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How to determine if a specified mass exists in a sample - WKB60865

Article number: 60865

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!

ENVIRONMENT

  • Empower

PROCEDURE

  1. 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.

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  1. 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.

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  1. In this example all expected masses are found and the expected intensities are acceptable.

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  1. 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

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It’s that easy!

 

ADDITIONAL INFORMATION

Final Notes

  • 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

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