Eliminating sulfates from solution

[faermi]

Hi!

I have a solution that contains sulfate that is used to catch Cl- from a waste gas current.

The problem is that I have to analyze it with liquid-liquid chromatography, and the conductivity of the solution is too high to inject it.

The question is... how could I eliminate the sulfates, but without touching the Cl- ? I've heard something about barium filters...

Thank you in advance!!

 

[cub3bead]

Hmmm...

BaCl2 is normally used to ppt BaSO4 in the wet chemistry methods for determining SO4. But you would then be adding additional Cl to the solution you are trying to determine the Cl in. Doesn't sound like the right step.

Is there a problem with using the wet chemistry method of determining the Cl by addition of AgNO3?

Have you considered dilution of the sample with DI water?

 

[jmj5152]

CaO?

 

[cub3bead]

CaSO4 is soluble to about 2000 ppm.

 

[siretb]

If it's for analysis only, how about barium hydroxyde? You would'nt have any extra chlorides with that.
If you attempt to precipitate the sulfate (calcium sulfate, barium sulfate) be aware that some metals can co precipitate. Fe(3) is one case.