|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
How Accurate-Mass Mass Spectral Data Gets Transformed Into Modular Structures Prior to Searching
|
| 1. Assigning subfragments (cells) to fragments | 2. Checking fragment assignments | |||
 |
 |
|||
Find all partitions of
the MW (638) that can account for most of the neutralized fragment
ions; assign the fragment ions accordingly. |
Only one of the partitions
is consistent with all of the MS3 fragmentation data |
|||
| 3. Calculating accurate masses of subfragments | 4. Arranging the subfragments into modular structures | |||
 |
 |
|||
| The mass defects of the subfragments, shown here as circles, must be assigned in the same way as the integral masses. A system of simultaneous linear equations can thus be formed and solved for the mass defects of the subfragments. | Using truth tables and the fragment assignments, it is possible to eliminate many of the possible spatial arrangements of the subfragments. | |||
| 5. Finding elemental compositions of subfragments and fragments | 6. Applying Chemical-Spatial Rules | |||
 |
 |
|||
| The atoms of the molecular formula must be allocated among the subfragments; no subfragment is independent of the other subfragments. This considerably limits the possible molecular formulas. | The subfragment (cell) elemental composition will restrict where a particular subfragment will fit into a modular structures. Some subfragments must connect two other subfragments; some subfragments can only connect to one other subfragment. |
|
|
| |
| |
| Copyright
© 2006 - 2008 MathSpec Inc. All rights reserved |
Design
by VisionaryStudio |