An airborne dual ionisation Chemical Ionisation Mass Spectrometer

机载双电离化学电离质谱仪

• 批准号: NE/E018092/1
• 负责人: Carl Percival
• 金额: $ 60.8万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FE018092%2F1
• 关键词: airborne; dual; ionisation; Chemical; Ionisation

Ammonia (NH3) and nitric acid (HNO3) are important components of the atmospheric nitrogen burden on regional scales and are major contributors to the nitrogen budget across the UK and western continental Europe. The gases are semi-volatile and can readily partition to aerosol particles as ammonium nitrate (NH4NO3), changing their pathways through the atmosphere. Deposited atmospheric nitrogen can change the nutrient balance of an ecosystem and has been shown to make an important contribution to excess nitrogen in aquatic and marine environments around the UK. NH3 is primarily emitted from agricultural sources and, since the introduction of catalytic converters, increasingly from urban environments. However, NH3 is efficiently lost to the semi-natural vegetation, typical of many natural upland ecosystems important in the UK. HNO3 is produced primarily by photooxidation of nitrogen oxides, which are emitted from combustion sources, mainly motor vehicles. Its production depends on photochemistry and is highest in the plumes of large urban areas. As sulphur declines across western Europe, regions of excess ammonia are becoming more widespread and ammonium nitrate aerosol is becoming a significant component for atmospheric nitrogen. Unlike, NH3 and HNO3, NH4NO3 has a low deposition velocity and is predominately removed by precipitation, hence the nitrogen footprint of a source region changes substantially depending on its phase. As these pathways become more important, so NH4NO3 becomes a significant contributor to regional climate as well as air quality. However, as NH4NO3 is relatively volatile, its concentration is dependent on the associated gaseous NH3 and HNO3 concentrations and evaporation can readily take place in the boundary layer. Furthermore, the particulate and gaseous species have very different surface loss rates. These complexities have made it difficult to obtain an accurate picture of the nitrogen burden. A major part of the problem is the lack of measurement capability. Whilst new instruments for NH3 and HNO3 exist within the UK and have been applied to the problem at the land surface, they cannot be used on mobile platforms, especially aircraft. This is necessary to study the important problem of larger scale transformations and spatial variability and link to models. This proposal hopes to deliver such capability to the UK community by using Chemical Ionisation Mass Spectrometric methods (CIMS). The CIMS technique generates ions of known gases, which are reacted with the atmospheric gas of interest in the inlet to a mass spectrometer where the known reactant ions are sampled. The choice of reactant ions is crucial as this determines the selectivity and sensitivity of the instrument to the sample gas. NH3 and HNO3 have both been measured by CIMS in the past with high sensitivity and selectivity using technological advances made in the USA over the last few years but the ion reaction schemes necessary for their detection are different for the two gases so the instrument has only been capable of measuring one or the other gas at any one time. We intend to purchase such an instrument and develop it by incorporating both ion reaction schemes together and rapidly switch between them providing data on both HNO3 and NH3 at the same time. We will test it in the laboratory, demonstrate its capabilities in a comparison exercise with several other instruments, and perform a surface based study using a mobile laboratory to probe surface heterogeneities in NH3, HNO3, and NH4NO3 fields. The instrument will be installed in the UK FAAM aircraft and then used together with particle measurements to probe the system on a regional scale around the UK in order to tackle the very important, but poorly understood problem of nitrogen transformation, transport and deposition.

氨(NH3)和硝酸(HNO3)是区域尺度上大气氮负荷的重要组成部分，也是英国和西欧大陆氮收支的主要贡献者。这种气体是半挥发性的，可以很容易地以硝酸铵(NH4NO3)的形式分配到气溶胶颗粒中，改变它们通过大气的路径。大气中沉积的氮可以改变生态系统的营养平衡，并已被证明对英国周围水生和海洋环境中过量的氮做出了重要贡献。NH3主要来自农业来源，自采用催化转化器以来，越来越多地来自城市环境。然而，NH3有效地流失到半自然植被中，这是英国许多重要的自然山地生态系统的典型特征。硝酸主要是通过氮氧化物的光氧化产生的，氮氧化物是从燃烧源排放的，主要是机动车辆。它的产量依赖于光化学，在大城市地区的羽流中产量最高。随着整个西欧硫磺的下降，氨过量的地区正变得更加普遍，硝酸铵气溶胶正在成为大气氮的重要组成部分。与NH3和HNO3不同，NH4NO3的沉积速度很低，主要通过降水去除，因此源区的氮足迹根据其相的不同而发生很大变化。随着这些途径变得更加重要，NH4NO3成为区域气候和空气质量的重要贡献者。然而，由于NH_4NO_3是相对易挥发的，其浓度取决于相关的气态NH_3和HNO_3浓度，蒸发很容易在边界层中发生。此外，颗粒物和气态物质的表面损失率非常不同。这些复杂性使得人们很难准确地了解氮的负担。问题的一个主要部分是缺乏测量能力。虽然新的NH3和HNO3仪器在英国已经存在，并已应用于陆地表面的问题，但它们不能用于移动平台，特别是飞机。这对于研究更大尺度的变换和空间变异性以及与模型的联系这一重要问题是必要的。这项提议希望通过使用化学电离质谱分析方法(CIMS)为英国社区提供这种能力。CIMS技术产生已知气体的离子，这些离子在质谱仪的入口处与感兴趣的大气气体反应，在质谱仪中对已知的反应物离子进行采样。反应物离子的选择至关重要，因为这决定了仪器对样品气体的选择性和灵敏度。过去，利用美国最近几年的技术进步，用CIMS测量NH3和HNO3都具有很高的灵敏度和选择性，但对于这两种气体，检测所需的离子反应方案不同，因此仪器在任何时候都只能测量一种或另一种气体。我们打算购买这样一台仪器，并通过将两种离子反应方案结合在一起并在它们之间快速切换来开发它，同时提供HNO3和NH3的数据。我们将在实验室中对其进行测试，在与其他几种仪器的比较中展示其能力，并使用移动实验室进行基于表面的研究，以探测NH3、HNO3和NH4NO3领域的表面非均质性。该仪器将安装在英国FAAM飞机上，然后与颗粒测量一起用于在英国各地的区域范围内探测该系统，以解决非常重要但知之甚少的氮转化、运输和沉积问题。

项目成果

Airborne observations of formic acid using a chemical ionization mass spectrometer

• DOI: 10.5194/amt-5-3029-2012
• 发表时间: 2012-01-01
• 期刊: ATMOSPHERIC MEASUREMENT TECHNIQUES
• 影响因子: 3.8
• 作者: Le Breton, M.;McGillen, M. R.;Percival, C. J.
• 通讯作者: Percival, C. J.

Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires

• DOI: 10.5194/acp-13-9217-2013
• 发表时间: 2013-09
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: M. Breton;A. Bacak;J. Muller;S. O'Shea;P. Xiao;M. Ashfold;M. Cooke;R. Batt;D. Shallcross

Profiling aerosol optical, microphysical and hygroscopic properties in ambient conditions by combining in situ and remote sensing

• DOI: 10.5194/amt-10-83-2017
• 发表时间: 2016-07
• 期刊: Atmospheric Measurement Techniques
• 影响因子: 3.8
• 作者: A. Tsekeri;V. Amiridis;F. Marenco;A. Nenes;E. Marinou;S. Solomos;P. Rosenberg;J. Trembath;G. Nott;J. Allan;M. Breton;A. Bacak;H. Coe;C. Percival;N. Mihalopoulos

Atmospheric composition in the Eastern Mediterranean: Influence of biomass burning during summertime using the WRF-Chem model

• DOI: 10.1016/j.atmosenv.2016.03.011
• 发表时间: 2016-05
• 期刊: Atmospheric Environment
• 影响因子: 5
• 作者: E. Bossioli;M. Tombrou;J. Kalogiros;J. Allan;A. Bacak;S. Bezantakos;G. Biskos;H. Coe;B. Jones;G. Kouvarakis;N. Mihalopoulos;C. Percival

Aerosol absorption over the Aegean Sea under northern summer winds

• DOI: 10.1016/j.atmosenv.2020.117533
• 发表时间: 2020-06
• 期刊: Atmospheric Environment
• 影响因子: 5
• 作者: Georgia Methymaki;E. Bossioli;J. Kalogiros;G. Kouvarakis;N. Mihalopoulos;A. Nenes;M. Tombrou