GC column that can tolerate 1N- NaOH

[LCJEN]

Hello Everyone,

I need to analyze DMF in the API, the sample seems only dissolve in basic solution ( 1N- NaOH), Can anyone suggest a GC column that can tolerate 1N- NaOH?
My first post in the forum, Thanks in advance for your responses.

[chromatographer1]

No capillary column should be able to tolerate this except maybe perhaps, a Wax phase or one of the porous polymers.

I would suggest that you try an ammonia solution instead of 1N NaOH, but I suppose you have tried that.

SO, a PACKED column is your only hope. I would suggest a porous polymer column, a Q would be as good as anything. Chromosorb 101 is an option also.

Or, a 1% Carbowax-20M or 1500 on Carbopack C would be another possibility over a porous polymer.

best wishes,

Rod

[chromatographer1]

No capillary column should be able to tolerate this except maybe perhaps, a Wax phase or one of the porous polymers.

I would suggest that you try an ammonia solution instead of 1N NaOH, but I suppose you have tried that.

SO, a PACKED column is your only hope. I would suggest a porous polymer column, a Q would be as good as anything. Chromosorb 101 is an option also.

Or, a 1% Carbowax-20M or 1500 on Carbopack C would be another possibility over a porous polymer.

Use steel or teflon tubing for the column.

best wishes,

Rod

[HbJ]

Rod hit the nail on the head.

Another hint from some of our internal methods: Try volatile amines like DMEA or EDIPA. We've found that they mimic the solvation properties of NaOH/KOH solutions quite well.

Regarding stability under the most harsh conditions, I've found the RTX-200 to be quite an inert beast. But mind you, I've _never_ injected an NaOH solution on it.

[chromatographer1]

HBJ

And I hope you never will.

Really bad idea. FYI


Rod

[HbJ]

Thanks for the hint Rod, I'll refrain from injecting some NaOH then

[kalidassa]

Hi you are going to perform in GC or in Head Space GC, If GC direct injection means try extraction method with any solvent, if in Head Space try dimethyl imidazolidone (DMI) as a solvent.

[jdezeeuw]

Hi Guys
I know how difficuly amine analysis is and this always has my special interest.
Last week I received a reaction from a user of a new column we developed 2 yrs ago together with an "amine-producing company"..:
this is what he shared:

"I have tested the Volatile Amine column under harsh conditions. 1 µL injections of the tertiary amine N-methyl-N-benzylethanolamine in 20 – 3000 mg/L concentration levels, with a split ratio of 1:10. The amine solutions are strongly alkaline (pH 13) including 0.1 M NaOH and 20% ethanol for enhanced solubility of the uncharged amine.
The results were so far (approximately 60 injections) most satisfying.
Best regards and thank you for your help !"

The column was tested in Chemical as well as in Pharma arena, and shows promess. If interested, there is a poster handout available.
http://blog.restek.com/?p=1006

rgsd,
jaap
Restek corporation

[Peter Apps]

With vaporizing injections the sodium hydroxide will stay in the inlet, which is nicer for the column but deposits of solid hydroxide will build up over time. I am sure that they will do intersting things to the inside surface of the inlet. Surely as a general prinicipal it is poor practice to inject solutions of non-volatile inorganics onto a GC.

Peter

[jdezeeuw]

we see this all the time.. lucky we have a liner and a choice for wool or other packing..