title: Mass correlated acceleration in a reflectron MALDI TOF mass spectrometer: an approach for enhanced resolution over a broad mass range.
abstract: Compared to continuous extraction, pulsed extraction (PE) of ions formed by matrix-assisted laser desorption/ionization (MALDI) in time-of-flight (TOF) mass spectrometers significantly improves mass resolution. Parameters such as extraction voltage, delay time, and correction pulse must be varied, however, to achieve optimum mass resolution over a broad mass range because the PE method is mass dependent. We previously reported a novel method, mass correlated acceleration (MCA), which we have now combined with a reflectron MALDI TOF mass spectrometer to further enhance mass resolution over a broader mass range. Unlike the PE method, MCA is not mass dependent and high resolution mass spectra can be achieved with a single tuning of instrument parameters. The ions may be brought into focus simultaneously, i.e., the multi-channel recording advantage can be more fully realized. The MCA dual-stage ion source design includes an extraction pulse region and an acceleration region that contains a time-dependent waveform correlated with mass. We demonstrate the validity of this novel technique with applications in peptide mixture analysis and protein digests of lysozyme and bovine serum albumin.
authors.affiliation: Middle Atlantic Mass Spectrometry Laboratory, Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Slava V
authors.initials: SV
authors.lastname: Kovtoun
authors.forename: Robert D
authors.initials: RD
authors.lastname: English
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Cotter
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D002138:Calibration; D002417:Cattle; D006801:Humans; D006868:Hydrolysis; D010455:Peptides / Q000032:analysis; D011506:Proteins / Q000737:chemistry; D012015:Reference Standards; D012710:Serum Albumin, Bovine / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*
chemical_list: D010455:Peptides; D011506:Proteins; D012710:Serum Albumin, Bovine