Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.5194/acp-18-12413-2018 |
Evidence for pyrazine-based chromophores in cloud water mimics containing methylglyoxal and ammonium sulfate | |
Hawkins, Lelia Nahid1; Welsh, Hannah G.1; Alexander, Matthew V.2 | |
2018-08-28 | |
发表期刊 | ATMOSPHERIC CHEMISTRY AND PHYSICS |
ISSN | 1680-7316 |
EISSN | 1680-7324 |
出版年 | 2018 |
卷号 | 18期号:16页码:12413-12431 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | Simulating aqueous brown carbon (aqBrC) formation from small molecule amines and aldehydes in cloud water mimics provides insight into potential humic-like substance (HULIS) contributors and their effect on local and global aerosol radiative forcing. Previous work has shown that these (Maillard type) reactions generate products that are chemically, physically, and optically similar to atmospheric HULIS in many significant ways, including in their complexity. Despite numerous characterization studies, attribution of the intense brown color of many aqBrC systems to specific compounds remains incomplete. In this work, we present evidence of novel pyrazine-based chromophores (PBCs) in the product mixture of aqueous solutions containing methylglyoxal and ammonium sulfate. PBCs observed here include 2,5-dimethyl pyrazine (DMP) and products of methylglyoxal addition to the pyrazine ring. This finding is significant as the literature of Maillard reactions in food chemistry tightly links the formation of pyrazine (and related compounds) to browning in foods. We investigated the roles of both cloud processing (by bulk evaporation) and pH in absorptivity and product distribution in microliter samples to understand the contribution of these PBCs to aqBrC properties. In agreement with previous work, we observed elevated absorptivity across the entire UV-visible spectrum following simulated cloud processing as well as higher absorptivity in more basic samples. Absorptivity of the pH 2 sample, following evaporation over a period of days, exceeded that of the unevaporated pH 9 sample. In addition, mixtures of ammonium sulfate and methylglyoxal at pH 5 that were dried in under 1 h and analyzed 24 h later were as absorptive as pH 9 samples allowed to react for 7 days, indicating that evaporation occurring during cloud processing may provide a reaction path-way favorable for carbonyl-ammonia chemistry even under acidic conditions of aerosol and cloud water. The fraction of pyrazine compounds in the product mixture increased by up to a factor of 4 in response to drying with a maximum observed contribution of 16% at pH 5. Therefore, cloud processing under acidic conditions may produce PBCs at the expense of imine-and imidazole-derived compounds. This finding has implications for further BrC reactivity and degradation pathways. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000442942600001 |
WOS关键词 | SECONDARY ORGANIC AEROSOL ; BROWN CARBON CHROMOPHORES ; MAILLARD MODEL SYSTEMS ; ATMOSPHERIC AEROSOLS ; LIGHT-ABSORPTION ; AQUEOUS AEROSOL ; GLYOXAL ; PRODUCTS ; IDENTIFICATION ; CHEMISTRY |
WOS类目 | Environmental Sciences ; Meteorology & Atmospheric Sciences |
WOS研究方向 | Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/30898 |
专题 | 地球科学 |
作者单位 | 1.Harvey Mudd Coll, Dept Chem, 301 Platt Blvd, Claremont, CA 91711 USA; 2.Pomona Coll, Dept Chem, Claremont, CA 91711 USA |
推荐引用方式 GB/T 7714 | Hawkins, Lelia Nahid,Welsh, Hannah G.,Alexander, Matthew V.. Evidence for pyrazine-based chromophores in cloud water mimics containing methylglyoxal and ammonium sulfate[J]. ATMOSPHERIC CHEMISTRY AND PHYSICS,2018,18(16):12413-12431. |
APA | Hawkins, Lelia Nahid,Welsh, Hannah G.,&Alexander, Matthew V..(2018).Evidence for pyrazine-based chromophores in cloud water mimics containing methylglyoxal and ammonium sulfate.ATMOSPHERIC CHEMISTRY AND PHYSICS,18(16),12413-12431. |
MLA | Hawkins, Lelia Nahid,et al."Evidence for pyrazine-based chromophores in cloud water mimics containing methylglyoxal and ammonium sulfate".ATMOSPHERIC CHEMISTRY AND PHYSICS 18.16(2018):12413-12431. |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论