HR: 08:15h
AN: B21C-02    [Abstracts]
TI: Aqueous Organometal Speciation by GC-ICP-MS and HPLC-ICP-MS
AU: * Hannigan, R
EM: hannigan@astate.edu
AF: Arkansas State University, Environmental Sciences, State University, AR 72467 United States
AB: Organometals, specifically organomercury, organotin and organolead, may only account for a small fraction of the total metal load in aquatic systems. Despite their lower relative abundance, organometal species may have a larger impact on the environment. Although biogeochemical studies of mercury, tin, and to a lesser degree lead, have been done, little is known about the transport and transformation of these organometals in the water column and, more specifically, at the sediment-water interface. Our knowledge is limited, in part, by the lack of instrumental techniques that provide simultaneous highly precise data about the metal species and binding ligand. We have developed a series of hyphenated techniques that allow for precise quantification of the elemental and organic forms of these metals. Most importantly these methods remove sample pre-treatment from the methods though headspace trap desorption, split injection and sequential chromatography with split detection providing detailed information about the metals and organics in stream water samples. Our data show that using headspace trap GC-ICP-MS it is possible to by-pass chromatographic separation of the species and detect elemental, dimethyl and methyl mercury in a single sample from a single injection. Additional research shows that GC-ICP-MS and HPLC-ICP-MS speciation of organotins provide differential speciation data with GC-ICP-MS detecting, at very low concentrations, butylins and HPLC-ICP-MS detecting, at very low concentrations, ethyltins. Integration of these techniques into a single system will eventually lead to a system which provides simultaneous detection of metals and organic binding ligands in a single sample.
UR: http://www.cas.astate.edu/geochemistry
DE: 0409 Bioavailability: chemical speciation and complexation
DE: 0452 Instruments and techniques
DE: 0489 Trace element cycling (4875)
DE: 0496 Water quality
SC: Biogeosciences [B]
MN: Fall Meeting 2005