Measuring 210Po in natural waters: A comparison of three methods with similar results
Year: 2025
Type: article
Abstract: Oceanographers have long used 210Po/210Pb disequilibria to quantify flux of particulate organic matter from the surface ocean. However, recent evidence by Roca-Martí et al. (2021) found that one of two commonly used methods to concentrate polonium from a natural water sample – coprecipitation with Fe(OH)3 – resulted in significantly lower 210Po activities than the other method – coprecipitation with Co-APDC. In this study, we employed the two methods used by Roca-Martí et al. (2021) and our own modified Fe(OH)3 technique to measure 210Po in freshwater lake, harbor, river, and bog water samples. We found a non-significant bias of ≤ 0.5 dpm 210Po 100 L-1 between all three methods. We found no evidence that 209Po was not fully equilibrated with natural 210Po in as little as 15 minutes. And finally, we found no indication that organic complexation of dissolved 210Po was interfering with polonium recovery. Our results do not negate the findings by Roca-Martí et al. (2021). The behavior of 210Po in marine systems may indeed be different. Understanding the root cause of this methodological discrepancy is critical not only for future studies involving the use of 210Po as a tracer of flux, but also for the many past studies that are now in question and may yet be salvaged if a correlation between the root cause and method discrepancy can be found.
Authors: James T. Waples, Gage J. Hunter, Rachel A. Smith
Institution: University of Wisconsin–Milwaukee
Language: English
Subfield: Radiological and Ultrasound Technology
Field: Health Professions
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,800
OpenAlex ID: W4411332235