EVISA Glossary on | Contact EVISA | Sitemap | Home   
 Advanced search
The establishment of EVISA is funded by the EU through the Fifth Framework Programme (G7RT- CT- 2002- 05112).

Supporters of EVISA includes:

Directory of scientists

Alan G. Howard
Senior Lecturer
University of Southampton, Department of Chemistry, Analytical & Environmental Chemistry, SO9 5NH  Highfield, Southampton, U.K.
+44 (0) 23 8059 2182
+44 1703 5 93 781
Alan G. Howard
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).

back to results page

Imprint     Disclaimer

© 2003 - 2024 by European Virtual Institute for Speciation Analysis ( EVISA )