PDF(Pubmed)
Abstract：
Volatile chemical products (VCPs) and other non-combustion-related sources have become important for urban air quality, and bottom-up calculations report emissions of a variety of functionalized compounds that remain understudied and uncertain in emissions estimates. Using a new instrumental configuration, we present online measurements of oxygenated organic compounds in a U.S. megacity over a 10-day wintertime sampling period, when biogenic sources and photochemistry were less active. Measurements were conducted at a rooftop observatory in upper Manhattan, New York City, USA using a Vocus chemical ionization time-of-flight mass spectrometer with ammonium (NH4 +) as the reagent ion operating at 1 Hz. The range of observations spanned volatile, intermediate-volatility, and semi-volatile organic compounds with targeted analyses of ~150 ions whose likely assignments included a range of functionalized compound classes such as glycols, glycol ethers, acetates, acids, alcohols, acrylates, esters, ethanolamines, and ketones that are found in various consumer, commercial, and industrial products. Their concentrations varied as a function of wind direction with enhancements over the highly-populated areas of the Bronx, Manhattan, and parts of New Jersey, and included abundant concentrations of acetates, acrylates, ethylene glycol, and other commonly-used oxygenated compounds. The results provide top-down constraints on wintertime emissions of these oxygenated/functionalized compounds with ratios to common anthropogenic marker compounds, and comparisons of their relative abundances to two regionally-resolved emissions inventories used in urban air quality models.
摘要：
挥发性化学产品（VCP）和其他与燃烧无关的来源已成为城市空气质量的重要因素，自下而上的计算报告了各种官能化化合物的排放，这些化合物在排放估算中仍未得到充分研究和不确定。使用新的仪器配置，我们提供了在10天冬季采样期间对美国特大城市中含氧有机化合物的在线测量，当生物源和光化学活性较低时。测量是在曼哈顿上城的屋顶天文台进行的，纽约市,美国使用Vocus化学电离飞行时间质谱仪，以铵（NH4）作为试剂离子，以1Hz运行。观测范围跨越波动，中间波动率，和半挥发性有机化合物，对约150个离子进行有针对性的分析，其可能的分配包括一系列官能化的化合物类别，如乙二醇，乙二醇醚，醋酸盐，酸，酒精,丙烯酸酯,酯类,乙醇胺,以及在各种消费者中发现的酮，商业,和工业产品。它们的浓度随着风向的变化而变化，在布朗克斯人口稠密的地区有所增强，曼哈顿,和新泽西州的部分地区，包括大量的乙酸盐，丙烯酸酯,乙二醇,和其他常用的含氧化合物。结果为这些含氧/官能化化合物的冬季排放提供了自上而下的限制，这些化合物与常见的人为标记化合物的比例，并将其相对丰度与城市空气质量模型中使用的两个区域解析排放清单进行比较。
