Gas Chromotograph/Mass Spectrometer System for the Determination of Atmospheric Sulfur Gases

目前大气化学研究的一个基本目标是增进对产生和销毁大气中存在的微量化合物的基本过程的了解。为了研究和了解影响大气组成的化学、物理和生物过程，有必要研究和开发改进的测量空气中存在的化合物的技术。该项目的目标是开发可靠的新分析技术，用于研究硫物种在全球对流层中的循环。这些技术的设计是为了能够测量气体物种的浓度，目前认为这些气体物种在大气中二硫化碳的生物地球化学循环中很重要。这些物种包括羰基硫化物、二硫化碳、硫化氢、二甲硫醚、甲硫醇和二氧化硫。海洋硫磺循环特别有趣，因为它可能将海洋中的生物活动与气候和云的形成联系起来。硫物种浓度的测量为发展对这些硫化物的通量和反应的定量了解提供了重要的数据。开发了一种具有同位素标记内标(GC/MS/ILS)的气相色谱/质谱计技术，并在美国国家科学基金会授权的ATM-8515000下进行了实验室测试。该仪器能够实时测量硫磺气体，比火焰光度检测的灵敏度高几倍。同位素标记的内标提高了精密度和准确度。本研究将构建一个野外可展开(飞机和船舶平台)的仪器，并在野外测试该仪器的性能。

A basic objective of current research on the chemistry of the atmosphere is to develop an improved understanding of the fundamental processes responsible for creating and destroying the trace chemical compounds present in the atmosphere. In order to study and understand the chemical, physical and biological processes influencing the composition of the atmosphere it is necessary to investigate and develop improved techniques for measuring the compounds present in the air. The objective of this project is to develop reliable new analytical techniques for studying the cycle of sulfur species through the global troposphere. These techniques have been designed to permit measurement of the concentrations of gaseous species currently thought to be important in the biogeochemical cycling of sulfur, carbon disulfide, through the atmosphere. These species include carbonyl sulfide, carbon disulfide, hydrogen sulfide, dimethyl sulfide, methyl mercaptan, and sulfur dioxide. The marine sulfur cycle is particularly interesting because it may link biological activity in the oceans to climate and cloud formation. Measurements of the concentrations of sulfur species provide data that are important for developing a quantitative understanding of the fluxes and reactions of these sulfur compounds. A technique of gas chromatography/mass spectrometer with isotopically labelled internal standards (GC/MS/ILS) has been developed and laboratory tested under NSF grant ATM-8515000. The instrumentation is capable of real time measurements of sulfur gases and is several times more sensitive than flame photometric detection. Isotopically labelled internal standards have improved precision and accuracy. This research will construct a field deployable (aircraft and ship platforms) instrument and test the performance of the instrument in the field.