Method for Extraction of Dissolved Gases From Groundwater for Radiokrypton Analysis
Method for Extraction of Dissolved Gases From Groundwater for Radiokrypton Analysis
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从地下水中提取溶解气体用于放射性氪分析的方法
DOI：
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发表时间：
2006
期刊：
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通讯作者：
N. Sturchio
中科院分区：
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作者：
P. Probst;R. Yokochi;N. Sturchio
氪的两种放射性同位素(Kr)是有价值的环境示踪剂，具有强大的应用价值，如确定地下水停留时间、海洋循环和混合速率以及冰川冰川的年龄。KR(t1/2=229,00000年)是10到10年时间尺度上的理想示踪剂。KR(t1/2=10.8年)是跟踪50年范围内的过程的理想选择。同位素分析使用了由阿贡国家实验室的Z.-T.Lu和同事开发的原子陷阱痕量分析(ATTA)设备。该设备使用调谐二极管激光器在磁光陷阱中保持和计数具有完全同位素选择性的单个Kr原子(Chen等人，1999；Du等人)。艾尔2003年)。ATTA分析目前需要~50μ的Kr的L，这是~700 L空气饱和水中所含的量。这项Kr/Kr分析的对象最近确定了埃及西部沙漠努比亚含水层的地下水的年龄，其历史长达106年。ATTA分析的结果与氯数据一致，标志着ATTA首次被用于确定地下水停留时间(Sturchio等人，2004年)。我们开发了一种新的高容量气体提取系统，EDGAR(用于放射性氪分析的溶解气体提取)，提供了一种简单、快速地获得适合于回收用于同位素分析的微摩尔量非反应痕量气体的大容量样品的方法。
Two radioactive isotopes of krypton (Kr) are valuable environmental tracers having powerful applications such as determining groundwater residence times, ocean circulation and mixing rates, and ages of glacial ice. Kr (t1/2 = 229,000 yr) is an ideal tracer on the 10 to 10 year time scale. Kr (t1/2 = 10.8 yr) is ideal for tracing processes in the <50 yr range. The isotopic analysis uses the Atom Trap Trace Analysis (ATTA) apparatus developed by Z.-T. Lu and colleagues at Argonne National Laboratory. This apparatus uses tuned diode lasers to hold and count individual Kr atoms of with complete isotopic selectivity in a magneto-optical trap ((Chen et al., 1999; Du et. al. 2003). ATTA analysis currently requires ~50 μL of Kr, which is the amount contained in ~700 L of airsaturated water. The object of this Kr/Kr analysis has recently dated groundwater from a Nubian aquifer in the Western Desert of Egypt to be as old as 106 years. The results of the ATTA analysis showed agreement to Cl data and marked the first time ATTA was used to determine groundwater residence time (Sturchio et al., 2004). We developed a new, high-volume gas-extraction system, EDGAR (Extraction of Dissolved Gases for Analysis of Radiokrypton) that provides a simple and rapid method for obtaining high-volume samples suitable for recovery of micromolar amounts of nonreactive trace gases for isotopic analysis.