Abstract
234Th is widely used as a natural tracer for study of biological mixing and particle scavenging processes in the ocean. This naturally occurring nuclide serves this purpose due to its convenient half-life (24.1 days), constant rate of production from 238U dissolved in seawater, and its strong tendency to attach to particles in seawater. As a beta/gamma emitter, 234Th may be determined using low-level gas-flow proportional counting, gamma spectrometry, and liquid scintillation counting (LSC). We describe here a technique which combines Cerenkov counting to evaluate 234Th (via 234Pa) with LSC alpha counting of 230Th added to the samples as a yield tracer. Our separation approach is based on a sample preparation procedure for marine sediments using nitric acid leaching in a “hot block”, and extraction chromatography (TEVA·Resin) for Th isolation. Samples are counted in plastic LSC vials, using Ultima Gold AB cocktail, in 1 M H 3PO 4 media. A series of sediment samples spiked with known amounts of 234Th yielded activities within a few percent of the anticipated values.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
