HPLC Separation of Carboxylic Acids Using Porous Graphitized Carbon and Gradient Elution with Formic Acid Solutions

A method is proposed for the HPLC separation of a mixture of carboxylic acids on a porous graphitized Hypercarb adsorbent under the conditions of gradient elution with formic acid solutions. The analytes were detected using a single quadrupole mass spectrometer. The stepwise gradient of formic acid without an addition of an organic solvent made it possible to achieve good resolution of the analyte peaks and decrease the limits of detection by a factor of 4.4–17.8 compared to their separation with 0.1% formic acid under isocratic conditions. The effect of methanol on the separation of analytes is less pronounced.