1.

3.

Click the Limits tab to see the Limits page. Verify that the Charge setting matches the polarity of the MS mode you used for spectral acquisition.

4.

Click the Elements tab to see the Elements in Use page. Verify the maximum number of elements used for calculation.

Removes all columns from the formula list except the Formula column. This option is meaningful only in the Auto Annotation > Generate Formulas feature in the Database Manager window.


Displays the Theoretical m/z column in the formula list.


Show m/z Delta
Delta Units 
Displays the Delta (units) column in the formula list.

Displays the Ring Double Bond Equivalents (RDBE) column in the formula list.


Specifies whether to use the nitrogen rule in the elemental composition calculation. The choices include:


Specifies whether to use an algorithm for the exclusion of implausible formulas with improbably high numbers of hydrogens.


Specifies whether to exclude formulas if the atoms cannot be connected in any way using valences common in organic chemistry.


Ring plus Double Bond Equivalent (RDBE)

Displays only formulas for which RDBE is within the From–To range. RDBE limits the calculated formulas to those that make sense from a chemical perspective.

Specifies whether Mass Frontier will consider isotopes of particular elements with a maximum number when calculating formulas. For information about isotope patterns, see Displaying Isotope Patterns.


Opens the Select Element dialog box where you can specify a new element. The application uses the new element when calculating formulas.


Opens the Enter Molecular Formula dialog box where you can specify a new formula. The software uses the new formula to derive upper limits for individual elements (see Elements in Use page). These limits are considered when the software calculates formulas.

v

To automatically calculate the m/z tolerance value

1.

In the Formula Generator window, click the Pick a Peak button, .
