Comprehensive Analytical System for Measuring Isoprene-derived Nitrates

用于测量异戊二烯衍生硝酸盐的综合分析系统

基本信息

批准号：
NE/J008389/1
负责人：
Claire Reeves
金额：
$ 53.19万
依托单位：
University of East Anglia
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ008389%2F1
关键词：
Comprehensive Analytical System Measuring Isoprene

项目摘要

A comprehensive understanding of the interactions between the biosphere and the atmosphere is crucial for: (i) Earth System science (ii) predicting the impact of future climate change. Isoprene is the most important biogenic volatile organic compound (VOC) in the atmosphere, with its emissions accounting for 1/3 of the global total VOC emissions (i.e. natural and anthropogenic combined). Through its degradation chemistry, isoprene impacts ozone and the formation of aerosols, which together impact global warming and the atmosphere's ability to cleanse itself of pollutants.Recent model studies show that the calculated impact of isoprene on ozone is critically dependent on the model isoprene chemical scheme, in particular the way the isoprene derived nitrates are treated. There is considerable uncertainty over how much of these nitrates are formed and what subsequently happens to them. Of particular importance is whether the nitrogen oxides, which are tied up in the nitrates, are later recycled or are lost from the atmosphere. This then impacts the amount of ozone that can be subsequently formed. Virtually everything that is known about isoprene nitrate chemistry is based on theoretical calculations, with most observational constraints based on measurements of either groups of nitrates as totals, or degradation products that come from more than one reaction and precursor species. For any substantial scientific progress to be made comprehensive measurement of individual nitrates is required, in laboratory studies to properly understand the chemistry of individual nitrates, and in the field to determine the true impact of isoprene on ozone and aerosol.Studies of isoprene degradation chemistry have been greatly limited by measurement techniques and their inability to identify and quantify individual organic nitrates. We therefore propose to:1. Develop an analytical gas chromatography mass spectrometry instrument capable of detecting and identifying individual isoprene derived nitrates2. Synthesise 18 individual isoprene derived nitrates to enable their unambiguous detection and identification and for their concentrations to be quantified down to atmospheric levels.The final products of this "Technology Led" proposal will be novel synthesis protocols and an analytical system that will allow calibrated measurements of 18 individual isoprene nitrates at concentrations down to atmospheric levels. The system can then subsequently be used in both laboratory and field studies. Such an analytical system will be unique and will enable isoprene chemistry to be studied at the level of individual reactions and products. This will facilitate a major advancement in the evaluation of model chemical mechanisms used to predict air quality and climate. It will enable a step change in the ability to constrain these mechanisms by allowing quantification of the rates and products of individual branches of these reaction schemes. Further it will allow the concentrations of individual isoprene nitrates to be measured in the real atmosphere and models tested against these data. Altogether this will enable the impact of isoprene nitrates on nitrogen oxide recycling and ozone to be quantified with well constrained models.The elevated ozone in England during the 2003 heatwave was attributed, in part, to elevated concentrations of isoprene. Future changes in climate and land-use are likely to affect isoprene emissions so understanding how isoprene impacts nitrogen oxide recycling is important for predicting future ozone concentrations. The potential advancements in scientific understanding that can be made following the development of the technology within this proposal are therefore essential for policy makers developing emission control strategies.

对生物圈与大气之间的相互作用的全面了解对于：（i）地球系统科学（ii）预测未来气候变化的影响。异戊二烯是大气中最重要的生物挥发性有机化合物（VOC），其排放量占全球总VOC排放的1/3（即自然和人为结合）。通过其降解化学，异戊二烯影响臭氧和气溶胶的形成，这共同影响了全球变暖和大气清洁污染物的能力。骨骼模型研究表明，异戊二烯对臭氧的计算影响非常依赖于模型的化学化学方案，特别是对异戊二烯衍生的硝酸盐的处理方式。这些硝酸盐中的多少以及随后发生的事情存在很大的不确定性。尤其重要的是，将氮氧化物绑在硝酸盐中，后来被回收还是从大气中丢失。然后，这会影响可以随后形成的臭氧数量。实际上，关于异戊二烯硝酸盐化学的所有知识都基于理论计算，大多数观察性约束基于对任何一组硝酸盐作为总数的测量，或来自多种反应和前体物种的降解产物。为了对任何实质性的科学进步进行全面测量单个硝酸盐，在实验室研究中，以适当地了解单个硝酸盐的化学性质，并在该领域确定异戊二烯对臭氧和气溶胶的真正影响。异质化学化学研究的研究受测量技术及其无法识别和量化单个有机硝酸盐的限制。因此，我们建议：1。开发能够检测和鉴定单个异戊二烯衍生的硝酸盐的分析气相色谱质谱仪。合成18个单独的异戊二烯衍生的硝酸盐，以实现其明确的检测和识别，并将其浓度量化为大气水平。该“技术LED”建议的最终产物将是新型的合成协议和一个分析系统，该系统将允许校准的测量值18个单独的异戊二烯硝酸盐，浓度降至大气水平。然后，该系统随后可以用于实验室和现场研究。这样的分析系统将是独一无二的，并且可以使异戊二烯化学在个体反应和产品的水平上进行研究。这将促进用于评估用于预测空气质量和气候的模型化学机制的主要进步。它将通过允许量化这些反应方案的各个分支的速率和产物来限制这些机制的能力变化。此外，它将允许在实际气氛中测量单个异戊二烯硝酸盐的浓度，并根据这些数据测试。总的来说，这将使异戊二烯硝酸盐对氮氧化物回收利用和臭氧的影响能够用良好的约束模型进行量化。在2003年，英国在2003年热浪中升高的臭氧升高是归因于异丙烯浓度升高的。气候和土地使用的未来变化可能会影响异戊二烯排放，因此了解异戊二烯如何影响氮氧化物回收对于预测未来的臭氧浓度很重要。因此，在该提案中发展技术之后，科学理解的潜在进步对于制定排放控制策略的政策制定者至关重要。