Chromatography Forum

Hello all

we have to determine residual solvents (hexanol, 2-EH) in very aggresive matrices containing NaOH and organic amines at a pH of ~13. This is wrecking columns and the lab production lab is hesitant to do any sample prep other than adding base or acid to adjust pH.

We do not really need good resolution because we have obvious peaks at high S/N. Is there an old school column that is impervious to injections of caustic matrices? We only require HPLC quality plate numbers.

I have already recommended liners with wool.

Thanks...

Why would neutralizing your samples affect hexanol, 2-EH results? Try that.

Are you tied to performing liquid injections? This sounds like a great problem for headspace analysis. Something like SPME.

Heck, if your samples are really concentrated, you might just be able to use a gas-tight syringe and static headspace.

Thanks, guys! I would do headspace myself but the lab in question is tied to liquid injections.....

I have strongly suggested adjusting to neutral pH with acid and the addition of a colored indicator.

just a small remark.
Be carfull when adding acid, the temperature could rise and cause the alcohols to evaporate.
if you can do it temperature controled than it is a good suggestion.

>we have obvious peaks at high S/N

I think the first attempt at a solution here is obvious - inject less and dilute and split more.

We put some crazy stuff on columns with 0.1ul injections and 2000 split ratio and they last us years.