The development and optimization of liquid chromatography (LC) separations can be time-consuming and costly, often requiring a number of steps, including literature research, column selection, method scouting, method development, and method optimization. In an effort to eliminate these steps, an instrument-free, software modeling tool was developed that gives users the ability to select compounds from a database and instantly model a separation on different column phases.
Optimization of the chromatogram model can be performed while maintaining critical pair separations by adjusting parameters, such as instrument/system effects (e.g., dwell volume and extra column volume); mobile phase preferences; number of gradient steps; and more. The first version contains an initial library of approximately 250 Drugs of Abuse (DoA) with plans to expand by adding additional compounds and more utility.
The initial platform build was completed by validation on a single column dimension by monitoring a set of compounds, collecting retention times using a fast/slow gradient; 30°C/60°C temperature points; and acetonitrile/ methanol mobile phases. The modeler was evaluated over four increasingly more complex stages of verification. In the final, most complex stage, new compounds not previously part of the initial DoA library were added and then compared by testing two different column dimensions, two different columns lengths, two different mobile phases, two different stationary phases, three different gradients programs, and three different temperatures against modeled retention time values. Some additional data outside of these runs were also collected for the development of a semi-empirical correction factor that was used to improve modeling accuracy and test the viability of adding future compounds to existing libraries.
To represent a typical MRM window, an acceptance criteria of +/- 15 seconds was. In the most complex portion of the verification, 704 retention time data points were collected in total for the 25 compounds used in the evaluation. Only 13 data points exceeded the +/- 15 second window with no compounds missing acceptance criteria by more than five seconds. The overall pass rate was 98.2%.
The modeler delivers a fast, no-cost starting point for LC method developers, novice, and expert, who either lack the expertise, or the time, to develop or optimize separations quickly and accurately. This novel, virtual method development software can improve turnaround time, increase throughput to existing methods, and offer an on-demand consultative user experience.
