Chromatographic speciation of organometallic compounds in the marine food web

• Main Author: Storton, Mark Lee
• Language: ENG
• Published: ScholarWorks@UMass Amherst 2001
• Subjects: Analytical chemistry|Oceanography|Ecology
• Online Access: https://scholarworks.umass.edu/dissertations/AAI3027262

The introduction and presence of metals in the marine environment and their reaction and bioaccumulation in organisms and in the marine food web is of environmental importance. The identification and quantification of inorganic and organometallic compounds in marine samples is of importance in studies of the marine food chain and the accumulation of both nutrients and potentially toxic compounds in higher order marine organisms in the marine ecosystem. The goal of this doctoral research was to develop and apply analytical methodology to the sampling, isolation, speciation and determination of metals and organometallic compounds, notably those of the carbon-bonding main group elements such as mercury, tin and selenium in marine samples. The introduction of metals into the marine environment was investigated by analysis of phytoplankton samples cultured by the National Marine Fisheries Service. Procedures for extraction, fractionation and gas chromatographic determination by derivatization and element-specific detection by microwave plasma emission spectrometry (GC-AED) were developed. The biological pathways and transfer of elements along the food chain was investigated on a variety of marine samples including dogfish liver, mussel and lobster heptopancreas. This study was conducted in part at the National Institute of Standards and Technology (NIST), Gaithersburg, MD. Specifically this research centered around providing an alternative procedure to existing methodology for the determination of organomercury compounds in marine samples. Derivatization procedures developed in this research were exhaustively compared with direct gas chromatography of methylmercury chloride, as previously used by NIST. A modified version of the method developed for the analysis of phytoplankton samples allowed both inorganic and organomercury to be simultaneously measured at the μg/g level and below.