An automated multidimensional preparative gas chromatographic system for isolation and enrichment of trace amounts of xenon from ambient air
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The monitoring of radioactive xenon isotopes is one of the principal methods for the detection of nuclear explosions in order to identify clandestine nuclear testing. In this work, a miniaturized, multiple-oven, six-column, preparative gas chromatograph was constructed in order to isolate trace quantities of radioactive xenon isotopes from ambient air, utilizing nitrogen as the carrier gas. The multidimensional chromatograph comprised preparative stainless steel columns packed with molecular sieves, activated carbon, and synthetic carbon adsorbents (e.g., Anasorb®-747 and Carbosphere®). A combination of purification techniques—ambient adsorption, thermal desorption, back-flushing, thermal focusing, and heart cutting—was selectively optimized to produce a well-defined xenon peak that facilitated reproducible heart cutting and accurate quantification. The chromatographic purification of a sample requires approximately 4 h and provides complete separation of xenon from potentially interfering components (such as water vapor, methane, carbon dioxide, and radon) with recovery and accuracy close to 100%. The preparative enrichment process isolates and concentrates a highly purified xenon gas fraction that is suitable for subsequent ultra-low-level γ-, ß/γ-spectroscopic or high-resolution mass spectrometric measurement (e.g., to monitor the gaseous fission products of nuclear explosions at remote locations). The Xenon Processing Unit is a free-standing, relatively lightweight, and transportable system that can be interfaced to a variety of sampling and detection systems. It has a relatively inexpensive, rugged, and compact modular (19-inch rack) design that provides easy access to all parts for maintenance and has a low power requirement.
KeywordsPreparative enrichment of xenon Noble gas Radioxenon Stable xenon Radon separation Carbon adsorbents CTBT IMS Nuclear safeguards
The authors would like to thank FOI, Swedish Defence Research Agency, Nuclear Weapons Issues and Detection, for its financial support for this research and for the loan of the radon monitor. The manufacture of columns by FOI workshops is gratefully acknowledged. The authors would like to thank Gammadata Instrument AB for the loan of the NaI(Tl)-detector, associated electronic equipment, software, a lead shield and radioxenon gas. The provision of radioxenon gas by Karolinska University Hospital is also appreciated.
- 1.Web-site www.ctbto.org
- 2.Saey P, Esarda bulletin No. 36, Prep Com CTBTO, Vienna, AustriaGoogle Scholar
- 4.Matthews K, De Geer L-E 263:235-240Google Scholar
- 10.Auer A, Axelsson A, Blanchard X, Bowyer T, Brachet G, Bulowski I, Dubasov Y, Elmgren K, Fontaine J, Harms W, Hayes J, Heimbigner T, McIntyre J, Panisko M, Popov Y, Ringbom A, Sartorius H, Schmid S, Schulze J, Schlosser C, Taffary T, Weiss W, Wernsperger B (2004) Appl Radiat Isotopes 60:863–877CrossRefGoogle Scholar
- 22.Stockburger H, Sartorius H, Sittkus A (1977) Z Naturforsch 32a:1249–1253Google Scholar
- 23.Anasorb®-747 Publication 1385 Rev 0401 SKC Inc., USAGoogle Scholar
- 24.Carbosphere® Data Sheet D5680 Alltech Associates, Inc. IL, USAGoogle Scholar
- 25.Grob R (1995) Modern practice of gas chromatography 3rd editionGoogle Scholar
- 26.West R, Astle T, Beyer W 1986-1987 CRC Handbook of Chemistry and Physics 67th edition. CRC Press, IncGoogle Scholar