Australia's Science Forum

A teacher has just told me they used to make a coating for glass and then do TLC, has anyone heard of it? I cannot find my plates, and we can't afford to buy any at the moment. It did sound a most peculiar process and has piqued my curiosity.

we make it ourselves and use it on a glass slide.
Procedure:
Weigh out 1g Silica and 4g Plaster of paris,
put in mortar and pestle and grind thoroughly - finer the better.
thoroughly clean a glass slide and place on a piece of paper towel.
transfer ground up powder to a beaker and add 10ml of water.
mix well to form a suspension
use a syringe to carefully put a thin layer of suspension onto slide - should be evenly spread across plate only about 1mm thick
repeat with other slides until you have used up all of your suspension.
Allow to set - usually overnight

cheers Trish

WOW! Thank you so much. I'm going to have a go at that.

Used TLC extensively in toxicology lab (1990s) for drugs of abuse screening. Plates were approx. 20 x 10 cm and we ran 20 samples plus controls on each plate. Plates were run in ethyl acetate, dried then viewed under UV lamp and sprayed with various chemicals to show up +ves.

Same as Xenon. Immunology lab, ethy acetate gel plates, viewed with varying colourmetric methods depending on assay.

Hi Guys
I have been asked to prepare the TLC plates. Does anyone know if it matters what type of Silica Gel you use. I ordered Silica Gel 60 from SSAPL because it said it was for chromatography. When it arrived it is labelled for flash chromatography. I rang and asked if it can be used for TLC and they didn't know. Hoping one of you legends out there can offer me a clue.
Cheers
Krysia