Historically trace metal and non-metal analyses have mainly evolved through the development of atomic spectrometry after world war II. Unfortunately, sources for atomic spectrometry (atomizers) are meant to produce atoms destroying the information of originally present chemical species. Even further, most of the techniques used (AAS, ICP-AES, ICP-MS) work best with liquid samples, calling for some sample preparation. Mineralization (digestion) of the sample will, however, destroy all the information of the elemental species from the very start.
In order to do elemental speciation analysis, the original distribution of chemical species must be either preserved within the sample or the speciation analysis must be performed in-situ (at-site). In all cases better knowledge about the chemistry and better control of the methodology is required compared to total element analysis. These requirements hinder the widespread use of speciation analysis in routine laboratories.
Directives and legislation about elemental speciation are to a great extend still missing with the exception for a few species, e.g. Cr(III)/Cr(VI) and organotin compounds. Therefore routine analytical laboratories lack the incentive to invest in the necessary technologies. Even further, existing rules and legislation forces analytical laboratories to perform total element determinations. This situation will, however, chance once legislation is adjusted to the present scientific knowledge.
Further chapters: About Speciation
last time modified: June 15, 2020