The Targeted Mass Trigger filter, which triggers the next scan only if the system detects a product ion in the list and if all other conditions that are selected are met. If the next scan has an MSn level of n + 1, the next scan is performed on the top N most abundant ions in the spectrum (not necessarily the product ion in the list). If the next scan has an MSn level of n, the next scan is performed on the same precursor ion, but you usually choose a different fragmentation technique. For example, if you perform a scan with HCD fragmentation and detect a product ion in the list, you can trigger a scan on the same precursor ion but with ETD fragmentation, which provides different product ions. You can also import the settings of the mass list table from (or export them to) a .csv, a .txt, or an .xml file.
The following flowchart shows the Targeted Mass Trigger filter.
The following table describes the parameters in the Targeted Mass Trigger Properties pane.
Parameter | Description |
|---|---|
| |
Mass List Table | |
Compound | (Optional) Specify the name of the ion. |
m/z | (Available when the Mass List Type is set to "m/z".) Specify the m/z of the ion on which the MS performs the scan. When Formula is defined, the m/z is calculated automatically. The accepted m/z range will vary depending on analyzer used (Quadrupole or Ion Trap) and HMRn+ license activation. |
Adduct | (Available when the Mass list Type is set to "m/z & z".) (Required when Formula is used) Define the adduct to be used for the defined compound formula or peptide sequence. |
z | (Available when the Mass List Type is set to "m/z &z".) (Optional in some cases) Specify the expected charge state of the precursor ion, which is used to determine collision energy or reaction times (when applicable). When Formula is defined, specify the expected charge state of the precursor ion. This is used to calculate the m/z. Range: 0–24; default: 1 |
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Mass Tolerance | Defines how close a measured mass must be to the mass in the mass list to be considered the same mass.
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Low | The low side of the mass tolerance width window. The low value defines how far below the reference mass the window starts on the low-mass side of the reference peak. Range (ppm): 0.01–1,000,000; default: 25 |
High | The high side of the mass tolerance width window. The high value defines how far above the reference mass the mass tolerance window extends on the high-mass side of the reference peak. Range (ppm): 0.01–1,000,000; default: 25 |
Use Group IDs | When checked, the elements in the list can be grouped by a unique identifier, 'Group ID'. Groups are subsets of the whole list. When determining the inclusion conditions, groups are considered independently of each other. Default: Deselected |
Trigger Only with Detection of at Least N Ions from the List | Trigger Only with Detection of at Least N Ions from the List. Default: Deselected When selected, the following option becomes available: n: Range: 1–1,000,000; default: 1 |
Only Ion(s) Within Top N Most Intense | Select to enable only ion(s) within Top N most intense. Default: Deselected When selected, the following option becomes available: n: Range: 1–1,000,000; default: 10 |
Only Ion(s) Above the Threshold (Relative Intensity, %) | Select to enable only ion(s) above the threshold (Relative Intensity, %). Default: Deselected When selected, the following option becomes available: Range: 1–100; default: 30 |
Trigger Type | When 'Continue Trigger' is set and the conditions of the trigger are met, the execution of this branch will continue. If the conditions are not met, the execution of this branch is terminated. Alternatively, when 'Block Trigger' is set and the conditions of this trigger met, the execution of the branch is terminated. If the conditions are not met, the execution of this branch is continued. |