The most common approach for identifying unknown analytes using mass spectrometry combines fragmentation rules with circular reasoning, working backwards from the answer. But with accurate-mass fragmentation data, you no longer need to work backwards.
Are you open to a new approach for identifying unknown analytes? If accurate fragmentation data is available in your laboratory, our patented pattern recognition software allows you to visualize your unknown molecule as being composed of underlying small "subfragments" that show how many of the fragment ions are related to each other. (See the cimetidine example below.) This pattern recognition software, now available as a simple and economical Excel® Add-In, uses the power of mathematics to rapidly transform accurate-mass fragmentation data into a structure-orientated graphical format.
See other examples. Dan's book describes in detail the theory of "partitioning" and how this novel approach has been implemented. This book is available on your local Amazon website: "Mass Spectrometry by the Numbers".
The Excel Add-In also includes mass spectrometric functions such as mass(), RDBE(), IsoCalc(), and Baserate() that are active in any Excel workbook, and hyperlinks to both the CompTox Chemistry Dashboard and Pubchem Compound. Also included is our new high resolution isotope calculator worksheet that plots the isotope distributions in color based on the selected resolution setting. (Isotope Worksheet).
For a quick overview on how the Excel Add-In works, please see the approach used to extract structural information for chloramphenicol from its accurate-mass fragmentation data: Chloramphenicol Example. This MS/MS data is from MassBank Spectrum KOX00157, Institute for Advanced Biosciences, Keio University.