Mass spectrometry stable isotopes and

Isotopes of a chemical element possess the same number of electrons and protons and different numbers of neutrons. For example, hydrogen and deuterium are isotopic elements. They both possess one proton and one electron. Hydrogen ( H) has no neutron whereas deuterium ( H or D) has one. Carbon 12 ( C) has 6 electrons, 6 protons, and 6 neutrons. Carbon 13 ( C) has 6 electrons, 6 protons, and 7 neutrons. The physico-chemical properties of isotopes are very similar because neutrons exert very little influence on reactivity. 

The structures of many compounds include atoms in the forms of several natural isotopes. Table 4.1 in Chapter 4 lists the natures and relative abundances of the various isotopes of the main chemical elements constituting analyzable molecules in GC-MS coupling. The mass spectra present grouped peaks corresponding to the statistical distributions of the isotopes present. Ions consisting of the same atoms with different isotopes are known as isotopic isomers or isotopomers. 

In the case of chemical elements presenting several isotopes in relative proportions that are sufficiently abundant for each one to be detectable, as is the case of chlorine and bromine (see below), the shape of an isotope pattern is essential for the interpretation of a mass spectrum because it reveals the number of chlorine or bromine atoms included in the raw formula of the ion. To illustrate isotope patterns, we will study carbon, chlorine, and bromine elements. 

---

H.R. Mottram, S.N. Dudd, G.J. Lawrence, A.W. Stott, R.P. Evershed, New chromatographic, mass spectrometry and stable isotope approaches to the classification of degradated animal fats preserved in archaeological pottery, Journal of Chromatography, 833, 209 221 (1999). 

Lesage, D., Virelizier, H., Jankowski, C.K., Tabet, J.C. 1998. Identification of isomeric tributylphosphate dimers formed by radiolysis using tandem mass spectrometry and stable isotopic labelling. Eur. Mass Spectrom. 4 47-54. 

Keshishian H, Addona T, Burgess M, Mani DR, Shi X, Kuhn E et al (2009) Quantification of cardiovascular biomarkers in patient plasma by targeted mass spectrometry and stable isotope dilution. Mol Cell Proteomics 8 2339-2349... 

H. Keshishian, T. Addona, M. Burgess, E. Kuhn, and S. A. Carr, Quantitative, multiplexed assays for low abundance proteins in plasma by targeted mass spectrometry and stable isotope dilution, Mol. Cell. Proteomics, 6 (2007) 2212-2229. 

To be able to determine unchanged cocaine and benzoylecgonine excreted in human urine in amounts that are generally below the limits of detection, Jindal and Vestergaard used gas chromatography-mass spectrometry and stable isotope labeled analogs (cocaine-dj and benzoyl-... 

Huang, M.C., Muddana, S., Horowitz, E.N., McCormick, C.C., Infante, J.P., and Brenna, J.T. (2000) High-Precision Isotope Ratio Mass Spectrometry and Stable Isotope Precursors for Tracer Studies in Cell Culture, Anal. Biochem. 287, 80-86. 

Crnogorac, G., Schwack, W. (2007) Determination of dithiocarbamate fungicide residues by liquid chromatography-mass spectrometry and stable isotope dilution assay. Rapid Communications in Mass Spectrometry, 21,4009-4016. 

Jung JS, Eberl T, Sparbier K, Lange C, Kostrzewa M, Schubert S, Wieser A. Rapid detection of antibiotic resistance based on mass spectrometry and stable isotopes. Eur J Clin Microbiol Infect Dis. 2014 33 949-55. 

Taylor SR, McLennan SM (1985) The Continental Crust Its Composition and Evolution. Blackwell, Boston Tuit CB, Ravizza G (2003) The marine distribution of molybdenum. Geochim Cosmochim Acta 67 A4950 Tumlund JR, Keyes WR, Peiffer GL (1993) Isotope ratios of molybdenum determined by thermal ionization mass spectrometry for stable isotope studies of molybdenum metabolism in humans. Anal Chem 65 1717-1722... 

Palermo M, Gomez-Sanchez C, Roitman E, Shackleton CH (1996) Quantitation of cortisol and related - -4-ene steroids in urine using gas chromatography/mass spectrometry with stable isotope-labeled internal standards. Steroids 61 583-589... 

Lopez-Capel, E., Bol, R., and Manning, D. A. C. (2005a). Application of simultaneous thermal analysis mass spectrometry and stable carbon isotope analysis in a carbon sequestration study. Rapid Comm. Mass. Spect. 19, 3192-3198. 

Enjalbal, C., Roggero, R., Cerdan, R., Martinez, J., Vial, H., and Aubagnac, J. L. (2004). Automated monitoring of phosphatidylcholine biosyntheses in Plasmodium falciparum by electrospray ionization mass spectrometry through stable isotope labeling experiments. Anal. Chem. 76,4515—4521. 

Beynon, R. J., leyland, D. M., Evershed, R. P., Edwards, R. H. T., and Cobum, S. P. (1996). Measurement of the turnover of glycogen phosphorylase by gas chromatography/mass spectrometry using stable isotope derivatives of pyridoxine (Vitamin B6). Biochem. J. 317, 613-619. 

Raymond M W., Howard C P, Miles J. M., and Gensh J E (1980) Determination of leucine flux in vivo by gas chromatography-mass spectrometry utilizing stable isotopes for trace and internal standard / Chromatogr 183, 403 09. 

FIGURE 40.19 Schematic of an accelerator mass spectrometer. Reprinted from Matteson, S. (2008) Issues and opportunities in accelerator mass spectrometry for stable isotopes. Mass Spectrometry Revieu s, 27(5), 470-484. Copyright (2008), with permission from Wiley Periodicals. 

Matteson, S. (2008) Issues and opportunities in accelerator mass spectrometry for stable isotopes. Mass Spectrometry Reviews, 27,470-484. 

Aranda, M. and Morlock, G. 2007, New method for caffeine quantification by planar chromatography coupled with electrospray ionization mass spectrometry using stable isotope dilution analysis, Rapid Commun. Mass Spectrom., 21 1297-1303. 

Jindal, S. P., and Vestergaard, P. Quantitation of Cocaine and Its Principal Metabolite, Benzoylecgonine, by GLC-Mass Spectrometry Using Stable Isotope Analysis as Internal Standard... 

ICP-MS is used in practically every discipline where inorganic analytical support is required. This includes environmental, geological, biological, medical, nuclear, metallurgical (semiconductor industry) and nutritional studies. An important advantage of ICP-MS in quantitative analysis, required in many fields of application, is the substantial gain in precision and accuracy that can be achieved by the use of isotope-dilution mass spectrometry, where stable isotopes or... 

Wolfe, R.R. 1984 Tracers in Metabolic Research Radioisotope and Stable Isotope/Mass Spectrometry Methods. A.R. Liss, NY. 

Silfer, J. A., Engel, M. H., Macko, S. A. and Jumeau, E. J. (1991). Stable carbon isotope analysis of amino acid enantiomers by conventional isotope ratio mass spectrometry and combined gas chromatography isotope ratio massspectrometry. Analytical Chemistry 63, 370 374. 

Liang, H.R. Foltz, R.L. Meng, M. Bennett, P. Ionization enhancement in atmospheric pressure chemical ionization and suppression in electrospray ionization between target drugs and stable-isotope-labeled internal standards in quantitative liquid chromatography/tandem mass spectrometry. Rapid Commun. Mass Spectrom. 2003, 17, 2815—2821. 

Mosandl A, Enantioselective capillary gas chromatography and stable isotope ratio mass spectrometry in the authenticity control of flavors and essential oils, Food Rev Int. 537—SSA, 1995. 

---