共查询到20条相似文献,搜索用时 31 毫秒
1.
Masaki Uesugi Masayasu Noguchi Akihiko Yokoyama Takashi Nakanishi 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(3):577-584
An improved method is proposed to determine the content of 210Pb in lead using 210Po measured by alpha-ray spectrometry. This improved method, which is based on radiochemical separation by DDTC–toluene extraction,
employs EDTA and citrate as masking reagents for the lead ions. To selectively extract polonium from an alkaline solution,
the pH dependency was examined using a liquid scintillation counting method. And pH 9 was chosen as an extraction condition.
Then 210Po was electrodeposited on a stainless steel disk, and the chemical recovery was followed by 209Po tracer. The effectiveness of the new method was validated by the agreement with the analytical results from five samples
as determined by gamma-ray spectrometry. 相似文献
2.
M. Yamamoto A. Sakaguchi J. Tomita T. Imanaka K. Shiraishi 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):93-103
To estimate the dietary intakes of 210Pb and 210Po for the Japanese adults and their annual effective doses, 210Pb and 210Po were measured for 240 daily diet samples collected at two locations of Ishikawa Prefecture in Japan over three years by
duplicate portion studies. No appreciable differences in intake rates of 210Pb and 210Po and their 210Po/210Pb ratios were seen among the years in each district, and between the two districts. The intake rates evaluated using 240
diet samples were 0.20 Bq/d/p for 210Pb and 0.61 Bq/d/p for 210Po as a median, respectively. Annual effective doses of 210Pb and 210Po for Japanese adults were estimated to be 0.050 and 0.053 mSv/y, respectively. 相似文献
3.
Dimitrios C. Xarchoulakos Konstantina Kehagia Nikolaos Kallithrakas-Kontos Constantinos Potiriadis 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(2):285-292
For the first time, a radiological study for the dissolved 238U, 234U, 210Pb and 210Po was held in major Greek rivers across the country. 234U/238U activity ratios are above one in all samples and 210Po/210Pb activity ratios are respectively below the unit indicating the disequilibrium in the samples. Quite satisfactory correlations were observed among 234U and 238U as well as among 210Po and 210Pb values. Uranium isotopes were separated by ion exchange and electroplated on stainless steel plates. 210Po was spontaneously deposited on nickel plates, while 210Pb was indirectly determined through the ingrowth of 210Po. The sources were measured by a-spectrometry. 相似文献
4.
Methodologies for the quantification of measurement uncertainties associated with the determination of 210Pb- and 210Po-specific activities by liquid scintillation counting (LSC) and alpha-particle spectrometry are presented, and are demonstrated
using the soil reference material IAEA-326. Major contributors to the combined uncertainty associated with the measurement
result of 210Pb were the uncertainties of net count rates in the 210Pb energy region of the sample spectrum and in the 210Bi energy region of the blank spectrum. The predominant sources of uncertainty in the measurement of 210Po were the uncertainties of net count rates in the regions of interest of 209Po and 210Po. The relative standard uncertainty of 210Po exponentially increases with the time interval between the sampling date and the separation date of Po, and this effect
is strongly dependent on the 210Po/210Pb activity ratio. When the specific activity of 210Pb is much higher than that of 210Po in the sample, the relative standard uncertainty of the 210Po determination increases significantly within a short time interval between the sampling date (or reference date) and the
separation date of Po in samples. 相似文献
5.
K. M. Rajashekara Y. Narayana K. Siddappa 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(2):379-388
The concentrations of 210Po and 210Pb have been measured in soil, sediment and rock samples collected from major rivers of coastal Karnataka, viz. Kali, Sharavathi
and Netravathi. The activity of 210Po and 210Pb in the samples were separated by radiochemical methods and the activity was counted using ZnS(Ag) alpha-counter. The activity
ratio of 210Po and 210Pb and the dependence of organic matter content on the activity of these radionuclides were studied. 相似文献
6.
Claudia Landstetter Christian Katzlberger 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):467-471
Screening measurements for 3H, 226Ra, 222Rn and 238U in ground water were performed within a ground- and drinking water project in Austria. The aim of this project is to get
an overview of the distribution of natural radionuclide activity concentration levels in ground water bodies. In some cases
this water is used for drinking water abstraction. In this paper methods and results of the screening measurements are presented.
Regions with high activity concentrations were identified and in these regions further investigation for 228Ra, 210Pb and 210Po will be conducted. 相似文献
7.
Chang Woo Lee Mun Ja Kang Wanno Lee Geun Sik Choi Young Hyun Cho Hee Reyoung Kim Kun Ho Chung 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(2):519-522
210Po in the daily diet in Korea was analyzed and the ingestion dose from an intake of 210Po was estimated by considering the dietary habit of a Korean person. The 210Po concentrations of a leafy vegetable (0.36 Bq·kg−1 for lettuce) in the terrestrial food were higher than those of grain, whereas Chinese cabbage had a lesser 210Po concentration (0.019 Bq·kg−1). The 210Po concentration of the animal product was similar to those detected in the grain and vegetable. The 210Po concentrations in the shell and crustaceous were high from 19.1 to 33.0 Bq·kg−1, however, its value fell in the overall range of the reported values. The effective dose from 210Po for an adult from the Korean population was about 269.4 μSv·y−1. Nearly 80% of the ingestion dose from the intake of 210Po was attributed to the consumption of seafood. It suggests that the marine food ingestion is a critical pathway for natural
210Po to the Korean population. 相似文献
8.
H. Kawakami Y. -L. Yang M. Kusakabe 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(2):561-566
The distributions of 210Po and 210Pb in the intermediate layer (400–2000 m) of the northwestern North Pacific were determined to elucidate the export flux of
particulate matter. 210Po generally showed depletion relative to 210Pb in the intermediate layer, suggesting that 210Po was scavenged by particles. Because the removal rate constants of 210Po in the western region were higher than those in the eastern region and this trend coincided with that of the particle fluxes
in the surface layer, the export production in the surface layer was assumed to influence the particle flux in the intermediate
layer of the northwestern North Pacific. 相似文献
9.
Yong Yi Peng Zhou Guangshan Liu 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):157-162
The atmospheric deposition fluxes of 7Be, 210Pb and 210Po at Xiamen were measured. The samples were collected from March 2004 to April 2005 and the sampling period was one month.
The 7Be and 210Pb activity were measured using HPGe γ-spectrometer after concentration using Fe(OH)3 co-precipitation method. The 210Po was counted with an α-spectrometer after the sample was digested and spontaneous plated onto a silver planchet. At Xiamen,
the atmospheric deposition fluxes of 7Be varied between 0.11 and 2.93 Bq·m−2·d−1 and the average was 1.64 Bq·m−2·d−1; 210Pb fluxes varied between 0.04 and 0.85 Bq·m−2·d−1, and the average was 0.51 Bq·m−2·d−1; 210Po fluxes varied between 0.002 and 0.133 Bq·m−2·d−1, and the average was 0.061 Bq·m−2·d−1. There were positive correlations between the deposition fluxes of 7Be, 210Pb or 210Po and the amount of precipitation. The residence time of aerosols varied between 6.0 and 54.0 days with a mean of 27.1 days,
which were calculated by 210Po/210Pb fluxes ratios. 相似文献
10.
This paper deals with the distribution of 210Po in the river bank soil samples of three major rivers namely Bharathapuzha, Periyar and Kallada river of Kerala. The dependence
of 210Po activity on organic matter content in the samples was also studied. The soil samples were collected and analyzed for 210Po radionuclide using standard radiochemical analytical method. Activity of 210Po increases with increase in organic matter content in samples. Along the Bharathapuzha river bank the 210Po activity ranges from 2.96 to 12.48 Bq kg−1 with mean 5.62 Bq kg−1. The organic matter percentage in the samples ranges from 0.4 to 2.8 and a good correlation with correlation coefficient
0.9 was found between activity and organic matter percentage. In the Periyar river environs 210Po activity ranges from 3.47 to 13.39 Bq kg−1 with mean value 9.27 Bq kg−1. Organic matter percentage in these samples ranges from 1.20 to 4.10 and the correlation coefficient between 210Po activity and organic matter percentage was found to be 0.8 In the Kallada river bank soil samples 210Po activity ranges from 4.46 to 6.45 Bq kg−1. The organic matter percentage ranges from 1.4 to 3. The correlation coefficient between 210Po activity and organic matter percentage in the samples was found to be 0.9. 相似文献
11.
It was found that heating of diluted nitric or hydrochloric acids in many years stored glass beakers can result in mBq quantities
of 210Po leached from beaker walls to the solution. In the case of freshly bought beakers acid leaching of 210Po was not observed. We suppose that acid leachable 210Po in old beakers is mainly due to implantation of radon progenies (from air) into superficial layers of glass beaker walls. 相似文献
12.
Tongke Zhao Lei Zhang Qiuju Guo Wenbin Dong 《Journal of Radioanalytical and Nuclear Chemistry》2017,313(2):379-384
The activity concentrations of 218Po, 214Pb and 214Bi [i.e. C(218Po), C(214Pb), and C(214Bi)] and the calculated concentration ratios [i.e. 1:C(214Pb)/C(218Po):C(214Bi)/C(218Po)] are necessary for assessing radon and its progenies exposure. In this study, a measurement method of radon progenies concentrations with both high sensitivity and low uncertainty, was developed based on the Kerr method. The field measurement results of radon progeny concentrations and calculated concentration ratios in both typical indoor and outdoor environments in Beijing, China, were reported. The effects of air exchange rate on concentration ratios of radon progenies in indoor environments were discussed. 相似文献
13.
D. Desideri M. A. Meli C. Roselli L. Feduzi 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(2):591-600
In various samples of Mytilus galloprovincialis, 210Po was determined by alpha-spectrometry while Mn, Fe, Ni, Cu, Zn, Cd, Sn, Hg and Pb by energy dispersive, polarised X-ray
fluorescence spectrometry (EDPXRF). The mussels of different sizes were taken from 7 sites in the central Adriatic Sea along
the Marche coastal region during the four seasons of the year. 210Po activity concentration ranged between 57 and 343 Bq·kg−1 dry weight. The concentration ranges of heavy metals (μg·g−1 dry weight) were as follows: Mn: 72.9–83.1; Fe: 45.1–754; Ni: 1.3–7.6; Cu: 17.9–156; Zn: 60.9–189; Cd: 0.6–1.0; Sn: 0.6–3.9;
Hg always <0.5; Pb: 2.0–9.0. The data obtained depend upon the site and the period of the sampling and they are also compared
with those obtained by other authors for the same organism in the Mediterranean and other Italian seas. 相似文献
14.
V. Goliáš D. Pittauerová R. Procházka Z. Třískala 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(3):461-470
Summary The activities of218Po,214Po and211Bi were determined in samples obtained of soil/gas. Sampling work was taken in Jáchymov (Czech Republic) at the outcrop of
the Geister-vein,by electrostatic precipitation from filtered soil gas on stainless steel disks.The samples were measured
in a field laboratory using a semi-conductor alpha-spectrometer.The activities of218Po,214Po and211Bi were calculated.Samples taken from active dump material (near-by radon source) exhibited a high211Bi/214Po ratio, while those of the vein outcrop (a relatively deeper source) had a low ratio.A mathematical model was employed to
determine the radon age calculated from the actinon/radon input ratio.This varied in a range of 5.6 to -7.7 seconds.Negative
age values are probably caused by the preference for actinon, which rapidly comes into equilibrium with the source of this
gas. 相似文献
15.
S. Osaki S. Sugihara Y. Maeda T. Osaki 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(1):147-152
Fall water, stem flow water and falling litter in a coniferous forest (C. japonica) and a broad-leaved forest (L. edulis), and rainwater on a grassland near the forests were collected, and their 7Be and 210Pb contents were measured. The average residence times of 7Be and 210Pb in the forest crowns were calculated from the balances of their radionuclides, those in the forest crown of C. japonica were 88 days for 7Be and 9.2 years for 210Pb, and those in the forest crown of L. edulis were 52 days and <1 year, respectively. 相似文献
16.
Zhongyu Wu Zhichao Lin Pamela Mackill Cong Wei John Noonan James Cherniack Deborah Gillis-Landrum 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(3):971-977
Measurement capability and data comparability are essential for emergency response when analytical data from cooperative laboratories
are used for risk assessment and post incident decision making. In this study, the current capability of food emergency response
laboratories for the analysis of 210Po in water was evaluated using a proficiency test scheme in compliance with ISO-43 and ILAC G13 guidelines, which comprises
a test sample preparation and verification protocol and an insightful statistical data evaluation. The results of performance
evaluations on relative bias, value trueness, precision, false positive detection, minimum detection limit, and limit of quantification,
are presented. 相似文献
17.
Zal U’yun Wan Mahmood Che Abd Rahim Mohamed Mei Wo Yii Zaharudin Ahmad Kamaruzzaman Ishak Abdul Kadir Ishak 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(1):107-113
Inventories and fluxes of 210Pb, 228Ra and 226Ra were determined in sediment cores collected at nine stations covering of the southern South China Sea and Malacca Straits
with the thickness of water column between 42 and 83 m depth. The inventories of 210Pb, 228Ra and 226Ra were calculated range from 0.15–2.55 Bq cm−2, 0.05–0.40 Bq cm−2 and 6.83–83.63 Bq cm−2, meanwhile the fluxes ranged from 0.005–0.079 Bq cm−2 yr−1, 0.009–0.048 Bq cm−2 yr−1 and 0.003–0.037 Bq cm−2 yr−1, respectively. The results show that the highest inventories and fluxes for 210Pb, 228Ra and 226Ra were found at station WC 01 and EC 05. Because there are additional sources of 210Pb, 228Ra and 226Ra, where water transport will brings more dissolved isotopes, influence of the transportation and deposition of suspended
particles, fast rate of regeneration and greater production of those radionuclides and others. 相似文献
18.
J. F. Ontiveros-Cuadras A. C. Ruiz-Fernández J. A. Sanchez-Cabeza L. L. Wee-Kwong L. H. Pérez-Bernal 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(3):947-956
210Pb activities were analyzed in surface sediments from the Coatzacoalcos River (Gulf of Mexico) to evaluate its distribution
according to sediment grain size and in different geochemical compartments by using sequential extraction techniques. The
geochemical fractionation experiments provided compatible results: by using the Tessier’s method [1] more than 90% of the 210Pb activity in the samples was found the residual fraction (primary and secondary minerals) and the remaining (<10%) in the
iron and manganese oxides fraction of the sediments; whereas using the Huerta-Diaz and Morse method [2] the 210Pb content was found in comparative amounts in the reactive, the silicate, and the pyrite fractions (accounting together for
>80%), and the rest was found in the residual fraction. The grain size fractionation analyses showed that the 210Pb activities were mostly retained in the clay fraction, accounting up to 60–70% of the 210Pb total activity in the sediment sample and therefore, it is concluded that the separation of the clay fraction can be useful
to improve the analysis of low 210Pb content sediments for dating purposes. 相似文献
19.
M. S. Al-Masri S. Mamish M. A. Al-Haleem K. Al-Shamali 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(1):49-55
Summary Levels of 210Pb, 210Po, 137Cs and some trace elements (Cu, Zn and Pb) in two most common mosses (Lycopodium cernuum and Funaria hygrometrica) distributed in the eastern Mediterranean sea region (Syrian coastal mountains series) have been determined. Radiochemical analysis has shown that these plants contain high levels of 210Pb, 210Po, 137Cs. The highest concentration of 210Pb, 210Po and 137Cs were found to be 1450, 1322 and 1140 Bq . kg-1 dry wt. in L. cernuum, respectively. F. hygrometrica was found to have higher values of 210Pb and 210Po concentrations and reached 2392 and 2119 Bq . kg-1 dry wt., respectively. Correlation coefficients for radionuclide levels in both plants versus their levels in soil have been determined: No correlation for 137Cs for both plants has been observed. This indicates that 137Cs in these plants is of atmospheric origin and the plants can be used as deposition indicators. In addition, a correlation with radionuclide levels was found only for 210Pb and 210Po in F. hygrometrica samples and was mainly related to 226Ra content in soil and the existing faults, which are the main source of these radionuclides. On the other hand, lead concentration in L. cernuum was found to be in the range of 5-86.6 ppm, while F. hygrometrica samples were found to contain around 58 ppm. Both plants seem to accumulate lead from the atmosphere where vehicle emissions are the main source of lead in the region. Comparable concentrations of Cu and Zn were found in all plant and soil samples. 相似文献