Stationary-phase characterization is traditionally performed with a small set of probe compounds selected to address specific retention mechanisms. With the limited number of chemistries exhibited by the probe compounds, however, no single characterization method will be able to address every situation completely. Using a more complex sample with a greater number of probe compounds has generally not been feasible due to the onerous task of managing extremely large amounts of data.
For many years and with varying degrees of success, automated systems for method development have been available and have been used to resolve the often conflicting goals of achieving robustness, good resolution, and quick run times. Modern approaches use a combined strategy of method screening and optimization of variables such as gradient and temperature. Previously, upfront screening of column, buffer, and solvent was often impractical due to the difficulty in tracking peaks from run to run—especially if MS detection was not used.
A new system for automated method development includes several key technologies that enable its application to the task of column characterization such as instrument control, MS peak matching, and project management.
In this tutorial, Advanced Chemistry Development’s AutoChrom is applied to the task of rigorous column characterization. AutoChrom has the ability to control the instrument, conduct MS-based peak tracking, and provides overall project management to analyze a large, diverse set of compounds, executing column, buffer, and mobile-phase screening to compare stationary-phase selectivity for several hundred analytes with varying solvents and buffers.
Using software to control the instrument and data system, AutoChrom automatically configures the system and creates complex injection sequences that reduce the amount of manual effort required by the user. Modern instrumentation such as column switchers and additional valves provide increased versatility in experiments.