Chromatography Forum

Posted: **Mon Oct 25, 2004 4:03 pm**

I've seen a method where someone describes mobile phase of:
acetonitrile/water/triethylamine (11:88:1 v/v) at pH2.5?
- to separate basic compounds.
I would have thought this would have a high pH?
Surely there would be no benefit in using triethylamine if they then titrated to pH2.5 with an acid?
Anyone guess what they are doing?
Thanks

Posted: **Mon Oct 25, 2004 4:19 pm**

Hi WK,

I've used this kind of mobil phase and in this situation triethylamine is working mainly as an ion par reagent and also reduces tailing efect if you work with basic compounds.

Posted: **Tue Oct 26, 2004 12:47 am**

I usually use a mixture of KH2PO4 20 mM, TEA and finally adjusted with phosphoric acid to pH 2.5.

Posted: **Tue Oct 26, 2004 7:32 am**

Thanks for the information.
I shall try it out today with any luck and advise.

Posted: **Wed Oct 27, 2004 6:59 pm**

For minimizing tailing, possibly.

Chromatography Forum

Triethylamine at pH2.5

Triethylamine at pH2.5