Synchronized Reverse Scan Collision Induced Dissociation in Digital Ion Trap Mass Spectrometer for Improving Fragment Ion Detection

Abstract

Development of fragment ion detection methods is of great importance for mass spectrometer advancement or substance identification. To date, collision induced dissociation (CID) remains the most commonly used ion activation method in MS/MS experiments, and the effectiveness of CID in an ion trap mass spectrometer is limited by low mass cutoff and weak fragmentation yields. Theoretically, controlling the q value is the key to maintain the fragment efficiency and trapping efficiency of MS/MS, thus improving the detection of fragment ion, while currently reported techniques usually require complex circuitry and often produce different CID patterns. In this paper, with the developed synchronized reversed scanning–collision induced dissociation (SRS-CID) technique, we demonstrate its effective improvement in fragment ion detection. The SRS-CID is implemented on a digital ion trap mass spectrometer (DITMS) by reverse scanning the q values during CID process, or specifically, the frequency is increased during the CID process. With the SRS-CID technique, the fragmentation efficiency of precursor ions can be slightly improved. For reserpine analyte, the trapping efficiency for low-mass fragment ions is improved at least 3 times, and for YGGFL, the trapping efficiency for low-mass fragment ions is improved at least 9 times. These experimental results can also be validated by simulations, and the kinetic energy variation plot suggests consecutive fragmentation occurs. In any case, the SRS-CID provides a solution to the low efficiency of fragment ion detection during tandem MS analysis, which will certainly be useful in the future.

Genetic Algorithm Optimized Printed Circuit Board Ion Funnel Tandem Subambient Pressure Ionization with Nanoelectrospray (SPIN) for High Sensitivity Mass Spectrometry

“…Both the reserpine molecular ion peak [M + H] + ( m / z 609) and YGGFL molecular ion peak [M + H] + ( m / z 556) can be identified (signal-to-noise ratio >3). Figure b plots the corresponding MS/MS of 0.1 nM reserpine, and some low-mass fragment ion spectral peaks can be found in Figure b including 397 [M-(OCH 3 ) 3 -C 6 H 2 -CO 2 ] + and 436 [M-OCH 3 -C 6 H 3 -NH-C 2 –C 2 H 4 ] + fragment ions Figures S9 and S10 show the mass spectra for different concentrations of reserpine standards.…”

“…Figure 4b plots the corresponding MS/MS of 0.1 nM reserpine, and some lowmass fragment ion spectral peaks can be found in Figure 4b including 397 [M-(OCH 3 ) 3 -C 6 H 2 -CO 2 ] + and 436 [M-OCH 3 -C 6 H 3 -NH-C 2 −C 2 H 4 ] + fragment ions. 39 Figures S9 and S10…”