Get Empowered: Empower CDS User Question | Tip #247, Calculating Peak Fronting

Welcome back to Get Empowered! In the last tip-of-the-week blog for Empower™ Chromatography Data System (CDS), we revisited our VLOG series showcasing Empower CDS as an important tool to implement Method Lifecycle Management (MLCM) and learned about determining your Method's Operable Design Regions (MODRS) with Empower CDS and DryLab®4 by the Molinár-Institute. (Episode #14 /Tip #246).

In this week's tip, we will answer an Empower CDS user question.

Q: Empower calculates peak tailing, however, how can I calculate peak fronting?

Great question. This can be done with a couple of simple Custom Fields.

Let's get started.

Step 1

The definition of USP Tailing is width @5% of peak height/(2 x front half of the peak). The front half of the peak is the time from width start point at 5% of peak height to retention time and reported as f@5% (figure 1).

Figure 1

Step 2

We can calculate the back half of the peak by subtracting the front half of the peak from the width@5% (figure 2).

Figure 2

Step 3

Using the USP Tailing formula, we could calculate fronting by the following: width @5% of peak height/(2 x back half of the peak) (figure 3).

Figure 3

Step 4

Alternatively we could use the symmetry calcution which is back half/front half and flip that around to be front half/back half (figure 4).

Figure 4

Step 5

If the value is greater than 1, the peak is fronted. Here is an example chromatogram with all the fields (figure 5).

Figure 5

It's that easy!

Final Note: This can be done with either the Pro or QuickStart interface.

Please rate this Empower Tip of the Week

Next week in Tip #248: We will learn how to create an HPLC column library in Empower CDS.

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