HPLC Analysis of Trifluoroacetic and Acetic Acid on Obelisc N Mixed-Mode HPLC Column

Trifluoroacetic acid (TFA) and acetic acid (AcOH) are very commonly used in organic chemistry. They were separated using an Obelisc N column which uses HILIC/anion-exchange. The mixed-mode of Obelisc N allows for better peak shape and retention of carboxylic acids. Sulfuric acid was used to enhance polar retention by suppressing ionization of the strong acid TFA.  


Column Obelisc N, 4.6x150 mm, 5 µm, 100A
Mobile Phase MeCN - 60%
Buffer H2SO4 - 0.05%
Flow Rate 1.0 ml/min
Detection UV, 210 nm


Class of Compounds  Acid, Hydrophilic, Ionizable
Analyzing Compounds Trifluoroacetic acid (TFA), Acetic acid (AcOH)

Application Analytes:

Acetic Acid
TFA (Trifluoroacetic Acid)