Deuterium mass spectrometry

Three of the species involve deuterium mass spectrometry is ideal, and can also be used for H20. 

Reversal of reaction (14) yields DBr in solution which cycles through the same reaction with the substrate aromatic compound to yield the deuterated product. In a t5q)ical experiment, conducted in the authors laboratory, reaction of 0.050 g of pyrene with 1 ml benzene-de and 0.040 g AlBr3 in a sealed tube for 5 days at 90° gave pyrene in which 92 percent of aU hydrogens had been exchanged for deuterium (mass spectrometry). A second treatment yields about 99 percent exchange of all hydrogens. 

The first mass spectrometric investigation of the thiazole ring was done by Clarke et al. (271). Shortly after, Cooks et al., in a study devoted to bicydic aromatic systems, demonstrated the influence of the benzo ring in benzothiazole (272). Since this time, many studies have been devoted to the influence of various types of substitution upon fragmentation schemes and rearrangements, in the case of alkylthiazoles by Buttery (273) arylthiazoles by Aune et al. (276), Rix et al. (277), Khnulnitskii et al. (278) functional derivatives by Salmona el al. (279) and Entenmann (280) and thiazoles isotopically labeled with deuterium and C by Bojesen et al. (113). More recently, Witzhum et al. have detected the presence of simple derivatives of thiazole in food aromas by mass spectrometry (281). 

Mass spectrometry has been used to determine the amount of H2 in complex gas mixtures (247), including those resulting from hydrocarbon pyrolysis (68). Mass spectrometry can also be used to measure hydrogen as water from hydrocarbon combustion (224,248). Moreover, this technique is also excellent for determining the deuterium hydrogen ratio in a sample (249,250). 

Infrared Spectrophotometry. The isotope effect on the vibrational spectmm of D2O makes infrared spectrophotometry the method of choice for deuterium analysis. It is as rapid as mass spectrometry, does not suffer from memory effects, and requites less expensive laboratory equipment. Measurement at either the O—H fundamental vibration at 2.94 p.m (O—H) or 3.82 p.m (O—D) can be used. This method is equally appticable to low concentrations of D2O in H2O, or the reverse (86,87). Absorption in the near infrared can also be used (88,89) and this procedure is particularly useful (see Infrared and raman spectroscopy Spectroscopy). The D/H ratio in the nonexchangeable positions in organic compounds can be determined by a combination of exchange and spectrophotometric methods (90). 

Deuterium exchange of conjugated enones and dienones on pretreated gas chromatography columns has been found useful for the characterization of these compounds by combined gas chromatography-mass spectrometry. ... 

Deuterium-labeling and mass spectrometry prove that the mechanism of the thermal O to N rearrangement of 4-alkoxypyridines to N-alkyl-4-pyridones is intermolecular (88CS347). 

His researches and those of his pupils led to his formulation in the twenties of the concept of active catalytic centers and the heterogeneity of catalytic and adsorptive surfaces. His catalytic studies were supplemented by researches carried out simultaneously on kinetics of homogeneous gas reactions and photochemistry. The thirties saw Hugh Taylor utilizing more and more of the techniques developed by physicists. Thermal conductivity for ortho-para hydrogen analysis resulted in his use of these species for surface characterization. The discovery of deuterium prompted him to set up production of this isotope by electrolysis on a large scale of several cubic centimeters. This gave him and others a supply of this valuable tracer for catalytic studies. For analysis he invoked not only thermal conductivity, but infrared spectroscopy and mass spectrometry. To ex-... 

Which bond of the ester is broken, the acyl—O or the alkyl—O bond The answer is found by the use of Hj O. If the acyl—O bond breaks, the labeled oxygen will appear in the acid otherwise it will be in the alcohol (see 10-10). Although neither compound is radioactive, the one that contains 0 can be determined by submitting both to mass spectrometry (MS). In a similar way, deuterium can be used as a label for hydrogen. In this case, it is not necessary to use mass spectrometry (MS), since IR and NMR spectra can be used to determine when deuterium has been substituted... 

Snyder AP, Harden CS. 1990. Determination of the fragmentation mechanisms of organophosphorus ions by water and deuterium oxide atmospheric-pressure ionization tandem mass spectrometry. II. Dialkylphosphonate ions. Org Mass Spectrom 25(6) 301-308. 

Scrimgeour, C. M., Begley, I. S. and Thomason, M. L. (1999) Measurement of deuterium incorporation into fatty acids by gas chromatography/isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry 13, 271. 

In related experiments by Johnson (1985), atomic deuterium was used instead of Hx to neutralize boron in Si. Similar results on spreading resistance were obtained. Furthermore, the distribution profile of D was measured by secondary-ion mass spectrometry (SIMS), as shown in Fig. 4. The distribution profile of D reveals 1) that the penetration depth of D is in good agreement with the resistivity profile and 2) that the D concentration matches the B concentration over most of the compensated region. In another sample, the B was implanted at 200 keV with a dose of 1 x 1014 cm-2, the damage was removed by rapid thermal anneal at 1100°C for 10 sec., and then D was introduced at 150°C for 30 min. As shown in Fig. 5, it is remarkable that the D profile conforms to the B profile. 

As for silicon, secondary ion mass spectrometry (SIMS) is the most widely used profiling analysis technique for deuterium diffusion studies in III-V compounds. Deuterium advantageously replaces hydrogen for lowering the detection limit. The investigations of donor and acceptor neutralization effects have been usually performed through electrical measurements, low temperature photoluminescence, photothermal ionization spectroscopy (PTIS) and infrared absorption spectroscopy. These spectroscopic investigations will be treated in a separated part of this chapter. 

Halcinonide dissolved in either methanol, deutero-methanol, aqueous ammonia-methanol, or deuterium oxide deuter-ated ammonia-methanol solvents appears stable after storage for six days at 50°, using nuclear magnetic resonance and mass spectrometry.70... 

Nazabal, A., Maddelein, M. L., Bonneu, M., Saupe, S. J., and Schmitter, J. M. (2005). Probing the structure of the infectious amyloid form of the prion-forming domain of HET-s using high resolution hydrogen/deuterium exchange monitored by mass spectrometry./ Biol. Chem. 280, 13220-13228. 

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