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In China, liquid residue was mostly found in sealed bronze vessels associated with alcohol drinks, which are supposed to conserve the complete composition of the beverage, including the additives. So far, most of them have not been sufficiently scientifically verified. In this study, the liquid residue in bronze jars from the late Western Han period in the burial area of Jin Yang ancient city site was investigated by GC/MS, LC–MS/MS, SEM and Raman spectroscopy. These sensitive versatile techniques had unintended consequences in addition to confirming the presence of fermentation products (monosaccharides, alditols, glycerol‐related substances and organic acids). The enrichment of oxalic acid, VLCFA (very‐long‐chain fatty acid), and alkaloids hints that multiple plants were involved in the beverage preparation. The quinazoline alkaloid products from the sediments reveal an important Rutaceae ingredient, which relates to multiple ancient spices and Chinese herbs. Therefore, the liquid residues from Jin Yang ancient city site imply that they are the earliest known herbal wine remains in East Asia to this day. [ABSTRACT FROM AUTHOR]

Size distributions of chemical species provide evidence for their sources and formation mechanisms. Size‐segregated aerosols with 12 sizes were collected over Northern Japan (Sapporo: 43.07°N and 141.35°E) during the spring (9 April–21 May) of 2001 and analyzed for water‐soluble organic and inorganic species. The dominances of SO42– and NH4+ in submicron (Da < 1.1 μm) and Na+ and Ca2+ in supermicron (Da > 1.1 μm) aerosols suggest substantial contributions from anthropogenic sources, sea‐salt and dust particles via long‐range atmospheric transport. Oxalic acid (C2) is the dominant organic species followed by malonic (C3) and succinic (C4) acid. A supermicron mode enrichment of C2 is heavily involved with the long‐range transport of dust particles, whereas submicron mode C2 was influenced by anthropogenic sources from the East Asian continent. The size distributions of shorter‐chain diacids (C3–C6), phthalic (Ph) and glyoxylic acid are consistent with those of C2, whereas azelaic acid (C9) is enriched in submicron and supermicron modes by the influences of continental and marine air masses. The mass concentration ratios of C3/C4 in submicron (1.5–2.3) and supermicron (1.2–1.8) mode demonstrated that water‐soluble organic aerosols in Sapporo were photochemically processed during long‐range transport. The Ph/C9 ratios show that the influence of anthropogenic sources on 9–28 April samples was pronounced in supermicron (2.5–2.9) than the submicron (1.1–1.2) particles, and vice‐versa on 6–21 May samples. These contrast distributions suggest that the continental air masses from East Asia and marine air masses from the surrounding ocean likely control the chemical composition of aerosols over Northern Japan. Plain Language Summary: Dicarboxylic acids make up a considerable portion of water‐soluble organic aerosols (OAs) in the atmosphere. We present the changes in the size distributions of water‐soluble secondary OAs during the ACE‐Asia campaign in the spring of 2001 in Northern Japan. The molecular distribution of dicarboxylic acids in size‐segregated aerosols with a predominance of oxalic acid (C2) followed by malonic acid implies that water‐soluble OAs over Northern Japan were photochemically aged. The substantial fraction of C2 on the supermicron mode aerosols is affected by the dust transported from the East Asian continent, suggesting its uptake or heterogeneous production on the surface of dust particles during long‐range transport to Northern Japan. Significant positive correlations of C2 and related compounds with Ca2+ in a supermicron mode further support a heterogeneous production of C2 in Ca2+‐enriched supermicron aerosols. The results suggest that the air masses from East Asia and the surrounding ocean mainly control the abundances of OAs over Northern Japan. The atmospheric abundance of secondary OAs could change due to the enhanced production of C2 in supermicron and submicron particles that can affect aerosol‐cloud interaction and radiative forcing of the most considerable fraction of water‐soluble secondary OAs. Key Points: The chemical composition of atmospheric aerosols over Northern Japan is controlled by continental and marine air massesOxalic acid size distribution is induced by the long‐range transport of dust particles and anthropogenic sourcesWater‐soluble organic aerosols over Northern Japan were photochemically processed during long‐range atmospheric transport [ABSTRACT FROM AUTHOR]

Chemical evolution of East Asian dust during transpacific transport has been given much attention for inorganic species such as sulfate, nitrate and ammonium. However, the role of organic species during the transport has almost entirely been ignored. To understand the formation mechanism of secondary organic aerosols (SOA) on dust surfaces, this study investigated the concentrations and compositions of dicarboxylic acids, keto-carboxylic acids, α-dicarbonyls and inorganic ions in size-segregated aerosols (9-stages) collected in Xi'an, central China during the two dust storm episodes in the springs of 2009 and 2011 and compared with those in nondust storm periods. During the events the ambient particulate dicarboxylic acids were 932–2240 ng m −3 , which are comparable and even higher than those in nondust periods. Molecular compositions of the above SOA are similar to those in nondust periods with oxalic acid being the leading species. In the presence of the dust storms, all the above mentioned SOA species in Xi'an were predominantly enriched on the coarse particles (>2.1 μm), and oxalic acid well correlated with NO 3 − (R 2 = 0.72, p < 0.001) rather than SO 4 2 − . This phenomenon differs greatly from the SOA in any other nondust period that is usually characterized by an enrichment of oxalic acid in fine mode and a strong correlation of oxalic acid with SO 4 2 − . We propose a formation pathway to explain these observations, in which nitric acid and/or nitrogen oxides react with dust to produce Ca(NO 3 ) 2 and form a liquid phase on the surface of dust aerosols via water vapor-absorption of Ca(NO 3 ) 2 , followed by a partitioning of the gas-phase water-soluble organic precursors (e.g.,glyoxal and methylglyoxal) into the aqueous-phase and a subsequent oxidation into oxalic acid. To the best of our knowledge, we found for the first time the enrichment of glyoxal and methylglyoxal on dust surface. Our data suggest an important role of nitrate in the heterogeneous formation process of SOA on the surface of dust. [ABSTRACT FROM AUTHOR]

Abstract: Rainfall samples were collected over a period of 3 years and 8 months in subtropical East Asia. They are categorized into different rainfall types and analyzed to assess the ionic composition and its effect on the acidity of wet deposition in southern Taiwan. Only 4% of samples had a pH of <5.0, indicating that the study area is not impacted significantly by acid rain. The volume-weighted mean (VWM) pH by rainfall type was Spring Rain 5.74, Typhoon Rain 5.56, Summer Rain 5.46, Typhoon Outer Circulation (TOC) Rain 5.45, Plum Rain 5.32 and Autumn–Winter Rain 5.29. Dilution effects were important to the equivalent ionic concentration of different rainfall types. HCO3 −, SO4 2− and Cl− were detected as major anions whereas NH4 +, Na+ and Ca2+ were major cations. CO2-derived HCO3 − was the major ionic species in all but Typhoon Rain and Spring Rain, in which the major species were Na+ and Cl− and Ca2+, respectively. Excluding HCO3 −, the major species were NH4 +, Na+ and Ca2+ in Plum Rain, the secondary photochemical products SO4 2−, NO3 − and NH4 + in TOC Rain and Summer Rain, and Na+ and Ca2+ in Autumn–Winter Rain. Calculation of arithmetic means showed that dicarboxylic acids contributed between 0.25% and 0.53% of the total ionic concentration and of these, oxalic acid contributed the least (81.3% of the dicarboxylic acid) to TOC Rain and the most (96.1% of the dicarboxylic acid) to Spring Rain, suggestive of long-range transport in the latter. Differences in wet deposition composition were shown to be a result of differences in local emissions and long-range transport (hence of prevailing wind direction) during the period of rainfall and of the frequency and volume of rain that typifies each rainfall type. Principal component analysis (PCA) further revealed that traffic-related and industrial organic and inorganic pollutants, their secondary photochemical products, sea salts, and dust are important contributors to wet deposition. Moreover, the ratio of malonic acid to succinic acid (M:S ratio) indicated that both traffic and secondary photochemical reactions are major contributors to all but TOC Rain, for which the M:S ratio of 4.54 indicates a relative abundance of pollutants from secondary photochemical reactions. An ion balance (IB) ratio analysis demonstrated the validity of the results in this research. [Copyright &y& Elsevier]

This study reveals the impact of biomass burning (BB) on secondary organic aerosols (SOA) formation in the North China Plain (NCP). Filter samples were analyzed for secondary inorganic aerosols (SIA), oxalic acid (C 2) and related aqueous-phase SOA compounds (aqSOA), stable carbon isotope composition of C 2 (δ13C(C 2)) and aerosol liquid water content (ALWC). Based on the PM 2.5 loadings, BB tracer concentrations, wildfire spots and air-mass back trajectories, we distinguished two episodes from the whole campaign, Episode I and Episode II, which were characteristic of regional and local BB, respectively. The abundances of PM 2.5 and organic matter in the two events were comparable, but concentrations and fractions of SIA, aqSOA during Episode I were much higher than those during Episode II, along with heavier δ13C(C 2), suggesting an enhanced aqSOA formation in the earlier period. We found that the enhancement of aqSOA formation during Episode I was caused by an increased ALWC, which was mainly driven by SIA during the regional BB event. Our work showed that intensive burning of crop residue in East Asia can sharply enhance aqSOA production on a large scale, which may have a significant impact on the regional climate and human health. Image 1 • Intensive regional biomass burning could lead to high aerosol liquid water content. • Aqueous-phase secondary organic aerosols was enhanced by aerosol liquid water. • Positive feedback loop between secondary inorganic, organic aerosols and aerosol water. • Regional biomass burning had heavier oxalic acid stable isotopes than locally. Our study shows that aqueous-phase SOA (aqSOA) were largely enhanced by the aerosol liquid water content (ALWC), which was mainly driven by secondary inorganic aerosols during the intensive regional biomass burning of the crop residues. [ABSTRACT FROM AUTHOR]