An improvement in the small-volume technique for determining thorium-234 in seawater Cai, Pinghe Dai, Minhan Lv, Dongwei Chen, Weifang 2006-06-28T17:27:53Z 2006-06-28T17:27:53Z 2005-06-09
dc.description Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Chemistry 100 (2006): 282-288, doi:10.1016/j.marchem.2005.10.016. en
dc.description.abstract The recently developed 2‐5 L small‐volume MnO2 coprecipitation method for determining 234Th in seawater has provided a new way to substantially increase, both temporally and spatially, the sampling resolution of 234Th and 234Th‐based particulate organic carbon export estimates in the upper ocean. In this study, we further optimize the technique by reducing reagent quantities and the use of an additional water bath heating step. This optimization allows the filtration of the MnO2 precipitate onto a 25‐mm diameter, 1.0 μm pore size QMA filter to be completed within < 30 minutes for unfiltered waters from the South China Sea. In addition, we have modified the MnO2 purification procedure to allow for alpha spetrometric measurements of 234Th recoveries. Results from recovery experiments suggest that reagent amounts can be reduced to 0.0375 mg KMnO4 and 0.1 mg MnCl2∙4H2O per liter of sample, while still maintaining high 234Th recovery. This study further confirms that the addition of a yield monitor is necessary for the application of this small‐volume method. en
dc.description.sponsorship Support for this work came from the Natural Science Foundation of China through grants #40206011, #49825162, and #90211020. This study was also supported by the China Ministry of Education through a program for Changjiang Scholars and Innovative Research Teams in Universities (PRSIRT). en
dc.format.extent 303369 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US en
dc.subject Thorium-234 en
dc.subject MnO2 coprecipitation en
dc.subject Beta counting en
dc.title An improvement in the small-volume technique for determining thorium-234 in seawater en
dc.type Preprint en
dspace.entity.type Publication
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