View Full Version : Catechol, Catechol, Pyrocatechol?

Ross Chambers
7-Jan-2008, 00:27
Stephen Anchell in the Cookbook says that these are synonymous.

My first mix of Pyrocat HD was from a Formulary kit as a trial.

It looked promising, so i ordered the makings from my local supplier.

However the "catechol" looked different to Formulary's. Theirs was a rather odd collection of differently shaped crystals and powder, with a distinctly brown tone.

My supplier's was a far cleaner looking and more regular small crystalline glossy one, with a slight touch of brown.

As well by a rough calculation Formulary's price is 8 cents/gram and my local's 52 cents/gram.

The purchase has been made, it's not an option to return the catechol, but I'd appreciate confirmation that this is probably just a higher grade, and that the synonymity quoted above is correct and -- as far as limited e-mail communication allows -- it will work?

Regards - Ross

Ross Chambers
7-Jan-2008, 00:29
Whoops, Header should have been:

Catechol, Catechin, Pyrocatechol?

You may observe my confusion :-)


Ole Tjugen
7-Jan-2008, 00:57
It's the same. 1,2 benzenediol and o-hydroxyphenol are also the same.

I've used the "high grade stuff" for years, since with shipping it ends up being cheaper than the Formulary's.

7-Jan-2008, 02:05
Also know as Pyrocatechin. It should be white crystals with a pinkish touch.

Once it goes a grey/brown it's usually old and unuseable, so always worth doing some tests first before trusting it for important films. However yours sounds fine and as it should be.


Ross Chambers
7-Jan-2008, 23:22
Thanks for the prompt answer. You may picture me at my suppliers (who seemed to have also multiplied the ordered quantity by 5 somehow) backing out of a $300 bill, when Formulary prices were so much lower comparatively. Fortunately we have a good relationship! The Formulary catechin did look rather like something swept from the floor, but worked fine. I understand that there are "analytical" and "technical" grades of chemistry, with markedly different prices?

Thanks - Ross