OBJECTIVE or GOAL
Welcome back to Get Empowered! In the last Empower tip-of-the-week, we learned how to display MS spectra from a particular MS scan along with UV spectra in the Mass Analysis window.
Today we will 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 desired component or an impurity in the sample. In this example we will look at 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.
- Select Component-based processing and enter the Expected Mass or Masses along with the Expected Intensities. In this case 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 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 this example all expected masses are found and the expected intensities are acceptable.
- In this example 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!
- This procedure can be followed using the QuickStart or Pro interface.
- For information on Empower training please go to www.waters.com/training and select Empower from the Topic menu