Mass spectrometer, diagram

What are the general components of a mass spectrometer diagram of a mass spectrometer is shown in Fig. 2. 

Figure A3.5.8. Schematic diagram of the cell used in a Fourier transfomr mass spectrometer.

In essence, a guided-ion beam is a double mass spectrometer. Figure A3.5.9 shows a schematic diagram of a griided-ion beam apparatus [104]. Ions are created and extracted from an ion source. Many types of source have been used and the choice depends upon the application. Combining a flow tube such as that described in this chapter has proven to be versatile and it ensures the ions are thennalized [105]. After extraction, the ions are mass selected. Many types of mass spectrometer can be used a Wien ExB filter is shown. The ions are then injected into an octopole ion trap. The octopole consists of eight parallel rods arranged on a circle. An RF... 

A schematic diagram of a reverse geometry mass spectrometer is shown in figure Bl.7.4. 

Figure Bl.7.4. Schematic diagram of a reverse geometry (BE) magnetic sector mass spectrometer ion source (1) focusing lens (2) magnetic sector (3) field-free region (4) beam resolving slits (5) electrostatic sector (6) electron multiplier detector (7). Second field-free region components collision cells (8) and beam deflection electrodes (9).

Another instrument used in physical chemistry research that employs quadnipole mass filters is the guided ion beam mass spectrometer [31]. A schematic diagram of an example of this type of instrument is shown in figure B 1.7.13. A... 

Figure Bl.7.13. A schematic diagram of an ion-guide mass spectrometer. (Ervin K M and Annentrout P B 1985 Translational energy dependence of Ar + XY —> ArX + Y from thennal to 30 eV c.m. J. Chem. Phys. 83 166-89. Copyright American Institute of Physics Publishing. Reproduced with pemiission.)...

Figure Bl.7.14. Schematic cross-sectional diagram of a quadnipole ion trap mass spectrometer. The distance between the two endcap electrodes is 2zq, while the radius of the ring electrode is (reproduced with pennission of Professor R March, Trent University, Peterborough, ON, Canada).

Figure Bl.7.17. (a) Schematic diagram of a single acceleration zone time-of-flight mass spectrometer, (b) Schematic diagram showing the time focusing of ions with different initial velocities (and hence initial kinetic energies) onto the detector by the use of a reflecting ion mirror, (c) Wiley-McLaren type two stage acceleration zone time-of-flight mass spectrometer.

Time-of-flight mass spectrometers have been used as detectors in a wider variety of experiments tlian any other mass spectrometer. This is especially true of spectroscopic applications, many of which are discussed in this encyclopedia. Unlike the other instruments described in this chapter, the TOP mass spectrometer is usually used for one purpose, to acquire the mass spectrum of a compound. They caimot generally be used for the kinds of ion-molecule chemistry discussed in this chapter, or structural characterization experiments such as collision-induced dissociation. Plowever, they are easily used as detectors for spectroscopic applications such as multi-photoionization (for the spectroscopy of molecular excited states) [38], zero kinetic energy electron spectroscopy [39] (ZEKE, for the precise measurement of ionization energies) and comcidence measurements (such as photoelectron-photoion coincidence spectroscopy [40] for the measurement of ion fragmentation breakdown diagrams). 

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).

FIGURE 13 44 Diagram of a gas chromatograph When connected to a mass spectrometer as in GC/MS the effluent is split into two streams as it leaves the column One stream goes to the detector the other to the mass spectrometer (Adapted with permission from H D Durst and G W Gokel Experimental Organic Chemistry Inti eti McGraw Hill New York 1987)... 

Schematic diagram of a mass spectrometer. After insertion of a sampie (A), it is ionized, the ions are separated according to m/z value, and the numbers of ions (abundances) at each m/z value are plotted against m/z to give the mass spectrum of A. By studying the mass spectrum, A can be identified,...

Fig. 1. Schematic diagram of a double-focusing Nier-Johnson magnetic sector mass spectrometer where ( " ) represents paths of ions having slightly...

Fig. 6. Schematic diagram of a four-sector mass spectrometer of EBEB geometry where ESA = electrostatic analyzer (30). The flexiceU is the coUision...

Figure 1 Schematic diagram of a Mattauch-Herzog geometry spark source mass spectrometer using an ion-sensitive plate detector.

Fig. 4.46. Schematic diagram of IBSCA measurement equipment this usually combined with a mass spectrometer (SIMS or SNMS).

Figure 9.12 Schematic diagram of the silica sheath electrospray needle used to interface capillary zone electi ophoresis with a mass spectrometer.

Mass spectrometers, workhorse instmments described in Chapter 2, require a vacuum to function. A mass spectrometer generates a beam of ions that is sorted according to specifications of the particular instrument. Usually, the sorting depends on differences in speed, trajectory, and mass. For instance, one type of mass spectrometer measures how long it takes ions to travel from one end of a tube to another. Residual gas must be removed from the tube to eliminate collisions between gas molecules and the ions that are being analyzed. As the diagram shows, collisions with unwanted gas molecules deflect the ions from their paths and change the expected mass spectral pattern. 

Figure 3.11. Schematic diagram of the model LIMA 2A laser microprobe mass spectrometer (Odom and Schueler 1990) to the number of ions detected.

Trimborn et al. (2000) have developed a mobile system for the on-line analysis of single airborne particles and for the characterisation of particle populations in aerosols, using a transportable laser mass spectrometer. A schematic diagram of their setup is shown in Figure 3.12. 

Figure 3.12. Schematic diagram of the instrumental setup of the mobile aerosol mass spectrometer LAMPAS 2 . (Trimborn et al. 2000.)...

Figure 3.14. Schematic diagram of the scanning microprobe matrix-assisted laser desorption ionisation (SMALDI) mass spectrometer. (Spengler and Hubert 2002.)...

The apparatus consists of a pulsed molecular beam, a pulsed ultraviolet (UV) photolysis laser beam, a pulsed vacuum ultraviolet (VUV) probe laser beam, a mass spectrometer, and a two-dimensional ion detector. The schematic diagram is shown in Fig. 1. 

Figure 7. Schematic diagram of a flowing-afterglow electron-ion experiment. The diameter of flow tubes is typically 5 to 10 cm and the length is 1 to 2 meters. The carrier gas (helium) enters through the discharge and flows with a velocity of 50 to 100 m/s towards the downstream end of the tube where it exits into a fast pump. Recombination occurs mainly in the region 10 to 20 cm downstream from the movable reagent inlet, at which the ions under study are produced by ion-molecule reactions. The Langmuir probe measures the variation of the electron density in that region. A differentially pumped mass spectrometer is used to determine which ion species are present in the plasma.

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