Fundamentals and periodic review
Temperature measurements in high temperature plasmas
Numerous attempts have been made to characterise the ICP in order to generate information on kinetics and mechanisms of analyte excitation within the plasma. The various approaches which have been adopted include the determination of plasma temperature and electron density, the effect of easily ionisable elements, examination of metastable argon states, and discussion of the role of argon in the plasma. In this project mass spectrometric data were used to determine the dissociation temperature of a variety of polyatomic interferences within the ICP-MS. These calculated temperatures were then used to elucidate the site of formation for different polyatomic interferences. The results of this strongly suggested that certain polyatomic species such as ArO+ were formed in the interface region rather than in the plasma itself, owing to the gross deviation of the temperatures for those expected for a system in thermal equilibrium. Optical studies using a fibre optic connected to a monochromator were also performed in order to investigate the presence of interferences both in the plasma and the interface region of the ICP-MS, and the influence of the shield torch on these interferences. It was possible to determine the presence of some species in the plasma, such as the strongly bound metal oxides, no species other than OH were detected in the interface region of the ICP-MS. This data did however, provide the opportunity to calculate the OH rotational temperature within the interface region of the ICP-MS.
Publications
Butler, O.T., Cook, J.M., Harrington, C.F., Hill, S.J., Rieuwerts, J. and Miles, D.L. (2006). Atomic spectrometry update: Environmental analysis. Journal of Analytical Atomic Spectrometry 21, 217-243.
Butler, O.T., Cook, J.M., Harrington, C.F., Hill, S.J., Rieuwerts, J. and Miles, D.L. (2007). Atomic spectrometry update: Environmental Analysis. Journal of Analytical Atomic Spectrometry 22, 187-221.
Evans, E.H., Ebdon, L. and Rowley, L (2002). Comparative study of the determination of equilibrium dissociation temperature in inductively coupled plasma-mass spectrometry. Spectrochimica Acta B57, 741-754.
Evans, E. H., Day, J. A., Palmer, C. D., Price, W. J., Smith, C. M. M. and Tyson, J. F. (2007). Atomic spectrometry update. Advances in atomic emission, absorption and fluorescence spectrometry, and related techniques. Journal of Analytical Atomic Spectrometry 22, 663-696.
Evans, E. H., Day, J. A., Palmer, C. D., Price, W. J., Smith, C. M. M. and Tyson, J. F. (2006). Atomic spectrometry update. Advances in atomic emission, absorption and fluorescence spectrometry, and related techniques. Journal of Analytical Atomic Spectrometry 21, 1-34.
Foulkes, M.E. (2003). Screening methods for semi-quantitative analysis of elemental speciation. Chapter 8. In Handbook of Elemental Speciation (Volume 1), Cornelis, R., Heumann, K., Caruso, J. and Crews, H.(Eds.). J.Wiley and Sons Ltd, Chichester, pp. 591-604.
Hill, S.J., Fisher, A., and Foulkes, M.E. (2006). Basic concepts and instrumentation for plasma spectrometry. Chapter 3. In Inductively Coupled Plasma Spectrometry and its Applications, Hill, S.J. (Ed.) Second Edition; Blackwell Publishing Ltd, Oxford, pp. 61-97.