Configure blank/cut subtraction in ²D

All settings are done in the processing method under General > Signals node, Blank/Cut Subtraction ²D tab. Follow the procedures below to configure each subtraction type.

Preparations

  • To be able to carry out the procedure as described, you need the privilege Processing Method > Edit signal parameters . Privileges are configured in the Control Panel.

  • If the project enforces method approval, the method status must be Generic. For details, see Method Approval.

Subtract specific cut from other cuts within ²D signal

  1. Under Subtraction type, select Cut subtraction ²D. Make the following changes in the Cut subtraction ²D section.

  2. Under Cut subtraction applied on, choose for which injections you want to subtract a blank.

  3. Under Blank Cut #, enter the number of the cut to be subtracted.

  4. Select whether the defined cut number shall be read from the current injection or from a specific injection. Click Browse to select a specific injection.

    If you use a specific cut from an external injection, you must have acquired that injection using the same ²D detector (same signal name or same signal description) as for the samples.

  5. Check the general settings in the Settings for blank/cut subtraction ²D section (see below).

Subtract a blank's ²D signal

  1. Under Subtraction type, select Blank subtraction ²D. Make the following changes in the Blank subtraction ²D section.

  2. To use the identical settings as for the first dimension: Select the Use same parameters as (¹D) Blank subtraction check box. To use different settings, keep the check box cleared. For details on blank subtraction in the first dimension, see Configure processing method for blank subtraction .

  3. Under Blank subtraction applied on, choose for which injections you want to subtract a blank.

  4. Select which blanks you want to use. To select a specific blank, click Browse.

    Ensure that the relevant blank or blanks contain matching ²D cut chromatograms. Matching ²D cut chromatograms means that:

    • the sample run and the blank run have been acquired using the same acquisition method and contain the same number of cuts

    • the cuts originate from the same ²D signal (same signal name or same signal description)

    • the cuts have the same begin time and end time in their ¹D signals (± 0.01 min, which is the time accuracy in the drivers acquisition method)

    All ²D cut chromatograms from the sample run must have matching cuts in the blank run. The blank signal is then subtracted the same way as in a 1D chromatogram.

  5. Check the general settings in the Settings for blank/cut subtraction ²D section (see below).

General settings for blank or cut subtraction ²D

  1. If required, select that blanks will also be subtracted if data rates are different.

    If a blank and a sample have different data rates, the data rate of the blank is adjusted. Data points are removed or created by interpolation (MS signals: linear interpolation; non-MS signals: spline interpolation). A corresponding warning is shown in the injection tree.

    Independent of the status of this check box, if a blank and a sample have different run times, blank subtraction is only performed on the common time range. A corresponding warning is shown in the injection tree. The new signal will contain corrected and not corrected data points.

  2. Only relevant for non-MS signals (with MS signals, signal name and signal description are the same): Select a suitable signal matching option. By default, the signal of a blank run will be subtracted if its name matches the signal name of the sample.

    The signal name is the short name of a detector, for example, DAD2A. For non-MS signals, the signal description typically includes more details, for example, DAD2A, Sig=235,10 Ref=550,60. By matching the one or the other, you define how flexible the processing method can be used with different acquisition methods.

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