Ion cyclotron resonance cell

Figure 3.14 Schematic representation of an ion cyclotron resonance cell (Penning trap) for high resolution mass spectrometry. The magnetic field is oriented and the ions are injected along the z axis. The ions are trapped along this axis by a trapping voltage (e.g., I V applied to the front and back plates 3 and 4). (Modified from C. Brunnee, Int. j. Mass Spectrom. 76, 125 (1987). Reproduced by permission from Elsevier.)...

Fig. 3.12. Series of electrospray ionization Fourier-transform ion cyclotron resonance mass spectra obtained in a two-dimensional mass spectrometry experiment. Proceeding from top to bottom (a) full mass spectrum of a fulvic acid mixture (b) stored waveform inverse Fourier transform (SWIFT) waveform ejection from the ion cyclotron resonance cell of ions of all but a narrow m/z range (c) the resulting isolated parent ion mass spectrum and (d) the product ion mass spectra produced by collision-induced dissociation. Reprinted from Fievre etal. (1997) with permission from the American Chemical Society.

What is the residence time for of benzene in an ion-cyclotron-resonance cell of length 10 cm with a drift field in both the source and analyzer of 0.25 V/cm The magnetic field is set at 7,800 gauss. Compare with the residence time of around 10" sec for a conventional mass-spectrometer source. 

Cage, B. Friedrich, J. Little, R.B. Wang, Y.S. McFarland, M.A. Hendrickson, C.L. Dalai, N. Marshall, A.G. Wavelength resolved laser-induced fluorescence emission of CgF3H3+ trapped in an ion cyclotron resonance cell. Chem. Phys. Lett. 2004,394, 188-193. 

Ion-Molecule Reactions In this approach, the structure of the target ion is determined by reacting it with a neutral molecule, and the products of the reaction are compared with those that result in a similar reaction with an ion of known structure. Reactions are conducted normally in the ion cyclotron resonance cell at a low pressure (ca. 10 torr) or in a quadrupole ion trap at a moderate pressure (ca. 10 torr). Sampled ions have a lifetime in the millisecond range and thus have survived fragmentation. Because those ion-molecule reactions that are detectable in mass spectrometry are usually exothermic, the intermediate adduct is rarely observed. Therefore, the structural features of the target ion or its adduct are derived from either the fragmentation pattern or from isotope-labeling experiments. 

The most widely used type of trap for the study of ion-molecule reactivity is the ion-cyclotron-resonance (ICR) [99] mass spectrometer and its successor, the Fourier-transfomi mass spectrometer (FTMS) [100, 101]. Figure A3.5.8 shows the cubic trapping cell used in many FTMS instmments [101]. Ions are created in or injected into a cubic cell in a vacuum of 10 Pa or lower. A magnetic field, B, confines the motion in the x-y... 

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).

Mclver R T 1970 A trapped ion analyzer cell for ion cyclotron resonance spectroscopy Rev. Sc/. Instrum. 41 555-8... 

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... 

Instruments are available that can perform MS/MS type experiments using a single analyzer. These instruments trap and manipulate ions in a trapping cell, which also serves as the mass analyzer. The ion trap and fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers are examples. 

Figure 2.19. Schematic of a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer (a) and a cylindrical cell (b). Reprinted from A. Westman-Brinkmalm and G. Brinkmalm (2002). In Mass Spectrometry and Hyphenated Techniques in Neuropeptide Research, J. Silberring and R. Ekman (eds.) New York John Wiley Sons, 47-105. With...

Fourier transform ion cyclotron resonance (FTICR) analyzer is excellent for MSn measurements (see Section 2.2.6), perhaps even more so, since the ions remain in the cell after detection. In principle one injection of ions is enough for a whole MSn sequence, including acquisition of a mass spectrum of each step. 

In the ion cyclotron resonance (ICR) cell CID is performed by resonant excitation of the precursor ion and subsequent collisions with the background gas. One serious drawback with on-resonance excitation in the ICR cell is that the risk for ion losses due to... 

Capillary electrophoresis (CE) either coupled to MS or to laser-induced fluorescence (LIF) is less often used in metabolomics approaches. This method is faster than the others and needs a smaller sample size, thereby making it especially interesting for single cell analysis [215] The most sensitive mass spectrometers are the Orbitrap and Fourier transform ion cyclotron resonance (FT-ICR) MS [213]. These machines determine the mass-to-charge ratio of a metabolite so accurate that its empirical formula can be predicted, making them the techniques of choice for the identification of unknown peaks. 

Hofstadler, S. A., Severs, J. C., Smith, R. D., Swanek, F. D., and Ewing, A. G. (1996). Analysis of single cells with capillary electrophoresis electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Rapid Commun. Mass Spectrom. 10, 919—922. 

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 ). 

Fourier Transform MS Fourier transform mass spectrometry (FTMS), which is a modem manifestation of ion cyclotron resonance, relies on the collection of ions in a high-vacuum cell and containment with a magnetic field. The ions orbit about the magnetic field axis. The ion masses and... 

An overview of commercial ICP mass spectrometers from different companies (quadrupole based ICP-MS with and without collision/reaction cell, double-focusing sector field instrumentation with single and multiple ion collectors, time-of-flight (ToF), ICP-ion trap-MS and non-commercial ICP-Fourier transform ion cyclotron resonance (FTICR) mass spectrometers is given in Figure 5.2. By using ion traps and FTICR mass spectrometers in ICP-MS isobaric interferences of atomic ions... 

Figure 16.8—Ion cyclotron resonance (ICR) mass spectrometer. Ion trajectories in the ICR cell are shown. Plates 5 and 6 are used for excitation, plates 3 and 4 are used to trap ions and plates 1 and l are used as the detection system. Ions can be formed inside or outside the ICR cell. Exampleofthe tg resouion a can be obtained with this type of spectrometer (R = 3 x I06), cf. 16.8.3.

Figure 8. Schematic diagram of typical ion-cyclotron resonance (ICR) cell used for ion-molecule reaction studies. Regions A, B, and C designate ion source, analyzer, and ion collector regions, respectively. Electrodes 2 and 4 are used to apply trapping potential, 1 and 3 for source drift potential, 5 and 6 for analyzer drift and RF fields, and 7 to 10 for total ion collection.148...

Figure 7.8 Excitation (a) and detection (b) of the ion cyclotron motion within an FTMS mass analyzer cell. Reprinted from Marshall, A.G. and Flendrickson, C.L., Fourier transform ion cyclotron resonance detection principles and experimental configurations. International Journal of Mass Spectrometry, 215, 59-75. Copyright (2002), with permission from Elsevier.

Selected topics in Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry instrumentation are discussed in depth, and numerous analytical application examples are given. In particular, optimization ofthe single-cell FTMS design and some of its analytical applications, like pulsed-valve Cl and CID, static SIMS, and ion clustering reactions are described. Magnet requirements and the software used in advanced FTICR mass spectrometers are considered. Implementation and advantages of an external differentially-pumped ion source for LD, GC/MS, liquid SIMS, FAB and LC/MS are discussed in detail, and an attempt is made to anticipate future developments in FTMS instrumentation. 

Figure 18 Use of ion-molecule reactions to change relative ion intensities. 204Pb+ and 2WHg+ were allowed to react with benzene in the Fourier transform ion cyclotron resonance (FT-ICR) analyzer cell for progressively longer periods.

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