PerkinElmer TORION T-9, User Manual

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Target Library Editor . 157
Target List Setup Tab
The Target List Setup is a subset library used to target compounds of particular interest to you. It
is different from the unknown library because it contains specific information that is influenced by
some of the instrument settings.
Mass List
The Mass List table shows the specific ions that are associated with each compound in the target
list. The following image shows the masses for Acetone.
Normally the tallest mass peak is designated as the
Main
ion and has an
Intensity
of 100. Each of
the other masses has an Intensity that is some percentage of the parent peak. For example the
second mass of Acetone 58 has an expected intensity that is 32% of the parent peak. The
Confidence is an absolute value. So the Confidence level for the 58 mass is 50. This allows the 58
mass to vary from 25% of the parent peak to 125% of the parent peak and still be acceptable.
There are three options for the
Type column. They are Main , Necessary, and Unnecessary .
•
As described above there is only one Main mass peak and it is usually the largest peak in the
spectrum. It is always assigned the value of 100% and a Confidence of 0. The Confidence
value is obtained by taking the ratio of a mass peak to the
Main
mass. As a result the
Main
mass peak does not need a
Confidence
level.
•
Necessary
masses must be present in a spectrum or the search algorithm will not identify
the peak.
• Unnecessary masses are in the spectrum but are not used by the search algorithm to
identify a compound.
Unnecessary masses are usually masses that are less than 20% of the main mass. The
search algorithm uses all of the masses to determine a goodness of fit and a peak area
during the library search process. That is why even though a mass may be considered
unnecessary for identification it is still important to leave these masses in the table.
The values in the masses table can be edited by highlighting the entry with the mouse and
typing in the new value.