Sciencemadness Discussion Board

Solvent for Auxins

Waffles SS - 15-8-2013 at 23:25

I want to make mixed solution of 3 different Auxin and keep this solution for long time.but i dont know what solvent is suitable and safe for all of them.

My Auxins are Indole butyric acid ,Naphthyl acetic acid,Gibberellic acid

For better solving I tried Potassium salt of these(i added these auxins to potassium hydroxide solution )but i read some where that Gibberellic acid decompose in Aqueous solution.

Then i tried to solve these auxins in EtOH(96%) but after awhile the color of solution turned dark and terrible odor produced(i think that should be ester of IBA or NAA)

what about acetone?
Someone has suggestion?

smaerd - 16-8-2013 at 04:46

The solvent may not be the concern. It's degredation that is the problem. Do you know how these solutions degrade?

Is it light, oxygen, chlorine in the tap water, etc? Do they polymerize, oxidize. etc?

Here's my advice. Make the the solvent is relatively free of impurities. Store in an amber bottle using a degassed solvent. Purge the bottle with CO2, N2, or Ar. Store in a cold place.

Waffles SS - 16-8-2013 at 10:24

Thanks smaerd,
Sure i use degassed Distilled water but Gibberellic acid decompose in water(even in degassed water or in amber bottle)
Quote:

Gibberellic acid is slowly hydrolyzed by water and rapidly decomposed by heat or chlorine (for example in water)
http://www.guidechem.com/reference/dic-586.html

http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@ter...

Decomposition of gibberellic acid in aqueous solutions
http://link.springer.com/article/10.1007%2FBF02928124

somebody know what is suitable solvent for these auxin?

Paddywhacker - 16-8-2013 at 23:11

10% ethanol in dimethyl sufoxide (DMSO) and store it in a fridge.

The ethanol is there to stop the DMSO from freezing solid, and DMSO is, like ethanol, a disinfectant, so moulds or bacteria cannot grow in your solution and degrade it. Also, DMSO is kinder to your plants than ethanol.

If you store an aqueous solution then you risk bacteria and moulds.

Protium1 - 17-8-2013 at 04:28

Paddywhacker's solution is probably a safe place to start from. I would also advise to keep solution protected from light, heat and also oxygen. Maybe wrap the container in aluminum foil and keep stoppered tight in the fridge.
Gibberelic acid has a hydroxyl group that can oxidize to a ketone, but also has a double-bond Beta to the ketone, so may be oxidized further. Perhaps a mild antioxidant such as Vitamin C (ascorbic acid) might be used in conjunction, or a protective layer of nitrogen in the storage container might help.
IF DMSO cannot be had, I'm sure EtOH would work just fine if kept cold, dark, and protected from too much atmospheric oxygen. Or anhydrous iso-propanol can be found at any well-stocked pharmacy.

[Edited on 8/17/2013 by Protium1]

[Edited on 8/17/2013 by Protium1]