Acetonitrile shortage: Use of isopropanol as an alternative elution system for ultra/high performance liquid chromatography

Acetonitrile is a choice of solvent for almost all chromatographic separations. In recent years, researchers around the globe faced acetonitrile shortage that affected routine analytical operations. Researchers tried to counter this shortage by applying many innovative solutions, including using ultra performance liquid chromatography (UPLC) columns that are shorter and smaller in diameter than traditional high performance liquid chromatography (HPLC) columns, thus significantly decreasing the volume of eluent required. Although utilizing UPLC in place of HPLC can alleviate the solvent demand to some extent, acetonitrile is generally thought of as the solvent of choice due to its versatility. In the following communication, we describe an alternative eluent system that uses isopropanol in place of acetonitrile as an organic modifier for routine chromatographic separations. We report here the development of an isopropanol based UPLC protocol for G5 PAMAM dendrimer based conjugates that was transferred to semi-preparative scale to purify functionalized forms of the dendrimer (50 mg).