Mass Spectrometry Element Analysis-Advances and New Perspectives in a Modern Analytical Method

Mass spectrometry is an extremely sensitive method for the determination of elements down to the sub-pg level. The different ionization methods used for mono-and multi-element analyses are discussed. Spark source mass spectrometry has been the most commonly multi-element technique in the past. However, inductively coupled plasma and glow-discharge mass spectrometry will probably replace spark source mass spectrometry in the future. Accurate trace element determinations can only be obtained with isotope dilution mass spectrometry. Because of a lack of accurate methods, isotope dilution is one of the few definitive calibration techniques that can be used for trace element analyses. The formation of negative and positive thermal ions on a hot metal surface is the most frequently applied ionization method in isotope dilution mass spectrometry. All elements which can be analyzed by this method are listed. A selected number of trace determinations with thermal ionization isotope dilution mass spectrometry are discussed, e.g. the analysis of ultra-low amounts of heavy metals in Antarctic snow, of halide traces in geochemical materials, and of nitrite and nitrate in food samples. Determinations of element species with the isotope dilution technique will become more and more important in the future.