Research is focussed on the development and application of chemical speciation methodologies for arsenic, selenium and antimony. Fundamental analytical chemistry work is related to optimization and understanding of HPLC-(UV)-HGAFS, i.e. a hyphenated speciation system comprising separation of elemental species by high performance liquid chromatography interfaced with UV demineralization (of organoarsenic, -selenium and antimony species) and subsequent on-line volatilization by formation of hydrides and atomic fluorescence detection. Special attention is paid to unwanted speciation alteration of the species in the analytical process (sampling, sample treatment, sample preparation, sample extraction, etc.) so that special procedures, such as e.g. on-site differentiation between valency states of an aqueous element, may be necessary to garantee the integrity of the species. Measurement of ultratrace levels of (inorganic) arsenic species in waters is carried out by using either cryotrapping of formed hydrides or coprecipitation, both followed by AFS detection. Radiotracers may be used as a tool in the speciation methodology development and for special purposes such as studying sorption processes to reveal e.g. accessible elemental fractions in soil. Neutron activation analysis (NAA), either in its radiochemical or instrumental form, is used to generate reference total element concentrations. Currently we are able to quantify the following elemental species: antimony (Sb(III/V)), arsenic (As(III), As(V), monoarsonic and dimethylarsinic acid, arsenobetaine, arsenocholine, trimethylarsine oxide and tetramethyl arsonium ion) and selenium (Se(IV), Se(VI), selenomethionine and selenocystine) in a variety of matrices (fish, mussels, shrimps, algae, wine, edible mushrooms, soil, aerosols, plants, lichens, urine, blood, fresh and sea water) on a routine basis. The application field is very wide incorporating environmental and health-related issues like food safety, (waste) water management, soil remediation, atmospheric emissions, medical treatments, etc.
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