title: A dual pressure linear ion trap Orbitrap instrument with very high sequencing speed.
abstract: Since its introduction a few years ago, the linear ion trap Orbitrap (LTQ Orbitrap) instrument has become a powerful tool in proteomics research. For high resolution mass spectrometry measurements ions are accumulated in the linear ion trap and passed on to the Orbitrap analyzer. Simultaneously with acquisition of this signal, the major peaks are isolated in turn, fragmented and recorded at high sensitivity in the linear ion trap, combining the strengths of both mass analyzer technologies. Here we describe a next generation LTQ Orbitrap system termed Velos, with significantly increased sensitivity and scan speed. This is achieved by a vacuum interface using a stacked ring radio frequency ion guide with 10-fold higher transfer efficiency in MS/MS mode and 3-5-fold in full scan spectra, by a dual pressure ion trap configuration, and by reduction of overhead times between scans. The first ion trap efficiently captures and fragments ions at relatively high pressure whereas the second ion trap realizes extremely fast scan speeds at reduced pressure. Ion injection times for MS/MS are predicted from full scans instead of performing automatic gain control scans. Together these improvements routinely enable acquisition of up to ten fragmentation spectra per second. Furthermore, an improved higher-energy collisional dissociation cell with increased ion extraction capabilities was implemented. Higher-collision energy dissociation with high mass accuracy Orbitrap readout is as sensitive as ion trap MS/MS scans in the previous generation of the instrument.
authors.affiliation: Thermo Fisher Scientific (Bremen) GmbH, Hanna-Kunath-Strasse 11, 28199 Bremen, Germany.
authors.forename: Jesper V
authors.initials: JV
authors.lastname: Olsen
authors.forename: Jae C
authors.initials: JC
authors.lastname: Schwartz
authors.forename: Jens
authors.initials: J
authors.lastname: Griep-Raming
authors.forename: Michael L
authors.initials: ML
authors.lastname: Nielsen
authors.forename: Eugen
authors.initials: E
authors.lastname: Damoc
authors.forename: Eduard
authors.initials: E
authors.lastname: Denisov
authors.forename: Oliver
authors.initials: O
authors.lastname: Lange
authors.forename: Philip
authors.initials: P
authors.lastname: Remes
authors.forename: Dennis
authors.initials: D
authors.lastname: Taylor
authors.forename: Maurizio
authors.initials: M
authors.lastname: Splendore
authors.forename: Eloy R
authors.initials: ER
authors.lastname: Wouters
authors.forename: Michael
authors.initials: M
authors.lastname: Senko
authors.forename: Alexander
authors.initials: A
authors.lastname: Makarov
authors.forename: Matthias
authors.initials: M
authors.lastname: Mann
authors.forename: Stevan
authors.initials: S
authors.lastname: Horning
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002256:Carbonic Anhydrases / Q000737:chemistry; D002417:Cattle; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry / Q000295:instrumentation*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011312:Pressure; D040901:Proteomics / Q000295:instrumentation*; D020539:Sequence Analysis, Protein / Q000295:instrumentation*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013997:Time Factors
chemical_list: D010455:Peptides; D012710:Serum Albumin, Bovine; D002256:Carbonic Anhydrases