Empower Tip: QDa MS Data in Empower

In this tip, we return to the topic of working with QDa Data in Empower and we’ll learn about expected mass processing. Empower provides two ways to determine if a specified mass exists in a sample. You may be looking for a specific mass because it identifies a component or an impurity in the sample. In this example, we can use component-based expected mass processing.

Let’s see how it’s done!

Bring the Sample Set (or injections) into Review, Open and apply the Method Set, go to the Processing Method, and click the MS Expected Mass tab. The Component Name and Retention Time are automatically populated based on what was entered in the Components tab.

Select Component-based processing and enter the Expected Mass or Masses. Optionally you can include the Expected Intensities. In this example, the compound of interest has a molecular ion with a base peak of 621, a fragment ion with mass of 603, a sodium adduct ion with mass of 643 and isotopic ions with masses of 622 and 644. The Peak Separation has a default value of 1 Dalton and sets the range over which Empower looks for the expected mass. For example, for mass 621 the range would be 620.5 to 621.5. The expected intensity is a % of the base peak and, if the % is equal to or higher than the entered value, it is acceptable.

In the first sample, all expected masses are found and the expected intensities are acceptable.

In the second sample, some of the expected masses are not found and the expected intensities are below the value entered in the Processing Method, therefore, Empower flags the peak.

It’s that easy!