Acquisition of an Isotope Ratio Mass Spectrometer

摘要我们请求资金购买一台质谱仪，用于使用13C和LSN进行稳定同位素研究。Europa 20/20仪器结合了高精度质谱仪、气相色谱-热导检测器和自动进样系统，可同时分析66个样品的质量和同位素组成。该仪器将不再使用放射性同位素14C对初级产品进行持续的时间序列测量，从而使我们免于从偏远的海洋地点处置的高昂成本。此外，它还可以同时对初级生产和氮循环进行分析。新仪器将取代我们目前用于15N分析的仪器--发射光谱仪，以提供更高的灵敏度和自动样品制备。还可以通过测量单个样品的样品质量(碳和氮)和同位素组成，而不是像目前要求的那样，通过多个样品和单独的分析来节省成本。我们现有的培训外国科学家了解全球变化研究既定方法的课程将被修改，以包括稳定同位素技术的教学。

ABSTRACT We request funds to purchase a mass spectrometer for stable isotope studies using 13C and lSN. The Europa 20/20 instrument combines a high precision mass spectrometer with a gas chromatograph-thermal conductivity detector and automated sample inlet system that permits analysis of 66 samples for both mass and isotopic composition. The instrument would eliminate the use of 14C, a radioactive isotope, for ongoing time-series measurements of primary production and so free us from the high costs of disposal from a remote oceanic site. In addition, it would permit concurrent analysis of both primary production and nitrogen cycling. The new instrument would replace our current instrument for 15N analysis, an emission spectrometer, to provide increased sensitivity and automated sample preparation. Savings would also accrue from measuring the sample mass (carbon & nitrogen) and isotope composition on a single sample rather than from multiple samples and separate analyses as is currently required. Our existing courses to train foreign scientists in established methods for global change research would be modified to include instruction in stable isotope techniques.