Fourier Transform Mass Spectroscopy

The apparatus for cyclotron resonance spectrometry is shown in Fig. 16.2. A magnetic field is applied perpendicular to the plane. There are two pairs of electrodes, one pair to excite the ions inside by a pulse or by an alternating current and one pair to measure the electric response. The whole cell is kept in high vacuum, in order to allow the ions without collisions. 

According to LorentT/ the force exerted on ions in the cell is 

Therefore, if the magnetic field acts only in z-direction, then we obtain from Eq. (16.5) the set of equations 

In the absence of an electrical field, a circular motion is possible. We show this by forming again the derivative with time with the second and third equations of the set of (16.6), 

---

The initial observation is that PMMA is essentially completely degraded to monomer by heating to 375°C in a sealed tube while heating a mixture of red phosphorus and PMMA under identical conditions yields a solid, non-deqraded, product as well as a lower yield of monomer. One may observe, by 3C NMR spectroscopy, that the methoxy resonance is greatly decreased in intensity and methyl, methoxy phosphonium ions are observed by 31P NMR. Additional carbonyl resonances are also seen in the carbon spectrum, this correlates with a new carbonyl vibration near 1800 cm 1 in the infrared spectrum and may be assigned to the formation of anhydride. The formation of anhydride was also confirmed by assignment of mass spectra obtained by laser desorption Fourier transform mass spectroscopy, LD-FT-MS. 

A different definition uses the peak width at half height as Am (50 % definition) for the calculation (see Fig. 1). This approach is used often for Fourier transform mass spectroscopy (FTMS) and time-of-flight (TOF) instruments. In modem mass spectrometers, the resolution is calculated directly by the computer from the peak width. 

Amsteg Jonathan. Fourier transform mass spectroscopy.. Mass Spectrom. 31P1325-1337,1996. 

Inagaku N., Sakm-ai S., and Katsuru a K., Affeet tris(2,3-bromo-propyl) phosphate with flame retardant of polystyrene , J. Appl. Polym. Sci., 1979, vol. 23, pp. 2023 - 2030. Brown C., Wilkie C., Smukalla J., and Cody B., Inhibition by red phosphorus of unimolecular thermal chain scission in poly(methyl methacrylate) investigation by NMR, FT-IR and laser decomposition/ Fourier transform mass spectroscopy, J. Polym. Sci. Polym. Chem. Ed., 1986, vol. 24, pp. 1297 - 1311. 

The sequence of a globular protein was confirmed by a combination of enzymatic digestion and HPLC with both Fourier-transform infrared spectroscopy (LC-FTIR spectroscopy) and mass spectrometry [11]. 

At present, most workers hold a more realistic view of the promises and difficulties of work in electrocatalysis. Starting in the 1980s, new lines of research into the state of catalyst surfaces and into the adsorption of reactants and foreign species on these surfaces have been developed. Techniques have been developed that can be used for studies at the atomic and molecular level. These techniques include the tunneling microscope, versions of Fourier transform infrared spectroscopy and of photoelectron spectroscopy, differential electrochemical mass spectroscopy, and others. The broad application of these techniques has considerably improved our understanding of the mechanism of catalytic effects in electrochemical reactions. 

Field desorption mass spectrometry [1606], C nuclear magnetic resonance, and fourier-transform infrared spectroscopy [1337] have been used to characterize oil field chemicals, among them, scale inhibitors. Ion... 

Detection in SFC can be achieved in the condensed phase using optical detectors similar to those used in liquid chromatography or in the gas phase using detectors similar to those used in gas chromatography. Spectroscopic detectors, such as mass spectrometry and Fourier transform infrared spectroscopy, are relatively easily interfaced to SFC compared to the problems observed with liquid mobile phases (see Chapter 9). The range of available detectors for SFC is considered one of its strengths. 

Ludlow, M., Louden, D., Handley, A., Taylor, S., Wright, B., and Wilson, I.D., Size-exclusion chromatography with on-line ultraviolet, proton nuclear magnetic resonance, and mass spectrometric detection and on-line collection for off-line Fourier transform infrared spectroscopy, /. Chromatogr. A, 857,89,1999. 

Goodacre, R. Shann, B. Gilbert, R. J. Timmis, E. M. McGovern, A. C. Alsberg, B. K. Kell, D. B. Logan, N. A. Detection of the dipicolinic acid biomarker in Bacillus spores using Curie-point pyrolysis mass spectrometry and fourier transform infrared spectroscopy Anal. Chem. 2000,72,119-127. 

McGovern, A. C. Ernill, R. Kara, B. V. Kell, D. B. Goodacre, R. Rapid analysis of the expression of heterologous proteins in Escherichia coli using pyrolysis mass spectrometry and Fourier transform infrared spectroscopy with chemometrics Application to a2- interferon production. J. Biotechnol. 1999, 72,157-167. 

Timmins, E. M. Howell, S. A. Alsberg, B. K. Noble, W. C. Goodacre, R. Rapid differentiation of closely related Candida species and strains by pyrolysis mass spectrometry and Fourier transform infrared spectroscopy. /. Clin. Microbiol. 1998,36, 367-374. 

Gas chromatography (GC) and with mass spectrometry (GC-MS) Fourier transform infrared spectroscopy (FTIR)... 

V.A. Basiuk, Pyrolysis of valine and leucine at 500°C identification of less volatile products using gas chromatography Fourier Transform infrared spectroscopy mass spectrometry, J. 

Due to its relatively low sensitivity, the combination of gas chromatography with Fourier transform infrared spectroscopy (GC-FTIR) is not a standard technique in semiochemical research. Nevertheless, it could come in handy for the identification of some compounds with utterly uninformative mass spectra [22]. 

More sophisticated detection methods for gas chromatography are also employed in the analysis of hydrocarbons gas chromatography-mass spectrometry (EPA 8270C) and gas chromatography-Fourier transform infrared spectroscopy (EPA 8410). These procedures have a significant advantage in providing better characterization of the contaminants and thus are of particular use where some environmental modification of the hydrocarbons has taken place subsequent to soil deposition. 

Other methods for the determination of aromatics in naphtha include a method (ASTM D5580) using a flame ionization detector and methods that use combinations of gas chromatography and Fourier transform infrared spectroscopy (GC-FTIR) (ASTM D5986) and gas chromatography and mass spectrometry (GC-MS) (ASTM D5769). 

---