In this video, Dwight Stoll, Professor of Chemistry at Gustavus Adolphus College, explores the identification of coeluting/hidden compounds using liquid chromatography (LC) and highlights the key benefits of two-dimensional liquid chromatography (2D-LC) compared to one-dimensional liquid chromatography (1D-LC). Stoll also outlines the techniques used for improving HPLC resolution, the limitations of conventional 1D-LC, and reveals his hopes for the future.