Speciation Issue

It is our privilege, as the guest editors, to introduce this themed issue in the Journal of Analytical Atomic Spectrometry devoted to speciation analysis. 27 contributions—including 3 reviews and 21 original research papers—from the university laboratories and research institutes in Europe and Asia provide a wide scope of the studies of chemical forms of elements in the environment and biology. Despite its mature age, speciation continues to be an attractive research area facing on a number of challenges being successfully addressed by the creativity of researchers assisted by the progress in instrumentation, especially in mass spectrometry and coupled techniques.

Since its birth in 1985, JAAS has always been a prominent forum documenting the progress in elemental speciation related research, starting from the early timid attempts at feasibility studies of hyphenated techniques, through to advanced method development till today’s proliferation of applications in key areas of environmental and industrial chemistry and life-sciences. One out of six papers ever published in JAAS have been devoted to speciation analysis and twice as many if we just take the last decade into account. Despite the increasing competition from other journals JAAS regularly publishes ca. 50 papers yearly on speciation analysis with the peak of 75 in 2004. The focus of the research is shifting from basic instrumental developments to tackling real world research problems, mainly in life sciences. It stimulates new analytical approaches suitable for studies of biomolecules, often labile, present at extremely low concentrations and for which no analytical standards exist. In the increasing number of cases, the maturity of analytical methodology based on atomic spectrometry produces data which are becoming fundamental in interdisciplinary studies in plant and animal physiology, clinical biology and pharmacology and nutrition referred to as metallomics.

The high number of speciation-related papers published is matched by their quality. Today, speciation analysis is the subject of one third of the 20 top JAAS papers with the highest Scopus citation score! Since all chemical, physical and biological characteristics of chemical substances are always related to the compounds, rather than to the elements they are made of, hardly any meaningful research related to trace elements can ignore the valuable information provided by speciation analysis.

This themed issue devoted to speciation analysis is meant to give an overview of the state-of-the-art research in this area. The papers included demonstrate that the core of speciation-related research has moved to life sciences. Indeed, 19 out of 25 manuscripts discuss analyses of body fluids, cell or tissue samples; the remaining articles deal with environmental samples (4) and the development of analytical techniques (2). This carries a clear message that speciation analysis is ready to handle complex samples and can provide valuable information on the interaction of metal species with biomolecules, fragile species that often cannot withstand any complex sample preparation or derivatization. Therefore, techniques avoiding any type of derivatization are preferred and, as a result, separation techniques working in the liquid rather than the vapour phase dominate not only this themed issue but also publications related to speciation analysis in general. This themed issue includes a harbinger of the future of speciation analysis: direct speciation analysis by X-ray absorption spectroscopy.

With respect to analytes, the issue confirms the predominant interest in the speciation of mercury, selenium and arsenic. Interestingly, the geographical location of the authors who responded to our invitation indicates the establishment of speciation research centers in Europe (18) and Asia (7). While this is certainly biased by the snapshot character of the time window of the special issue, it shows the emergence of speciation-related research in Asia.

We wish to thank all contributors for their positive response to our invitation and their efforts to prepare their contributions for the deadline.

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