17th International Mass Spectrometry Conference :: Prague, 2006
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|Session:||Inductively Coupled Plasma Mass Spectrometry|
|Presentation date:||Mon, Aug 28, 2006|
|Presentation time:||16:50 – 17:10|
Maria Betti1, Laura Aldave de las Heras1, Aurelien Pitois1, Nicole Rausch1, Gabriele Tamborini1, Ilaria Marchetti11 European Commission, DG JRC, Institute for Transuranium Elements, Karlsruhe, Germany
Correspondence address: Maria Betti, European Commission, DG JRC, Institute for Transuranium Elements, Nuclear Chemistry, Analytical chemistry Section, P. O. Box 2340, Karlsruhe, 76125 Germany.
Keywords: Chromatography, Liquid (LC); Electrophoresis Capillary; Electrospray Ionization (ESI); Mass Spectrometry, Isotope Ratio.
Novel aspect: ICP-MS in study of long-lived radionuclides.
One of the major drawbacks when measuring radionuclides are the isobaric interferences that cannot be resolved directly by mass spectrometry and radiochemical separations need to be applied before the analysis. Fifteen years ago, in our laboratory we started to solve this problem by coupling the ICP-MS on-line to a chromatographic system. Since that time different methodologies have been developed for the determination of long-lived radionuclide such as fission products and actinides in nuclear and environmental samples radioactively contaminated. Recently, a capillary electrophoresis system has been coupled on-line to an Electrospray Mass Spectrometer as well as to a High Resolution ICP-MS. The first instrumental arrangement has allowed the complex formation of fission products during their separation to be studied. With the second one, quantitative methodologies for the determination of long-lived radionuclides have been developed. This system is at the present used for investigating potential uranium protein targets in human serum. In order to develop and optimize the method, commercially available human serum proteins were used. Optimisation of the conditions for uranium binding assays in vitro, taking into account synergistic and competition effects, has been investigated and evaluated for transferrin, ceruloplasmin, homopexin, IgG and serum albumin. CE separation efficiency has been optimised after having performed a systematically study of parameters such as voltage, buffer concentration and pH. Moreover, different buffer systems have been tested in order to preserve native protein structure and stability of uranium complexes. Instrumental parameters such as capillary position, interface alignment, and sheath liquid concentration and composition have been also investigated.
In this lecture all the different approaches experimented in our laboratory will be presented and discussed in terms of analytical figures of merit, applicability to different matrices and in combination to other instrumental analytical techniques like, for instance Secondary Ion Mass Spectrometry and Glow Discharge Mass Spectrometry when information on speciation at solid and liquid state are to be obtained.