Thermal ion mass spectrometry

Esat TM (1995) Charge collection thermal ion mass spectrometry of thorium. Int J Mass Spectrom Ion Proc 148 159-170... 

Moran et al. [565] and Guo et al. [566] have determined 230thorium and 232thorium in seawater using, thermal ion mass spectrometry and secondary ion mass spectrometry, respectively. 

Creaser, R. A., Papanastassiou, D.A. and Wasserburg, G. J. (1991) Negative thermal ion mass spectrometry of osmium, rhenium, and iridium. Geochimica et Cosmochimica Acta, 55, 397-401. 

The use of UTEVA-Resin, an extraction chromatographic resin to be described in more detail below, has also been described for robotic separations of actinides in a glove box64-66 These authors designed their process to allow columns to run dry between steps to simulate what could happen in an unattended open-column process. In addition, corrosive solvents were avoided. They reported >90% recoveries and fractions that were suitable for thermal ion mass spectrometry (TIMS) source preparation without further purification or treatment. 

Kober B. (1987) Single-zircon evaporation combined with Pb emitter-bedding for PbA Pb-age investigations using thermal ion mass spectrometry, and implications to zirco-nology. Contrib. Mineral. Petrol. 96, 63 -71. 

Thermal ion mass spectrometry has traditionally been the method of choice to obtain precise Pb isotope determinations, with a typical RSD of 0.01% (2o) for the Pb/ ° Pb ratio. Moreover, TIMS allows precise measurement of all four Pb isotopes, especially with the double or triple spike techniques [54], allowing the radiogenic ones ( b, ° Pb, ° Pb) to be normalized to Pb which is non-radiogenic. Also, to distinguish among anthropogenic Pb sources, it can be... 

Since negative thermal ion mass spectrometry (N-TIMS) for rhenium/osmium dating (see O Sect. 17.18) was developed about 1990, not too much work has been published. This is probably due to the high rhenium blanks from the current generation of clean platinum filaments and to problems in achieving isotopic exchange and equilibrium between sample and spike for osmium. Another drawback is the non-homogeneity of samples. Because of this, rhenium and osmium concentrations may vary hy up to 40% in the same sample. 

Desorption ionization (DI). General term to encompass the various procedures (e.g., secondary ion mass spectrometry, fast-atom bombardment, californium fission fragment desorption, thermal desorption) in which ions are generated directly from a solid or liquid sample by energy input. Experimental conditions must be clearly stated. 

A review pubHshed ia 1984 (79) discusses some of the methods employed for the determination of phenytoia ia biological fluids, including thermal methods, spectrophotometry, luminescence techniques, polarography, immunoassay, and chromatographic methods. More recent and sophisticated approaches iaclude positive and negative ion mass spectrometry (80), combiaed gas chromatography—mass spectrometry (81), and ftir immunoassay (82). 

Low ionizing potentials or soft ionization methods are necessary to observe the parent ions in the mass spectra of many S-N compounds because of their facile thermal decomposition. Mass spectrometry has been used to investigate the thermal breakdown of S4N4 in connection with the formation of the polymer (SN). On the basis of the appearance potentials of various S Ny fragments, two important steps were identified ... 

We have undertaken a series of experiments Involving thin film models of such powdered transition metal catalysts (13,14). In this paper we present a brief review of the results we have obtained to date Involving platinum and rhodium deposited on thin films of tltanla, the latter prepared by oxidation of a tltanliua single crystal. These systems are prepared and characterized under well-controlled conditions. We have used thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES) and static secondary Ion mass spectrometry (SSIMS). Our results Illustrate the power of SSIMS In understanding the processes that take place during thermal treatment of these thin films. Thermal desorption spectroscopy Is used to characterize the adsorption and desorption of small molecules, In particular, carbon monoxide. AES confirms the SSIMS results and was used to verify the surface cleanliness of the films as they were prepared. 

Cochran JK, Masque P (2003) Short-lived U/Th-series radionuclides in the ocean tracers for scavenging rates, export fluxes and particle dynamics. Rev Mineral Geochem 52 461-492 Cohen AS, O Nions RK (1991) Precise determination of femtogram quantities of radium by thermal ionization mass spectrometry. Anal Chem 63 2705-2708 Cohen AS, Belshaw NS, O Nions RK (1992) High precision uranium, thorium, and radium isotope ratio measurements by high dynamic range thermal ionization mass spectrometry. Inti J Mass Spectrom Ion Processes 116 71-81... 

Applications Early MS work on the analysis of polymer additives has focused on the use of El, Cl, and GC-MS. The major drawback to these methods is that they are limited to thermally stable and relatively volatile compounds and therefore are not suitable for many high-MW polymer additives. This problem has largely been overcome by the development of soft ionisation techniques, such as FAB, FD, LD, etc. and secondary-ion mass spectrometry. These techniques all have shown their potential in the analysis of additives from solvent extract and/or from bulk polymeric material. Although FAB has a reputation of being the most often used soft ionisation method, Johlman el al. [83] have shown that LD is superior to FAB in the analysis of polymer additives, mainly because polymer additives fragment extensively under FAB conditions. 

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. 

T. Walczyk. Iron Isotope Ratio Measurements by Negative Thermal Ionisation Mass Spectrometry using FeF Molecular Ions. Int. J. Mass Spectrom. Ion Proc., 161(1997) 217-227. 

A. Deyhle. Improvements of Boron Isotope Analysis by Positive Thermal Ionization Mass Spectrometry Using Static Multicollection of CS2BO2 Ions. Int. J. Mass Spectrom., 206(2001) 79-89. 

In this report we present NEXAFS results for the kinetics of ethylidyne formation. Previous data is scarce and comes mostly from thermal desorption (TDS) experiments (2). The only reported study of isothermal rates of reactions for this system was done by Ogle et. al. using secondary ion mass spectrometry (SIMS) (10). 

The relatively small mass differences for most of the elements discussed in this volume requires very high-precision analytical methods, and these are reviewed in Chapter 4 by Albarede and Beard (2004), where it is shown that precisions of 0.05 to 0.2 per mil (%o) are attainable for many isotopic systems. Isotopic analysis may be done using a variety of mass spectrometers, including so-called gas source and solid source mass spectrometers (also referred to as isotope ratio and thermal ionization mass spectrometers, respectively), and, importantly, MC-ICP-MS. Future advancements in instrumentation will include improvement in in situ isotopic analyses using ion microprobes (secondary ion mass spectrometry). Even a small increase in precision is likely to be critical for isotopic analysis of the intermediate- to high-mass elements where, for example, an increase in precision from 0.2 to 0.05%o could result in an increase in signal to noise ratio from 10 to 40. 

Traditionally thermal ionization mass spectrometry was the instrument of choice for the isotopic analysis of metals because thermal ionization produced an ion beam with a very small kinetic energy spread ( 0.5 eV). Therefore only a magnetic mass analyzer is needed to resolve one isotope from another. Moreover, ionization of unwanted material, such as atmospheric contaminates, hydrocarbons from pump oil, or production of doubly ionized particles is almost non existent, thus background counts are minimized and signal-to-noise ratio is maximized. 

WaIczyk T (1997) Iron isotope ratio measurements by negative thermal ionization mass spectrometry using FeF4" molecular ions. Int J Mass Spectrom Ion Proc 161 217-227... 

Moriguti T, Nakamura E (1993) Precise lithium isotope analysis by thermal ionization mass spectrometry using lithium phosphate as an ion source. Proc Japan Acad Sci 69B 123-128 Moriguti T, Nakamura E (1998a) High-yield lithium separation and precise isotopic analysis for natural rock and aqueous samples. Chem Geol 145 91-104... 

Wheat CG, Mottl MJ (2000) Composition of pore and spring waters from Baby Bare Global implications of geochemical fluxes from a ridge flank hydrothermal system. Geochim Cosmochim Acta 64 629-642 White DE, Thompson JM, Fournier RO (1976) Lithium contents of thermal and mineral waters. In Lithium Resources and Requirements by the Year 2000. Vine JD (ed) U.S. Geol Surv Prof Pap 1005 58-60 Xiao YK, Beary ES (1989) High-precision isotopic measurement of lithium by thermal ionization mass spectrometry. Int J Mass Spect Ion Proc 94 101-114... 

Wachsmann M, Heumann KG (1992) Negative thermal ionization mass spectrometry of main group elements, part 2. 6th group Sulfur, selenium, and tellurium. Int J Mass Spectrom Ion Proc 114 209-220... 

A striking feature of the ILs is their low vapor pressure. This, on the other hand, is a factor hampering their investigation by MS. For example, a technique like electron impact (El) MS, based on thermal evaporation of the sample prior to ionization of the vaporized analyte by collision with an electron beam, has only rarely been applied for the analysis of this class of compounds. In contrast, nonthermal ionization methods, like fast atom bombardment (FAB), secondary ion mass spectrometry (SIMS), atmospheric pressure chemical ionization (APCI), ESI, and MALDI suit better for this purpose. Measurement on the atomic level after burning the sample in a hot plasma (up to 8000°C), as realized in inductively coupled plasma (ICP) MS, has up to now only rarely been applied in the field of IE (characterization of gold particles dissolved in IE [1]). This method will potentially attract more interest in the future, especially, when the coupling of this method with chromatographic separations becomes a routine method. 

Volkening, J., Koppe, M., and Heumann, K. G. (1991) Tungsten isotope ratio determinations by negative thermal ionization mass spectrometry. International Journal of Mass Spectrometry and Ion Processes, 107, 361-368. 

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