Create a sequence for mass-based fraction collection (MBFC)
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Create a sequence for mass-based fraction collection (MBFC)

To create a sequence for MBFC, you first have to configure your instruments and the acquisition method in OpenLab CDS.

Configure instruments

Your instrument must contain a Fraction collector (FC) and a Mass Detector (MSD) module.

  • MSD: Check the Fraction collection enabled option to access the Mass-based fraction collection parameters section in the acquisition method.

  • FC: The MSD must be listed in Peak Detectors section (detected automatically).

Configure acquisition method

You have to configure two parts of the method to support MBFC:

  • Mass detector (MSD)

  • Fraction collector

Configure Mass detector (MSD)

  1. Select the Advanced Acquire section.

    If you have selected the Fraction collection enabled option when configuring the instrument, the Mass-based fraction collection parameters section is then displayed.

  2. Define the compounds to be considered to trigger fraction collection.

  3. Click to add a target compound(s).

  4. Define the Compound name and the Monoisotopic mass or the Compound formula.
    If you define a formula, OpenLab CDS calculate the Monoisotopic automatically.

  5. Select Adducts ions and the Charge State.
    Ions will interact with the neutral molecule in the ionization source to create the ion that will be tracked by the Mass detector to trigger a fraction.
    You can select one or several adducts per compound.
    OpenLab CDS sets Positive or Negative automatically in the Polarity column according to the selected adduct.

The Fraction collection peak trigger column propose five options (A, B, C, D , NOT). These options correspond to the Fraction Collector configured in the fraction collector part of the method.

You cannot edit the m/z column. It corresponds to the mass / charge that the MSD detects. Value is calculated with m= [monoisotopic mass + adduct mass] and z= charge of the ion generated.

In the Mass-based fraction collection parameters table, you define:

  • the MSD parameters values used by the mass detector to ionize and detect the ions (fragmentor voltage, detector gain factor, dwell time),

  • the Fraction target mass column among three values T1, T2 and T3.
    Those three values correspond to three sequence columns displayed for a MBFC instrument: SQ: T1 fraction target mass 1 to SQ: T3 fraction target mass 3. You have the option to define target masses (monoisotopic masses) to be used instead of the ones defined in the method during the sample acquisition. This allows you to override method target masses by keeping the ionization parameters, adducts and charges and MSD parameters defined in the method by the value defined in corresponding Fraction target mass column of the sequence.

Configure Fraction Collector

The Fraction collector interface supports both UV and Mass based fraction collection.

To configure the Fraction collector:

  1. Select Enabled to activate Fraction collection (common for both UV and MS).

  2. Select the MS tab of the table.

  3. Fill out the corresponding fields in the table.

    • Use: Check as many signals as expected.

    • Peak Detector: Select the MSD module.

    • Used Signal: Select the signals configured in the Mass-based fraction collection parameters table for the Mass detector (A, B, C, D, NOT in Use Signal)

    • Peak Detection Mode: Select the integration parameter used to detect a peak and assign a value in the corresponding field (ex : threshold). You can define graphically the value from the Fraction preview section by using an already acquired chromatogram as template.

In the Trigger Combinations section, you define the conditions for peaks detected in both MS and UV detectors.

In the Advanced section, you can configure the delays (time or volume) to be applied when collecting a fraction. In case of MBFC, you cannot use delay volume, only delay time. Select either Use time and define a time in seconds or As calibrated (Time)

  • As calibrated (Time) uses the delay time computed by the delay calibration tool that is stored in the Fraction collector firmware

  • As calibrated (Time) can be used only if delay calibration was done with an acquisition method similar to the current one (same Main pump flow, Make-up pump flow, Split rate, Delay Coil).

Other options (Use Volume, As calibrated) are dedicated to UV and cannot be used for MBFC.

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