Aluminium speciation in environmental samples: a review

Abstract

Because of its toxic effects on living beings, Al may represent an environmental hazard, particularly under increased acidic conditions. Growing environmental concern over the presence of increased Al concentrations in soil solutions and fresh waters resulted in the development of numerous analytical techniques for the determination of Al species. Al has a very complex chemistry that is significantly influenced by pH. Different Al species are present in environmental solutions, and many of them are unstable. Contamination of samples and reagents by extraneous Al represents an additional problem in speciation of Al at trace concentrations. Due to these reasons quantitative determination of particular chemical forms of Al is still a very difficult task for analytical chemists. The most important analytical methodologies of the last decade and new trends for the speciation of Al in environmental samples are comprehensively reviewed here.

Study of interactions between relevant organic acids and aluminium in model solutions using HPLC and IC

“…From above stated facts it is obvious that the use of some hyphenated techniques combining different chromatography and atomic spectroscopy methods (Borrmann & Seubert 1999;Drábek et al 2005;Ščančar & Milačič 2006) is more adequate for Al speciation in the environment rich in organic ligands. Nevertheless, the use of the Al speciation method proposed by Drábek et al (2003) is still useful for environment studies and routine soil analysis as it was proved by our previous works performed on acidified Spodsols and Cambisols originating from Czech mountains -the Jizerské, Krkonoše, and Novodhradské hory Mts.…”

“…Soil acidification may substantially mobilize and release Al into soil solution, ground and surface waters. This phenomenon is emphasized particularly in poorly buffered soils (Ščančar & Milačič 2006). The released mononuclear ionic Al species may undergo polymerization or may be complexed by available organic or inorganic ligands (Poléo 1995;Bi et al 2004).…”

Aluminium speciation and internal detoxification mechanisms in plants: where do we stand?

“…However, the speciation of Al in biological samples has been hampered by the technical constraints limiting the separation and identification of Al complexes. 7 The lack of a suitable isotope, the relatively low sensitivity of nuclear magnetic resonance (NMR) and X-ray detection based techniques and the unstable nature of Al-complexes, which can suffer changes in speciation during extraction and analytical procedures, are the major hurdles for accurate speciation of Al in plants.…”

Identification of the tri-Al tricitrate complex in Plantago almogravensis by hydrophilic interaction LC with parallel ICP-MS and electrospray Orbitrap MS/MS detection

“…Al speciation studies in plants have been frustrated by the technical constraints limiting the separation and identification of Al complexes. 16 The complex aqueous coordination chemistry of Al, the lack of a suitable multiisotopic profile and the typical instability of metal complexes that renders concentration procedures unfeasible have slowed the understanding of the physiology of Al detoxification in tolerant plants. Most studies have been based on 27 Al NMR spectroscopy with a consequence that only plants accumulating extremely high concentrations could be examined.…”