Radiochemical determination of plutonium in sea water, sediments and marine organisms

doi:10.1016/S0003-2670(01)80923-5

Analytica Chimica Acta

Volume 56, Issue 3, October 1971, Pages 355-364

https://doi.org/10.1016/S0003-2670(01)80923-5 Get rights and content

Abstract

A radiochemical procedure is described for the determination of plutonium in large samples of sea water, sediments and organisms with a sensitivity of 0.004 d.p.m. per 100 1 of sea water (for a 50-1 sample), 0.02 d.p.m. per kg of sediments (100-g sample) and 0.002 d.p.m. per kg of marine organisms (1-kg sample). An iron (II) hydroxide coprecipitation method is used for the concentration of plutonium in sea water. A nitric-hydrochloric acid leaching method is adapted for the treatment of sediments and ashed organisms. Factors influencing the recovery, contamination and blank activity are discussed.

Résumé

Une méthode radiochimique est décrite pour le dosage du plutonium dans des échantillons d'eaux de mer, de sédiments et d'organismes marins, avec des sensibilités de 0.004 d.p.m./l00 1 (prise d'échantillon 50 1), 0.02 d.p.m./kg (prise de 100 g) et 0.002 d.p.m./kg (prise de 1 kg) respectivement. Le plutonium est concentré par coprécipitation avec l'hydroxyde de fer(II). Un traitement au mélange acide nitrique-acide chlorhydrique est proposé pour sédiments et cendres d'organismes. Divers paramétres sont examinés.

Zusammenfassung

Es wird ein radiochemisches Verfahren beschrieben, mit dem Plutonium in grossen Proben von Meerwasser, Sedimenten und Organismen mit einer Empfindlichkeit von 0.004 d.p.m./100 1 in Meerwasser (bei einer 50 1-Probe), 0.02 d.p.m./kg in Sedimenten (100 g-Probe) und 0.002 d.p.m./kg in maritimen Organismen (l kg-Probe) bestimmt werden kann. Für die Anreicherung des Plutoniums in Meerwasser wird eine Eisen(II)-hydroxid-Mitfällungsmethode angewendet. Sedimente und veraschte Organismen werden mit einem Gemisch von Salpeter- und Salzsäure ausgezogen. Die Faktoren, die den erfassten Anteil, die Kontamination und Blindaktivität beeinflussen, werden diskutiert.

References (18)

M.G. Lai et al.
(1967)
U. Hollstein et al.
Health Phys.
(1962)
K.M. Wong et al.
M.C. Bertoli
Anal. Chem.
(1967)
G.H. Coleman
The Radiochemistry of Plutonium
Natl. Acad. Sci. Natl. Res. Counc. Publication NAS-NS 3058
(1965)
N. Chu
Anal. Chem.
(1971)
E.I. Geiger
Health Phys.
(1959)
W.J. Major et al.
Health Phys.
(1964)

There are more references available in the full text version of this article.

Cited by (103)

Separation of anthropogenic radionuclides from aqueous environment using raw and modified biosorbents
2022, Journal of Environmental Radioactivity
Citation Excerpt :
This is usually achieved using co-precipitation [Qiao et al., 2009], ion-exchange, or solvent extraction procedures in combination with α-spectrometry [Eroglu et al., 1998; Hirose, 2009]. Co-precipitation can be carried out using various chemical compounds, such as Mn compounds [Becker et al., 2004; Benkrid and Noureddine, 2007; Sidhu, 2003; Wong et al., 1978], Fe compounds [Becker et al., 2004; Chen et al., 1993; Eroglu et al., 1998; Kwong et al., 2004; Wong, 1971], as well as water-soluble metal-binding polymers [Smith et al., 1998], and TiSi [Lujanienė et al., 2009]. The use of sorbents can also be a convenient method of preliminary concentration.
In this study, two types of biosorbents were used to remove ¹³⁷Cs and plutonium isotopes from aqueous solutions - moss (Ptilium crista - castrensis) and oak sawdust (Quercus robur), both in the form of natural and modified state. Sorbent modification significantly increases the sorbent surface area (for moss sorbents - from 4.0 to 47.2 m²/g, and for sawdust sorbents - from 1.1 to 26.3 m²/g), pore volume (from 10⁻³ to 10⁻²), concentration and amount of basic cations and anions, as well as active functional groups on the sorbent surface. The main functional groups on the surface of natural sorbents modified with iron hydroxide interacting with analytes are carboxyl and hydroxyl groups. For carbonized sawdust and its subsequent activation with concentrated HCl, in addition to carboxyl and hydroxyl groups, acetyl groups also become active. Carbonated sawdust treated with HCl showed the highest average removal efficiency and sorption capacity for radiocesium and plutonium isotopes in laboratory column experiments - for ¹³⁷Cs ∼78.6% and ∼196.6 Bq/g and for ^239+240Pu ∼83% and ∼41.5 Bq/g, respectively. The moss and moss modified with iron hydroxide also showed good properties of adsorbing plutonium isotopes in field (in-situ) experiments. The best results on the sorption of ¹³⁷Cs in field experiments were shown by carbonated sawdust activated with HCl, and for isotopes of plutonium - the raw moss and moss modified with iron hydroxide. The results of the study showed that sorbents can be used not only for purification of water from plutonium isotopes but allow the operational sampling and more accurate measurement of radiocesium and plutonium isotopes in the fresh water reservoirs by the dynamic flow method.
On the use of MnO<inf>2</inf> cartridges for the plutonium determination in seawater
2019, Journal of Environmental Radioactivity
Citation Excerpt :
The solution was allowed to cool and then transferred to 7–8 M HNO3. In the next step the solution was poured directly over a preconditioned (8 HNO3) anion exchange column (Bio-Rad AG 1 × 8) (Wong, 1971; La Rosa et al., 2001). The column was than washed with 8 M HNO3, eluting interfering elements like e.g. U, Am and rare earths, followed by a 10 M HCl wash to remove Th.
To analyze plutonium (Pu) in open ocean waters can be challenging due to the low seawater concentrations. In this study we compared two techniques for Pu determination, one in-situ MnO₂ cartridge system and the more commonly used MnO₂ precipitation technique. During the pre-pilot GEOTRACES cruise ANT XXX-1 (2005) we tested MnO₂ cartridges for the pre-concentration of Pu from seawater at 19 sampling stations on a transect in the southeastern Atlantic Ocean between Vigo (Spain) and Cape Town (South Africa). Our in-situ sampling setup consisted of one particle cartridge followed by three MnO₂ cartridges in a series. Through the system we pumped between 956 and 2700 l of surface seawater with a flow rate between 1.6 and 5.2 l/min. We found that the adsorption efficiency of a single MnO₂ cartridge to adsorb Pu was rather constant and on average a 58 ± 7%. The adsorption efficiency was also found to be independent of seawater: temperature in the range of 18.3–29.2 °C, salinity range 34.2–37.1‰, and conductivity in the range of 46.8–58.4 mS/cm. In parallel with the in-situ sampling, discrete surface water samples between 259 and 281 l were taken and Pu was pre-concentrated using the MnO₂ precipitation method. We find a good agreement between the Pu concentrations determined with the two different techniques. The in-situ pre-concentration technique requires more radiochemical work in the laboratory but has the advantage that large seawater volumes can be sampled without the necessity for radiochemical processing on-board the ship. The much larger volumes sampled with the in-situ technique compared with the precipitation technique, enables accurate determination of Pu-isotopic ratios with a low relative standard deviation. We have shown in this study that in-situ MnO₂ cartridge technique can be used in a reliable way for the determination of dissolved Pu seawater concentration in open ocean waters.
Plutonium determination in seawater by inductively coupled plasma mass spectrometry: A review
2016, Talanta
Citation Excerpt :
Overall, various and effective approaches of Pu determination in seawater have been developed, and these designed protocols have been widely applied to enhance understanding of ocean processes. For an analytical methodology, although the iron hydroxide co-precipitation method has been widely applied for total Pu determination and speciation of reduced and oxidized Pu in seawater samples [97–98], it can be further optimized because it functions not only for pre-concentration of Pu, but also for separation of Pu from seawater matrix and interfering elements, especially U. The pH is a key parameter for Pu separation during the co-precipitation step, but almost no work has been carried out to clarify in detail the effect of pH on precipitation efficiency of Pu, and there is also no detailed information on the relationship between pH and precipitation efficiency of U. For emergency preparedness in radiological incidents, timely evaluating the radioactivity status of seawater is strongly required.
Knowing the concentration and isotopic ratio of Pu in seawater is of critical importance for assessing Pu contamination and investigating oceanic processes. In recent decades, the concentration of ^239+240Pu in seawater, particularly for surface seawater, has presented an exponential decreasing trend with time; thus determination of Pu in seawater has become a challenge nowadays. Here, we have summarized and critically discussed a variety of reported analytical methods for Pu determination in seawater sample based on inductively coupled plasma mass spectrometry (ICP-MS) analytical technique for rapid ultra-trace detection of Pu. Generally, pretreatments for seawater sample include co-precipitation, valence adjustment and chemical separation and purification procedures, all of which are comprehensively reviewed. Overall, the selected anion-exchange, extraction resins and operation condition are important for decontamination of interference from matrix elements and achieving satisfactory chemical yields. In addition, other mass spectrometric and radiometric detections are briefly addressed and compared with the focus on assessing ICP-MS. Finally, we discuss some issues and prospects in determination and application of Pu isotopes in seawater samples for future research.
Monte Carlo uncertainty calculation of <sup>210</sup>Pb chronologies and accumulation rates of sediments and peat bogs
2014, Quaternary Geochronology
Citation Excerpt :
In order to validate the 210Pb chronology, the weapons fallout tracer 239,240Pu was analyzed in a nearby core (C2), which shows an identical magnetic susceptibility signal, notably a peak in the 69–70 cm section (Ontiveros-Cuadras et al., 2014). 239,240Pu was purified by using ion interchange resins and electroplating (Wong, 1971; Puphal and Olsen, 1972; Merino et al., 2000). Analytical quality was achieved through the analysis of Certified Reference Materials IAEA-300 (Ballestra et al., 1994), IAEA-384 (Povinec et al., 2007) and IAEA-385 (Pham et al., 2008).
²¹⁰Pb dating is a key technique to study sedimentary records of environmental change in the Anthropocene over a time scale of 100–150 years. Uncertainty estimation of ²¹⁰Pb ages and accumulation rates, when provided by the authors, are usually based on quadratic propagation of uncertainties. In this work, we describe the use of Monte Carlo simulation to estimate ²¹⁰Pb dating uncertainties in sediment and peat cores. The methodology allows, by using nowadays common computers, the assessment of ²¹⁰Pb dating uncertainties in a simple manner, using readily-accessible computers and widely-used proprietary spreadsheet software, and avoiding the derivation of rather complex formulae. Results were calculated and compared with quadratic propagation uncertainties in a marine, lacustrine and peat bog core. The analysis of the uncertainty budgets indicated that, overall, the total and unsupported (or base) ²¹⁰Pb concentrations are the largest contributors to uncertainty, as well as the layer depths when sediment accumulation rates were calculated. Beyond ²¹⁰Pb dating, the Monte Carlo scheme described here could be used in any field of the analytical sciences, including other radiochronological applications.
Plutonium as a chronomarker in Australian and New Zealand sediments: A comparison with 137Cs
2011, Journal of Environmental Radioactivity
The construction of high resolution chronologies of sediment profiles corresponding to the last 50–100 years usually entails the measurement of fallout radionuclides ²¹⁰Pb and ¹³⁷Cs. The anthropogenic radionuclide, ¹³⁷Cs, originating from atmospheric nuclear weapons testing can provide an important “first appearance” horizon of known age (1954–1955), providing much-needed validation for the sometimes uncertain interpretations associated with ²¹⁰Pb geochronology. However, while ¹³⁷Cs usually provides a strong signal in sediment in the northern hemisphere, total fallout of ¹³⁷Cs in the southern hemisphere was only 25% that of the north and the low activities of ¹³⁷Cs seen in Australian and New Zealand sediments can make its horizon of first appearance somewhat arguable. Low ¹³⁷Cs fallout also limited the size of the 1963–1964 fallout peak, a peak that is usually seen in northern hemisphere sediment profiles but is often difficult to discern south of the equator.
This paper shows examples of the use of nuclear weapons fallout Pu as a chronomarker in sediment cores from Australia (3 sites) and New Zealand (1 site). The Pu profiles of five cores are examined and compared with the corresponding ¹³⁷Cs profiles and ²¹⁰Pb geochronologies. We find that Pu has significant advantages over ¹³⁷Cs, including greater measurement sensitivity using alpha spectrometry and mass spectrometric techniques compared to ¹³⁷Cs measurements by gamma spectrometry. Moreover, Pu provides additional chronomarkers associated with changes in the Pu isotopic composition of fallout during the 1950s and 1960s. In particular, the ²³⁸Pu/^239+240Pu activity ratio shows distinct shifts in the early 1950s and the mid to late 1960s, providing important known-age horizons in southern hemisphere sediments. For estuarine and near-shore sediments Pu sometimes has another significant advantage over ¹³⁷Cs due to its enrichment in bottom sediment relative to ¹³⁷Cs resulting from the more efficient scavenging of dissolved Pu in seawater by sediment particles.
Fallout radionuclide tracers identify a switch in sediment sources and transport-limited sediment yield following wildfire in a eucalypt forest
2009, Geomorphology
Fire can alter sediment sources and transport rates in river basins, changing landforms and aquatic habitats and degrading downstream water quality. Variability in the response between environments, between fires, and with time since fire makes predicting the catchment-scale effect of individual fires difficult. This study applies the fallout radionuclides ¹³⁷Cs and ²¹⁰Pb_xs to trace the sources and transport of fine sediment through a river network following a wildfire of moderate to extreme severity in the 629-km² eucalypt-forested Nattai River water-supply catchment near Sydney, Australia. The tracer analysis showed that post-fire erosion caused a switch in fine (< 10 µm) sediment sources from 80% subsoil derived from gully and river bank erosion to 86% topsoil derived from hillslope surface erosion. The fine sediment phosphorus content increased 4–10 fold over pre-fire levels. Annual post-fire sediment yields estimated from suspended solids rating curves were 109–250 times higher than they would have been without fire. A large additional amount of sediment remained stored within the river network for at least four years, particularly in lower-gradient reaches. Analysis of a sediment core showed that surface erosion following a previous fire had supplied at least 29% of total catchment sediment yield over the past 36 years. It is concluded that wildfire can alter catchment sediment budgets in two ways. Firstly, a spatially-diffuse pulse of elevated erosion is associated with moderate or intense rainfall events in post-fire years. Secondly, pulses of elevated catchment sediment yield are driven by the timing and river sediment transport capacity of runoff events. Severe post-fire erosion and high interannual hydrologic variability can result in large sediment stores persisting within the river network for many years. Fallout radionuclide tracers are shown to be useful in quantifying fine sediment sources and transport dynamics following wildfire, and the contribution of wildfire to catchment sediment yield.

View all citing articles on Scopus

¹: Present address: Scripps Institution of Oceanography, La Jolla, Calif. 92037, U.S.A.

View full text

Radiochemical determination of plutonium in sea water, sediments and marine organisms

Abstract

Résumé

Zusammenfassung

Health Phys.

Anal. Chem.

The Radiochemistry of Plutonium

Natl. Acad. Sci. Natl. Res. Counc. Publication NAS-NS 3058

Anal. Chem.

Health Phys.

Health Phys.