Photoionization, mass spectrometry

Since 1960 mass spectrometry has always been an important tool to investigate the molecular composition of sulfur vapor, sulfur melts, and the solid dlotropes [201]. Mostly spectra obtained by electron impact (El) ionization have been reported, except for one study in which the main species present in sulfur vapor (S2-Ss) were studied by photoionization mass spectrometry [202]. The following ionization potentials were reported (in eV) [202] ... 

Cool, T.A. et al., Selective detection of isomers with photoionization mass spectrometry for studies of hydrocarbon flame chemistry,. Chem. Phys., 119,8356,2003. 

Cool, T.A. et al., Photoionization mass spectrometry and modeling studies of the chemistry of fuel-rich dimethyl ether flames, Proc. Combust. Inst., 31,285,2007. 

One rather unfortunate aspect of the M + hydrocarbon (and M + OX) reactions mentioned thus far is that the products of the reactions were not detected directly, but were instead inferred via the pressure and temperature dependencies of the measured rate constants for metal reactant consumption and by comparison to ab initio calculations. Exceptions are the reactions of Y, Zr + C2H4 and C3H6, for which the Weisshaar group employed the 157 nm photoionization/mass spectrometry technique to identify the products of the reaction as those resulting from bimolecular elimination of H2.45 47 95... 

Rauha JP, Vuorela H and Kostiainen R. 2001. Effect of eluent on the ionization efficiency of flavonoids by ion spray, atmospheric pressure photoionization mass spectrometry. J Mass Spectrom 36 1269-1280. 

T. A. Cool, K. Nakajima, C. A. Taatjes, A. Mcllroy, P. R. Westmoreland, M. E. Law, and A. Morel. Studies of a Fuel-rich Propane Flame with Photoionization Mass Spectrometry. Proc. Combust. Inst., 30(2005) 1681-1688. 

T. J. Kauppila, T. Kuuranne, E. C. Meurer, M. N. Eberlin, T. Kotiaho, and R. Kostiainen. Atmospheric Pressure Photoionization Mass Spectrometry Ionization Mechanism and the Effect of Solvent on the Ionization of Naphthalenes. Anal. Chem., 74(2002) 5470-5479. 

A. Raffaelli and A. Saba. Atmospheric Pressure Photoionization Mass Spectrometry. Mass Spectrom. Rev., 22(2003) 318-331. 

Photoionization mass spectrometry, by way of contrast, is a low-tem-perature variant. It employs a monochromated UV source to detect accurately the onset of molecular dissociation (see Section II,A). The heats of formation of KrF2 (28) and HOF (24) have been so measured. 

A simpler comparison is possible between gaseous H202 and HOF (Fig. 3). The latter has been regarded as a hydroxofluoride (242) whose enthalpy has been estimated indirectly by photoionization mass spectrometry (24). 

Bos, S. J., Leeuwen, S. M., and Karst, U. (2006). Erom fundamentals to applications recent developments in atmospheric pressure photoionization mass spectrometry. Anal. Bioanal. Chem. 384, 85-99. 

Cai, Y, Kingery, D., McConnell, O., and Bach, A. C., II. (2005). Advantages of atmospheric pressure photoionization mass spectrometry in support of drug discovery. Rapid Commun. Mass Spectrom. 19, 1717—1724. 

Raffaelll, A., and Saba, A. (2003). Atmospheric pressure photoionization mass spectrometry. Mass Spectrom. Rev. 22, 318-331. 

Takino, M., Daishima, S., and Nakahara, T. (2003). Determination of perfluorooctane sulfonate in river water by liquid chromatography/atmospheric pressure photoionization mass spectrometry by automated on-line extraction using turbulent flow chromatography. Rapid Commun. Mass Spectrom. 17, 383—390. 

Zheng, J., and Shamsi, S. A. (2006). Capillary electrochromatography coupled to atmospheric pressure photoionization mass spectrometry for methylated benzo[a]pyrene isomers. Anal. Chem. 78, 6921-6927. 

Kauppila, T. J. Kotiaho, X Kostiainen, R. Bruins, A. P. Negative ion-atmospheric pressure photoionization-mass spectrometry. J Am Soc Mass Spectrom 2004, 15, 203-211. 

Hansen, N. Klippenstein,S. J. Miller,]. A. Wang, J. Cool, T. A. Law, M. E. Westmoreland, P. R. Kasper, T. Kohse-Hoinghaus, K. Identification of CjH,j Isomers in Fuel-Rich Flames by Photoionization Mass Spectrometry and Electronic Structure Calculations. Phys. Chem. A 2006,110, 4376-4388. 

Starkey, J. A., Mechref, Y, Muzikar, J., McBride, W. J., and Novotny, M. V., Determination of salsolinol and related catecholamines through on-line preconcentration and liquid chromatography/atmospheric pressure photoionization mass spectrometry. Analytical Chemistry 78(10), 3342-3347, 2006. 

Total photoabsorption Total photoionization Photoelectron spectroscopy Photoionization mass spectrometry Electron-energy-loss spectroscopy, dipole (e, e) Dipole (e, 2e) or (e, e + ion) (from sums of partials) Electron energy loss-ejected electron coincidence, dipole (e, 2e) Electron-ion coincidence, dipole (e, e + ion)... 

Femtosecond photoionization mass spectrometry might be useful in the study of the three-dimensional structure of large biomolecules. When a selectively excitable and ionizable chromophore is located on the outer (surface) part of large molecule, one can be detached in the picosecond time scale. However, when the excitable chromophore is located in the inner part of the big molecule, its detachment will require a much longer time, which is needed for spatial rearrangement of the molecule. So, even the simple mass spectrometry of bioorganic molecules with femtosecond laser ionization can reveal some details of their spatial structure. 

Silathietanes can be readily prepared from the appropriate bis(chloromethyl)silane and KSH or by intramolecular hydrosilation in the presence of Wilkinson s catalyst (Scheme 97) (81JOM(204)13). Electron impact and photoionization mass spectrometry support the loss of silathione ions (R2Si=S) (R = Me, Et) indicating a transannular interaction, though decomposition by the loss of silenes and thioaldehyde also readily occurs (81JOM(214)145). 

Detection. Nearly all of the vapor-phase organic compounds will respond when added to a flame ionization detector, Consequently, this detector is most commonly used. Other special-purpose detectors include photoionization, mass spectrometry, atomic emission, ion mobility, mercury oxide reduction, and chemiluminescence detectors. 

In this section we discuss the more important experimental results for continuum oscillator strengths measured by electron spectroscopy that have been reported up to mid 1978. The discussion is divided on the basis of target species rather than the type of experiment since this stresses the interrelation and complementary nature of many of the experiments. As the experimental work is far from complete in many cases, only a limited picture of the overall breakdown processes is available at present. In particular, a very limited amount of work has been reported for inner shells. More data are generally available for mass fragmentation (photoionization mass spectrometry) than for partial ionization cross sections (photoelectron spectroscopy). 

Photoionization-mass spectrometry Electron-impact lomzauon high-kinetic-energy ion beam... 

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