Ow Cheok Kee wrote:
> Hi, anyone out there could help urgently how 
> to neutralize thioacetic acid that has washed 
> down the sink. Thank you before hand.

Are you doing the Wachstein-Meisel method for
cholinesterase? I didn't know anyone did it any
more - partly because the specificity is low,
but mainly because of thioacetic acid (called
thiolacetic acid in the original publications,
but it's not thioglycollic acid).

For the benefit of spectators: thioacetic acid
is a liquid with a truly horrible stench that
can fill a floor of a building in minutes, just
from measuring out the 0.1 ml or so needed in
an enzyme histochemistry substrate mixture. The
odour is what I call "skunktuous," but "very
strong tom cat urine" may be more accurate.

I used this stuff a few times in the 1960s, 
and flushed it down the sink. We were all glad
to see it go! The stench didn't persist. If yours 
is lingering and sending its fragrance up the 
plughole, I suggest an oxidizing agent, to 
destroy the offending thio groups. Potassium 
permanganate (0.5% in 2% sulphuric acid) is 
effective for thio groups in sections of tissue, 
and might reasonably be expected to work on any 
thioacetic acid that's stuck in the crud lining 
your drainpipes.

Please let us all know what you do, and if it
works.

-- 
-------------------------
John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1
   kiernan@uwo.ca
   http://publish.uwo.ca/~jkiernan/