Modification of an Isotope Dilution GC/MS System for Atmospheric Chemistry Experiments on Ships and Aircrafts Under Turbulent Conditions

用于船舶和飞机湍流条件下大气化学实验的同位素稀释 GC/MS 系统的改进

• 批准号: 9013931
• 负责人: Donald Thornton
• 金额: $ 9.08万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-15 至 1992-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9013931&HistoricalAwards=false
• 关键词: Modification; Isotope; Dilution; GC; MS

The PIs developed a gas chromatograph/mass spectrometer (GC/MS) under NSF grant ATM-8717861 and coupled it with isotopically labeled internal standards for near real-time determinations of sulfur dioxide (SO2), dimethyl sulfide (DMS), carbon disulfide (CS2), and carbonyl sulfide (OCS) in the atmosphere. In its present configuration, the GC/MS can be used for measurements in relatively mild turbulent conditions such as those encountered in the marine mixed layer. These four compounds can be measured with an average frequency of one per 8 minutes using simultaneously collected air samples. The PIs plan to modify the sample handling and calibration systems to achieve response times of three minutes with detection limits of 1 part-per-trillion by volume (pptv) with a precision of 1 pptv. They also plan to install a turbomolecular pump that will allow uninterrupted use of the GC/MS under the turbulent conditions that occur in aircraft in the continental boundary layer and on ships under a wide range of sea states. With this added capability the GC/MS could be used to conduct atmospheric chemistry experiments which are designed to evaluate fluxes and budgets of sulfur gases, to measure ocean-atmosphere exchange of sulfur gases, to study sources and sinks of OCS and CS2, and to study chemical transformation of dimethyl sulfide and sulfur dioxide and their role in affecting climate via aerosol formation in the troposphere.

PI开发了气相色谱/质谱仪 (GC/MS），并将其与 近实时同位素标记内标 二氧化硫（SO2）、二甲基硫醚（DMS）、 二硫化碳（CS2）和硫化羰（OCS） 气氛 在目前的配置中，GC/MS可用于 对于在相对温和的湍流条件下的测量， 在海洋混合层中遇到的。 这四种化合物 可以以平均每8分钟一次的频率进行测量 同时采集空气样本。 PI计划修改样本处理和校准 系统实现三分钟的响应时间， 1 part-per-trillion by volume（pptv）的限值，精度为 1 pptv。 他们还计划安装一个分子泵， 允许在湍流条件下不间断地使用GC/MS 发生在飞机上的大陆边界层和 船舶在不同的海况下航行。 有了这个附加功能 GC/MS可用于进行大气化学 实验，旨在评估通量和预算的 含硫气体，测量海洋-大气交换的含硫气体， 研究OCS和CS2的源和汇，并研究化学 二甲基硫醚和二氧化硫的转化及其 通过对流层气溶胶的形成影响气候。