Fourier Transform Ion Cyclotron Resonance Mass Spectrometers

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

The gaseous dichlorocarbene radical cation reacted with alkyl halides via a fast electrophilic addition to form a covalently bonded intermediate (CI2C—X—R)+ in a Fourier transform ion cyclotron resonance mass spectrometer. This intermediate fragments either homolytically or heterolytically to produce net halogen atom or halogen ion transfer product. Addition of carbonyls to the carbene ion is followed by homolytic cleavage of the C-O bond to yield a new carbene radical cation. 

General Methods. The instrument that will be used to execute the gas-phase experimental portion of the proposed research is a Finnigan 2001 dual-cell Fourier transform ion cyclotron resonance mass spectrometer (FTMS or FTICR), equipped with both electron impact (FI) and electrospray ionization (FSl). FTMS is a high-resolution, high-sensitivity technique that allows the entrapment and detection of gas-phase species. Gas-phase ions are trapped in a magnetic field, much like a reactant sits in a flask in solution. The instrument is a mass spectrometer therefore, we will often refer to the mass-to-charge (m/z) ratio of ions, which is the method we use to identify species. (M-l) or (M-H) refers to a molecule M that has been deprotonated for example, HjO has an (M-f) ion of m/z 17 (HO ). 

Burton, R. D., Matuszak, K. P., Watson, C. H., and Eyler, J. R. (1999). Exact mass measurements using a 7 tesla Fourier transform ion cyclotron resonance mass spectrometer in a good laboratory practices-regulated environment. J. Am. Soc. Mass Spectrom. 10 1291-1297. 

Thus the interpretation of ESI-MS spectra of POPAM dendrimers recorded on an FT-ICR (Fourier-Transform Ion Cyclotron Resonance) mass spectrometer leads to drastic overestimation of defects in the sample molecules (Fig. 7.4). The... 

Belov ME, Anderson GA, Wingerd MA, et al. An automated high performance capillary liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometer for high-throughput proteomics. J Am Soc Mass Spectrom 2004 15(2) 212-232. 

Output from both gated continuous wave and pulsed carbon dioxide lasers has been used to desorb ions from surfaces and then to photodissociate them in a Fourier transform ion cyclotron resonance mass spectrometer. Pulsed C02 laser irradiation was most successful in laser desorption experiments, while a gated continuous wave laser was used for a majority of the successful infrared multiphoton dissociation studies. Fragmentation of ions with m/z values in the range of 400-1500 daltons was induced by infrared multiphoton dissociation. Such photodissociation was successfully coupled with laser desorption for several different classes of compounds. Either two sequential pulses from a pulsed carbon dioxide laser (one for desorption and one for dissociation), or one desorption pulse followed by gated continuous wave irradiation to bring about dissociation was used. 

Huang, N. Siegel, M. M. Kruppa, G. H. Laukien, F. H. 1999. Automation of a fourier transform ion cyclotron resonance mass spectrometer for acquisition, analysis, and e-mailing of high-resolution exact-mass electrospray ionization mass spectral data. ./. Am. Soc. Mass Spectrom., 10, 1166-1173. 

Meng, Z., Qi, S., Soper, S.A., Limbach, P.A., Interfacing a polymer-based micro-machined device to a nanoelectrospray ionization Fourier Transform ion cyclotron resonance mass spectrometer Anal. Chem. 2001, 73, 1286-1291. 

High-resolution Fourier transform ion cyclotron resonance mass spectrometers have also been used for ICP-MS [134,135]. Quadrupole mass spectrometers used in alternate stability regions to obtain higher resolution than typical have also been used for ICP-MS [136,137]. 

Fourier-transform ion cyclotron resonance mass spectrometer electrospray ionization mass spectrometry ethidium bromide triethylamine... 

Concerning the first field of application, the kinetics and equilibrium constants for several halide transfer reactions (equation 1) were measured in a pulsed electron high pressure mass spectrometer (HPMS)4 or in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR)5. From measurements of equilibrium constants performed at different temperatures, experimental values were obtained for the thermochemical quantities AG°, AH° and AS° for the reaction of equation 1. The heat of formation (AH°) of any carbocation of interest, R+, was then calculated from the AH0 of reaction and the AH° values of the other species (RC1, R Cl and R +) involved. 

For simultaneous detection of an entire atomic mass range, ICP has also been used with the quadmpole ion traps (QIT), Fourier transform ion cyclotron resonance mass spectrometers (FTICR), and multichannel mass spectrometers. ... 

Next to CE, on-line coupling of capillary lEF and MS is attractive. For protein characterizatiorr, CIEF-MS on a Fourier-transform ion-cyclotron resonance mass spectrometer (FT-ICR-MS) irrstrament was pioneered by the group of Smith [99-100]. They demonstrated the high-resolution analysis of E. coli proteins, reveahng >400 proteins (2-100 kDa) from an injection of only 300 ng. 

Houk R. S. and Eyler J. R. (1997) High-resolution inductively coupled plasma Fourier transform ion cyclotron resonance mass spectrometer, Anal Chem 69 3714-3721. 

Fig. 20.1. Scheme of the instrumental setup for the Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR-MS)... 

SA Hofstadler, E Schmidt, Z Guan, DA Laude Jr. Concentric tube vacuum chamber for high magnetic field, high pressure ionization in a Fourier transform ion cyclotron resonance mass spectrometer. J Am Soc Mass Spectrom 4 168, 1993. 

Several techniques have been used to investigate the reactivity of the metal carbide cluster ions formed in a laser vaporization source. The earliest investigations performed by Castleman s group relied on a preliminary mass selection of the desired cluster. The ion beam was then injected into a drift tube where the selected cluster encounters the reactant mixed with helium as a buffer gas. The FTICR (Fourier-transform ion cyclotron resonance) mass spectrometer studies reported by Byun, Freiser and co-workers basically rely on the same principle even though the total pressure of the reaction chamber is 10 torr, compared with 0.7 torr in Castleman s experiments. A new method of forming met-car ligand complexes was then reported by Castleman et al. this involved the direct interaction of the vaporized metal with mixtures of methane and selected reactant gases. ... 

The rate of reaction between alkyl cations and acetylene and diacetylene has been investigated (Table 2) in order to increase understanding of soot formation in fuel-rich flames. The experiments were performed in a Fourier transform ion cyclotron resonance mass spectrometer. The rate depends on the cation precursor . ... 

Fig. 3.7. Data (time) domain signal produced by 9.4-Tesla Fourier-transform ion cyclotron resonance mass spectrometer (left), and frequency domain signal (i.e. mass spectrum) after fast Fourier transformation and frequency-to-mass calculation (right). The sample was a mixture of poly(ethylene) glycol polymers used for internal calibration.

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