Speciation concerns the identification and quantitation of specific forms of
an element, e.g. the analysis of edible fish tissue to determine the
concentrations of methylmercury and inorganic mercury present. As different
forms of an element may exhibit differing toxicities and mobilities in the
environment, it is clearly of importance to be able to distinguish between
the individual species present in a particular sample.
As is generally the case in analytical chemistry, speciation analysis requires
a multi-step approach, typically including the following operations:-
These are often the weakest links in the analytical chain. In speciation
analysis, removal of the sample from its' natural surroundings may induce
pronounced chemical and physical changes causing the species distribution to
alter.
Sample preparation and work-up
The group has worked on the following techniques:-
Solid phase extraction for the preconcentration
of metals and organometallic species from natural waters.
For other speciation applications, traditional
liquid-liquid extraction techniques have been used. Also included in this
reference list are several applications where liquid-liquid extraction is used
in addition to other analyte isolation techniques.
Instrumental analysis
For the separation and detection of various species, gas chromatography
coupled with microwave-induced plasma atomic emission spectrometry
(GC-MIP-AES) or atomic absorption spectrometry
(GC-AAS) is used. Other, more theoretical
studies of instrument performance can be accessed
here:
