Thermal ionisation mass spectrometry

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]. 

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. 

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. 

This procedure uses only one calibration standard. To achieve good accuracy the ion abundances of the standard should be as close as possible to those of the sample. This method has been used for both organic and inorganic IDMS, especially using thermal ionisation mass spectrometry (TIMS). 

Sahoo, S. K., Yonehara, H., Kurotaki, K., Fujimoto, K., and Nakamura, Y. 2002. Precise determination of U-235/U-238 isotope ratio in soil samples by using thermal ionisation mass spectrometry. J Radioanal Nucl Ch 252(2), 241-245. 

Taylor, R. N., Croudace, I. W., Warwick, P. E., and Dee, S. J. 1998. Precise and rapid determination of U-238/U-235 and uranium concentration in soil samples using thermal ionisation mass spectrometry. Chem Geol 144(1-2), 73-80. 

In this chapter we will focus on the determination of those nuclides that are widely used as tracers, and where the analysis can be performed without access to highly specialized equipment such as AMS (accelerator mass spectrometry) or TIMS (thermal ionisation mass spectrometry). We describe detailed analytical methods for the nuclides " Th, Th, °Po, °Pb, Be, Ra, Ra, Ra, Ra and Rn. For the determination of other nuclides key references have been listed in Tables 13-1 and 13-2. 

Schmitt, A.D., Galer, S.J.G., and Abouchami, W. (2009) High-precision cadmium stable isotope measmements by double spike thermal ionisation mass spectrometry. J. Anal. At. Spearom., 24 (8), 1079-1088. 

Luguet, A., Nowell, G.M., and Pearson, D.G. (2008) Os-184/Os-188 and Os-186/Os-188 measurements by negative thermal ionisation mass spectrometry (N-TIMS) effects of interfering element and mass fractionation corrections on data accuracy and precision. Chem. Geol,... 

Cohen, A.S. and Waters, F.G. (1996) Separation of osmium from geological materials by solvent extraction for analysis by thermal ionisation mass spectrometry. Anal. Chim. Acta, 332 (2-3), 269-275. 

Walczyk, T. (1997) Iron isotope ratio measurements by negative thermal ionisation mass spectrometry using... 

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