to have a useful practical on British beer?
I very soon had to find out that this law was not about how much beer Lambert can drink until he has to throw up. Actually, it was not about beer at all (what a disappointment!)
But once being there I thought it is rather impolite and quite embarrassing to leave, so I decided to stay.

Our main assignment was to find the concentration of a solution of chlorophyll. So we had two bottles of chlorophyll, which had the colour of those weird green jelly things children sometimes eat. The known solution was the one we used to verify our results - mixing them with distilled water in various different amounts (20, 40, 60, 80 and 100%) - to get a graph we could use to determine the absorbance of the unknown one.
Also, we had the spectrophotometer, which is a machine that tries very hard to look important and difficult whereas all it actually is, is a box you put your sample-filled cuvette in to then read the number it gives you on a little screen.

In conclusion, this was a fairly easy practical - so now let´s try to understand what we did.....

Cheers!

footwear

Footwear is, as you are undoubtedly aware of, something you wear on your foot.....

Criminals tend to take their feet with them when committing a crime, which therefore leads to footwear marks being an excellent source of information for any future CSI (Confusion of Science Illuminator) as I will be one.

One method of looking at such marks might be to dig out the ground with the foot print, which would lead to monstrous holes all over a crime scene plus a big mess in the laboratory.

But I just did some manicure - so I really wouldn´t want my nails to be messed up! I don´t have enough slaves to do the work, either.

The other method is to simply take a picture of whatever it is you imagine to have seen. It sounds fairly easy. Who hasn´t taken a picture before? So why on earth should that be any difficult?
But the problem is, that your picture has to be good the first time it is taken. You can re-print it a thousand times if you want to try the patience of your employer, but chances are, that you won´t be able to go back to the crime scene itself.
To take a good picture, the camera has to be positioned in one plane with the piece of evidence. There are two places the camera of a CSI is supposed to be - around the neck or on an (enormous) tripod - so that it wouldn´t break as they are really expensive!

Health and Safety Advice before the practical:

• Beware of the tripod - it snaps!
• Don´t let the camera drop - Kev will kill you!

But setting up the tripod was not the only difficulty we came across.
Our first footprint was to be taken from the back of a car. How on earth can we look into the camera if it is about half a metre above our heads? ("you are not allowed to use the table to stand on for safety reasons - but if I don´t see you doing it I won´t be able to tell you off - do we understand each other?") - nevertheless, it was not the easiest thing in the world.
Reflective materials have the nature to - well - reflect. So where do we put the flash to be able to gain a picture we can actually see something on?
Following are two of the better pictures we took:





Followed by the picture of a footprint cast taken inside the laboratory:

introduction.....

..is unnecessary as nothing I have to say is of any importance whatsoever.

The reason for why I am keeping this blog is, that I was asked by several people about what I do during my days - so I thought I´d just pretend to.....

Honestly, I will try to give an overview of my academical work, describe my practicals and some of the things I learnt.
I hope you enjoy some of what I write! :)