Grant: Research Tools and Instruments - Category 1 (<$150,000)

Anthropogenic emissions of inorganic mercury (HgII) have increased long-range transport of Hg and pollution of remote pristine areas. On a global basis, the major sources of Hg to the atmosphere are emissions from coal-fired energy production and waste combustion, fluxes that are likely to increase with further industrialization and population growth. In general, HgII in the atmosphere enters aquatic ecosystems where it can be converted though microbial methylation into methylmercury (MeHg). MeHg concentrations in the environment are of special concern because MeHg is a neurotoxin that is easily bioaccumulated by humans and wildlife that consume fish and other aquatic organisms. The current RTI proposal requests funds to purchase a system to allow us to expand our analytical techniques to low-level MeHg analysis, allowing us to measure the highly neurotoxic, bioaccumulated form of Hg independently from other less harmful inorganic Hg species in environmental samples. The system is capable of analyzing MeHg in a variety of environmental matrices, including air, plants, biota, water, and sediment. MeHg is detected using a combination of dual stage pre-concentration and atomic fluorescence detection, after distillation, ethylation, and GC separation. This provides the most sensitive, selective, and resilient MeHg analysis available to date. The method of analysis is not automated and as a result there are a number of components that are required. These components include equipment for the purification of samples by distillation, and the ethylation, separation by gas chromatography, and detection using cold vapour atomic fluorescence spectrometry.