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The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the ACEAsia campaign from Gosan, Jeju Island, Korea; Sapporo, Japan, and Chichi-jima Island in the western North Pacific, as well as on the NOAA R/V Ronald H. Brown. Total extracts were analyzed by GC-MS to determine both polar and aliphatic compounds. Total particles, organic matter and lipid and saccharide compounds were high during the Asian dust episode (early April 2001) compared to levels at other times. The organic matter can be apportioned to seven emission sources and to significant oxidation producing secondary products during long-range transport. Terrestrial natural background compounds are vascular plant wax lipids derived from direct emission and as part of desert sand dust. Fossil fuel utilization is obvious and derives from petroleum product and coal combustion emissions. Saccharides are a major polar (water-soluble) carbonaceous fraction derived from soil resuspension (agricultural activities). Biomass burning smoke is evident in all samples and seasons. It contributes up to 13% of the total compound mass as water-soluble constituents. Burning of refuse is another source of organic particles. Varying levels of marine-derived lipids are superimposed during aerosol transport over the ocean. Secondary oxidation products increase with increasing transport distance and time. The ACEAsia aerosols are comprised not only of desert dust, but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuels use in urban areas.

Atmospheric particulate matter, collected over the polluted east Asia/Pacific region in spring 2001 during research flights with the National Center for Atmospheric Research (NCAR) C-130 aircraft, was analyzed for different types of organic compounds using capillary gas chromatography–mass spectrometry. More than 70 organic species were detected in the aerosols and grouped into different compound classes on the basis of functional groups, including n-alkanes, polycyclic aromatic hydrocarbons, fatty acids, dehydroabietic acid, alkanols, water-soluble sugars (including glucose, sucrose, mycose, and levoglucosan), monocarboxylic and dicarboxylic acids, urea, and phthalates. Interestingly, the water-soluble compounds (72–133 ng m−3) were found to account for 16–50% (average 34%) of the total identified compound mass (TCM). Organic compounds were further categorized into several groups to suggest their sources. Fossil fuel combustion was recognized as the most significant source for the TCM (contributing 33–80% of TCM, average 50%), followed by soil resuspension (5–25%, average 19%) and secondary oxidation products (4–15%, average 9%). In contrast, the contribution of natural sources such as terrestrial plant wax and marine lipids (fatty acids and alkanols) was relatively small (3.4% and 9.4% on average, respectively). Biomass burning was suggested to contribute only a minor portion to the TCM of the Asian aerosols during the spring season (1.4% on average based on levoglucosan). However, levoglucosan may have been hydrolyzed and/or oxidized in part during long-range transport, and therefore this value represents a lower limit. The organic compound compositions of these samples are very different from those reported for aerosol particles of the Atlantic Ocean and from the earlier data for the mid-Pacific in terms of the abundant presence of water-soluble compounds consisting of saccharides, anhydrosaccharides, and the secondary dicarboxylic acids. This study demonstrated, ‘An edited version of this paper was published by AGU.’Copyright 2004, American Geophysical Union, Journal of Geophysical Research,109

The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the ACEAsia campaign from Gosan, Jeju Island, Korea; Sapporo, Japan, and Chichi-jima Island in the western North Pacific, as well as on the NOAA R/V Ronald H. Brown. Total extracts were analyzed by GC-MS to determine both polar and aliphatic compounds. Total particles, organic matter and lipid and saccharide compounds were high during the Asian dust episode (early April 2001) compared to levels at other times. The organic matter can be apportioned to seven emission sources and to significant oxidation producing secondary products during long-range transport. Terrestrial natural background compounds are vascular plant wax lipids derived from direct emission and as part of desert sand dust. Fossil fuel utilization is obvious and derives from petroleum product and coal combustion emissions. Saccharides are a major polar (water-soluble) carbonaceous fraction derived from soil resuspension (agricultural activities). Biomass burning smoke is evident in all samples and seasons. It contributes up to 13% of the total compound mass as water-soluble constituents. Burning of refuse is another source of organic particles. Varying levels of marine-derived lipids are superimposed during aerosol transport over the ocean. Secondary oxidation products increase with increasing transport distance and time. The ACEAsia aerosols are comprised not only of desert dust, but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuels use in urban areas.

The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the ACEAsia campaign from Gosan, Jeju Island, Korea; Sapporo, Japan, and Chichi-jima Island in the western North Pacific, as well as on the NOAA R/V Ronald H. Brown. Total extracts were analyzed by GC-MS to determine both polar and aliphatic compounds. Total particles, organic matter and lipid and saccharide compounds were high during the Asian dust episode (early April 2001) compared to levels at other times. The organic matter can be apportioned to seven emission sources and to significant oxidation producing secondary products during long-range transport. Terrestrial natural background compounds are vascular plant wax lipids derived from direct emission and as part of desert sand dust. Fossil fuel utilization is obvious and derives from petroleum product and coal combustion emissions. Saccharides are a major polar (water-soluble) carbonaceous fraction derived from soil resuspension (agricultural activities). Biomass burning smoke is evident in all samples and seasons. It contributes up to 13% of the total compound mass as water-soluble constituents. Burning of refuse is another source of organic particles. Varying levels of marine-derived lipids are superimposed during aerosol transport over the ocean. Secondary oxidation products increase with increasing transport distance and time. The ACEAsia aerosols are comprised not only of desert dust, but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuels use in urban areas.

Atmospheric particulate matter, collected over the polluted east Asia/Pacific region in spring 2001 during research flights with the National Center for Atmospheric Research (NCAR) C-130 aircraft, was analyzed for different types of organic compounds using capillary gas chromatography–mass spectrometry. More than 70 organic species were detected in the aerosols and grouped into different compound classes on the basis of functional groups, including n-alkanes, polycyclic aromatic hydrocarbons, fatty acids, dehydroabietic acid, alkanols, water-soluble sugars (including glucose, sucrose, mycose, and levoglucosan), monocarboxylic and dicarboxylic acids, urea, and phthalates. Interestingly, the water-soluble compounds (72–133 ng m−3) were found to account for 16–50% (average 34%) of the total identified compound mass (TCM). Organic compounds were further categorized into several groups to suggest their sources. Fossil fuel combustion was recognized as the most significant source for the TCM (contributing 33–80% of TCM, average 50%), followed by soil resuspension (5–25%, average 19%) and secondary oxidation products (4–15%, average 9%). In contrast, the contribution of natural sources such as terrestrial plant wax and marine lipids (fatty acids and alkanols) was relatively small (3.4% and 9.4% on average, respectively). Biomass burning was suggested to contribute only a minor portion to the TCM of the Asian aerosols during the spring season (1.4% on average based on levoglucosan). However, levoglucosan may have been hydrolyzed and/or oxidized in part during long-range transport, and therefore this value represents a lower limit. The organic compound compositions of these samples are very different from those reported for aerosol particles of the Atlantic Ocean and from the earlier data for the mid-Pacific in terms of the abundant presence of water-soluble compounds consisting of saccharides, anhydrosaccharides, and the secondary dicarboxylic acids. This study demonstrated, ‘An edited version of this paper was published by AGU.’Copyright 2004, American Geophysical Union, Journal of Geophysical Research,109

The alteration products of cholesterol subjected to hydrothermal conditions have been analyzed by gas chromatography–mass spectrometry. Four sets of experiments were conducted at temperatures ranging between 150 and 300 °C for 24 h. The reaction mixtures of the first set included only cholesterol and water, whereas those of the second, third and fourth sets also contained oxalic acid, natural sediment and montmorillonite, respectively. The alteration rate and the number of observed alteration products increased with higher temperature and acidity of the reaction mixtures. At lower temperatures cholestenes and cholestenones were major compounds. Cholestene concentrations increased at higher temperatures in all sets and were highest at 200 °C in acidic medium, at 250 °C in the presence of sediment and at 300 °C with montmorillonite. Cholestane concentrations also increased at elevated temperatures, being greatest in the absence of both sediment and montmorillonite. Diacholestenes were detected in an acidic medium at all temperatures and with montmorillonite at >200 °C. Monoaromatic steroid hydrocarbons were found above 200 °C. Thus, backbone rearrangements were the major alteration processes and bond cleavage (cracking) was predominant in an acidic medium, whereas aromatization was enhanced in the presence of both sediment and montmorillonite. These products confirm that reductive biomarker alteration in hydrothermal systems occurs rapidly and at high temperatures (>250 °C).

Fine organic aerosol samples (d_p ≤ 2.1 µm) were collected systematically during the entire year 1982 at four urban sites in the greater Los Angeles area and at one remote station: West Los Angeles, Downtown Los Angeles, Pasadena, Rubidoux, and San Nicolas Island. Samples were taken at 6-day intervals and composited to form monthly sample sets. The aerosol sample composites were subjected to high resolution gas chromatography (HRGC) and gas chromatography/rnass spectrometry (GC/MS). The objective is to quantify the abundance and seasonal variation of individual organic compounds that may be diagnostic for the contribution of particular emission sources to the ambient organic complex. More than 80 organic compounds are quantified, including the series of a-alkanes, g-alkanoic acids, n-alkenoic acids, n-alkanals, and aliphatic dicarboxylic acids, as well as aromatic polycarboxylic acids, diterpenoids, polycyclic aromatic hydrocarbons, polycyclic aromatic ketones and quinones, nitrogen-containing organic compounds, and other organics. Primary organic aerosol constituents are readily identified, revealing an annual pattern with high winter concentrations and low summer concentrations in the Los Angeles area. In contrast, dicarboxylic acids of likely secondary origin show a reverse pattern, with high concentration in late spring/early summer. The total ambient annual average dicarboxylic acids concentration shows a steady increase when moving in the prevailing summer downwind direction from the most western urban sampling site (West Los Angeles) to the farthest eastern sampling location (Rubidoux), with an increase from 199 ng m^(-3) at West Los Angeles to 312 ng m^(-3) at Rubidoux. The occurrence of aromatic polycarboxylic acids in the fine particulate matter is discussed in detail in this study, including possible sources and formation pathways. The total aromatic polycarboxylic acid concentration reveals elevated summer concentrations when compared to the annual conce