Acquisition and Development of an Ultra Violet Laser Sulfur Isotope Microprobe for the Analysis 32S, 33S, 34S, and 36S in Sulfide Minerals

用于分析硫化矿物中 32S、33S、34S 和 36S 的紫外激光硫同位素微探针的获取和开发

• 批准号: 0215953
• 负责人: Douglas Rumble
• 金额: $ 21.18万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0215953&HistoricalAwards=false
• 关键词: Acquisition; Development; Ultra; Violet; Laser

0215953RumbleThe acquisition of a new isotope-ratio-monitoring, gas chromatograph inlet mass spectrometer (IRMS-GC MS) equipped with four collectors and four channel output for simultaneous analysis of the ion beams of SF6 will make it possible to develop a new ultraviolet (UV) laser fluorination microprobe for the analysis of 32S, 33S, 34S, and 36S in sulfide minerals. Based on previous experience with the successful in situ microanalysis of oxygen isotopes in silicate minerals, it should be possible to measure 50-micrometer diameter spots on sulfide minerals with a precision of 0.1 to 0.2 per mil in d33S and d34S and 0.05 per mil in ?33S. Analysis for d36S will be at a lower level of precision owing to the rarity of the isotope 36S. A new UV laser macroprobe and GC purification system has already been built and validated for 400 micrometer diameter spot measurements of sulfur isotopes using an existing mass spectrometer that is incapable of GC-continuous flow operation. The new IRMS-GC MS requested from NSF-MRI is needed to improve analytical spatial resolution from 400 to 50 micrometers. The new sulfur isotope microprobe will be used to test the validity of the discovery of mass-independent sulfur isotope anomalies in Archean rocks by direct fluorination of sulfide minerals. The proposed relationship between the anomalies and the oxygenation of Earth's atmosphere will be tested by detailed measurements of drill cores spanning the Archean-Proterozoic transition. The mechanisms responsible for fixing mass-independent signatures in rocks will be investigated through spatially resolved analyses of inter-mineral fractionations and intra-mineral isotopic heterogeneity. The new microprobe's capacity to analyze microgram samples will be put to use in a laboratory study of the fractionation of sulfur isotopes by microbes. Use of the new sulfur isotope microprobe will be open to qualified users from throughout the research community.

0215953 Rumble获得一种新的同位素比监测、气相色谱入口质谱仪（IRMS-GC MS），配备四个收集器和四个通道输出，用于同时分析SF6离子束，这将使开发一种新的紫外（UV）激光微探针成为可能，用于分析硫化物矿物中的32 S、33 S、34 S和36 S。根据以往的经验，成功地在原位微量分析硅酸盐矿物中的氧同位素，它应该可以测量50微米直径的斑点上的硫化物矿物的精度为0.1至0.2每密耳d33 S和d34 S和0.05每密耳？33S 由于同位素36 S的稀有性，d36 S的分析将处于较低的精确度水平。一个新的紫外激光宏观探针和GC纯化系统已经建成，并验证了400微米直径的点测量硫同位素使用现有的质谱仪，是无法GC连续流操作。NSF-MRI要求的新IRMS-GC MS需要将分析空间分辨率从400微米提高到50微米。新的硫同位素探针将用于检验通过硫化物矿物直接示踪法在太古代岩石中发现与质量无关的硫同位素异常的有效性。异常和地球大气氧化之间的关系将通过对太古代-元古代过渡时期的岩心进行详细测量来检验。 将通过矿物间分馏和矿物内同位素异质性的空间分辨分析来研究负责固定岩石中质量独立特征的机制。新的微探针分析微克样品的能力将用于微生物对硫同位素分馏的实验室研究。 新的硫同位素微探针将向整个研究界的合格用户开放。