Isotopes, mass spectrometry

Table 1 lists MORE studies to date and Figures 2 and 3 present data from different areas of ridge. The first study of U-series disequilibria in MORE was the pioneering work of Condomines et al. (1981) (Fig. 2A). These workers analyzed samples having a relatively wide range in composition (Mg 72 to 57) from the FAMOUS region of the Mid-Atlantic Ridge (MAR 37°N) by combined alpha spectrometry (for U and Th isotopic ratios) and mass spectrometry (isotope dilution measurements for U and Th... 

In mass spectrometry isotope marked analytes are ideal internal standards and therefore quite often used. 

Deutsch, J.C., Determination of p-hydroxyphenylpyruvate, p-hydroxyphenyllactate and tyrosine in normal human plasma by gas chromatography-mass spectrometry isotope-dilution assay, J. Chromatogr. B, 690, 1, 1997. 

Barker, J., and Gamer, R. C. (1999). Biomedical applications of accelerator mass spectrometry-isotope measurements at the level of the atom. Rapid Commun. Mass Spectrom. 13 285-293. 

Physical methods directly related to chemical composition have been used in efforts to detect adulterations of citrus products. Physical measurements include spectrophotometry (UV, fluorescence, colorimetry), gravimetric determinations (ash, specific gravity), mass spectrometry (isotope ratios), chromatography, and optical rotation. 

Matthews, D. E., and Hayes, J. M. (1976). Systematic errors in gas chromatography-mass spectrometry isotope ratio measurements. Anal. Chem. 48, 1375-1382. 

Useful isotope combinations in mass spectrometry. Isotopes of other atoms that are possibly associated must always be taken into account, as is shown in the framed section. 

Thermal elimination reactions of molecules in the gas phase and in solution usually occur by 1,2-processes by a variety of mechanisms (Banthorpe, 1963) some 1,4-elimination processes have also been suggested (Harding et al., 1967). In mass spectrometry, isotopic labelling shows that elimination of water from primary aliphatic alcohols occurred mainly by 1,4-processes, the remainder being 1,3- and 1,5-reactions, provided the aliphatic chain was sufficiently long (Benz and Biemann, 1964 S. Meyerson and Leitch, 1964). Similar studies showed that dehydrochlorination of 1-chloropentane and 1-chlorobutane luider electron impact proceeded preferentially by 1,3-elimination processes (Duffield et at., 1966). 

For example, little is known about the isotopic composition of formaldehyde in the atmosphere. Formaldehyde is a chemical intermediate in hydrocarbon oxidation. The carbon (8 C) and hydrogen (8D) isotopic composition of atmospheric formaldehyde is analyzed using continuous flow gas chromatography isotope ratio mass spectrometry." Isotope ratios were measured using GC-IRMS (Finnigan MAT 253 stable isotope ratio mass spectrometer, single-sector field with electron impact ion source and multiple ion collection) with a precision of 1.1 and 50%(lo ) for 8 C and 8D, respectively. The accuracy of the online continuous flow isotope technique was verified by calibrating three aliquots of the gas phase standard via the offline dual inlet IRMS technique. The concentration of formaldehyde in ambient air was determined on IRMS major ion peak areas (i.e., mass 44 for 8 C and mass 2 for 8D)." ... 

MEVIS/IPM, membrane inlet mass spectrometry/isotope pairing method TCD, gas chromatography-thermal conductivity detector AIT, acetylene inhibition technique IPM, isotope pairing method with isotope ratio mass spectrometry MIMS, membrane inlet mass spectrometry Stoichiometery, benthic flux DICiDIN stoichiometry MIMS + N03, membrane inlet mass with N03 amendment 15N2 production, 15N03 or 15NH4 conversion to 15N2. 

Following the classification of the analytical methods given by ISO 32 [3] two major type of calibration materials can be certified. For relative methods such as all spectrometric ones, pure substances are necessary. They can be certified for the stoichiometry and degree of purity but also for isotopic composition. The latter case is a prerequisite for measurements of radioactive materials and for stable isotope mass spectrometry (isotope dilution TIMS or ICP-MS). For comparative methods, pure substances and mixtures of substances are necessary, as well as matrix materials for which the element to be determined is perfectly known and also the major compounds that produce a matrix influence on the signal (e.g. alloys, gases). 

The objective of this symposium and this book is to acquaint the readers with the latest advances in the field of elemental analysis and to focus on what avenues of future research to explore in this area. The subjects included are various elemental analysis techniques such as atomic absorption spectrometry, inductively coupled plasma emission and mass spectrometry, isotope dilution mass spectrometry. X-ray fluorescence, ion chromatography, gas chromatography-atomic emission detection, other hyphenated techniques, hetero-atom microanalysis, sample preparation, reference materials, and other subjects related to matrices such as petroleum products, lubricating oils and additives, crude oils, used oils, catalysts, etc. 

Protein-protein interaction studies using protein chips (240), mass spectrometry isotope-coded affinity tag technology (241), and the yeast two-hybrid system (242). 

Vogel JS, Turteltaub KW, Finkel R, Nelson DE. Accelerator mass spectrometry—isotope quantification at attomole sensitivity. Anal Chem 1995 67 353A-359A. 

Seebacher, J. MaUick, P. Zhang, N. Eddes, J.S. Aebersold, R. Gelb, M.H. Protein cross-linking analysis using mass spectrometry, isotope-coded cross-linkers, and integrated computational data processing. J. Proteome Res. 2006, 5, 2270-2282. 

See also Amperometry. Blood and Plasma. Clinical Analysis Sample Handling Inborn Errors of Metabolism. Fluorescence Derivatizatlon Fluorescence Labeling. Gas Chromatography Mass Spectrometry. Isotope Dilution Analysis. Liquid Chromatography Clinical Applications. 

Demmelmair, H., Schmidt, H.L. (1993) Precise 513C determination in the range of natural abundance on amino acids from protein hydrolysates by gas chromatography-isotope ratio mass spectrometry. Isotopes in Environmental and Health Studies, 29, 237-250. 

Vogel, J.S., Turteltaub, K.W., Finkel, R., and Nelson, D.E. (1995) Accelerator mass spectrometry isotope quantification at attomole sensitivity. Anal. Chem., 67, 353A-359A. 

GC-MS Supelco SPB-1 Mass spectrometry, isotope chluhon 50 fmol/injection 1993 (95)... 

Barker, J. Gamer, R.C. Biomedical Applications of Accelerator Mass Spectrometry-Isotope Measurements at the Level of the Atom. Rapid Commun. Mass Spectrom. 1999,13, 285-293. 

In combination with mass spectrometry isotope selective spectroscopy becomes possible, even if the spectral lines of the different isotope spectra... 

See also Biochemical Applications of Mass Spectrometry Biomedical Applications of Atomic Spectroscopy Chromatography-MS, Methods Fast Atom Bombardment Ionization in Mass Spectrometry Isotopic Labelling in Mass Spectrometry. 

See also Fragmentation in Mass Spectrometry Ion Energetics in Mass Spectrometry Ion Structures in Mass Spectrometry Isotopic Labelling in Mass Spectrometry Neutralization-Reionization in Mass Spectrometry Photoelectron-Photoion Coincidence... 

See also Ion Dissociation Kinetics, Mass Spectrometry Ion Imaging Using Mass Spectrometry Ion Molecule Reactions in Mass Spectrometry Isotope Ratio Studies Using Mass Spectrometry Mass Spectrometry, Historical Perspective Metastable Ions MS-MS and MS Neutralization-Reionization in Mass Spectrometry. 

Using X-Ray Diffraction Interstellar Molecules, Spectroscopy of Isotope Ratio Studies Using Mass Spectrometry Isotopic Labelling in Mass Spectrometry Labelling Studies in Biochemistry Using NMR MRI of Oil/Water in Rocks Time of Flight Mass Spectrometers. 

Spark source mass spectrometry isotope dilution... 

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