Chemical speciation analysis for the life sciences
In the area of life sciences, chemical analysis is meant to provide information about the metabolism, function and toxicity of chemical compounds in biological organisms and by this help to study the mechanisms involved.
Figure: Elements of the Human Body
As in other areas, chemical analysis is acting as an information science, providing the data to answer certain questions, such as:
Data on the metabolism, i.e. intake, absorption, exchange and excretion of nutrients, minerals and toxicants by biological organisms.
Data on the chemistry, bio-chemistry and physiology of exchanged compounds.
Data on the bioavailability, bioaccumulation and toxicity of chemicals for plants, animals and humans.
NB!: Such characteristics depends primarily on chemical species not on their elemental composition !
Therefore, with respect to trace elements, trace element analysis does not provide the required information for a deep understanding of biological processes and because of such limitations, its application is often not sufficient in modern research. Despite such lack, trace element analysis is firmly established in routine analysis and therefore widely applied.
The role of trace elements in life science is still sometimes discussed from the elemental point of view (atomistic) while it is clear that biological mechanisms are based on molecular aspects.
In this sence some topics often discussed in conferences, monographies and other publications are at least with respect to titles not really supported by meaningful science but mainly by traditions resulting from the history of scientific development.
Such topics with limited scientific background are:
Trace metals in human health and nutrition
Trace element determination
Toxicity of elements
Intake recomendations for elements
Especially the role of metals in biological systems can only be studied, when the metals involved are analysed in the form their are present. Such is the main aim of speciation analysis, which therefore plays a fundamental role in the area of metallomics, an integrated research field related to biometals and in symbiosis with genomics and proteomics. Trace element species most often discussed by scientists in this areas are enzymes
(Zn), vitamins (Co), metallo-proteins (Se, Fe, Cu, Zn), metallo-drugs (Pt), toxins
(As, Hg, Cr(VI), Cd, Pb) and their metabolic forms.
Elemental detection provided by atomic and elemental mass spectrometry can therefore only play the role of a special filter, enhancing the separation of the target elemental species from the overwhelming number of species present in such complex systems. However, trace element detection can only be a part of a multitechnique approach that more and more often has to include high resolution molecular mass spectrometry and other techniques in order to gain insight in the area of metallomics.
Related reviews related to chemical speciation analysis for life science
C.G. Vogiatzis, G.A. Zachariadis, Tandem mass spectrometry in metallomics and the involving role of ICP-MS detection: A review, Anal. Chim. Acta, 819 (2014) 1–14. doi: 10.1016/j.aca.2014.01.029
Dirk Wesenberg, Gerd-Joachim Krauss, Dirk Schaumlöffel, Metallo-thiolomics: Investigation of thiol peptide regulated metal homeostasis in plants and fungi by liquid chromatography-mass spectrometry, Int. J. Mass Spectrom., 307 (2011) 46–54. doi: 10.1016/j.ijms.2010.10.026
Yasumitsu Ogra, Toxicometallomics for Research on the Toxicology of Exotic Metalloids Based on Speciation Studies, Anal. Sci., 25 (2009) 1189-1195. doi: 10.2116/analsci.25.1189
A.R. Timerbaev, Capillary electrophoresis coupled to mass spectrometry for biospeciation analysis: critical evaluation, Trends Anal. Chem., 28/4 (2009) 416-425. doi: 10.1016/j.trac.2009.02.001
Richard W. Strange, Martin C. Feiters, Biological X-ray absorption spectroscopy (BioXAS): a valuable tool for the study of trace elements in the life sciences, Curr. Opin. Structural Biol., 18 (2008) 609–616. DOI: 10.1016/j.sbi.2008.06.002