Mass ion-cyclotron resonance

B1.7.6 FOURIER TRANSFORM ION CYCLOTRON RESONANCE MASS SPECTROMETERS... 

Figure Bl.7.18. (a) Schematic diagram of the trapping cell in an ion cyclotron resonance mass spectrometer excitation plates (E) detector plates (D) trapping plates (T). (b) The magnetron motion due to tire crossing of the magnetic and electric trapping fields is superimposed on the circular cyclotron motion aj taken up by the ions in the magnetic field. Excitation of the cyclotron frequency results in an image current being detected by the detector electrodes which can be Fourier transfonned into a secular frequency related to the m/z ratio of the trapped ion(s).

Vartanian V H, Anderson J S and Laude D A 1995 Advances in trapped ion cells for Fourier transform ion cyclotron resonance mass spectrometry Mass Spec. Rev. 41 1-19... 

Rapid scanning mass spectrometers providing unit resolution are routinely used as chroaatographic detectors. Ion separation is accomplished using either a magnetic sector, quadrupole filter or ion trap device. Ions can also be separated by time-of-flight or ion cyclotron resonance mass analyzers but these devices are not widely used with chromatograidiic inlets and will not be discussed here [20]. 

Jensen P.K., Pasa-Tolic L., Anderson G. A., Horner J. A., Lipton M.S., Bruce J.E., and Smith R.D., Probing proteomes using capillary isolectric focusing-elec-trospray ionization Fourier transform ion cyclotron resonance mass spectrometry, Anal. Chem. 71, 2076, 1999. 

Fourier-Transform Ion-Cyclotron Resonance Mass Spectrometry... 

B. Asamoto (ed.), FT-ICR/MS Applications of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, VCH Publishers, New York, NY (1991). 

Fourier transform ion cyclotron resonance mass spectrometry... 

CsFeo.72Agi.28Te2,1053 and Cs2Ag2ZrTe4. The latter has a structure that comprises 2D slabs of Ag- and Zr-centered tetrahedral separated by Cs+ cations.1054 Gas-phase silver chalcogenide ions of the type [Ag2 i E ] (E = S, Se, Te) with < 14 have been investigated by laser-ablation Fourier transform ion cyclotron resonance mass spectrometry.1055... 

In analyses where molecular masses are being matched, more accurate mass measurements provide more reliable matches and identifications.26,65,66 In a reference laboratory the mass accuracy to several decimal points, provided by a Fourier transform ion cyclotron resonance mass analyzer, may be desirable. In field or portable systems there is usually a trade-off in mass accuracy for size and ruggedness. Reliable identifications can be made with moderate mass accuracy, even 1 Da, if a large enough suite of molecular ions is recorded and used to search the database. If both positive ion and negative ion spectra are... 

Wunschel, D. S. Fox, K. F. Bruce, J. E. Muddiman, D. C. Smith, R. D. Analysis of double-stranded polymerase chain reaction products from the Bacillus cereus group by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Rapid Comm. Mass Spectrom 1996,10, 29-35. 

Wu, Z. Jernstroem, S. Hughey, C. A. Rodgers, R. R Marshall, A. G. Resolution of 10,000 compositionally distinct components in polar coal extracts by negative-ion electrospray ionization Fourier transform ion cyclotron resonance. Mass Spectrom. Ener. Fuels 2003,17, 946-953. 

Leinweber, F.C., Schmid, D.G., Lubda, D., Wiesmuller, K., Jung, G., Tallarek, U. (2003). Silica-based monoliths for rapid peptide screening by capillary hquid chromatography hyphenated with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Rapid Commun. Mass. Spectrom. 17, 1180-1188. 

Kalkhof, S. et al. (2005a) Chemical cross-linking and high-performance fourier transform ion cyclotron resonance mass spectrometry for protein interaction analysis Application to a calmodulin/target peptide complex. Anal. Chem. 77, 495-503. 

Multiple mass analyzers exist that can perform tandem mass spectrometry. Some use a tandem-in-space configuration, such as the triple quadrupole mass analyzers illustrated (Fig.3.9). Others use a tandem-in-time configuration and include instruments such as ion-traps (ITMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS or FTMS). A triple quadrupole mass spectrometer can only perform the tandem process once for an isolated precursor ion (e.g., MS/MS), but trapping or tandem-in-time instruments can perform repetitive tandem mass spectrometry (MS ), thus adding n 1 degrees of structural characterization and elucidation. When an ion-trap is combined with HPLC and photodiode array detection, the net result is a profiling tool that is a powerful tool for both metabolite profiling and metabolite identification. 

Resolutions in the range of 10,000 to 20,000 are achievable with modem time-of-flight mass spectrometry (TOFMS). Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) is more costly but capable of resolutions exceeding 100,000. Resolutions exceeding 10,000 can provide low to sub parts-per-million mass accuracies. One ppm is equivalent to a mass accuracy of 0.001 for a molecular weight of 1,000 Da. 

J. S. Sampson, A. M. Hawkridge, and D. C. Muddiman. Generation and Detection of Multiply-Charged Peptides and Proteins by Matrix-Assisted Laser Desorption Electrospray Ionization (MALDESI) Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. J. Am. Soc. Mass Spectrom., 17(2006) 1712-1716. 

A. G. Marshall. Milestones in Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Technique Development. Int. J. Mass Spectrom., 200(2000) 331-356. 

S. D.-H. Shi, C. L. Hendrickson, and A. G. Marshall. Counting Individual Sulfur Atoms in a Protein by Ultrahighresolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Experimental Resolution of Isotopic Fine Structure in Proteins. Proc. Natl. Acad. Sci. U.S.A., 95(1998) 11532-11537. 

M. E. Belov, M. V. Gorshkov, H. R. Udseth, G. A. Anderson, and R. D. Smith. Zeptomole-Sensitivity Electrospray Ionization-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry of Proteins. Anal. Chem., 72(2000) 2271-2279. 

M. Ramstrom, I. Ivonin, A. Johansson, H. Askmark, K. E. Markides, R. Zubarev, P. Hakansson, S.-M. Aquilonius, and J. Bergquist. Cerebrospinal Fluid Protein Patterns in Neurodegenerative Disease Revealed by Liquid Chromatography Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Proteomics, 4(2004) 4010-4018. 

Usually, concentration is measured as a pressure and may differ widely according to the type of mass spectrometer used. The triple quadrupole mass spectrometer may operate with pressures up to 1 x 10 1 Pa in the reaction region. At the other extreme, ion cyclotron resonance mass spectrometers operate poorly at pressures >1 X 10 4 Pa. A pressure of 1 x 10 4 Pa may be regarded as fairly high pressure for FT-ICR measurements. Converting the pressure into a more normal value of concentration means that reactions are carried out at concentrations < 10 9M (often several orders of magnitude < 10 0 M). 

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