The International Union for Pure and Applied Chemistry (IUPAC) has published guidelines or recommendations for the definition of speciation analysis. According to these definitions, chemical species are specific forms of an element defined as to isotopic composition, electronic or oxidation state, and/or complex or molecular structure.
In the literature the following types of elemental species are often distinguished:
Type: Oxidation species
Examples: Fe(II)/Fe(III); As(III)/As(V); Sb(III)/Sb(V); Se(IV)/Se(VI); Cr(III)/Cr(VI)
Interest: Study of redox processes; Different toxicity
Examples: Cis-Platin; Humic acid complexes, Gd-based contrast agents
Interest: Study of complex stability, study of the influence of ligands on complex characteristics such as mobility, bioavailability and toxicity
Type: Organometallic compounds
Examples: Methylmercury; Tetraethyllead; Tributyltin; Arsenobetaine
Interrest: Different toxicity; bioavailability and bioaccumulation in organisms; contamination of food; fate in the environment; degradation reactions
Examples: Metalloproteins; Arsenosugar; Selenoamino acids
Interest: Study of biological function; Study of metabolism;
The different types of species have dfifferent stabilities and therefore require different attention with respect to sampling, sample preparation and analysis. Oxidation species and complexes do have limited thermodynamic and kinetic stability and therefore can easily be transformed during analysis. Biomolecules do have limited stability mostly under biological conditions with respect to temperature, pH and redox state and can easily be degraded during analysis under harsh conditions. Organometallic compounds are the most stable chemical species and therefore can often be separated even under more harsh conditions as used for gas chromatographic separation.
Related EVISA Resources: Brief summaries
Speciation as a discipline in Analytical Chemistry – Definitions
Why should elemental speciation be done ?
Why is elemental speciation analysis not done routinely ?
Speciation analysis as a tool to enhance the quality of life
Speciation and Toxicity
Research fields related to elemental speciation
Chemical speciation analysis for the life sciences
Chemical speciation analysis for nutrition and food science
Trace element speciation analysis for environmental sciences
Speciation analysis for the study of metallodrugs and their biomolecular interactions
Speciation Analysis - Striving for Quality
Problems to be solved in the field of speciation analysis
Error sources in speciation analysis - Overview
Sample preservation for speciation analysis - General recommendations
Species transformation during speciation analysis
Certified Reference Materials for Chemical Speciation Analysis
Standard methods for elemental speciation analysis
Tools for elemental speciation analysis ICP-MS - A versatile detection system for speciation analysis LC-ICP-MS - The most often used hyphenated system for speciation analysis GC-ICP-MS CE-ICP-MS for speciation analysis ESI-MS: The tool for the identification of species Atomic Fluorescence Spectrometry as a Detection System for Speciation Analysis Fractionation as a first step towards speciation analysis Flow-injection inductively coupled plasma mass spectrometry for speciation analysis Gel electrophoresis combined with laser ablation ICP-MS for speciation analysis Non-chromatographic separation techniques for speciation analysis
last time modified: July 18, 2016