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

当前大气化学研究的一个基本目标是进一步了解产生和破坏大气中微量化合物的基本过程。为了研究和了解影响大气成分的化学、物理和生物过程，有必要研究和开发用于测量空气中存在的化合物的改进技术。该项目的目标是开发可靠的新分析技术，用于研究通过全球对流层的硫物种循环。设计这些技术是为了测量目前被认为对硫（二硫化碳）在大气中的生物地球化学循环很重要的气体种类的浓度。这些物质包括羰基硫化物、二硫化碳、硫化氢、二甲基硫化物、甲基硫醇和二氧化硫。海洋硫循环特别有趣，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。硫的浓度的测量提供了重要的数据，以发展对这些硫化合物的通量和反应的定量认识。在美国国家科学基金会（NSF）资助的ATM-8515000下，建立了气相色谱/质谱同位素标记内标技术（GC/MS/ILS）。该仪器能够实时测量硫气体，并且比火焰光度检测灵敏几倍。同位素标记的内标提高了精度和准确性。本研究将构建一个现场可部署（飞机和船舶平台）的仪器，并在现场测试仪器的性能。

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.