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1.
Profile of selenium in soil and crops in seleniferous area of Punjab,India by neutron activation analysis 总被引:1,自引:0,他引:1
N. Sharma R. Prakash A. Srivastava U. S. Sadana R. Acharya N. T. Prakash A. V. R. Reddy 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(1):59-62
In the Nawanshahr–Hoshiarpur region of Punjab, India, more than 1000 hectares of agricultural land is significantly affected
by high levels of selenium (Se). Studies were carried out to examine Se levels in soil and crops such as wheat grains, wheat
husk, rice, maize and mustard using neutron activation analysis. The Se concentrations in soil and crop products were found
to be ranging from 2.7 to 6.5 mg kg−1 and 13 to 670 mg kg−1, respectively, indicating significantly high selenium in these crop products. Two reference materials were analysed for Se
contents by INAA as controls. 相似文献
2.
Tassiane C. M. Matsubara Márcio A. Bacchi Elisabete A. De Nadai Fernandes 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(1):201-205
Phosphorus is an essential element for plants and animals, playing a fundamental role in the production of biochemical energy.
Despite its relevance, phosphorus is not commonly determined by instrumental neutron activation analysis (INAA), because 32P does not emit gamma-rays in its decay. There are alternative methods for the determination of phosphorus by INAA, such as
the use of beta counting or the measurement of bremsstrahlung originated from the high energy beta particle from 32P. Here the determination of phosphorus in plant materials by measuring the bremsstrahlung production was further investigated, to optimize an analytical protocol for minimizing interferences and overcoming the poor
specificity. Eight certified reference materials of plant matrices with phosphorus ranging between 171 and 5,180 mg kg−1 were irradiated at a thermal neutron flux of 9.5 × 1012 cm−2 s−1 and measured with a HPGe detector at decay times varying from 7 to 60 days. Phosphorus solutions added to a certified reference
material at three levels were used for calibration. Counts accumulated in the baseline at four different regions of the gamma-ray
spectra were tested for the determination of phosphorus, with better results for the 100 keV region. The Compton scattering
contribution in the selected range was discounted using an experimental peak-to-Compton factor and the net areas of all peaks
in the spectra with energies higher than 218 keV, i.e. Compton edge above 100 keV. Amongst the interferences investigated,
the production of 32P from sulfur, and the contribution of Compton scattering should be considered for producing good results. 相似文献
3.
Stacey D. Haskins David G. Kelly Ron D. Weir 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(2):1331-1339
Ten feather samples, including primary and secondary flight and tail feathers, were analysed for the trace element composition of vane and rachis structures using instrumental neutron activation analysis (INAA), inductively coupled plasma-mass spectrometry (ICP-MS), and cold vapour atomic absorption spectroscopy (CVAAS). Five environmentally significant elements, Cr, As, Se, Sb and Hg, were analysed by INAA and ICP-MS/CVAAS. A further seventeen elements were analysed by ICP-MS. The majority data obtained by INAA and ICP-MS/CVAAS were not statistically significantly different (p = 0.05), although the removal of isobaric interferences using dynamic reaction cell technology was essential to produce ICP-MS data that were consistent with INAA for Cr, As and Se. Significantly higher trace element concentrations were observed for vane relative to rachis for all elements, except Cu and Hg. These elements displayed vane/rachis ratios of 0.7 ± 0.2 and 1.0 ± 0.2, respectively. In general, vane and rachis subgroups afforded data that were consistent with a normal distribution, with RSDs in the range (12–83) % for INAA analyses. A total of 18 outliers were noted amongst the various feather, structure, element combinations, with 14 outliers being observed in the vane and/or rachis structures of the same tail feather. Given the significant differences in vane and rachis concentrations observed for many elements, the large RSDs reported for elements and the potential for outliers, the determination of environmental trace element burden using feathers is significantly enhanced by the analysis of multiple feathers using INAA. 相似文献
4.
Clémens S Monperrus M Donard OF Amouroux D Guérin T 《Analytical and bioanalytical chemistry》2011,401(9):2699-2711
Methylmercury (MeHg) and total mercury (THg) in seafood were determined using species-specific isotope dilution analysis and
gas chromatography combined with inductively coupled plasma mass spectrometry. Sample preparation methods (extraction and
derivation step) were evaluated on certified reference materials using isotopically enriched Hg species. Solid–liquid extraction,
derivation by propylation and automated agitation gave excellent accuracy and precision results. Satisfactory figures of merit
for the selected method were obtained in terms of limit of quantification (1.2 μg Hg kg−1 for MeHg and 1.4 μg Hg kg−1 for THg), repeatability (1.3–1.7%), intermediate precision reproducibility (1.5% for MeHg and 2.2% for THg) and trueness
(bias error less than 7%). By means of a recent strategy based on accuracy profiles (β-expectation tolerance intervals), the
selected method was successfully validated in the range of approximately 0.15–5.1 mg kg−1 for MeHg and 0.27–5.2 mg kg−1 for THg. Probability β was set to 95% and the acceptability limits to ±15%. The method was then applied to 62 seafood samples
representative of consumption in the French population. The MeHg concentrations were generally low (1.9–588 μg kg−1), and the percentage of MeHg varied from 28% to 98% in shellfish and from 84% to 97% in fish. For all real samples tested,
methylation and demethylation reactions were not significant, except in one oyster sample. The method presented here could
be used for monitoring food contamination by MeHg and inorganic Hg in the future to more accurately assess human exposure. 相似文献
5.
An approach for rapid quantitation of 5-hydroxymethylfurfural (HMF) in honey using planar chromatography is suggested for
the first time. In high-performance thin-layer chromatography (HPTLC) the migration time is approximately 5 min. Detection
is performed by absorbance measurement at 290 nm. Polynomial calibration in the matrix over a range of 1:80 showed correlation
coefficients, r, of ≥ 0.9997 for peak areas and ≥ 0.9996 for peak heights. Repeatability in the matrix confirmed the suitability of HPTLC–UV
for quantitation of HMF in honey. The relative standard deviation (RSD, %, n = 6) of HMF at 10 ng/band was 2.9% (peak height) and 5.2% (peak area); it was 0.6% and 1.0%, respectively, at 100 ng/band.
Other possible detection modes, for example fluorescence measurement after post-chromatographic derivatization and mass spectrometric
detection, were also evaluated and can coupling can be used as an additional tool when it is necessary to confirm the results
of prior quantitation by HPTLC–UV. The confirmation is provided by monitoring the HMF sodium adduct [M + Na]+ at m/z 149 followed by quantitation in TIC or SIM mode. Detection limits for HPTLC–UV, HPTLC–MS (TIC), and HPTLC–MS (SIM) were 0.8 ng/band,
4 ng/band, and 0.9 ng/band, respectively. If 12 μL honey solution was applied to an HPTLC plate, the respective detection
limits for HMF in honey corresponded to 0.6 mg kg−1. Thus, the developed method was highly suitable for quantitation of HMF in honey at the strictest regulated level of 15 mg kg−1. Comparison of HPTLC–UV detection with HPTLC–MS showed findings were comparable, with a mean deviation of 5.1 mg kg−1 for quantitation in SIM mode and 6.1 mg kg−1 for quantitation in TIC mode. The mean deviation of the HPTLC method compared with the HPLC method was 0.9 mg kg-1 HMF in honey. Re-evaluation of the same HPTLC plate after one month showed a deviation of 0.5 mg kg−1 HMF in honey. It was demonstrated that the proposed HPTLC method is an effective method for HMF quantitation in honey.
相似文献
6.
Rabindra N. Roy Lakshmi N. Roy Shahaf Ashkenazi Joshua T. Wollen Craig D. Dunseth Michael S. Fuge Jared L. Durden Chandra N. Roy Hannah M. Hughes Brett T. Morris Kevin L. Cline 《Journal of solution chemistry》2009,38(4):449-458
The values of the second dissociation constant, pK
2, of N-(2-hydroxyethyl) piperazine-N′-2-ethanesulfonic acid (HEPES) have been reported at twelve temperatures over the temperature range 5 to 55 °C, including
37 °C. This paper reports the results for the pa
H of eight isotonic saline buffer solutions with an I=0.16 mol⋅kg−1 including compositions: (a) HEPES (0.01 mol⋅kg−1) + NaHEPES (0.01 mol⋅kg−1) + NaCl (0.15 mol⋅kg−1); (b) HEPES (0.02 mol⋅kg−1) + NaHEPES (0.02 mol⋅kg−1) + NaCl (0.14 mol⋅kg−1); (c) HEPES (0.03 mol⋅kg−1) + NaHEPES (0.03 mol⋅kg−1) + NaCl (0.13 mol⋅kg−1); (d) HEPES (0.04 mol⋅kg−1) + NaHEPES (0.04 mol⋅kg−1) + NaCl (0.12 mol⋅kg−1); (e) HEPES (0.05 mol⋅kg−1) + NaHEPES (0.05 mol⋅kg−1) + NaCl (0.11 mol⋅kg−1); (f) HEPES (0.06 mol⋅kg−1) + NaHEPES (0.06 mol⋅kg−1) + NaCl (0.10 mol⋅kg−1); (g) HEPES (0.07 mol⋅kg−1) + NaHEPES (0.07 mol⋅kg−1) + NaCl (0.09 mol⋅kg−1); and (h) HEPES (0.08 mol⋅kg−1) + NaHEPES (0.08 mol⋅kg−1) + NaCl (0.08 mol⋅kg−1). Conventional pa
H values, for all eight buffer solutions from 5 to 55 °C, have been calculated. The operational pH values with liquid junction
corrections, at 25 and 37 °C have been determined based on the NBS/NIST standard between the physiological phosphate standard
and four buffer solutions. These are recommended as pH standards for physiological fluids in the range of pH = 7.3 to 7.5
at I=0.16 mol⋅kg−1. 相似文献
7.
The new analytical method using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure for simultaneous determination
of diacylhydrazine insecticide residues in fruits and vegetables was developed using ultra-performance liquid chromatography
coupled with tandem mass spectrometry (UPLC-MS/MS). The four insecticides (tebufenozide, methoxfenozide, chromafenozide, and
halofenozide) were extracted from six fruit and vegetable matrices using acetonitrile and subsequently cleaned up using primary
secondary amine (PSA) or octadecylsilane (C18) as sorbent prior to UPLC-MS/MS analysis. The determination of the target compounds
was achieved in less than 3.0 min using an electrospray ionization source in positive mode (ESI+) for tebufenozide, methoxfenozide,
and halofenozide and in negative mode (ESI−) for chromafenozide. The limits of detection were below 0.6 μg kg−1, while the limit of quantification did not exceed 2 μg kg−1 in different matrices. The QuEChERS procedure by using two sorbents (PSA and C18) and the matrix-matched standards gave satisfactory
recoveries and relative standard deviation (RSD) values in different matrices at four spiked levels (0.01, 0.05, 0.1, and
1 mg kg−1). The overall average recoveries for this method in apple, grape, cucumber, tomato, cabbage, and spinach at four levels ranged
from 74.2% to 112.5% with RSDs in the range of 1.4–13.8% (n = 5) for all analytes. This study provides a theoretical basis for China to draw up maximum residue limits and analytical
method for diacylhydrazine insecticide in vegetables and fruits. 相似文献
8.
Y. C. Wong D. W. M. Sin Y. C. Yip L. Valiente A. Toervenyi J. Wang G. Labarraque P. Gupta D. Soni Surmadi E. Hwang C. Yafa O. Cankur E. Uysal G. Turk R. Huertas 《Accreditation and quality assurance》2009,14(3):151-158
A Comité Consultatif pour la Quantité de Matière (CCQM) inter-laboratory comparison program, CCQM-P97, for the analysis of
cadmium and lead in Herba Demodii Styracifolii was organized by the Hong Kong Government Laboratory. The objective of the program was to establish comparability of trace
metals analysis in herbal matrices amongst the participating national metrology institutes. The arithmetic mean values of
the 13 participants were 0.3186 mg kg−1 (RSD = 11.3%) and 1.650 mg kg−1 (RSD = 11.0%) for cadmium and lead, respectively. The participants using double-isotope dilution mass spectrometry technique
for their quantification were found to provide similar mean values to those of non-isotope dilution mass spectrometry users.
The observation indicated that trace metal analysis in herbal matrices was not method-dependent, but the use of the highest
metrological IDMS approach gave a better precision than other routine calibration methods. 相似文献
9.
Samuel Melaku Ilse Gelaude Frank Vanhaecke Luc Moens Richard Dams 《Mikrochimica acta》2003,142(1-2):7-12
Microwave digestion reduction-aeration and pyrolysis combined with cold vapour atomic absorption and cold vapour atomic fluorescence
are compared for the determination of total mercury in several biological and environmental matrices. The biological samples
were digested in a mixture of HNO3/H2O2, the environmental samples in a mixture of HNO3/HClO4. After reduction with SnCl2, the mercury was collected by two-stage gold amalgamation. After microwave digestion reduction-aeration, detection limits
of 1.4 ng g−1 and 0.6 ng g−1 were obtained for cold vapour atomic absorption spectrometry (CVAAS) and cold vapour atomic fluorescence spectrometry (CVAFS),
respectively, for 250 mg of environmental samples. For biological samples (500 mg) the detection limits were 0.7 ng g−1 (CVAAS) and 0.4 ng g−1 (CVAFS). After pyrolysis, detection limits of 3.5 ng g−1 and 1.6 ng g−1 for CVAAS and CVAFS, respectively, were obtained for a 10 mg sample. Pyrolysis can only be applied when the organic content
of the sample is not too high. Accurate results were obtained for 8 certified reference materials of both environmental and
biological origin. In addition, a real sludge sample was analysed.
Author for correspondence. E-mail: richard.dams@rug.ac.be
Received September 18, 2002; accepted December 3, 2002
Published online May 5, 2003 相似文献
10.
Panayot K. Petrov Jožica Majda Serafimovska Sonja Arpadjan Dimiter L. Tsalev Trajče Stafilov 《Central European Journal of Chemistry》2008,6(2):216-221
The influence of EDTA, carboxylic acids, amino-and hydroxocarboxylic acids, monosaccharides and humic substances on the generation
of arsines in hydride generation atomic absorption spectrometry (HGAAS) was investigated. EDTA (0.02 mol L−1), ascorbic acid (0.02 mol L−1) and glucose or fructose (0.2 mol L−1) are useful additives for levelling sensitivities for As(III), monomethylarsonate (MMA) and dimethylarsinate (DMA). The presence
of glycine, malonic, tartaric acids, BICIN and soil humin extracts leads to differences in analytical signal response between
these arsenic species. An analytical application to the determination of the sum of As(III), monomethylarsonate (MMA) and
dimethylarsinate (DMA) as well as the sum of toxicologically relevant hydride forming arsenic fraction As(III) + As(V) + MMA
+ DMA in EDTA soil/sediment extracts using continuous flow HGAAS was demonstrated. The limit of detection was 0.2 mg kg−1 As. Within-day and between-day precision were in the range 3–7% and 4–10%, respectively, for arsenic contents of 0.7–25 mg
kg−1, with recoveries 95–103%.
相似文献
11.
R. Zwicker B. M. Zwicker S. Laoharojanaphand A. Chatt 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(1):211-216
Neutron activation analysis (NAA) methods were employed for the determination of total arsenic, and water soluble As(III)
and As(V) compounds in freshwater fish/shellfish and plant samples from Southern Thailand. Total arsenic concentrations varied
from 0.05 to 425 mg kg−1. Water soluble arsenic species were separated by solvent extraction using ammonium pyrrolidinedithiocarbamate (APDC)/methylisobutylketone
(MIBK) followed by NAA. The water soluble As(III) and As(V) levels varied from 0.07 to 26.4 and 0.03 to 22.9 mg kg−1, respectively. The As(III) and As(V) detection limits were 0.007 for fish/shellfish, 0.005 for As(III) and 0.006 mg kg−1 for As(V) in plants. This separation method allows for the determination of water soluble As(III) and As(V) using commonly
available and inexpensive laboratory equipment and chemicals, which can be coupled to a variety of quantification techniques. 相似文献
12.
Lina Kantiani Marinella Farré Josep Manuel Grases i Freixiedas Damià Barceló 《Analytical and bioanalytical chemistry》2010,398(3):1195-1205
A fully automated method has been developed for analysis of eighteen antibacterial compounds, including penicillins, cephalosporins
and sulfonamides, in animal feed with limits of quantification in the range 0.25–5.79 μg kg−1. The method is based on pressurized liquid extraction of 3 g homogenized feed with water and online clean-up of 500 μL of
the extract with C18HD cartridges. The purified sample was directly analysed by liquid chromatography–electrospray tandem mass spectrometry (SPE–LC–ESI-MS–MS).
Chromatographic separation was achieved within 10 min by use of a C12 Phenomenex Hydro-RP reversed-phase analytical column and a mobile phase gradient (water + 0.1% formic acid–methanol + 0.1%
formic acid). The method was validated, revealing capability for detection of concentrations as low as 0.09 μg kg−1, decision limits (CCα) and detection capabilities (CCβ) in the range 10–174 μg kg−1 and 22–182 μg kg−1, respectively, and inter-day precision ranging from 0.7 to 8.3%. Recovery, with internal standard correction, was in the
range 93–134% for all analytes. The method was then applied to analysis of fifteen feed samples, nine of which contained at
least one antimicrobial at concentrations between 0.006 and 1.526 mg kg−1. The performance data and results from the method were compared with those from a previous method developed by our group,
using offline SPE, by analyzing the same set of samples by both methods. The online SPE approach resulted in slightly improved
sensitivity, with LODs of 0.09–2.12 μg kg−1 compared with 0.12–3.94 μg kg−1 by the offline approach. In general, better recovery was achieved by use of online purification (for 72% of the analytes)
and the correlation between the two methods was good. The main advantages of the new online method are rapid and automated
sample pre-treatment, and reduction of sample manipulation, enabling high-throughput analysis and highly accurate results.
Because of all these characteristics, the proposed method is applicable and could be deemed necessary within the field of
food control and safety. 相似文献
13.
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
14.
From vapor pressure osmometry data, the activity of water, osmotic coefficients and mean ionic activity coefficients of glycine
(m=0.006−3.2 mol⋅kg−1), L-histidine (m=0.005−0.23 mol⋅kg−1), L-histidine monohydrochloride (m=0.008−0.63 mol⋅kg−1), glutamic acid (m=0.004−0.05 mol⋅kg−1), sodium L-glutamate (m=0.007−0.6 mol⋅kg−1), and calcium L-glutamate (m=0.008−0.6 mol⋅kg−1) have been obtained in aqueous solutions at 298.15 and 310.15 K. The Pitzer equations and the mean spherical approximation
(MSA) are used for theoretical modeling. The results are supplied as reference thermodynamic material for the characterization
of more complex molecules such as proteins. 相似文献
15.
Catherine Tessini Claudia Mardones Lorena Rivas Dietrich von Baer 《Accreditation and quality assurance》2009,14(7):381-387
High-performance liquid chromatography (HPLC) to determine shikimic acid is used as a complementary tool to differentiate
wine varieties. In order to correctly classify, measurement uncertainty of shikimic acid by HPLC in red wine was estimated
considering the following components: uncertainty associated with the preparation of shikimic acid stock solution, uncertainty
associated with quantification using a calibration curve, and uncertainty associated with precision. The most important contribution
to total uncertainty was the method precision. The expanded uncertainty (U) for different wine varieties was between 2.6 and
8.5%. The method was applied to determine the concentration of shikimic acid in different emerging wine varieties cultivated
in Chile, such as Carmenère, Shiraz, and Pinot Noir, comparing them with classical varieties, such as Cabernet Sauvignon and
Merlot. Shiraz wines presented lower shikimic acid concentrations (between 27 and 86 mg L−1 with U
(k=2) = 2.6%) than Cabernet Sauvignon wines (between 41 and 142 mg L−1 with U
(k=2) = 8.1%), but their concentrations were higher than found in Merlot (from 9 to 41 mg L−1 with U
(k=2) = 4.3%) and Carmenère wines (between 7 and 49 mg L−1 with U
(k=2) = 5.8%). Pinot Noir was the variety with the lowest concentration of this acid (7–14 mg L−1 with U
(k=2) = 8.5%).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
N. Kumar M. Graham S. K. Jha S. S. Chaturvedi 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(1):203-208
The understanding of the bio-geochemical behavior of the uranium radionuclides in the environmental matrices is crucial for
the health safety point of view. The research was carried out in munitions testing sites New Golloway (SW) of Scotland at
the Dunderann firing range which is contaminated with depleted uranium and site is particularly important because it provides
a controlled environment for the investigation of post depositional association of Depleted Uranium (DU) in contaminated soils.
This study used the modified BCR sequential extraction method to investigates the association of DU in at the different sampling
location and in a control soil and were followed by elemental analysis using inductively coupled-optical Emission spectroscopy
(ICP-OES).The Certified Reference Material (CRM) were used for the validation of the concentration. The concentrations of
(Bureau of Reference) BCR-extracted Uranium (U) were in the range of 4–40 (±13.2) mg kg−1 for the DU-contaminated sites whilst U was barely detectable in the soil from the control site (Rebury Gun) RGW. With the
exception of RGH and RGW, the values for BCR-extracted U compared well with those obtained using Aqaua-regia. The obtained
result showed that the maximum Uranium deposition is at RGE and it is 20 mg kg−1 before hitting the target, the 6 mg kg−1 at RGH and minimum is at RGG and RGW control site. 相似文献
17.
Larivière D Tremblay M Durand-Jézéquel M Tolmachev S 《Analytical and bioanalytical chemistry》2012,403(2):409-418
This article describes a robust methodology using the combination of instrumental design (high matrix interface—HMI), sample
dilution and internal standardization for the quantification of beryllium (Be) in various digested autopsy tissues using inductively
coupled plasma mass spectrometry. The applicability of rhodium as a proper internal standard for Be was demonstrated in three
types of biological matrices (i.e., femur, hair, lung tissues). Using HMI, it was possible to achieve instrumental detection
limits and sensitivity of 0.6 ng L−1 and 157 cps L ng−1, respectively. Resilience to high salt matrices of the HMI setup was also highlighted using bone mimicking solution ([Ca2+] = 26 to 1,400 mg L−1), providing a 14-fold increase in tolerance and a 2.7-fold decrease in method detection limit compared to optimized experimental
conditions obtained without the HMI configuration. Precision of the methodology to detect low levels of Be in autopsy samples
was demonstrated using hair and blood certified reference materials. Be concentration ranging from 0.015 to 255 μg kg−1 in autopsy samples obtained from the U.S. Transuranium and Uranium Registries were measured using the methodology presented. 相似文献
18.
J. J. LaBrecque P. R. Cordoves M. A. Cordoves K. Perez D. Palacios J. A. Alfonso 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(3):669-674
This work presents the results of 137Cs, 40K, 232Th and 238U concentration (Bq kg−1) values in coastal marine sediments collected from 38 sites along the coastline of the island of Margarita, Venezuela. The
purpose was to determine baseline values for these radionuclides in surface marine sediments and to detect if there were any
anomalously high concentration values. Only three of the 38 sediments analyzed had measurable values above the detection limit
of 0.9 Bq kg−1 for 137Cs and the highest only being 1.4 Bq kg−1. While, the concentration (Bq kg−1) ranges for the primordial radionuclides, 40K, 232Th and 238U were as follows: 12.2–211.7, <1.5–9.8 and <4.4–20.7, respectively. These concentration ranges for the primordial radionuclides
can be considered as baseline values for surface marine sediments for areas that are considered not polluted by man or contaminated
by nature. Finally, the concentration range of 137Cs can also be employed as baseline values, which only seem to have been the result of the atmospheric testing of nuclear
weapons in the past. 相似文献
19.
N. M. Antovic I. Antovic N. Svrkota 《Journal of Radioanalytical and Nuclear Chemistry》2010,284(3):605-614
232Th activities in the South Adriatic Sea-water, surface sediment, mud with detritus, seagrass (Posidonia oceanica) samples, and the mullet (Mugilidae) species Mugil cephalus, as well as soil and sand from the Montenegrin Coast, were measured using the six-crystal spectrometer PRIPYAT-2M, which
has relatively high detection efficiency and a good sensitivity, and allows a short acquisition time, and measuring samples
of any shape, without preliminary preparation and calibration measurements for different sample geometries. An average 232Th activity concentration in surface soil layer is found to be 40.33 Bq kg−1, while in sand—4.7 Bq kg−1. The absorbed dose rate in air due to 232Th gamma radiation from surface soil layer ranged from 11.76 to 63.39 nGy h−1, with a mean of 24.06 nGy h−1. Corresponding average annual effective dose rate has been found to be 0.03 mSv y−1. The absorbed dose rates due to the thorium gamma radiation in air at 1 m above sand surface on the Montenegrin beaches have
been found to be from 0.41 to 9.08 nGy h−1, while annual effective dose rates ranged from 0.0005 to 0.011 mSv y−1. 232Th activity concentration in seawater ranged from 0.06 to 0.22 Bq L−1, as in the mullet (Mugil cephalus) whole individuals from 0.63 to 1.67 Bq kg−1. Annual intake of 232Th by human consumers of this fish species has been estimated to provide an effective dose of about 0.003 mSv y−1. 相似文献
20.
P. K. Shetty Y. Narayana K. M. Rajashekara 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(1):159-163
The present work investigated the activity concentrations of natural radionuclides 226Ra, 232Th and 40K in beach sand samples along coastal Kerala including high background radiation area. The activity of 232Th ranges from below detectable level to 23029.9 Bq kg−1 with a mean value of 2660.2 Bq kg−1 for 0–10 cm depth interval. For 10–20 cm depth, the 232Th activity ranged from below detectable to 4452.2 Bq kg−1 with a mean value of 815.5 Bq kg−1. The variation of 226Ra activity with depth is parallel with the 232Th activity distribution in beach sand. Its activity varied from below detectable to 5169.5 Bq kg−1 with a mean value 487.6 Bq kg−1 at 0–10 cm depth. For 10–20 cm depth interval, the 226Ra activity ranges from below detectable to 1823.6 Bq kg−1 with a mean value 296.0 Bq kg−1. Similarly the activity varies from below detectable to 1826.6 Bq kg−1 with a mean value of 211.0 Bq kg−1 for a depth interval of 20–30 cm. The activity of 40K at different depth is also discussed. Statistical analysis of radioactivity was also carried out. The results of these investigations are presented in this paper. 相似文献