Analysis of organic acids using a Mixed-Mode LC Column and an ACQUITY QDa Mass Detector

Organic acids (OA) are an important group of compounds for many industries including food and beverages, animal feeds, and human health. The analysis of OA is commonly carried out by liquid chromatography (LC) either by anion-exchange, reversed-phase or mixed-mode separation. Anion-exchange chromatography of OA has acceptable resolution, but run times are usually long. The reversed-phase separation has limited resolution for OA. Mixed-mode separations have greater resolution for OA than the reversed-phase LC, and the run times are often shorter than those in anion-exchange chromatography. The detection techniques that are often used in the analysis of OA include conductivity, UV/Vis, and differential refractive index (DRI). These detection techniques are not selective for OA, which makes OA analysis susceptible to interference from co-eluting compounds.

In this application note, Water Corporation describes the development of an analytical solution based on the Waters Atlantis Premier C18 AX Column and the Waters ACQUITY™ QDa Mass Detector to address the major issues in OA analysis. The Atlantis BEH C18 AX Column offers excellent retention and resolution for OA analysis. The ACQUITY QDa Mass Detector is a highly selective detector for OA. The combination of these two technologies provides an excellent solution to the issues in the challenging OA analysis.