Thermo Scientific TSQ 8000, Руководство пользователя

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4
Creating a Method
Creating a MS Instrument Method
Thermo Scientific TSQ 8000 Evo User Guide 57
iv. Use the Neutral Loss Mass column when you want to perform a neutral loss
scan. Enter the mass of the target precursor ion in this column. The scan mass
range must be at least 2.5 amu wide and must begin at 1 + the precursor ion
mass.
v. In the Collision Energy column, enter the collision energy (for SRM methods)
in eV. The collision of a precursor ion with the collision gas at a particular energy
fragments the precursor ions into product ions. By varying the collision energy, a
single precursor ion can be fragmented into several product ions. An SRM
transition is defined by a precursor ion being fragmented into a particular
product ion mass using a certain collision energy. The Collision Energy column
is unusable unless you define a precursor and product ion mass.
vi. In SIM or SRM mode, use the Dwell or Scan Times column to define the
amount of time (in seconds) that the MS will look at your SIM ion mass or your
SRM product ion mass. If you are in full-scan mode, the
Dwell or Scan Times
column determines the amount of time to scan across the designated range. Set
this value to have 5–20 scans across your GC peak. If you have too few scans, the
GC peak area is inaccurate. If you have too many scans, the MS signal becomes
less precise. This column must be set to a value between 0.0005 and 5 s for SRM
and SIM methods. The default is 0.2 s. For full scan methods, the minimum
scan time depends on the mass range so that the scan rate does not exceed
13,000 amu/s.
vii. Use the Tune File Name to select a tune file to be used for this scan. Select the
autotune file you created in Chapter 3, “Tuning,” . If you wish to use the same
tune file for multiple scans, you can fill down this column by right-clicking on a
tune file name.
viii. (Optional) Use the Scan Name column to enter a description of the scan. You
may use the name as a label to indicate the compound used with the scan.
ix. Use the SIM Widths column to set the width range of the SIM window. The
range of values can be between 0.01 and 10. The default is 1 amu, which means
the MS will collect all the ions from your SIM mass ±0.5 amu.
Note The system controls the collision gas so it will be ready when an
MS/MS scan is requested.
Note Selecting a tune file to open without a date-time stamp opens the most
recent tune of the tune type selected. To use a specific tune file, select a tune
file of that prefix with the date-time stamp that you want.
Tip Use a tune file without the date-time stamp to create your method.
Note Scan Name, SIM Widths, Data Type, and Q1 Resolution columns are
not shown by default. To view them, right-click one of the column headers to
pull up the menu to display the hidden columns