Federer Urs, Kaufmann Patrik R, Hutterli Manuel A, Schüpbach Simon, Stocker Thomas F
Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland.
Environ Sci Technol. 2008 Nov 1;42(21):8039-43. doi: 10.1021/es801244e.
Ice cores are a widely used archive to reconstruct past changes of the climate system. This is done by measuring the concentration of substances in the ice and in the air of bubbles enclosed in ice. Some species pertaining to the carbon cycle (e.g., CO2, CH4) are routinely measured. However, information about the organic fraction of the impurities in polar ice is still very limited. Therefore, we developed a new method to determine the content of total organic carbon (TOC) in ice cores using a continuous flow analysis (CFA) system. The method is based on photochemical oxidation of TOC and the electrolytic quantification of the CO2 produced during oxidation. The TOC instrument features a limit of detection of 2 ppbC and a response time of 60 s at a sample flow rate of 0.7 mL/min and a linear measurement range of 2-4000 ppbC. First measurements on the ice core from Talos Dome, Antarctica, reveal TOC concentrations varying between 80 and 360 ppbC in the 20 m section presented.
冰芯是重建气候系统过去变化的一种广泛使用的档案资料。这是通过测量冰中以及冰中所包含气泡内空气中物质的浓度来实现的。一些与碳循环相关的物种（例如二氧化碳、甲烷）会被常规测量。然而，关于极地冰中杂质有机部分的信息仍然非常有限。因此，我们开发了一种使用连续流动分析（CFA）系统来测定冰芯中总有机碳（TOC）含量的新方法。该方法基于TOC的光化学氧化以及氧化过程中产生的二氧化碳的电解定量分析。TOC仪器的检测限为2 ppbC，在样品流速为0.7 mL/min时响应时间为60秒，线性测量范围为2 - 4000 ppbC。对来自南极塔洛斯穹顶的冰芯的首次测量显示，在所呈现的20米深度区间内，TOC浓度在80至360 ppbC之间变化。
