Thermo Scientific TSQ 8000, User Manual

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4
Creating a Method
Creating a MS Instrument Method
Thermo Scientific TSQ 8000 Evo User Guide 71
– The Lowest Dwell Time is the actual lowest dwell time achieved by the
method settings. When the Optimize check box is selected, if the actual
lowest dwell time is considerably lower than the requested dwell time, then
the minimum window has been reached, and if the actual lowest dwell time
is considerably higher than the requested dwell time, then the requested
window has been reached.
iii. Under Peak Width , you can change the minimum baseline peak width and
desired scans per peak. These values are used to calculate the SRM/SIM Time.
The minimum baseline peak width should be set roughly to the shortest
chromatographic peak time in your analysis.
iv. Under SRM Resolution , check the Set Resolution for Each Unique Transition
Scan checkbox if you want to adjust the Precursor (Q1) Resolution or Product
(Q3) Resolution for individual analytes. If this box is not checked, the settings
apply to all compounds in the method.
– Use the Precursor (Q1) Resolution column to set the full width at 50%
(FWHM) of the precursor mass for SRM scans. The combo-box options are
Normal, Wide (1.5 FWHM) , or Widest (2.5 FWHM) for each scan after a
precursor mass has been entered. The default setting is Normal, which uses
the tuned resolution values from the tune file specified in the
Tune File
Name column. Opening the precursor peak width increases the ion signal
into the collision cell, which might improve the sensitivity of your method;
however, it may also increase the background noise level.
– Use the Product (Q3) Resolution column to set the full width at 50%
(FWHM) of the product mass for SRM scans. The combo box options are
Normal , Wide (1.5 FWHM) , or Widest (2.5 FWHM ) for each scan after a
product mass has been entered. If the product mass is removed from a scan
to run a SIM or FS scan event, the Product (Q3) Resolution column returns
to the default value of Normal, which uses the tuned peak width at 10% or
50% as specified in the Tune File Name column. Selecting Wide (1.5
FWHM) or Widest (2.5 FWHM) increases the product ion peak width to
1.5 and 2.5 amu FWHM respectively, resulting in an increase of ions
reaching the detector. The increase in ions at the detector may improve the
sensitivity of your method; however, it may also increase the background
noise level, as well as introduce isotopic interference from +/- 1 amu ions.
Note To achieve the highest transition speeds capable on the instrument,
the resolution of all transitions must be set to Wide or Widest for both
Q1 and Q3 resolution.
Note When the window optimizer is activated the Window , Pre-width , and
Post-width columns are no longer available in the compound list editor. If your
method is linked to a file or imported from a file with values in these columns, the
values are stored in memory and can be recovered by deactivating the window
optimizer.