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Investigations into the hydride generation chemistry of arsenic and antimony compounds
The study of hydride generation as an analytical technique has occupied a section of analytical chemistry for a considerable period of time. Applications of the technique have built upon the existing background of chemistry with few forward steps. The progress of analytical chemistry requires that the fundamental chemistry be studied so that it may then be applied within the understood limitations. Hydride generation is a technique that is heavily influenced by a variety of factors including but not limited to pH and oxidation state. The required oxidation state for hydride generation of arsenic and antimony is +3 and depending upon sample preparation, adjustment of the oxidation state is required. Bromide has been identified as a reductant for pentavalent arsenic and antimony and can be applied to reduce selenium to the hydride forming state of Se IV. Experiments are then described that demonstrate the limitations and application of bromide as a reductant for the simultaneous reduction of arsenic, antimony and selenium to the optimum hydride forming state, prior to hydride generation. The post-column chemistry of arsenic is examined with the application of microwave-assisted chemistry to the digestion of organoarsenical species. A mixture of bromide and bromine is applied under conditions that are also successful for the post column digestion of organoselenium compounds. The significance of the post column digestion is that it will assist in the development of simultaneous determination of arsenic and selenium species. The post-column chemistry of antimony has thus far been limited to the addition of borohydride under conditions that compromise the sensitivity of the species studied and is limited to those species that are borohydride active. There are several reports in the literature of unidentified antimony species that were not identified by the technique of hydride generation. Therefore, the application of photo-oxidation to those species would enable their subsequent determination by hydride generation. Two small projects with graphite furnace atomic absorption spectrometry are also discussed. The first project describes the development of a method for the determination of gold in cell structures. The second describes the measurement of bismuth in transferrin protein.
Scott, David Joseph, "Investigations into the hydride generation chemistry of arsenic and antimony compounds" (2003). Doctoral Dissertations Available from Proquest. AAI3096314.