Chromatography Forum

hi there
according to Dionex acclaim trinity p1 can use two type of buffer which are ammonium acetate and phosphate( potassium or sodium) but i read articles they often used ammonium acetate buffer or ammonium formate. Why does they use phosphate buffer? i am separating a mixed organic acid so Which buffer can i choose?
please help me.

Phosphate has a lower UV cutoff, but is non-volatile, and so incompatible with mass spec. Formate and acetate are volatile, but have a higher UV cutoff and so are problematic with UV detection down around 210 nm or below.

As the developing chemist of this column, I confirm that Acclaim Trinity P1 is compatile with both volatile buffer (ammonium aceate and ammonium format) and non-volatile buffer such as sodium or potassium phosphate.
Depending on the analyte of interest and the detector method, a suitable buffer can be selected. For example, if the objective is to analyze drug counterions, such as chline, Na+, K+, Cl-, MSA, .... by HPLC, and the detection method is CAD or ELSD, the mobile phase needs to be volatile such as ammnoium acetate. On the other hand, if you want to determine both drug and the counterion, for example, nicotine tartrate or nicotine salicylate at the same time, UV detection should be selected for good linearity and sensitivity because the analytes of interest have strong chromophore. This way, a phosphate buffer can be used.
I have examples of applications for both buffers. If you have specific separation challenges and such application could benefit from the Acclaim Trinity column, please send your question or request to my email: xiaodong.liu@dionex.com.