Analytical Chemistry
Our work is focused towards
the development and understanding of novel approaches to the study of
species which are present either at low concentration or in very small
samples. Such approaches are often then used in our environmental
research. Examples of such investigations include:
- The development of novel instrumentation for the study of arsenic,
antimony, selenium and sulphur species in the aquatic environment.
Techniques involve the linking of chromatographic, chemical and
spectroscopic instrumentation to provide novel approaches to
species-specific analysis.
- Analysis in combinatorial chemistry. How does one analyse a single bead which is less than 1mm in diameter?
- Electrically driven planar chromatography. What happens when thin layer chromatography is carried out in a high voltage field?
- The design, synthesis and characterisation of high purity
solid phase chelating agents for the collection of trace elements from
natural waters. Materials for the analytical preconcentration, metal
recovery and effluent treatment.
Environmental Chemistry
To understand the
processes which control the distribution and fate of material in the
environment it is necessary to identify changes which occur to the
chemical as it is cycled between the atmosphere, earth and biological
organisms. Arsenic, for example, occurs naturally as an arsenide ore,
is oxidised into solution through arsenite to arsenate, which is then
taken up by marine plants. These plants methylate the arsenic and
incorporate it into a sugar. When the plant dies the arseno-sugars are
released into the water where microbial decay results in
dimethylarsinate. At each stage a change has occurred to the chemical
form of the arsenic; by obtaining information on the chemical
structures of an element (its 'speciation') it is possible to
investigate the processes which influence the dispersal, toxicity and
eventual fate of both natural and pollutant chemicals in the
environment. Examples of research topics which have been studied in
recent years include:
- The study of chemical and biological factors influencing the
chemical forms and distribution of arsenic, selenium and antimony in
the aquatic environment. How speciation governs the mobility and
environmental impact of chemicals in the environment.
- An investigation of chemical probes employed in the study of sediment-metal interactions.
- The development of techniques for the study of tin and lead
compounds and the study of their behaviour in estuarine and coastal
waters.
- The identification of dimethylsulphoniopropionate (DMSP) and
other precursors of atmospheric dimethylsulphide (DMS) in marine
organisms. DMSP is used by marine algae to protect them against the
stresses of temperature and salinity changes. It, and compounds like
it, break down to release DMS into the atmosphere which oxidises
contributing to `acid rain' and potentially altering climate. We now
have the means to find a wide range of DMS-precursors, is DMSP the only
one? How is it broken down to DMS? - isolation and characterisation of
an algal enzyme.
- Radiochemistry: the study of organically-bound tritium and
its behaviour in the aquatic environment (in collaboration with Dr I.
Croudace, SOES).
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