Instrumental techniques for trace analysis

Keywords Trace elements Radionuclides Environment Water Soil Aerosol Plant Neutron activation analysis Atomic absorption spectrometry Inductively coupled plasma-atomic emission spectroscopy Inductively coupled plasma-mass spectrometry X-ray fluorescence Electrochemical methods Speciation 

Production of metals has been among the first human industrial activities, and thus sinee ancient times man influences the state of metals in nature. Thanks to human activity metals are redistributed in ways different from natural ones and new metal compounds are obtained and released into the environment. Thus the natural cycle of metals is disturbed. Sinee metals and metalloids are distributed everywhere in nature and cover a large concentration interval between mg/kg and more to ng/kg and less, and partieipate in a number of important geochemical and biochemical processes this disturbanee leads to serious impaet on living organisms. This is one of the reasons that determination of metals and metalloids in environmental materials is an object of constant interest. 

Although most analytical techniques have reached maturity and their possibilities are well defined still the analysis of environmental materials cannot be considered without problems due mainly to two reasons  

It is already recognized that the quality of analysis and the justification of final 

Another question which is rarely discussed is the variety of determined elements. Generally it seems that the type of determined elements depends more on the method used in the investigation than on the real need of determination. Elements such as Pb, Cd, Zn, Cu are among the very important pollutants but they are also easily determined by atomic absorption spectrometry (AAS), a very popular method. Therefore a considerable number (if not the majority) of environmental investigations deal with these elements only. The elements that remain outside the scope of popular analytical techniques are actually those that still have unknown functions in the organisms, and the necessity of their determination came forward quite recently. A good example in this respect are rare earth elements and platinum metals in plants. 

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Djingova R and Kuleee 1 (2000) Instrumental techniques for trace analysis. In Marker B and Friese K, eds. Trace elements, their distribution and effects in the environment, pp. 137-185. Elsevier, Amsterdam. 

The position of ICP-AES among other instrumental techniques for trace analysis is well established. Although instrumentation is still developing it is more in respect to reduce laborious introductions of dilferent types of corrections than increase the quality of analysis. As an interesting example in this respect a comparison of ICP-AES analysis of soil and sediment standard reference materials done in 1985 (Liese, 1985a) and 1998 (Leivuori, 1998) may be done. In 1985 the content of 21 elements in IAEA soil, five and 19 elements in IAEA SL-1 has been determined after introduction of two type of corrections. The accuracy was 0.1-18% and precision below 10%. In 1998 in a sediment standard reference material (NIST-SRM-2704 - Buffalo River Sediment) ten elements were determined (for the rest of the elements in this study ETAAS is preferred) with accuracy of 0.1-16% and precision below 10%. The same result is obtained if a comparison of analysis of plant standard reference materials is done (Liese, 1985a Kos et al., 1996 Djingova et al., 1998). 

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