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, 4.6×150 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


Application Column

Primesep B

The Primesep family of mixed-mode columns offers a wide variety of stationary phases, boasting unprecedented selectivity in the separation of a broad array of chemical compounds across multiple applications. Corresponding Primesep guard columns, available with all stationary phases, do not require holders. SIELC provides a method development service available to all customers. Inquire about our specially-tailored custom LC-phases for specific separations.

Select options
Application Analytes:
Aromatic Acids
Carboxylic Acids

Application Detection:
UV Detection
SIELC Technologies usually develops more than one method for each compound. Therefore, this particular method may not be the best available method from our portfolio for your specific application. Before you decide to implement this method in your research, please send us an email to so we can ensure you get optimal results for your compound/s of interest.