Fourier transform mass spectrometry

The first application of ion cyclotron resonance (ICR) to mass spectrometry is due to Sommer. [58] 

Ions of each mass have their characteristic cyclotron frequency. It can be demonstrated that ions excited by an AC irradiation at their own frequency and with the same energy, thus the same Vo potential, applied during the same time TSKC, will have an orbit with the same radius, and with an appropriate radius will all pass close to the detection plate  

This equation, demonstrated in [62], is indeed independent of the m/z ratio. Thus broadband excitation will bring all the ions onto the same radius, but at frequencies depending on their m/z ratio, provided that the voltage is the same at each frequency. This can be best performed by applying a waveform calculated by the inverse Fourier transform, namely SWIFT [63], As usual for a technique based on Fourier transform, the resolution depends on the observation time, which is linked with the disappearance of the detected signal (relaxation time). Here the disappearance of the signal mainly results from the ions being slowed by 

Principle of the Fourier transform a sound signal whose intensity is measured as a time-dependent function is made up of many frequencies superposed one over the other, each with its own intensity. The Fourier transform allows one to find the individual frequencies and their intensities. Reproduced (modified) from Finni-gan MAT documentation, with permission. 

Signal intensity as a function of time is transformed, through a Fourier transform, into intensity as a function of frequency, and hence into an intensity to m/z relationship. Redrawn from Amster I.J., J. Mass. Spectrom., 31, 1325-1337, 1996, with permission. 

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Amster I J 1996 Fourier transform mass spectrometry J. Mass Spectrom. 31 1325-37... 

Freiser B S 1988 Fourier transform mass spectrometry Techniques for the Study of Ion-Molecule Reactions ed J M Farrar and W H Saunders (New York Wiley-Interscience)... 

MALDI = matrix assisted laser desorption, ftms = Fourier transform mass spectrometry TOF = time of flight. 

Mass Spectrometry. Field desorption mass spectrometry has been used to analy2e PPO (179). Average molecular weight parameters (M and could be determined using either protonated (MH + ) or cation attachment (MNa + ) ions. Good agreement was found between fdms and data supphed by the manufacturer, usually less than 5% difference in all cases up to about 3000 amu. Laser desorption Fourier transform mass spectrometry was used to measure PPG ion and it was claimed that ions up to m/2 9700 (PEG) can be analy2ed by this method (180). 

The laser desorption experiments which we describe here utilize pulsed laser radiation, which is partially absorbed by the metal substrate, to generate a temperature jump in the surface region of the sample. The neutral species desorbed are ionized and detected by Fourier transform mass spectrometry (FTMS). This technique has... 

Aaserud, D. ]., Prokai, L., and Simonsick, W.J., Jr., Gel permeation chromatography coupled to Fourier transform mass spectrometry for polymer characterization, Anal. Chem., 71, 4793, 1999. 

M.V. Buchanan (ed.), Fourier Transform Mass Spectrometry Evolution, Innovation, and Applications, ACS Symposium Series No. 359, American Chemical Society, Washington, DC (1987). 

Laser desorption methods (such as LD-ITMS) are indicated as cost-saving real-time techniques for the near future. In a single laser shot, the LDI technique coupled with Fourier-transform mass spectrometry (FTMS) can provide detailed chemical information on the polymeric molecular structure, and is a tool for direct determination of additives and contaminants in polymers. This offers new analytical capabilities to solve problems in research, development, engineering, production, technical support, competitor product analysis, and defect analysis. Laser desorption techniques are limited to surface analysis and do not allow quantitation, but exhibit superior analyte selectivity. 

FAB Fast atom bombardment FTMS Fourier-transform mass spectrometry... 

Stump, M. J. Jones, J. J. Fleming, R. C. Lay, J. O., Jr. Wilkins, C. L. Use of double-depleted 13C and 15N culture media for analysis of whole cell bacteria by MALDI time-of-flight and Fourier transform mass spectrometry. J. Am. Soc. Mass Spectrom. 2003,14,1306-1314. 

Brown, R. S. Wilkins, C. L. Laser desorption Fourier transform mass spectrometry of synthetic porphyrins. Anal. Chem. 1986,58,3196-3199. 

Fourier transform mass spectrometry is made possible by the measurement of an AC current produced from the movement of ions within a magnetic field under ultra-high vacuum, commonly referred to as ion cyclotron motion.21 Ion motion, or the frequency of each ion, is recorded to the precision of one thousandth of a Hertz and may last for several seconds, depending on the vacuum conditions. Waveform motion recorded by the mass analyzer is subjected to a Fourier transform to extract ion frequencies that yield the corresponding mass to charge ratios. To a first approximation, motion of a single ion in a magnetic field can be defined by the equation... 

Li, Y. Tang, K. Little, D. P. Koster, H. Hunter, R. L. Mclver, R. T. High-resolution MALDI Fourier transform mass spectrometry of oligonucleotides. Anal. Chem. 1996, 68, 2090-2096. 

Ledford, E. B., Jr. Rempel, D. L. Gross, M. L. Space charge effects in Fourier transform mass spectrometry Mass calibration. Anal. Chem. 1984,56, 2744-2748. 

Fourier Transform Mass Spectrometry Fourier Transform Nuclear Magnetic Resonance Spectrometry... 

Lee, S., Young, N.L., Whetstone, P.A., Cheal, S.M., Benner, W.H., Lebrilla, C.B., and Meares, C.F. (2006) A method to site-specifically identify and quantitate carbonyl end products of protein oxidation using oxidation-dependent element coded affinity tags (O-ECAT) and nanoLiquid chromatography Fourier transform mass spectrometry./. Proteome Res. 5(3), 539-547. 

B. A. Budnik, K. B. Jensen, T. J. Jorgensen, A. Haase, and R. A. Zubarev. Benefits of 2.94 Micron Infrared Matrix-Assisted Laser Desorption/Ionization for Analysis of Labile Molecules by Fourier Transform Mass Spectrometry. Rapid Commun. Mass Spectrom., 14(2000) 578-584. 

Fourier-transform mass spectrometry takes advantage of ion-cyclotron resonance to select and detect ions [366,534,535,563-565]. 

Amster, I.J. Fourier Transform Mass Spectrometry. J. Mass Spectrom. 1996, 31, 1325-1337. 

Lorenz SA, Moy MA, Dolan AR, Wood TD. 1999. Electrospray ionization fourier transform mass spectrometry quantification of enkephalin using an internal standard. Rapid Commun Mass Spectrom 13 2098. 

Que, A. H., Mechref, Y., Huang, Y., Taraszka, J. A., Clemmer, D. E., and Novotny, M. V. (2003). Coupling capillary electrochromatography with electrospray Fourier transform mass spectrometry for characterizing complex oligosaccharide pools. Anal. Chem. 75, 1684—1690. 

To overcome this, instrumental techniques such as pulsed high-pressure mass spectrometry (PHPMS), the flowing afterglow (FA) and allied techniques like the selected-ion flow tube (SIFT), and ion cyclotron resonance (ICR) spectrometry and its modem variant, Fourier transform mass spectrometry (FTMS), have been developed. These extend either the reaction time (ICR) or the concentration of species (PHPMS, FA), so that bimolecular chemistry occurs. The difference in the effect of increasing the pressure versus increasing the time, in order to achieve bimolecular reactivity, results in some variation in the chemistry observed with the techniques, and these will be addressed in this review as needed. 

Fourier Transform Mass Spectrometry Buchanan, M. V, Ed. ACS Symposium Series 359 American Chemical Society Washington DC, 1987. A. G. Marshall. Acc. Chem. Res. 1985, 18, 316. 

Laser ablation coupled to ion cyclotron resonance Fourier transform mass spectrometry (in both positive and negative ion modes) can be used to distinguish natural and... 

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