Revisiting Delayed Extraction for MALDI Ions

FIGURE 7.20 (a) Schematic of the ion storage optics utilized by Boyle et al., and (b) ESI-TOF mass spectrum of cytochrome c (MW = 12,360.9 Da) using ion storage. (Reprinted with permission from reference 31). 

FIGURE 7.22 (a) Electrospray ionization mass spectrum ofTrp-Met-Arg-Phe amide withy, = +40V, and (b) electrospray Ionization CID mass spectrum with y, , = +I50V. (Reprinted with permission from reference 34). 

FIGURE 7.23 MALDI-activated fragmentation spectrum of substance P fragment 2-11 following 10-ms trapping time and a laser power density of 3.5 x 10 W/cm. (Reprinted with permission from reference 35). 

FIGURE 7.24 Schematic comparison of the relative energies and positions of ions having (a) an initial kinetic energy, (b) an initial spatial distribution, and (c) an initial kinetic energy after a time del.  

Da) obtained in the reflectron mode (corresponding to effective path lengths of 2.0, 3.0, and 6.6 m, respectively). In the longest (4.2 m) instrument, mass resolution for the MH+ ion cluster is 1 part in 12,500, although the peak corresponding to the ions remains unresolved. 

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