Mass spectroscopy analysis

The author would like to thank W. H. Davis, Jr., and R. K. Lyon for helpful discussions. The excellent technical assistance of J. C. Dowling is also gratefully acknowledged. Thanks also to T. R. Ashe and C. S. Hsu for performing the gas chromatography/mass spectroscopy analyses to identify the products. 

R.P.W. Scott, C.G. Scott, M. Munroe and J. Hess Jr., Interface for on-line liquid chromatography-mass spectroscopy analysis, J. Chromatogr., 99 (1974) 395-405. 

From the analytical point of view, reactions were efficiendy monitored using a combination of FTIR (Fourier transform infrared), TLC (thin-layer chromatography), and MALDI-TOF mass spectroscopy analysis of crudes resulting from the cleavage of small resin samples. 

Figure 5.10 is the dynamic TGA scan of neat PTFE in air and N2. Under each atmosphere studied, it is readily apparent that the onset of degradation occurs at about 500°C. TGA data are also in excellent agreement with a more sensitive and structurally informative pyrolysis/mass spectroscopy analysis. Figure 5.11 is a... 

Similar studies were carried out with benzoic acid on porous palladium electrodes [150]. The objective of this work was to investigate the adsorption processes and the reactivity of benzoic acid on different noble metals, in order to compare these results with those obtained for related aromatic compounds. On-line mass spectroscopy analysis of volatile products revealed that the adsorption of benzoic acid is irreversible at platinum while it is mainly reversible on palladium. Accordingly, different catalytic activity of platinum and palladium was found in the electrooxidation. 

In the first studies, antibodies were used to elucidate the dynamic nature of poliovirus [51]. Antibodies were raised against peptides representing VP4 and the N termini of VPl. In the crystal structures of all of the picornaviruses, these termini lie at the capsid-RNA interface and are therefore not exposed to external solvent [27, 46, 52-55]. These antibodies bound to the virus when the particles were heated to 37°C but did not bind when added to virus at room temperature or when the virus was heated to 37°G and then cooled to room temperature. Therefore, although difficult to visualize with the static structure of the capsid, the only explanation for these results is that these buried termini are transiently exposed. This exposure is facilitated by higher temperatures and was proposed to be part of the normal infection process. This idea of dynamic capsid structures was subsequently supported by mass spectroscopy analysis of flock house virus [56] and rhinovirus [57] and by a series of drug—poliovirus structures [58]. 

The metal loading was measured by inductively coupled plasma-mass spectroscopy analysis. The itricrostructure and location of the metallic active phase were investigated on a Topcon EM002B transmission electron microscope working at 200 kV accelerating voltage and with a point-to-point resolution of 0.17 nm. The sample was prepared by... 

Rafferty, Sean M. 2002. Identification of nicotine by gas chromatography/mass spectroscopy analysis of smoking pipe residue. Journal of Archaeological Science 29 897-907. 

Lapierre, C., Pollet, B., Monties, B., and Rolando, C. (1991) Thioacidolysis of spruce lignin Gas chromatography-mass spectroscopy analysis of the main dimers recovered after Raney nickel desulfurization. Holzforschung 45(1), 61-68. 

The thermal variation of specific heat measured by adiabatic calorimetry is showninfig 1 At about 347 K a jump of occurs which corresponds to a first order transition. This is confirmed by 0. S. C. measurement which gives an enthalpy of transition AH = 1160+ 100 cal/mole. This transition which presents an endothermic signal is however irreversible, at least down to 4 K, To obtain the initial phase it is necsssary to crystallize again the trensformed product in eceto-nitrile. However the irreversibility is not due to solvent inclusion as evidenced by mass spectroscopy analysis,... 

The crystal structure of bovine cytochrome c oxidase (Complex IV) homodimer has been determined to a resolution of 1.8 A (Shinzawa-Itoh et al., 2007). This integral membrane protein complex composed of thirteen different subunits per monomer is responsible for the reduction of molecular oxygen to water during aerobic respiration, with concomitant proton pumping across the mitochondrial inner membrane. A combination of high resolution X-ray structure analysis of the integral lipids in bovine Complex IV with mass spectroscopy analysis of their chain lengths and the positions of the unsaturated bonds of the... 

Tseng, K., Liu, J., Lebrilla, C. B., Collins, S. D. and Smith, R. L. Fabrication and design of open microchannels for capillary electrophoresis separations and matrix-assisted laser/desorption mass spectroscopy analysis. Proc SPIE Int Soc Opt Eng, 3606, 137, 1999. 

An astonishing aspect of formic acid oxidation on palladium is the formation of CO2 at potentials of hydrogen oxidation and oxygen evolution. On-line mass spectroscopy analysis of volatile products reveals the production of CO2 not only in the double-layer region but also near 0.25 and 1.75 V [101]. The fact that the current and the CO mass signal during a potential scan do not follow the same pattern indicates that HCOOH oxidation proceeds through parallel mechanisms. 

Ogumi Z., Sano A., Inaba M., Abe T. Pyrolysis/gas chromatography/mass spectroscopy analysis of the surface film formed on graphite negative electrode, J. Power Soirrces 2001,97-98, 156-158. 

Mass spectroscopy Analysis of elements and structure determination Usually solid extracts ... 

SIMS Scanning ion mass spectroscopy. Analysis of polymeric is a good application of SIMS, where metallic elements are often not observed. It is a microanalytical surface method of material examination. 

Under these conditions, mass spectroscopy analysis indicated a NO conversion only in the first step, but an important part of NO is oxidized to NO2 in homogeneous phase. XPS investigation of the samples subjected to the mixture of NO with oxygen showed the oxidation of copper in a very high extent. 

A high percentage of the sputtered secondary particles are neutral and must be post-ionized for mass spectroscopy analysis (SNMS) (62). Post-ionization can be achieved by electron impact in a plasma or by an electron beam. Alternatively, resonant and nonresonant laser ionization can be applied. Applications of SNMS for catalyst characterization have still not been reported. 

General and Selective Isolation Procedure for Gas Chromatography/Mass Spectroscopy Analysis of Steroids in Tissues and Body Fluids... 

The fullerenes were discovered in 1985 by Smalley and Kroto who, while performing mass-spectroscopy analysis of carbon vapor, observed... 

The cytosolic PHA was studied using gas chromatography-mass spectroscopy analysis of dichloroethane extracts of dried cell material (20-60mg) as described previously (4). All cell samples were washed six times with warm methanol before being subjected to the previously described propanolysis method. Samples were analyzed using a Kratos MS25 GC-MS with a DB-WAX column. 

Loesing R, Guryanov GM, Phillips MS, Griffis DP (2002) Comparison of secondary ion mass spectroscopy analysis of ultrashallow phosphorus using Cs, O2, and CsCs primary ion beams. J Vac Sci Technol B 20 507-511. doi 10.1116/1.1450588... 

VanHoenacker G, Sandra P. High temperature Uquid chromatography and liquid chromatography-mass spectroscopy analysis of octylphenol ethoxylates on different stationary phases. J Chromatogr A 2005 1082(2) 193—202. 

This work was supported by nzymSys, Inc. and the Department of Energy QX)E) through award number DE-EE0003226 ("Improving Reliability and Durability of Efficient and Qean Energy Systems"). A.M.M. acknowledges Hector Fabian Garces from University of Connecticut for assistance with the mass spectroscopy analysis. 

Based on mass spectroscopy analysis, it was found that oligomer and polymer with ethylene oxide units are electro-chemically decomposable species during charging and R0C02Li is relatively electrochemically stable. The formation of large amount of these species could be related to strong catatytic effect from nanosized transition metal nanograins. 

Another family of diphosphines displaying a trans coordination mode, SPAN-phos 48(a-d), has also been tested in this reaction [102]. Surprisingly, even if the corresponding trans-[RhI(CO)48] render systems as active as the Suss-Fink analogs, when tested in an elementary step, they show no reaction in the oxidative addition of Mel (vide supra). The observed catalytic activity has been attributed to dinuclear species formed under catalytic conditions. The dinuclear compounds [Rh2(y -Cl)2(CO)248aj, 64, react with Mel at 25 °C with a fci value of around 0.025 s M and currently they represent the fastest phosphine-based systems reported for methanol carbonylation. According to spectroscopic and gas chromatography/mass spectroscopy analysis, the products of the Mel-oxida-tive addition are dinuclear monoacetyl derivatives 65 (Scheme 9.9). 

Gupta YN, Chakraborty A, Pandey GD, Setua DK. High resolution thermogravimetry/coupled mass spectroscopy analysis of flame retardant rubber. / Appl Polym Sci 2003 89(8) 2051-2057. 

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