Tip #116: Working with ACQUITY QDa MS data in Empower Software (Part 16)

Welcome back to Get Empowered! In the last Empower tip-of-the-week post for Empower Chromatography Data Software, we learned how to display MS spectra from a particular MS scan along with UV spectra in the Mass Analysis window (Tip  #115).

Working with ACQUITY QDa MS data in Empower:

• #100: How to view the base mass and mass spectra for the peaks in a chromatogram
• #101: How to work with 2D ACQUITY QDa MS data
• #103: Viewing different spectral views in the Mass Analysis window
• #104: Extracting chromatograms and spectra while working in the Mass Analysis window
• #105: Why it is important to align chromatograms when collecting data from both a PDA and a ACQUITY QDa mass detector
• #106: How to optimize sensitivity by extracting a single mass rather than working with a TIC plot
• #107: How to smooth the chromatogram using the Processing Method
• #108: How to smooth the chromatogram using a Derived Channel in the Method Set
• #109: How to track peaks using the ACQUITY QDa mass detector
• #110: Using CODA (component detection algorithm) as a tool when scouting for peaks
• #111: Using MS 3D subtraction to remove background interference
• #112: How to create a MS Spectra Library from data collected with the ACQUITY QDa mass detector
• #113: How to use a MS Spectra Library to identify spectra from unknown peaks via the manual technique
• #114: How to use a MS Spectra Library to identify spectra from unknown peaks via the automated technique
• #115: How to display MS spectra from a particular MS scan along with UV spectra in the Mass Analysis window

In this week’s tip, 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. Today, we will look at ‘component-based’ Expected Mass Processing.

Let’s get started.

Step 1

Bring the Sample Set (or injections) into Review and open and apply the Method Set. Go to the Processing Method and click the ‘MS Expected Mass’ tab (figure 1).

Figure 1

Step 2

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 (figure 2).

Figure 2

Step 3

In this example, all expected masses are ‘found’ and the expected intensities are ‘acceptable’ (figure 3).

Figure 3

Step 4

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 (figure 4).

Figure 4

It’s that easy!

Final notes:

• This procedure can be followed using the QuickStart or Pro interface.
• ACQUITY QDa Mass Detector is compatible with the Alliance HPLC system.

Please rate this Empower Tip of the Week

Next week in Empower Tip #117– We will continue this series on working with ACQUITY QDa MS data in Empower (Part 17).

REGISTER for [inform] 2019 – Waters Informatics Users’ Conference
May 20-23, 2019 | Austin, Texas| Learn More

More Resources:

• Get the latest Empower projects, options, and more. Check out the New Waters Marketplace.
• Want to learn more? Check out our Empower training courses and eLearning.
• Build your technical skills and professional network. Share, ask, and interact with peers from around the globe in dynamic discussions by joining our Informatics Community Forum.
• Empower is the first cloud-deployable, compliance-ready, enterprise chromatography data software – Learn more about Empower Cloud