Multielement Analytical Spectroscopy in Plant Ionomics Research

The study of the ionome (ionomics) is defined as quantitative and simultaneous measurement of the element composition of living organisms and changes in this composition in response to physiological stimuli, development stage, and genetic modifications (Salt etal., Ann. Rev. Plant Biol., Vol. 59, 2008). The necessity of understanding the regulation processes of elements in the organisms demands determination of many elements in the organism, tissue, and cell (Baxter, Plant Biol., Vol. 12, 2009). A prospect for ionomics is environmental pollution where great variety of conditions and pollutants exist resulting in concentration and interelemental changes in the plant ionome. The capabilities of and problems with several multielement analytical techniques, including instrumental neutron activation analysis (INAA), X-ray fluorescence, inductively coupled plasmaatomic emission spectrometry (ICP-AES), inductively coupled plasmamass spectrometry (ICP-MS), and atomic absorption spectrometry (AAS), which are adequate and most promising in ionomic and environmental studies of plants, are reviewed. References are confined mainly to the last 1015years. Information about concentrations, roles, binding forms, and pollution sources of the elements and comparison between methods with respect to limits of detection, determined elements, interferences, and economic considerations are tabulated. Some combinations of instrumental techniques supplementing each other are highly valued, namely, ICP-MS and ICP-AES and INAA and AAS or ICP-AES.