Orthogonal acceleration single-pass time-of-flight mass spectrometry for determination of the exact masses of product ions formed in tandem mass spectrometry experiments

✍ Scribed by T. Keough; M. P. Lacey; M. M. Ketcha; R. H. Bateman; M. R. Green

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 161 KB
• Volume: 11
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(19971015)11:15<1702::aid-rcm73>3.0.co;2-l

✦ Synopsis

A hybrid magnetic sector/orthogonal acceleration single-pass time-of-flight (oaTOF) mass spectrometer has been used to measure the exact masses of product ions formed in high-and low-collision-energy MSMS experiments. Methods for both external and internal calibration of the mass scale have been evaluated. Mass accuracies of ± 25 ppm are routinely achieved for product ions having masses greater than 200 Da. Best case mass accuracies of ± 10 ppm have been obtained. Mass accuracy at low mass is limited by the current speed of the time-to-digital converter (TDC). Experiments at reduced accelerating voltages suggest that doubling the TDC acquisition rate will increase low-mass accuracy six-fold. A number of applications of exact mass MSMS are presented, including: characterization of a side-reaction product formed in a combinatorial library synthesis, differentiation of isobaric residues in small peptides and a 'mimicked' MS 3 measurement to confirm the identity of an unusual product ion previously observed in an ion trap MSMS experiment.