A Carbon-13 Isotope Analyzer

同位素碳分析为研究代谢途径和追踪环境中的碳转化提供了有价值的工具。该项目将尝试开发一种方便测量碳同位素（13C/12C）比率的光学技术。该仪器将利用线性光电二极管阵列对含碳分子等离子体发射产生的光谱进行成像。光谱处理算法将用于消除光谱干扰，并校正由于样品压力和功率耦合变化而引起的表观同位素比移位。在第一阶段的研究中，将确定使用CO分子测定同位素比率的最佳带头。该标准将包括12C同位素的其他跃迁造成的最小污染。在第二阶段的工作中，将研究不同的激发源和样品制备技术，目的是将仪器与自动化碳氮分析仪耦合。第一阶段工作的结果有望使测定碳同位素比的精度达到0.01%或0.1 &amp；单位，这将使该方法既适用于自然丰度研究，也适用于示踪剂添加研究。与质谱仪相比，该仪器的相对简单和低成本将大大扩展同位素丰度测量的应用。Aerodyne是一个众所周知的积极的表演者，并将为工作提供出色的支持。该产品一旦可用，将在需要处理大量碳同位素比样品的生态学研究中得到相当大的应用。

Isotopic carbon analysis provides a valuable tool for studies of metabolic pathways and for tracing carbon transformations in the environment. This project will attempt to develop an optical technique for the convenient measurement of carbon isotopic (13C/12C) ratios. The instrument will utilize a linear photodiode array to image the spectra arising from plasma emission of the carbon-containing molecules. Spectral processing algorithms will be applied to remove spectral interferences and to correct for apparent isotopic ratio shifts due to variations in sample pressure and power coupling. In this Phase I study, the optimal bandheads for isotopic ratio determination using the CO molecule will be identified. The criteria will include a minimal contamination from other transitions of the 12C isotope. Different excitation sources and sample preparation techniques will be studied with the intent of coupling the instrument to an automated carbon-nitrogen analyzer in the Phase II work. The results of the Phase I effort are expected to result in the ability to determine the isotope ratio of carbon to a precision of 0.01% or 0.1 & unit which would make the method applicable to both natural abundance studies and tracer addition studies. The relative simplicity and low cost of this instrument compared to mass spectrometers will greatly expand the applications of isotopic abundance measurements. Aerodyne is a known positive performer and will provide excellent support for the work. The product, when available, should find considerable use in ecological studies requiring the processing of large numbers of carbon isotope ratio samples.