TLC

Every sloth needs a little tender loving care once in a while, but unfortunately I'm not getting any here. Evil Technician is off somewhere wiring up faulty circuits and I think Senile Technician has fallen asleep halfway through dunking a digestive. I do have the other type of TLC here, though, as Mrs H is doing a practical with her Year 13 chemists today - Thin Layer Chromatography. I hope they are grateful, as its  thanks to me they can do it at all.


The trouble with TLC plates, is that here they are supposed to show the chromatograms of various pain killers under ultra violet light. However, the UV light we had in the department was the wrong wavelength (longwave) to make the dust on the TLC plates glow green, and even with the right type of UV light (shortwave - Timstar sells one that works for this) the pain killer spots are hard to see. And under normal light they just look plain boring.


So, after a little research, I discovered that you can use stains to develop the chromatograms instead. The best stain I found was Potassium Permanganate (made by adding 1.5g potassium permanganate, 10g of potassium carbonate, couple of drops of sodium hydroxide and 200ml of distilled water).


To get the chromatogram in the first place, all you do is crush up your painkillers with some ethanol, then using a capillary tube add tiny spots along a line 1cm from the bottom of the plate. Put this is a developing chamber (I used a jam jar with a lid) with 10ml of ethyl acetate in until the solvent reaches 1cm from the top of the plate. Then remove the plate and wait for it to dry.


Once its dry the fun can start. If you have a UV that works use it now to see the spots. Then dip your TLC plate into the potassium permanganate stain. It will come out pink, and perhaps a few brown or yellow spots might be already visible. But after some gentle heating in front of an electric heater or something, more dots will magically appear.

This is the one I did. From left to right the painkillers I used were paracetamol, ibruprofen, aspirin and Anadin extra (you can see from this Anadin extra has both paracetamol and aspirin in it). And the best thing about was - it looks so pretty (just like me, only more pink and less sloth-like). Sadly it doesn't last forever, as the pink stain goes brown and fades over time. (Luckily I'm already brown, and hang around much longer.)


Anyway, Mrs H is eternally grateful for all my hard work on her practicals. She said I could hang out in her lab anytime and she tickled my tummy for extra TLC. She really is my favourite teacher. And I'm sure I'm her favourite technician too - I've definitely never seen her tickle Senile or Evil technicians' tummies anyway!