Abstracts of Annual Meeting of the Geochemical Society of Japan

Biological activities have been detected in extreme environments such as super-arid dessert environments. We examined whether amino acid concentration could be used as parameters of biological activities in extreme environments. We determined amino acid concentration of dessert soils sampled at 5 sites in Atacama dessert, Chile, where is one of the most desiccated place on the earth. Amino acid concentration in Atacama is quite low, and the soil obtained at the site with the lowest rainfall level showed the lowest amino acid concentration. Amino acid concentration was correlated to phosphatase activity and viable microbial count.

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Groundwater flow and residence times are fundamental parameters for quantifying water resources, yet difficult to estimate. Noble gases are excellent groundwater tracers and chronometers because they are inert and have isotopes produced by radioactive decay of U, Th and K. Recently we performed groundwater studies in a region close to the most populated region of eastern Canada.

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Proteinoid is a proto-protein formed from monoammonium malate. And the proteinoid formed a micro-globular structure called proteinoid microsphere. We discuss about the relationship between the properties of proteinoid and proteinoid microsphere. Diameter of proteinoid is approximately 1 micro m. The size became larger with increasing of metal ion concentration. When the diameter is larger than ca. 3 micro m, the proteinoid microsphere is aggregation and precipitation. In addition, we characterize the chemical properties of proteinoid in the proteinoid microsphere.

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Introduction. Secondary organic aerosols (SOA) constituting up to 90% of atmospheric particles have multiple feedbacks on our climate and health systems. Glyoxal and methylglyoxal are important precursors for the formation of SOA via their oxidation and oligomerization reactions in aqueous aerosols and cloud droplets. They are also used as indicators to evaluate the oxidation of volatile organic compounds (VOCs) in the atmosphere.Experimental. Atmospheric total suspended particle (TSP) samples (n = 698) were collected over 6 hours to 7 days at Gosan site in Jeju Island, South Korea, using a high volume aerosol sampler from 2001-2008. Glyoxal and methylglyoxal were isolated by water extraction and then derivatized to dibutoxyacetals. The derived dibutoxyacetals were identified by the gas chromatography-mass spectrometry (GC-MS) technique. The quantitation was carried out by comparing the peak area of dibutoxyacetals with the peak area of authentic dibutyl succinate on capillary gas chromatograms (GC-FID).Results and Discussion. Concentrations of glyoxal and methylglyoxal ranged from 0.06 to 106 ng m^-3 and from below detection limit (0.01 ng m-3) to 111 ng m^-3, respectively. The median, 25th and 75th concentrations of glyoxal were observed highest in January and lowest in summer months (June-August). The concentrations of methylglyoxal maximized from February to April and minimized during summer months. Highest concentrations in winter months are due to their: a) higher emissions from the combustion sources in northeast China from which air masses are transported to Gosan site; b) lesser photolysis; and c) enhanced gas to particle partitioning. Maximum concentrations in spring are linked with higher ozone concentrations, indicating their enhanced production in the atmosphere from the photochemical processing. Lowest concentrations in summer months are mainly due to the dilution of polluted plumes at Gosan site by the clean air masses transported from the Yellow Sea, China Sea and western Pacific Ocean. The interannual variations of the concentrations of glyoxal and methylglyoxal were non-linear over the time period of 2001-2008. Overall, the monthly median, 25th percentile and 75th percentile concentrations of glyoxal and methylglyoxal increased up to factors of 5.4 and 15.5, respectively, from 2001-2002 to 2007-2008. The incremental trends are related with the increase of CO and O3. The results suggest their enhanced emission from the combustion sources and the subsequent photochemical production associated with both increased oxidant and isoprene from 2001-2002 to 2007-2008. Atmospheric Implications. This study for the first time reports the seasonal and interannual variations of the concentrations of aerosol phase glyoxal and methylglyoxal in the atmosphere over almost decadal scale (2001-2008) in East Asia. Their increasing trend suggests their augmented role in the production of SOA in East Asia.

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