Chapter 6 Using Tools and Applications
6 | Hint: You can sort the results in a column by clicking the |
column header. |
Results include:
•Index— Sequential number assigned to each result.
•Input m/z— Entered m/z for each composition calculation.
•Calculated Mass— Calculated mass for the entered m/z and charge state for each theoretical composition.
•mDa Error and ppm Error— Error for each calculation.
•Double Bond Equivalents (DBE)— Value that corresponds to the number of double bonds or rings that the
from each calculated composition. If the target mass is a protonated molecular ion, (M+H)+, the DBE value includes 0.5 and corresponds to an even electron state. To convert the reported DBE value to the actual number
of double bonds or rings, add 0.5. For example,
H2C=NH2+ has an (M+H)+ total mass of 30.0344 and a reported double bond equivalent of 0.5, with an actual number of double bonds of 1.
•Formula— Elemental composition for each mass.
•Isotope Match Score— Number between 0 and 1.0 that reflects how well the observed peak matches the theoretical formula, based on mass and isotope pattern. A higher number represents a better match.
NOTE: An Isotope Match Score of 0.00000 is always reported for fragment ion calculations.
If no results are displayed, it may indicate that the specified Tolerance is too limiting and no matches were found.