Australia's Science Forum

Help!!

I've had methylene blue spilt on my prep room floor. I've soaked up all the liquid, but how do i get rid of the nasty stain. Any suggestions?

Spinkle area with zinc dust. Then add some 1M HCl. Puddle this around with your fingers (use gloves if you are worried by 1M HCl), rubbing the surface of the floor. If it stops fizzing add a bit more HCl. Keep it up until stain goes. You may be left with a slight residual colouring, depending how strongly the dye is adsorbed on the flooring material. The hydrogen produced from acid on zinc acts to reduce double bonds in the dye molecule. This method can be used to decolour or "bleach" many dyes.
Good Luck
Wombat

Hi Wombat
Just a question-Do you mean zinc powder?

Mother
Yes, I meant zinc powder
Wombat

Any dilute acid will be suffice, 0.5M HCl will certainly do the trick.