Description

LC method development typically involves a lot of trial and error. It occupies precious lab resources and can take a considerable amount of time.

Our Pro EZLC chromatogram modeler dramatically speeds up LC method development. Add analytes, test column chemistries, and optimize run conditions virtually and instantly—without needing to make a single injection. And it’s completely free to use.

Additional Resources

• Pro EZLC Chromatogram Modeler

Restek Recommended Tools & Parts

• Raptor Biphenyl LC Columns
• Raptor C18 LC Columns

Transcript

Method development typically involves a lot of trial and error. It occupies precious lab resources and can take a considerable amount of time.

Restek’s Pro EZLC chromatogram modeler is designed to dramatically speed up your method development. You can add analytes, test column chemistries, and optimize run conditions virtually and instantly—without needing to make a single injection. And it’s completely free to use.

When you first access the Pro EZLC modeler, you will start in the compounds tab. You can choose from specific libraries of the compounds that have been developed by the expert chromatographers here at Restek.

In this demonstration, we’re going to select the Drugs of Abuse library.

A table of compounds will now appear. You can select your specific compounds of interest by scrolling through the table and clicking on them. The compound row will turn blue when selected and can be unselected by clicking again. You can also use the search box above the table to find compounds by typing their name or CAS number.

As you add compounds, a blue box with a white check mark may appear in the compound row beside the CAS number. This indicates the compound is an isobar of another compound you have selected.

After you have selected your compounds of interest, you need to choose which column or phase you would like to model the compounds on. Click the drop-down menu to select a phase—here we’re selecting a Raptor Biphenyl column—and then click the Generate Model button.

An interactive, modeled chromatogram will appear on the right-hand side of the interface. Below the chromatogram are the run conditions, and a table of your selected analytes.

Our compound list includes five isobars, which we can view in the Available Isobars dropdown list below the modeled chromatogram. The resolution of all critical pairs is above the accepted value of 1.5, giving us an opportunity to shorten our model’s run time without sacrificing separation.

In the Conditions tab on the left, you can optimize your separation by choosing column dimensions, inputting any volume effects, changing your mobile phase, adjusting temperature, and editing your gradient program.

You also have the Optimize Gradient Slope button. This button will automatically calculate a new gradient to increase or decrease the resolution of the closest critical pair toward the target resolution. In our example, we’ll set the target resolution to 2 and click the button.

The results section at the bottom of the tab and the modeled chromatogram have updated automatically, showing a shorter run time. Our isobar resolution remains high, so we’ll click the button again.  We can continue to optimize by clicking the button until we’re pleased with the separation, or the button has greyed out. This indicates that no further refinements are available. Thanks to our optimizations, we’ve shortened our runtime by almost three minutes—and we did it in seconds without using an instrument.

Finally, we can add a re-equilibration step, which will get the column back to the starting conditions for the next run.

Once you’re satisfied with the simulated chromatogram and resolution values, you can name and save your model. This keeps it within your Restek account to reference later. You can also print it out for immediate use. Help is also available to ensure you get the most out of this robust tool.

Sign up for a free Restek account to access this powerful software and speed up your method development today.

If you have any questions or would like more information about the Pro EZLC chromatogram modeler, visit us at restek.com