Triethylamine TEA is an organic base and sometimes used in some HPLC methods to adjust the mobile phase pH.

Get improved peak shape and selectivity when separating simple sugars with TEA and Cogent TYPE-C™ columns as long as the concentration of TEA does not exceed 0.1%. This improved peak shape is thought to be due at least partly to an ion-pairing mechanism of the TEA on the surface of the stationary phase material.

Alternatively, ammonium acetate, a near-neutral pH is obtained with this additive, so it is a popular choice for keeping most organic acids ionized, which is generally preferred for ANP methods. In addition, it is LC-MS compatible, in contrast to a near neutral pH phosphate buffer.

Our research has indicated that TEA may be difficult to remove from columns once introduced therefore if TEA is to be used with a column, the column should be dedicated to methods with TEA. The same research has shown though that TEA can be used to obtain advantageous changes in chromatography in under certain conditions.