Chemical Forums

Specialty Chemistry Forums => Citizen Chemist => Topic started by: Peter57 on July 11, 2013, 04:44:36 PM

Title: what gives tannic acid its colour?
Post by: Peter57 on July 11, 2013, 04:44:36 PM

what gives tannic acid its colour? is it possible to remove the colour by mixing it as a solution and distilling?

Title: Re: what gives tannic acid its colour?
Post by: Arkcon on July 11, 2013, 04:56:34 PM

Tannic acid is available as a reasonably pure substance.  Its brown.  You can't purify away any impurities and change its color.  Mixing a solution won't purify it or change its color.  Distilling a powdered organic compound isn't possible.  And mixing, then distilling is also a process that doesn't purify anything.

Title: Re: what gives tannic acid its colour?
Post by: Peter57 on July 11, 2013, 05:10:34 PM

Ok, thanks,

is it possible to synthesise low molecular weight tannic acid from the raw stuff?

Title: Re: what gives tannic acid its colour?
Post by: arthur1972 on May 13, 2017, 10:57:08 AM

Quote from: Peter57 on July 11, 2013, 04:44:36 PM

what gives tannic acid its colour? is it possible to remove the colour by mixing it as a solution and distilling?

I also bought 5 drums tannic acid from one China tannic acid factory http://www.tnjchem.com/buy-tannic-acid-tannin-from-china-suppliers-at-best-price_p2327.html and found the same problem. Their explanation is that tannic acid is easy to absorb moisture, easy to oxidize in the air, and the color deepens after oxidation. I checked some  books and says the same.