Active hydrogens in PEG columns?

[Tremenda]

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

[chromatographer1]

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

[Tremenda]

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?

[chromatographer1]

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

[Tremenda]

And just to make sure:

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

Thanks again

Regards

[chromatographer1]

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

[Consumer Products Guy]

And just to make sure:

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

Thanks again

Regards

Yes.