Development of an achiral supercritical fluid chromatography method with ultraviolet absorbance and mass spectrometric detection for impurity profiling of drug candidates. Part I: Optimization of mobile phase composition

In a second step, we investigated the effects of ammonium acetate concentration (between 0 and 25 mM in the methanol co-solvent) on retention and peak efficiency. Two types of silica supports were tested by working with ACQUITY UPC2 HSS C18 SB and BEH columns. 20 mM ammonium acetate in methanol with 2% water was finally selected as the best co-solvent composition.