ProEZGC Chromatogram Modeler – there is much more to the program than just the Welcome Screen

When you log into the ProEZGC Chromatogram Modeler software, you will see the screen below, which is what I refer to as the Welcome Screen. This is the starting point for all, and unfortunately all some customers will think there is to the ProEZGC software.

For those of you who have used ProEZGC, you know that all you need to do is to add a compound name or CAS# into the box titled Search by Name or CAS# to get started (remember, only one compound name or CAS# per line).

For this post, I would like you all to see that there is more to ProEZGC than just the screen above and the screen below. In this example, I typed in the names of four common compounds/solvents and clicked the blue Solve button.

After reviewing the search results for all stationary phases, I selected the results for the Rtx-502.2 column.

I then clicked on the Conditions tab (the dark blue tab between Compounds and My EZGC) and were presented with a new page (see below).

From this page you can choose different dimensions of the same column (in this case, the Rtx-502.2), modify the GC oven temperature program, and if you select Custom at the bottom of the page in the Results section, you can change carrier gas flow rates (see screen below) and a few other parameters.

Notice the blue arrow under Control Parameters and to the right of Column Flow in the screen above?  So what does the arrow represent? It allows you to change the remaining top parameters (Column Flow, Average Velocity, Holdup Time and/or Inlet Pressure - whichever parameters the arrow is not pointing to) in the Control Parameters section without affecting the parameter the arrow is pointing to.  See example below.  Notice that I moved the arrow from Column Flow to Average Velocity by double-clicking in the empty space to the left of 39.70 cm/sec.

By keeping the Average Velocity the same and changing the length of the capillary column, notice how the Column Flow (carrier gas flow rate value) increases, as do the Holdup Time* and Inlet Pressure.

• Holdup Time is the time it takes for a non-retained compound to travel through the column.

One last comment; under Results you have three selections to pick from.  The default is Speed, and for most analysis this is fine.  As the name implies, when this button is selected, analysis times are minimized.  I showed you all how to select the Custom button for the most control of carrier gas parameters.  My favorite button, however, is Efficiency.  Analysis times may be a little longer, but separations are usually improved, and that is my goal, to show a customer maximum compound separation with reasonable analysis times.

If you have never seen or tried changing conditions by selecting the Conditions tab, I encourage you to do so. To learn more about Pro EZGC, visit the Help Section and the Restek Video Library. Let us know if you have any questions.