Resolution settings are used for the differentiation of adjacent peaks (spectra) and m/z values (calculations). Since Mass Frontier only processes centroid spectra, the differentiation is defined here as the spacing between resolved peaks (spectra) or as the smallest difference in m/z values that is distinguished (calculations). No additional parameters, such as peak width, are taken into account.

Mass frontier supports following resolution types:

• Unit Resolution
  
  
• Resolving power  M/ΔM
  
  
• Mass Resolution   ΔM
  
  

where
M = m/z   (mass-to-charge ratio)

ΔM = M₂ - M₁   (M₁, M₂ are two adjacent peaks)

Peaks (m/z values) that fall into the ΔM band will be merged into a single peak (m/z values).

To change resolution settings, open a Mass Settings dialog window:

• Choose Option | Mass Settings from the main menu

To set the Resolution setting for all calculations in Mass Frontier, you must define Resolution type in the User Defined Type group box and set the appropriate value and unit in the Unit and Value group boxes.

For imported spectra or GC/LC/MS chromatograms from a file, you have two options for the setting of the resolution (Resolution & Precision of Experimental Spectra group box). You can either adopt the resolution saved in a file (Acquired from Source check box), or you can set your own resolution settings to be used for calculations (User Defined Type check box). Please note that it is not possible to improve the resolution of experimental data by using User Defined Type. You should not set resolution values that are better than the resolution of the mass spectrometer actually used for data acquisition. This option allows you to artificially reduce the resolution of experimental data when working with low- and high-resolution spectra in the same data set (spectra search, target analysis, classification).

Note:
Changing the Resolution in Mass Settings dialog window does not affect spectra that are opened (Chromatogram Processor) and fragments that have already been calculated (Fragments & Mechanisms and Fragments Comparator modules). If you require spectra or fragments with a new setting, you must reload these spectra or regenerate these fragments.