Thermal ionization mass calcium analysis

Ireland TR, Fahey AJ, Zinner EK (1991) Hibonite-bearing microspherules a new type of refractory inclusions with large isotopic anomalies. Geochim Cosmochim Acta 55 367-379 Johnson CM, Beard BL (1999) Correction of instrumentally produced mass fractionation during isotopic analysis of Fe by thermal ionization mass spectrometry. Int J Mass Spect 193 87-99 Jungck MHA, Shimamura T, Lugmair GW (1984) Calcium isotope variations in Allende. Geochim Cosmochim Acta 48 2651-2658... [Pg.286]

Thermal ionization mass spectrometry has been used extensively in the geological nuclear and analytical sciences for stable isotope measurements A new technique resonance ionization mass spectrometry offers a comprehensive approach to sensitive and selective elemental and isotopic analysis Recent developments in thermal and resonance ionization mass spectrometry are reviewed) and specific applications of the technology to zinc and calcium metabolism studies and to trace element analysis of foodstuffs are summarized ... [Pg.1]

Figure 1. Schematic representation of the calcium mass spectrum in (a) natural materials, (b) a Ca- Ca tracer solution used for separating natural mass dependent isotopic fractionation from mass discrimination caused by thermal ionization, and (c) a typical mixture of natiwal calcium and tocer calcium used for analysis. The tracer solution has roughly equal amounts of Ca and Ca. In (c) the relative isotopic abundances are shown with an expanded scale. Note that in the mixed sample, masses 42 and 48 are predominantly from the tracer solution, and masses 40 and 44 are almost entirely from natural calcium. This situation enables the instrumental fractionation to be gauged from the Ca/ Ca ratio, and the natural fractionation to be gauged from the sample Ca/ Ca ratio.

$Figure 1. Schematic representation of the calcium mass spectrum in (a) natural materials, (b) a Ca- Ca tracer solution used for separating natural mass dependent isotopic fractionation from mass discrimination caused by thermal ionization, and (c) a typical mixture of natiwal calcium and tocer calcium used for analysis. The tracer solution has roughly equal amounts of Ca and Ca. In (c) the relative isotopic abundances are shown with an expanded scale. Note that in the mixed sample, masses 42 and 48 are predominantly from the tracer solution, and masses 40 and 44 are almost entirely from natural calcium. This situation enables the instrumental fractionation to be gauged from the Ca/ Ca ratio, and the natural fractionation to be gauged from the sample Ca/ Ca ratio.$

The studies of calcium metabolism in normal children are underway with 15-20 children to be studied in the near future The data generated from these studies will be used as the basis for studies of diseases of calcium metabolism in children We anticipate being able to study a number of children with FOP and possibly contribute to innovative therapies for these children by monitoring changes in calcium kinetics Improvements in the thermal ionization source for the quadrupole mass spectrometer are underway a substantial improvement in sesitivity is expected from this effort The model used for data analysis is under continuing investigation in order to improve its predictive and experimental design capabilities ... [Pg.38]

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