Mass thermal ionisation

The mass action law or Saha equation for thermal ionisation of seed atoms is... 

Principles and Characteristics In the early mass-spectrometric ionisation techniques, such as El and Cl, the sample needs to be present in the ionisation source in its gaseous phase. Volatilisation by applying heat renders more difficult the analysis of thermally labile and involatile compounds, including highly polar samples and those of very high molecular mass. Although chemical derivatisation may be used to improve volatility and thermal stability, many compounds have eluded mass-spectrometric analysis until the emergence of fast atom bombardment (FAB) [72]. 

PTI-MS Positive thermal ionisation-mass (2) Rotation planar chromatography... 

TI-IDMS Thermal ionisation-isotope dilution mass spectrometry (see ID-TIMS)... 

Flegal and Stokes [59] have described a sample processing technique necessary for avoiding lead contamination of seawater samples prior to lead stable isotope measurements by thermal ionisation mass spectrometry. Levels down to 0.02 ng/kg were determined. 

Flegal and Stukas [406] described the special sampling and processing techniques necessary for the prevention of lead contamination of seawater samples, prior to stable lead isotopic ratio measurements by thermal ionisation mass spectrometry. Techniques are also required to compensate for the absence of an internal standard and the presence of refractory organic compounds. The precision of the analyses is 0.1 -0.4% and a detection limit of 0.02 ng/kg allows the tracing of lead inputs and biogeochemical cycles. 

Cohen and O Nions [16] determined femtogram quantities of radium radionucleides in seawater by thermal ionisation mass spectrometry. 

Thermal ionisation mass spectrometry has been used to determine pg/kg levels of 230thorium and 232thorium in seawater [40]. 

Buesseler and Halverson [ 92 ] have described a thermal ionisation mass spec-trometric technique for the determination of 239plutonium and 240plutonium in seawater. The mass spectrometric technique was more sensitive than a spectrometry by more than order of magnitude. 

Chassery et al. [97] studied the 87Sr/86Br composition in marine sediments, observing excellent agreement between results obtained by ICP-MS and thermal ionisation mass spectrometry. Low level a-spectrometry with lithium drifted germanium detectors has been used to determine 90strontium in seawater [59]. 

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. 

Schmitt AD, Bracke G, Stille P, Kiefel B (2001) The calcium isotope composition of modem seawater determined hy thermal ionisation mass spectrometry. Geostandard Newsletter 25 267-275 Schmitt A-D, Stille P, Venneman T (2003a) Variations of the " Ca/ Ca ratio in seawater during the past 24 million years evidence from 5 Ca and values of Miocene phosphates. Geochim Cosmochim Acta 67 2607-2614... 

C. F. Boutron, V. I. Morgan, and D. J. Mackey, Recent Advances in Measurement of Pb Isotopes in Polar Ice and Snow at Sub-Picogram Per Gram Concentrations Using Thermal Ionisation Mass Spectrometry, Anal. Chim. Acta 2002,453, 1. 

NoweU G. M., Kempton P. D., Noble S. R., Fitton I. G., Saunders A. D., Mahoney I. I., and Taylor R. N. (1998) High precision Hf isotope measurements of MORB and OIB by thermal ionisation mass spectrometry insights into the depleted mantle. Chem. Geol. 149, 211-233. 

Rickaby R. E. M., Greaves M. J., and Elderfield H. (2000) Cd in planktonic and benthic foraminiferal shells determined by thermal ionisation mass spectrometry. Geochim. Cosmochim. Acta 64, 1229-1236. 

Eagles, J. Fairweather-Tait, S.U., Mellon, F.A. et al.. Comparison of fast-atom bombardment, thermal ionisation and ICP-MS for the measurement of Zn/ Zn stable isotopes in human nutrition studies. Rapid Comm. Mass Spectrom., 3(6) (1989) 203-205. 

Thermal ionisation mass spectrometry U, Pu isotopic abundances... 

ESCA = electron spectrometry for chemical analysis IC = ion chromatography SIE = selective ion electrode TIMS = thermal ionisation mass spectrometry. 

Laser Excited Atomic Fluorescence Spectrometry (LEAFS) (40, 41, 46-48), Thermal Ionisation Mass Spectrometry (TIMS) (6, 42, 43, 45, 49-53), Electrothermal Atomization Atomic Absorption Spectrometry (ETA-AAS) (24, 28, 54, 55), Differential Pulse Anodic Stripping Voltammetry (DPASV) (27, 49, 56, 57),... 

W. Chisholm, K. J. R. Rosman, J. P. Candelone, C. F. Boutron, M. A. Bolshov, Measurement of bismuth at pg g concentrations in snow and ice samples by thermal ionisation mass spectrometry of lead isotopic ratios in Greenland and Antarctic snow and ice with picogram per gram concentrations, Anal. Chim. Acta, 347 (1997), 351-358. 

The low concentrations of Pb found in Greenland and Antarctic snow and ice makes reliable concentration and isotopic composition measurements difficult to determine. Contamination with anthropogenic Pb during sample collection or drilling must be minimised, then extreme precautions must be taken to access a contamination-free sample (12, 28). Sensitive analytical methods which can analyse pg quantities of Pb are also required. A number of different methods meet this requirement however, discussion in this chapter will be limited to Thermal Ionisation Mass Spectrometry (TIMS) because this is the only technique, to date, to be successfully used to measure isotope abundances in polar ice. IDMS is an integral part of the technique used to measure the isotopic composition of the samples. 

Primary Reference Material PRM a reference material certified with (a) primary method(s). In practice such materials are mainly pure substances, manufactured materials, rarely matrix materials as already explained above. PRMs of matrix materials are very limited in number. NIST has available some CRMs certified with thermal ionisation-isotope dilution mass spectrometry (TMDMS) which has been classified by the Comite Consultatif sur la Quantite de Matiere (CCQM) of BIPM as primary method. PRMs also exist for gas analysis. The Netherlands Meet Instituut (NMI) in Delft, The Netherlands has available several primary gas RMs prepared by gravimetry... 

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