Separation of Aromatic Carboxylic Acids by Mixed-Mode HPLC

This application on Primesep B demonstrates the easy tuning of methods developed on Primesep columns. Aromatic carboxylic acids are easily separated and retention times can be shifted by simply changing the mobile phase modifier. Switching between formic, trifluoroacetic acid, phosphoric, and perchloric acids in a constant ratio of acetonitrile and water changes elution times, which is not possible on reversed-phase C18 columns. This effect is due to both the change in mobile phase pH and the counter ion that interacts with the basic functional group on the column. Mass spec compatible mobile phases of water, acetonitrile (MeCN, ACN) and, formic or trifluoracetic acid (TFA) can be chosen for LC/MS applications.


Column Primesep B, 4.6x150 mm, 5 µm, 100A
Mobile Phase MeCN
Buffer TFA, H3PO4, HClO4, FA
Flow Rate 1.0 ml/min
Detection UV, 250 nm


Class of Compounds Acid, Hydrophilic, Ionizable, Vitamin, Supplements
Analyzing Compounds Carboxylic Acids
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Application Analytes:
Aromatic Acids
Carboxylic Acids

Application Detection:
UV Detection