|Abstract Title:||Source, Processing, and Field Studies of Stable Isotope Ratios of Atmospheric Mercury|
|Presenter Name:||Satoshi Irei|
|Company/Institution:||National Institute for Minamata Disease|
|Session:||Atmospheric Hg cycling: Source and Emissions|
|Day and Session:||Wednesday 27th July - Session Four|
|Start Time:||16:00 UTC|
Abstract Information :
Atmosphere has a crucial role in the global transport of mercury. Atmospheric mercury, however, are mixtures of gaseous mercury from variety of sources, and concentration measurements alone have limitation to understand source identification and processing information. Naturally occurring stable isotopic compositions of mercury provide additional information beside the concentration information, thus, potentially allow us to gain more detailed information on those issues.
At the National Institute for Minamata Disease, we conduct stable isotope researches of mercury using Neptune Plus multicollector-ICP-MS. In this presentation we introduce our recent researches on the development of sampling and analytical techniques, stable mercury isotope ratio studies from biomass burning and commercially available mercury-contained products.
?Sampling and measurements of total gaseous mercury from open grass field burning in the Aso region, Kumamoto, Japan showed the increase of atmospheric concentrations of total gaseous mercury by factor or three or more. The stable isotope ratios showed lighter compositions in the mass 199 and 200 of Hg than 0 ?, and the observations approximately coincided to those of plant mercury reported by others.
Measurement results of stable isotope ratios of mercury in thermometers and fluorescent tubes, which can be the major source of mercury in waste treatment facilities, showed that very similar isotopic compositions of thermometer mercury to those of mercury reported for cinnabar ores and elemental mercury, and those differences were insignificant. Meanwhile, the stable isotope ratios of gaseous and adsorbed mercury in fluorescent tubes showed very unique values, thus, the stable isotope ratios can be used to fingerprint those. Results in the limited studies here demonstrate that the mercury isotopic measurements do not always promise to trace mercury from specific sources, but are very useful to fingerprint, depending on sample species.