Orthogonal acceleration time-of-flight mass spectrometry

Abstract

The principles and applications of time‐of‐flight mass spectrometry involving instruments with independent (orthogonal) axes for ion generation and mass analysis are reviewed. This approach, generally referred to as orthogonal acceleration time‐of‐flight mass spectrometry, has proved particularly advantageous for the combination of continuous ionization sources with time‐of‐flight mass spectrometry. The history of the technique is briefly discussed along with the instrumental principles pertaining to all the stages of the instrumentation from ion source to detector. The applications of commercial and customized instruments are discussed for several ionization methods including electrospray, matrix assisted laser desorption/ionization, electron ionization, and plasma ionization. © 2000 John Wiley & Sons, Inc., Mass Spec Rev 19: 65–107, 2000

From large analogical instruments to small digital black boxes: 40 years of progress in mass spectrometry and its role in proteomics. Part II 1985–2000

“…The excellent sensitivity, speed, resolution, mass accuracy and mass calibration stability of the oaTOF instruments that were commercially introduced in the decade of the 90s provided a significant improvement over the tandem 4-sector instruments when analyzing product ions of collision-induced dissociation. [48] A statement such as this could also be expanded, as per the opinion of Graham Cooks (personal communication), to include triple quadrupoles which probably had a comparable influence on the diminishing use of magnetic sector MS.…”

Performance metrics for evaluating system suitability in liquid chromatography—Mass spectrometry peptide mass mapping of protein therapeutics and monoclonal antibodies

“…21,27,28 Although the optimal setting can vary for different compounds, a general recommendation is to fill less ions for optimization of mass accuracy and more ions for larger dynamic ranges. 28 Other ion detection systems that use timeto-digital converters (TDCs), commonly used in TOF instruments, are also known to have limited dynamic range as a result of low ion current, 29,30 although improvements had been made using analog-to-digital (ADC) detection to obtain larger dynamic ranges. 31 Accumulation of a larger number of transients (i.e., longer MS 1 scans: M0, M3, M6, M7, M9 in Fig.…”

Observations of gas phase hydrochloric acid in the polluted marine boundary layer

“…The campaign average sensitivity, as determined through both direct calibrations and standard additions, was 104 ± 66 Hz ppt À1 , a factor of 3 lower than our previously reported sensitivity to formic acid (338 Hz ppt À1 ) [Bertram et al, 2011]. This decreased sensitivity toward HCl, relative to formic acid, is likely due to a combination of the relative transmission of the two acids through the inlet manifold (discussed below) coupled with the mass-dependent ion duty cycle that limits sensitivity at low m/Q [Guilhaus et al, 2000].…”