Ion Assisted Measurements of Trace Gases and Particle Growth

离子辅助测量痕量气体和颗粒生长

• 批准号: 9021522
• 负责人: Fred Eisele
• 金额: $ 44.94万
• 依托单位: Georgia Tech Research Corporation - GA Tech Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-03-01 至 1994-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9021522&HistoricalAwards=false
• 关键词: Ion; Assisted; Measurements; Trace; Gases

A mass spectrometer of special design is used to identify and measure ions in the atmosphere. These ions are individual molecules of atmospheric gases bearing either positive or negative electrical charges. The apparatus, developed over several years of laboratory work, is capable of extracting from the atmosphere ions existing in concentrations well below one part in a trillion, and injecting them into the vacuum chamber of a mass spectrometer. Measurement of the masses of the ions by the spectrometer permits their chemical identification. An atmospheric-pressure flow tube into which specific ions can be injected is used for the measurement of trace atmospheric species, including gas-phase sulfuric, methanesulfonic and malonic acids, pyridine, and ammonia, all of which are believed to be measurable at concentrations as low as 0.001 part per trillion in clean air. Variants of the technique will be used to search for large naturally occurring ion clusters, and to study clusters formed, or charged, by specific ion species such as protonated pyridine or the nitrate ion. Ion-assisted measurements will be made of ozone, sulfur dioxide, nitrogen oxides, and possibly of the OH free radical. The extreme sensitivity of these ion measurements opens up new possibilities of detecting, and measuring hitherto unsuspected low levels of atmospheric trace gases of natural or man-made origin, some of which may come from biological sources, e.g., pyridine. It is expected that these studies of the properties of atmospheric ions will help to clarify the molecular details of the conversions of gases to particles in the atmosphere. Implied in this is a better understanding of the nucleation of water droplets, and this of cloud formation.

一个特殊设计的质谱仪被用来识别 测量大气中的离子。 这些离子是独立的 带有正或负电荷的大气分子 负电荷。 该装置，开发了超过 几年的实验室工作，能够从 大气中离子的浓度远低于 万亿分之一，并将它们注入真空室， 质谱仪 离子质量的测量， 光谱仪允许它们的化学鉴定。 一种大气压流管， 可用于测量痕量大气 物种，包括气相硫酸，甲磺酸和 丙二酸，吡啶和氨，所有这些都被认为是 在浓度低至0.001份/ 万亿的清洁空气。 该技术的变体将用于搜索大型 自然产生的离子簇，并研究形成的簇， 或者通过特定的离子种类如质子化吡啶 或硝酸根离子。 离子辅助测量将对臭氧、硫 二氧化物、氮氧化物和可能的OH自由基。 这些离子测量的极端灵敏度 迄今为止探测和测量的新可能性 未预料到的低水平的大气痕量气体的天然或 人为来源，其中一些可能来自生物来源， 例如，在一个实施例中，吡啶。 预计这些研究将 大气离子的性质将有助于澄清分子 气体转化为颗粒的细节 气氛 这是一个更好的理解。 水滴的成核，以及云的形成。