Triethylamine at pH2.5

[WK]

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

[Basil]

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.

[syx]

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

[WK]

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

[fatBrain]

For minimizing tailing, possibly.