Michael Schubert , Juergen Kopitz , Sabine Taeglich , Richard K. Bibby , Lorenzo Copia , Bradley McGuire , Stephen Wangari , Astrid Harjung
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引用次数: 0
Abstract
Due to its short half-life (87 days), naturally occurring radio-sulfur (35S) is applicable as aqueous environmental tracer for investigating groundwater residence times shorter than one year. Being a pure β-decaying radionuclide, 35S is detected straightforwardly by means of liquid scintillation counting (LSC). The rather low 35S activities in natural waters require (i) a careful sample preparation aiming at extracting 35SO42− from large-volume water samples (ca. 20 L) resulting in samples ready for LSC measurement and (ii) an optimal device-specific setup of the LSC to maximize the 35S signal-to-noise-ratio. A few publications that discuss approaches for sample preparation and device-specific LSC setup optimization are available. This paper presents a summarizing step-by-step instruction for both optimized sample preparation and LSC setup. For practical reasons, two different sample preparation approaches are presented, one for samples with low total sulphate inventories (up to 350 mg) and one for samples with elevated total sulphate inventories (350–1500 mg). LSC setup optimization aiming at the measurement of the two resulting types of samples is described for three LSC devices, namely Quantulus GCT, TriCarb 3170 TR/SL, and Quantulus LB 1220.
期刊介绍:
The Journal of Environmental Radioactivity provides a coherent international forum for publication of original research or review papers on any aspect of the occurrence of radioactivity in natural systems.
Relevant subject areas range from applications of environmental radionuclides as mechanistic or timescale tracers of natural processes to assessments of the radioecological or radiological effects of ambient radioactivity. Papers deal with naturally occurring nuclides or with those created and released by man through nuclear weapons manufacture and testing, energy production, fuel-cycle technology, etc. Reports on radioactivity in the oceans, sediments, rivers, lakes, groundwaters, soils, atmosphere and all divisions of the biosphere are welcomed, but these should not simply be of a monitoring nature unless the data are particularly innovative.