Exploring pH to increase productivity and yield in crude purification
Designed to address analytical and preparative chromatography under low, neutral and high pH, in combination with also aggressive inorganic buffers and/or elevated temperatures, the new EternityXT UHPLC and HPLC family of columns are the next generation of AkzoNobel’s pre-packed columns for improved efficiency and increased flexibility in the laboratory. These columns are provided in a wide range of particle sizes, between 1.8µm and 10µm, and analytical to preparative dimensions for fast turnaround, easy method transfer and seamless scale-up from the discovery stage to manufacturing.
The issue of loadability under certain chromatographic conditions is critical when drug companies need to isolate material for characterisation, toxicity studies and also manufacturing. The amount of sample that can be loaded onto the column to obtain the key substance at a required purity, translates into a productivity and yield, which in turn will influence costs and determining the feasibility of a project.
The example shown in the figure illustrates two preparative chromatograms for the purification of of a monobase, the alkaloid tryptamine, from an impurity that elutes ahead of the compound of interest. On the left hand side, the chromatographic result shows the sample is loaded onto the column equilibrated at pH of 2.5. Here the impurity elutes under the main amine peak affecting productivity and yield. On the other hand, the chromatographic result shown on the right hand side indicates that as amines are better retained under basic conditions, it is possible to separate the impurity that elutes ahead of the main peak and therefore obtain better purification results. These results exemplify the benefits of exploring pH as an option when carrying out preparative chromatography and choosing a stationary phase material that can withstand a wide range of pH.
