Separation of pharmaceutically active compounds by multimodal chromatography with ultraviolet detection

This research focused on pharmaceutically active ingredients analyzed by mixed-mode liquid chromatography. For this purpose, 16 analytes were chosen with acidic, basic, or neutral properties that were analyzed under different conditions. These analytes play an important role in the pharmaceutical industry and improved separation will make drug control more efficient. Mixed-mode chromatography is becoming an increasingly popular method for the analysis of diverse compounds due to the process being based on the combination of two or more interaction modes. The use of the mixed-mode stationary phase can be especially beneficial for the development of new drugs which may have specific physical and chemical properties. Data obtained from measurements on three different mixed-mode columns (WAX-1, WCX-1, and HILIC-1) were used to construct the plots illustrating the relationship between the retention factors of the analytes and organic modifier content, buffer concentration, and buffer pH. As a result of the known chemical structures of the analyzed molecules and analysis of these plots, possible interaction mechanisms in various chromatographic systems were proposed. Conclusions enabled suggestions for the optimization of chromatographic conditions to be made as well as the improved selection of the stationary phase for different types of analytes.