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This study characterized the water-soluble organic carbon (WSOC) and ionic components of PM2.5 (particles less than 2.5 µm in diameter) from April to June 2016, at Baengnyeong Island The study utilized a particle-into-liquid sampler (PILS) coupled with a total organic carbon (TOC) analyzer and ion chromatography (PILS-TOC-IC). The PM2.5 mean concentration in this study was 23.8±16.7 µg m-3, and the mean of WSOC concentration was 1.6±1.5 µg m-3. Ionic compounds increased by 3.8% in the period in which the air quality standard of PM2.5 (35 µg m-3) was exceeded because the concentration of ionic components increased due to generation by chemical reactions and emissions from a primary source in a nearby urban area. The wind direction and speed were mostly in the northwest and southwest directions and the higher concentration of PM2.5 was also shown in the same directions. In comparison with the previous study, the WSOC/OC ratio was 0.5±0.3 in Baengnyeong Island, which was higher than that at roadside and urban sites and lower than at the background site (Sweden, Aspvreten). It was considered that insoluble OC constituted a major proportion of primary OC that was emitted in urban areas, and the higher WSOC/OC ratios of rural and background sites were affected by inflow. The ratio of nitrate and sulfate in Baengnyeong Island was lower than urban areas in China in other studies, because of emitted aerosols from coal combustion or vehicle emission. The results indicate that Baengnyeong Island was affected by formation of secondary aerosols by chemical reactions and inflow from China as well as domestic emissions. The slope of H+Aersol/SO42- in Baengnyeong Island was 0.079, which was a result of neutralized particle acidity in ambient air. The molar ratio of nitrate and ammonium with sulfate in Baengnyeong Island showed ammoniumrich conditions because ammonium nitrate was increased to homogeneous reaction of ammonia and nitric acid in the gas-phase. [ABSTRACT FROM AUTHOR]

Abstract: Solvent extractable organic compounds (SEOC), organic carbon, elemental carbon and water soluble organic carbon (WSOC) in PM2.5 samples collected in Shanghai, China in 2002 and 2003 were measured to determine the composition and sources of the organic matter in atmospheric aerosols. Distinct seasonal variations were detected with higher concentrations of organic matter in winter. The concentration of total carbon of about 20μgm−3 in winter was about three times the summer value. About 30% of the total carbon was water soluble. Unresolved complex mixture (UCM) and fatty acids were the most abundant components quantified in SEOC, similar to other Chinese cities previously studied. High ratio of UCM to n-alkanes (U:R) and the composition of triterpanes indicated that engine exhaust was a major source of the airborne organic matter. Emissions from coal burning had more impact in the rural areas, according to the U:R value and PAHs composition. Chemical mass balance (CMB) modeling shows that about half of the organic carbon was from engine exhaust and about 15% was from coal burning. No clear spatial variation in the concentration of the organic matter was found between urban and rural areas. Our results showed that due to the rapid urbanization and relocation of industrial plants from urban areas to rural areas in the past 20 years, air pollution in rural areas is becoming a serious problem in Shanghai and the Yangtze River delta. [Copyright &y& Elsevier]

The study represents the seasonal characteristics (carbonaceous aerosols and elements) and the contribution of prominent sources of PM 2.5 and PM 10 in the high altitude of the eastern Himalaya (Darjeeling) during August 2018-July 2019. Carbonaceous aerosols [organic carbon (OC), elemental carbon (EC), and water soluble organic carbon (WSOC)] and elements (Al, Fe, Ti, Cu, Zn, Mn, Cr, Ni, Mo, Cl, P, S, K, Zr, Pb, Na, Mg, Ca, and B) in PM 2.5 and PM 10 were analyzed to estimate their possible sources. The annual concentrations of PM 2.5 and PM 10 were computed as 37±12 μg m -3 and 58±18 μg m -3 , respectively. In the present case, total carbonaceous species in PM 2.5 and PM 10 were accounted for 20.6% of PM 2.5 and 18.6% of PM 10 , respectively, whereas trace elements in PM 2.5 and PM 10 were estimated to be 15% of PM 2.5 and 12% of PM 10 , respectively. Monthly and seasonal variations in mass concentrations of carbonaceous aerosols and elements in PM 2.5 and PM 10 were also observed during the observational period. In PM 2.5 , the annual concentrations of POC and SOC were 2.35 ± 1.06 μg m -3 (66% of OC) and 1.19±0.57 μg m -3 (34% of OC), respectively, whereas annual average POC and SOC concentrations in PM 10 were 3.18 ± 1.13 μg m -3 (63% of OC) and 2.05±0.98 μg m -3 (37% of OC), respectively. The seasonal contribution of POC and SOC were ranging from 55 to 77% and 33 to 45% of OC in PM 2.5 , respectively, whereas in PM 10 , the seasonal contributions of POC and SOC were ranging from 51 to 73% and 37 to 49% of OC, respectively. The positive relationship between OC & EC and OC & WSOC of PM 2.5 and PM 10 during all the seasons (except monsoon in case of PM 10 ) indicates their common sources. The enrichment factors (EFs) and significant positive correlation of Al with othe crustal elements (Fe, Ca, Mg, and Ti) of fine and coarse mode aerosols indicate the influence of mineral dust at Darjeeling. Principal component analysis (PCA) resolved the four common sources (biomass burning + fossil fuel combustion (BB + FFC), crustal/soil dust, vehicular emissions (VE), and industrial emissions (IE)) of PM 2.5 and PM 10 in Darjeeling., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)