2D MS/MS Spectra Recorded in the Time Domain Using Repetitive Frequency Sweeps in Linear Quadrupole Ion Traps

Abstract

Ion trap mass spectrometers have emerged as powerful on-site analytical platforms, in spite of limited mass resolution, due to their compatibility with ambient ionization methods and ready implementation of tandem mass spectrometry (MS/MS). When operated at constant trapping voltage, ions can be activated at their secular frequencies and all MS/MS experiments can be performed, including the two-dimensional tandem mass scan (2D MS/MS scan) in which all precursor ions and their subsequent product ions are both identified and correlated. In the new method of performing this 2D MS/MS experiment presented here, the precursor ions are excited by a nonlinear (inverse Mathieu q) frequency sweep while the resulting product ions are identified by their ejection time within a repeating orthogonally applied nonlinear (inverse Mathieu q) frequency sweep. This resulting compact representation contains the total fragmentation behavior of a collection of ionized compounds and captures detailed chemical information efficiently (typically in 1 s). The approach is implemented using a simple single mass analyzer instrument. This methodology was tested on three different multicomponent mixtures: drugs of abuse, peptides, and fentanyl analogs. The data are compared with those obtained by more common MS/MS scan methods.

Narrowband Modulation Two-Dimensional Mass Spectrometry and Label-Free Relative Quantification of Histone Peptides

“…2D MS can be performed on Fourier transform ion cyclotron resonance (FT-ICR) or linear ion trap mass spectrometers and has been successfully applied to the analysis of small molecules, polymers, and in bottom-up and top-down proteomics. − In most studies using 2D MS, the analytes were within an m / z range of several hundred units. In the case of modified histones, the m / z range is typically less than 10 units depending on the charge state of the protein.…”

Bacterial growth monitored by two-dimensional tandem mass spectrometry

“…30 The 2D MS/MS scan was performed in 900 milliseconds with precursor ions of m / z 600–900 being fragmented by one waveform while the resulting fragment (product) ions were continuously ejected using a second waveform as described previously. 31 A depiction of the methodology can be found in the ESI (Fig. S1†).…”

Novel Ion Trap Scan Modes to Develop Criteria for On-Site Detection of Sulfonamide Antibiotics

“…The 2D MS/MS scan is performed by rapidly sweeping through all possible product ion frequencies and iterating this sweep continuously to preserve precursor/product ion relationships. 23 The observed output is spliced into individual product ion sweeps, and those individual sweeps are combined into a single matrix in MATLAB. The simultaneous combinations of scans were accomplished by applying product ion ejection waveforms at the same time as those corresponding to the individual MS/MS scans.…”