A Standardized 2D-LC Screening Platform for Peak Purity Determination in Pharmaceutical Analysis

The determination of peak purity in chromatographic methods used in pharmaceutical analysis is a vital step in evaluating specificity to ensure the safe production of medicines. Current peak purity assessments accomplished through diode array detectors (DAD) and mass spectrometry (MS) have some challenges that could lead to misinterpreted purity values when the sample under evaluation is susceptible to the limitations of these techniques. Two-dimensional liquid chromatography (2D-LC) has the ability to resolve difficult-toseparate mixtures, and has been widely adapted to biological compounds. This study proposes a 2D-LC screening method as a means of determining peak purity of active pharmaceutical ingredients (API) and their related substances. Results confirm that the 2D-LC screen was successful in separating API/impurity mixtures in all 10 test cases studied. Selection of screening conditions including mobile phase choice and column selection is discussed along with the effectiveness and idiosyncrasies of peak purity analysis by 2D-LC.