Rapid determination of 210Po in water samples

A new rapid method for the determination of ²¹⁰Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that can be used for emergency response or routine water analyses. If a radiological dispersive device event or a radiological attack associated with drinking water supplies occurs, there will be an urgent need for rapid analyses of water samples, including drinking water, ground water and other water effluents. Current analytical methods for the assay of ²¹⁰Po in water samples have typically involved spontaneous auto-deposition of ²¹⁰Po onto silver or other metal disks followed by counting by alpha spectrometry. The auto-deposition times range from 90 min to 24 h or more, at times with yields that may be less than desirable. If sample interferences are present, decreased yields and degraded alpha spectrums can occur due to unpredictable thickening in the deposited layer. Separation methods have focused on the use of Sr Resin?, often in combination with ²¹⁰Pb analysis. A new rapid method for ²¹⁰Po in water samples has been developed at the SRNL that utilizes a rapid calcium phosphate co-precipitation method, separation using DGA Resin^® (N,N,N′,N′ tetraoctyldiglycolamide extractant-coated resin, Eichrom Technologies or Triskem-International), followed by rapid microprecipitation of ²¹⁰Po using bismuth phosphate for counting by alpha spectrometry. This new method can be performed quickly with excellent removal of interferences, high chemical yields and very good alpha peak resolution, eliminating any potential problems with the alpha source preparation for emergency or routine samples. A rapid sequential separation method to separate ²¹⁰Po and actinide isotopes was also developed. This new approach, rapid separation with DGA resin plus microprecipitation for alpha source preparation, is a significant advance in radiochemistry for the rapid determination of ²¹⁰Po.     

Determination of 210Pb and 210Po in mineral and biological environmental samples

The paper deals with the determination of ²¹⁰ Pb and ²¹⁰ Po in mineral and biological environmental samples. ²¹⁰ Pb and ²¹⁰ Po were preconcentrated from filtered water samples by coprecipitation with iron(III) hydroxide at pH 9-10 using ammonia solution and the precipitate was dissolved with HCl and mineralized with H2O2. ²¹⁰ Pb and ²¹⁰ Po in soil or sediment, algae and mussel samples were sequentially leached out at 250 °C with HNO₃ +HF, HClO₄ and HCl. About 10-20% of the leaching solution was used for ²¹⁰ Po determination which was carried out at 85-90 °C for 4 hours by suspending a silver disk in a HCl solution of pH 1.5 and containing some hydroxylamine hydrochloride and sodium citrate. No preliminary separation was required and essentially quantitative recoveries were obtained by using standard ²⁰⁹ Po tracer. The remains of the leaching solution were used for the determination of ²¹⁰ Pb which was first separated by a BIO-RAD-AG 1-X4 resin column, then purified by using Na2S to precipitate as PbS and finally precipitated as PbSO₄ for source preparation. Starting from 3 g sediment (30 liter water), the lower limits of detection of the method were 0.73 Bq.kg^-1 (0.078 mBq.l^-1 ) for ²¹⁰ Pb and 0.25 Bq.kg^-1 (0.016 mBq.l^-1 ) for ²¹⁰ Po. The procedure has been checked with two certified samples supplied by the International Atomic Energy Agency (IAEA) and reliable results were obtained. Most of the analyzed samples were sediments, showing average yields of 84.2±5.2% for ²¹⁰ Pb and 96.4±4.1% for ²¹⁰ Po.     

Determination of 210Po content of vietnamese tobacco samples

Smoking is one of the leading causes of preventable death. In recent years, numerous countries have initiated the prohibition of smoking in restaurants, workplaces and public spaces. The Vietnamese government intends to follow the precautions against public smoking as well. Over and above the number of some hazardous chemical components found in tobacco, ²¹⁰Po isotope content could enhance the probability of the development of lung cancer. In this study 14 Vietnamese tobacco products (commercial cigarettes and pipe tobacco) ²¹⁰Po activity concentration were determined using PIPS semiconductor alpha spectrometry. The results showed that the 210Po activity concentration of the investigated samples varied between 7.40 ± 1.09–128.64 ± 11.22 mBq g^?1. The average ²¹⁰Po content of commercial cigarettes was 15.5 mBq g^?1, whilst the average of pipe tobacco was 20.4 mBq g^?1. To estimate the risk of inhalation of ²¹⁰Po isotopes originating as a result of smoking, dose estimations were carried out.     

Determination of 210Pb, 210Bi and 210Po in natural drinking water

A new method for the radioanalytical determination of the ²²²Rn progenies ²¹⁰Pb, ²¹⁰Bi and ²¹⁰Powill be presented, which has been improved for analyses of water samples fromdifferent regions in Austria. 1–2 liter samples were taken in polyethylenebottles prefilled with conc. HNO₃ to obtain 0.2M acidic solutions,thus avoiding adsorption effects. After adding 1.6 mg of inactive lead carrier,the water sample was evaporated to dryness, converted to the chloride formand dissolved in 1M HCl.     

Analysis of210Po in marine samples

A method for determining²¹⁰Po in marine samples by wet dissolution, deposition onto silver disc and counting by -spectrometry is described. Recovery of polonium was obtained with²⁰⁸Po tracer.²¹⁰Po levels in fish from the Brazilian coast and sediments from Antarctic region were determined. Levels in fish ranged from 0.5 to 5.3 Bq·kg^–1 wet and for sediments, mean values of 10 mBq·kg^–1 were obtained.     

Determination of210Po in lead

A quantitative separation procedure for²¹⁰Po in lead has been developed by cupferron and dithizone extraction. The²¹⁰Po activity is plated on a silver foil for counting with a ZnS(Ag) scintillator, or by α-spectrometry with a surface barrier semiconductor. Different lead samples were analyzed ranging from very old lead with a negligible²¹⁰Po content to recently manufactured lead samples showing up to 9100 disintegrations per hour and per gram of lead. The reproducibility and the accuracy of the analyses are satisfactory.     

Radiochemical determination of210Po and210Pb in water

A method for²¹⁰Po and²¹⁰Pb determination in water samples is described. The nuclides are concentrated, in presence of added²⁰⁸Po and lead carrier, by evaporation. Then the polonium is plated electroless from the acidic solution on a copper planchet and measured by alpha spectrometry.²¹⁰Pb separation from the other isotopes is based on the solutility of PbSO₄ in citrate.²¹⁰Pb content is determined by measuring the activity of its daughter²¹⁰Bi. The critical steps in the isolation of lead have been examined and discussed.     

Radiochemical analysis of210Po in coal gasification samples

The concentrations of²¹⁰Po in samples from a coal gasifier were determined by -pulse height analysis following separations from complex organic matrices. Samples were dissolved using wet acid digestion and persulfate fusion techniques and then extracted with trilaurylamine. Polonium was auto-deposited onto silver disks using²⁰⁹Po as a tracer for yield determination. The precision of the experimental method, determined on coal, was ±6% at the 95% confidence level. Excellent agreement was attained with published data on an EPA coal sample.This work was sponsored by the Office of Health and Environment, Office of Environmental Programs, and the Office of Coal Processing, U.S. Department of Energy, under contract DE-AC05-840R21400, with Martin Marietta Energy Systems, Inc.     

Determination of210Pb and210Po in human tissues of Japanese

To determine the levels of²¹⁰Pb and²¹⁰Po in human tissues of people in Japan, various tissue samples were obtained at autopsy from the cadavers of 22 oncologic cases, mainly in Niigata Prefecture in northern Japan, from 1986 to 1988.Wet ashing, followed by electrochemical deposition and alpha spectrometry were used to separate and determine the²¹⁰Pb and²¹⁰Po present. Among the tissues analyzed, the highest concentrations of²¹⁰Pb and²¹⁰Po were observed in bone (sternum), liver, and kidneys. The total body burden of²¹⁰Pb and²¹⁰Po was found to be approximately 427 pCi and 514 pCi, respectively. This estimated²¹⁰Po value did not differ significantly from values found in populations in the U.S.A. and European countries.     

Transfer of210Pb and210Po to the environment during mining and processing of uranium ores

Transfer of²¹⁰Pb and²¹⁰Po from an uranium mine and mill to the environment was studied by measuring their concentrations in different stages of uranium extraction technology, in waste products from the mill and in environmental waters. A slightly modified radiochemical method was used for²¹⁰Po and²¹⁰Pb determination.     

Determination and Distribution of 210Po in Tobacco Plants from Poland

The aim of this study was the determination one of the most radiotoxic elements, ²¹⁰Po in different parts of tobacco plant from Poland. Investigation revealed that polonium is non-uniformly distributed within tobacco plant. Tobacco leaves constituting about 50% of the wet mass, contain 87.1% of the total burden of ²¹⁰Po. Among the analyzed leaves about 66% of polonium is located in the oldest, over-ground part. The data obtained here indicate that ²¹⁰Po is generally taken up by tobacco from the dry or wet deposition of the radioactive fall-out onto the plant. Moreover, ²¹⁰Po concentration in tobacco leaves from Poland are higher than that in the other countries.     

Determination of 210Po in air filters from metallurgic industry

Journal of Radioanalytical and Nuclear Chemistry - The elevated concentration of 210Po attached to aerosol particles inside a non-ferrous metal refinery was studied. The aerosols were collected on...     

Levels of 210Po and 210Pb in cigars

²¹⁰Po and ²¹⁰Pb concentrations have been determined in 58 cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest ²¹⁰Po content. The mean levels of ²¹⁰Po in Brazilian, European and Dominican cigars were almost identical and somewhat lower than the levels observed for cigars from other Latin American countries. Cuban, American and European cigars contained low levels of ²¹⁰Pb. Cigars from the remaining countries contained twice as much ²¹⁰Pb. The mean ²¹⁰Po/²¹⁰Pb ratio showed an excess of polonium. In the case of a one cigar-a-day smoker, the calculated annual absorbed dose due to ²¹⁰Po is -16 mGy.     

A bone ash standard for90Sr,210Pb,210Po,uranium and the actinides

Possibilities and problems of experimental differentiation of two chemical or particle forms of element M (Acentral atom or group, Bcomplex, metalorganic or bioinorganic species, colloid, etc.) between which mutual equilibria can exist at their partition in two-phase systems, when the gross (analytical) concentrations are determined in each phase (by AAS, NAA, or radiometrically) are outlined for: (1) static distribution (batch separation) between two immiscible phases, when both the partial concentrations of A and B and their distribution coefficients generally can be determined by a single or fractional separation, (2) dynamic distribution (chromatographic separation) between the peaks of two metal species, when the potentialities can be strongly affected by secondary equilibria or when the sample-eluent interactions can be assessed.     

Determination of 210Pb in environmental samples

Summary Measurement of ²¹⁰Pb has gained a highly scientific attention due to its wide range of environmental applications. The most commonly used analytical techniques: gamma-spectrometry, beta-counting and alpha-spectrometry were used to measure environmental samples (geological, soil, sediment). Our paper is aiming at comparing the capabilities and limits of application of these three different analytical techniques for ²¹⁰Pb measurement in various environmental samples. In addition, analytical data of ²¹⁰Pb measurements with the three different techniques (gamma-spectrometry, beta-counting and alpha-spectrometry) are discussed to highlight the degree of comparability and the most probable sources of discrepancies and errors. Based on the demanded investigation, one analytical technique will be chosen for routine analysis, while the other techniques, if they are available, could be used for analytical quality assurance measures. It was essential to compare the analytical efficacy of each technique, which differ concerning the detection limit (MDA), sensitivity, analytical effort, the duration of analysis and waiting time before analysis.     

Sequential analysis methodology for 210Po and uranium analysis by extractive liquid scintillation spectrometry

Journal of Radioanalytical and Nuclear Chemistry - A methodology for separation and purification of 210Po from uranium, thorium and daughters has been studied. Solvent extraction coupled with...     

210Pb and210Po in tobacco-with a special focus on estimating the doses of210Po to man

Studies have been carried out on the solubility of Pu(III) oxalate by precipitation of Pu(III) oxalate from varying concentrations of HNO₃/HCl (0.5–2.0M) solutions and also by equilibrating freshly prepared Pu(III) oxalate with solutions containing varying concentrations of HNO₃/HCl, oxalic acid and ascorbic acid. Pu(III) solutions in HNO₃ and HCl media were prepared by reduction of Pu(IV) with ascorbic acid. 0.01–0.10M ascorbic acid concentration in the aqueous solution was maintained as holding reductant. The solubility of Pu(III) oxalate was found to be a minimum in 0.5M–1M HNO₃/HCl solutions containing 0.05M ascorbic acid and 0.2M excess oxalic acid in the supernatant.     

Determination of uranium concentration in domestic water samples by fission track method

The sensitive and simple fission track detection technique using a dry method with Melinex-0 plastic track detector has been applied for the determination of uranium concentration in samples of domestic water supply plants collected from different states of India, namely West Bengal, Uttar Pradesh, Rajasthan, Punjab and Delhi. Our analyses show that uranium concentration of water samples collected from different types of domestic water supply plants vary from 0.6±0.02 to 19.2±0.6 g/l. The present investigations may be useful from the point of view of radiation hygiene.     

Determination and interpretation of environmental water samples contaminated by uranium mining activities

Interpretation of environmental behavior of uranium is based on several steps of data analysis and statistical inference. First step is sampling and analyzing of uranium in field samples by routine laboratory methods. Such methods have to fulfill multiple requirements like robustness, efficiency, low detection limit and precision. A comparison of different approaches in assigning uncertainty to experimentally obtained analytical data shows that classical error estimation is not significantly inferior to more sophisticated modern techniques like inverse regression or orthogonal regression. A second step is the correlation of analytical data with current state of insight into environmental behavior of uranium. Such a correlation furthers the choice of adequate geochemical models and quality of geochemical data base for subsequent detailed analysis, e.g. by geochemical modeling. An appraisal of the individual steps in this complex analysis is given on the basis of statistical procedures for calibration and an E_H-pH diagram of uranium for atmospheric conditions.     

Determination and interpretation of environmental water samples contaminated by uranium mining activities

Interpretation of environmental behavior of uranium is based on several steps of data analysis and statistical inference. First step is sampling and analyzing of uranium in field samples by routine laboratory methods. Such methods have to fulfill multiple requirements like robustness, efficiency, low detection limit and precision. A comparison of different approaches in assigning uncertainty to experimentally obtained analytical data shows that classical error estimation is not significantly inferior to more sophisticated modern techniques like inverse regression or orthogonal regression. A second step is the correlation of analytical data with current state of insight into environmental behavior of uranium. Such a correlation furthers the choice of adequate geochemical models and quality of geochemical data base for subsequent detailed analysis, e.g. by geochemical modeling. An appraisal of the individual steps in this complex analysis is given on the basis of statistical procedures for calibration and an E_H-pH diagram of uranium for atmospheric conditions. Received: 30 July 1998 / Revised: 18 November 1998 / Accepted: 26 November 1998