Chromatography Forum

Dear All,

I would like to inject some MBDSTFA (derivatising agent) into a CP Wax 52 CB column composed of 100% of polyethylene glicol.

Glicols are, of course, alcohols, however, in the form of a polymer inside a column, do they still contain free alcohol groups and, therefore, they cannot be used with derivatising agents?


Regards

Yes they do have hydroxyl functional groups and no you SHOULD not use derivitizing agents on this column. But if you do, you will have a unique column which may vary with time in selectivity and polarity and will probably never have reproducible results from day to day.

best wishes,

Rodney George

Thanks for your reply

Does that mean that a PEG column in which MBDSTFA has been injected is basically destroyed and needs to be disposed of?

You could wash it in a methanol wash and try to recover it for purely trial and error purposes, like if you wanted to see if a known volatile was present in a sample.

But practically, in a situation where I wanted to report results, it is not functional for research.

(To save money.......

Of course, you might try using it for a known analysis and see if it performs the separation. Just always report the column as a modified CP-Wax column.)

Good luck,

Rodney George

And just to make sure:

A 100% Dimethypolylsiloxane column should be fine with derivatising agents. Is this correct?

Thanks again

Regards

Any silicone column with an active functional group of methyl, or propyl, or phenyl, or octyl, or biphenyl should be ok.

And just to make sure:

A 100% Dimethypolylsiloxane column should be fine with derivatising agents. Is this correct?

Thanks again

Regards

Yes.