Chromatography Forum

Hi,everbody!

Somebody can you help me?
I looking for an apolar solvent,which is NOT soluble in formic acid.

Formic acid is soluble in alphatic hydrocarbons,such as Hexane?
I find opposite information about it at the internet.

Thanks.

Are you interested in solubility, or miscibility ? Formic acid will dissolve in hexane to some extent (it is soluble), but as you add more of it you might find that it forms two phases (they are immiscible) (I am not placing any bets because at the back of my mind sits the possibility that pure dry formic acid makes dimers in the liquid phase that cancel out the O-H polarity to some extent).

Peter

Thanks,

I interested in solubility.ahh,okey,but how many weight percent of formic acid soluble in Hexane?

Or are there any kind of apolar solvent which is insoluble to formic acid?

There is no such thing as "absolutely insoluble". Everything is soluble in anything to some extent. If you indicate what you are tring to accomplish, we can provide more relevant advice.

I would like to wash my nonpolar organic phase with formic acid at fast stirring to solved some component to formic acid phase. Then I would like to make a phase separation with sedimentation to have a nonpolar phase and a formic acide phase. But I need a nonpolar solvent,which is not solube in formic acid.

If formic acide soluble in that nonpolar solvent in a small amount, it doesen't metter. But the best if that solublity excent low.

Thanks.

Formic acid is listed as "somewhat soluble" in hydrocarbons. Essentially thatmeans that you *will* form two layers if you mix formic acid with something like hexane, but you will end up with some formic acid dissolved in the hexane and vice versa. The same thing would be true (to a lesser extent) for water and hexane.

Thanks your reply.

Will H2O, HCOOH/C5 or C6 system work for you?

Maybe,but I try to replace water with formic acid,because the organic phase make stable emulsion with water.

And what about higher hidrocarbons,or its isomers?

Water will keep formic away from organic. Dont extract violently, may be gentle slow rocking for longer.

Thanks,and about how many percent of water I should add to formic acid?

Is it correct, you want to wash your organic phase with acid to remove something?

Try 10 % formic in water in any ratio that works for you. It depends on chemistry and concentrations. So may be from 0.3% /99.7% to 60%/40% W/Hexane. If residues of acid need to be removed, wash few more times with just water after this.

Keep in mind that you may need 2-3 washes with acid and 2-3 washes with water.