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1.
《Analytical letters》2012,45(2):356-366
A fast, simple and sensitive method for determining of lead in hair dyes using graphite furnace atomic absorption spectrometry with slurry sampling was developed. Multivariate optimization was used to establish optimal analytical parameters through a fractional factorial and a central composite design. The samples were submitted for direct analysis without prior digestion and were diluted in 2.5% v/v HNO3 and 1.5% v/v H2O2. Palladium (chemical modifier) and rhodium (permanent modifier) were selected from several potential modifiers. The optimal conditions were a pyrolysis time of 10 s (liquid and dust dyes) 20 s (cream dyes), a pyrolysis temperature of 789°C (liquid dyes) or 750°C (cream and dust dyes) and an atomization temperature of 1800°C for all dyes. Under optimum conditions, the calibration graph is linear in the 1.50–50.0 µg L?1 concentration range, with a detection limit of 0.33, 0.44, and 0.39 µg L?1 for liquid, dust, and cream hair dyes, respectively. The relative standard deviation ranged from 1.63 to 4.56%. The recovery rate ranged from 85 to 108%, and no significant differences were found between the results obtained with the proposed method and the microwave decomposition analysis method of real samples. The concentration ranges obtained for lead in the hair dyes samples were 1.00–11.3 µg L?1 for liquid dyes, 14.0–100 µg kg?1 for dust dyes, and 19.9–187 µg kg?1 for cream dyes.  相似文献   

2.
《Analytical letters》2012,45(17):2747-2757
Abstract

Brazilian sugarcane spirits were analyzed to elucidate similarities and dissimilarities by principal component analysis. Nine aldehydes, six alcohols, and six metal cations were identified and quantified. Isobutanol (LD 202.9 µg L?1), butiraldehyde (0.08–0.5 µg L?1), ethanol (39–47% v/v), and copper (371–6068 µg L?1) showed marked similarities, but the concentration levels of n-butanol (1.6–7.3 µg L?1), sec-butanol (LD 89 µg L?1), formaldehyde (0.1–0.74 µg L?1), valeraldehyde (0.04–0.31 µg L?1), iron (8.6–139.1 µg L?1), and magnesium (LD 1149 µg L?1) exhibited differences from samples.  相似文献   

3.
《Analytical letters》2012,45(10):1758-1768
This paper reports the determination of the mineral composition of watercress (Nasturtium officinale Cruciferae, Brassicaceae), grown in soils from three cities in the Bahia State of Brazil, and in a fourth city where plants were grown in a hydroponic system. The sampling was carried out during the summer and winter. Analyses were performed with inductively coupled plasma optical emission spectrometry (ICP OES), and the accuracy was confirmed with a certified reference material of apple leaves.

Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed different mineral compositions of the samples collected in the summer and winter.

Samples collected in the summer had a higher concentration of the nutrients iron, calcium, and magnesium, and the samples collected in the winter had a higher concentration of manganese and copper. The average contents of the samples (expressed as wet weight) were 2.50 and 3.03 mg g?1 for calcium, 0.37 and 0.86 mg g?1 for magnesium, 8.68 and 10.84 µg g?1 for iron, 8.42 and 8.47 µg g?1 for zinc, 0.61 and 0.47 µg g?1 for copper, and 7.78 and 5.03 µg g?1 for manganese for summer and winter, respectively. These results are in agreement with values previously reported in the literature. Samples collected from the hydroponic system in the winter had a lower concentration of all nutrients.  相似文献   

4.
Environmental gamma radiation levels around the new Bhabha Atomic Research Centre site at Visakhapatnam have been assessed. Natural and anthropogenic radionuclide activity concentrations in soil samples collected were determined using high-resolution gamma spectroscopy. Average activity concentrations of 238U, 226Ra, 232Th and 40K were found to be 38, 38, 230 and 520 Bq kg?1, respectively. No anthropogenic radionuclide except fallout 137Cs having mean concentration range ≤ 0.2–2.2 Bq kg?1 was detected in the soil samples. The observed values are compared with the values reported for different areas in India and other parts of the world. The annual total external gamma radiation dose to the members of public estimated using the above observations ranged from 0.13 to 0.38 mSv y?1 with an average of 0.25 mSv y?1.  相似文献   

5.
《Analytical letters》2012,45(10):1634-1649
A selective method for the determination of fourteen nitroimidazoles and their hydroxy-metabolites in honey was developed based on improved molecularly imprinted solid-phase extraction followed by liquid chromatography–tandem mass spectrometry. The separation of analytes was performed on a C18 column using a mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water with gradient elution. The method was suitable for metronidazole, hydroxymetronidazole, dimetridazole, ronidazole, hydroxydimetridazole, ipronidazole, hydroxyipronidazole, carnidazole, menidazole, nimorazole, ornidazole, secnidazole, ternidazole, and tinidazole. The procedure was evaluated according to EU Commission Decision 2002/657/EC requirements by determining linearity, specificity, recovery, repeatability, within-laboratory reproducibility, decision limit, detection capability, matrix effects, and stability. The method determined nitroimidazoles and their hydroxy-metabolites below the recommended concentration level of 3 µg kg?1. The decision limits and detection capabilities ranged from 0.110 µg kg?1 to 0.387 µg kg?1 and from 0.179 µg kg?1 to 0.508 µg kg?1, respectively. The results from stability tests indicated that all analyzed nitroimidazoles were stable in honey stored at 4°C for at least 28 weeks and that elevated temperature and exposure to light exposure accelerated their degradation. The method was successfully applied to the analysis of a wide variety of honey samples.  相似文献   

6.
Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), methylmercury (MeHg+) and butyltins (mono-, di- and tri-butyltin, MBT, DBT and TBT) were monitored in oysters (Crassostrea sp.) and sediments collected in different sampling points of the UNESCO reserve of the biosphere of Urdaibai (Bay of Biscay) from March 2006 to June 2007. In the case of oyster samples, concentrations in the 290–1814 µg kg?1 (PAHs), 70–475 µg kg?1 (PCBs), 75–644 µg kg?1 (MeHg+) and 200–1300 µg kg?1 (as a sum of the three butyltins) ranges were obtained. In most samples TBT was the most abundant butyltin, followed by DBT and MBT. It should be highlighted that most samples exceeded the highest range (367 µg kg?1) found in the last mussel watch programme carried out by the National Oceanic and Atmospheric Administration (NOAA) for butyltins in oyster samples. This could be due to the presence of a shipyard in the estuary. Sediment concentrations ranged as follows: total PAHs (856–3495 µg kg?1) and total PCBs (58–220 µg kg?1). Organometallic species were always below the limits of detection (LODs) (0.24 µg kg?1 for MeHg+, 0.6 µg kg?1 for MBT, 0.48 µg kg?1 for DBT and 1.1 µg kg?1 for TBT). In both sediment and oyster PAH sources were mostly combustion. In the case of PCBs, 4-6 chlorine-atom congeners were the most abundant ones. Slight differences in the profile of PAHs as well as PCBs can be detected when the matrices were compared with each other. Finally, in the case of PAHs, sediment and water column played the main role in the accumulation pathway into the organisms in all the sampling stations.  相似文献   

7.
《Analytical letters》2012,45(11):1952-1964
The distributions of cadmium and lead in marine sediments, surrounding soil, stones, and atmospheric particulate matter were determined at different locations in Split, Croatia. The determination of cadmium and lead was performed by flame atomic absorption spectrometry whereas atmospheric particulate matter samples were analyzed by inductively coupled plasma–optical emission spectrometry. Cadmium concentrations in the stones and soil were between 0.2 to 0.6 µg g?1 and 0.2 to 0.9 µg g?1. The concentration in the atmospheric particulate matter were <0.2 µg m?2 d?1(detection limit) to 1.4 µg m?2 d?1. Lead concentrations in marine sediments, stones, soil, and atmospheric particulate matter ranged from 31.2 to 144.4 µg g?1, 9.3 to 29.4 µg g?1, 11.3 to 66.1 µg g?1, and 0.5 to 241.4 µg m?2 d?1, respectively. The relationship between determined parameters was established using principal component analysis and the results are in agreement with the assumption that anthropogenic sources play important roles for lead and cadmium distribution.  相似文献   

8.
Persistence and dissipation of fluopicolide and propamocarb were studied on cabbage and soil as per good agricultural practices over a period of 2 years. A modified QuEChERS analytical method in conjunction with gas chromatography (GC) and GC–mass spectrometry was used for analysis of fluopicolide and its metabolite, 2,6-dichlorobenzamide, and propamocarb in cabbage and soil. The results of the method validation were satisfactory with recoveries within 74.5–100.81% and relative standard deviations 4.8–13.9% (n = 6). The limit of detection (LOD) and limit of quantification (LOQ) of both fluopicolide and 2,6-dichlorobenzamide were 0.003 µg mL?1 and 0.01 mg kg?1, respectively. The LOD and LOQ of propamocarb were 0.03 µg mL?1 and 0.1 mg kg?1, respectively. During 2013, the initial residue deposits of fluopicolide on cabbage were 0.60 and 1.48 mg kg?1 from treatments at the standard and double doses of 100 and 200 g a.i. ha?1 which dissipated with the half-life of 3.4 and 3.7 days. During 2014, the residues were 0.49 and 1.13 mg kg?1 which dissipated with the half-life of 4.2 and 5.1 days. Propamocarb residues on cabbage were 5.36 and 12.58 mg kg?1 in the first study (2013) and 4.85 and 10.26 mg kg?1 in the second study (2014) from treatments at the standard and double doses of 1000 and 2000 g a.i. ha?1, respectively. The residues dissipated with the half-life of 4–5.5 days. The preharvest interval, the time required for fluopicolide + propamocarb residues to dissipate below the maximum residue limits (notified by EU) at the standard dose, was 11.8 and 14 days during 2013 and 2014. Residue of 2,6-dichlorobenzamide was always <LOQ in cabbage. Residues of fluopicolide, 2,6-dichlorobenzamide and propamocarb were <LOQ in field soil at harvest.  相似文献   

9.
《Analytical letters》2012,45(12):2095-2103
Titanium was determined in nano-titanium(IV) oxide food packaging by microwave digestion with inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). Microwave digestion was optimized using different acid combinations. Both spectrometry techniques showed good reproducibility, repeatability, and recovery. For ICP-AES, the limit of detection was 5.0 mg kg?1, the linear dynamic range was 100–5000 µ g L?1, the average recoveries for blank samples spiked with titanium were between 94.7% and 100.1%, and the relative standard deviations were from 2.1% to 7.1%. By ICP-MS, the limit of detection was 0.3 mg kg?1, the linear dynamic range was 0.5–200 µ g L?1, the recoveries were 88.4%–96.3%, and the relative standard deviations were 6.3%–7.4%. These results indicated that methods were effective for the determination of titanium in food packaging.  相似文献   

10.
In this article, we present results obtained from a radiometric survey that was conducted in the Leepa Valley of Azad Jammu & Kashmir, Pakistan. The purpose of current study is to appraise the radioactivity levels and the associated health hazards due to the terrestrial radionuclide in soil and rock samples. In this regard, 16 soil and 17 rock samples were collected from different locations of the Leepa Valley. After processing the samples, activity concentrations of primordial (232Th, 226Ra and 40K) and anthropogenic (137Cs) radionuclides were determined using a P-type coaxial high purity germanium detector. From the results obtained the mean activity concentrations of radionuclides 226Ra, 232Th and 40K in the soil samples were found to be 31.25 ± 0.46, 44.1 ± 1.07 and 575 ± 8.89 Bq kg?1 respectively. Whilst, in rock samples 226Ra, 232Th and 40K mean activities were found as 28.46 ± 0.45, 48.63 ± 1.12 and 666.7 ± 9.39 Bq kg?1, respectively. The 137Cs concentration level in soil and rock samples is found to be 15.04 ± 0.29 and 5.7 ± 0.16 Bq kg?1, respectively. The average radium equivalent activity (R aeq) was found as 143.16 and 142.93 Bq kg?1 in soil and rock samples, respectively. These findings are less than the recommended safe value of 370 Bq kg?1 as given in OECD report (1979). The values of external (H ex) and internal hazard index (H in) are also less than unity. Mean value of absorbed dose rate was found as 69.78 nGy h?1 for the soil samples, which is in good agreement with the world wide average value (70 nGy h?1). Mean value of absorbed dose rate from rock samples was found as 70.01 nGy h?1. Mean values of the annual effective dose is also lower than the values reported for different other countries of the world.  相似文献   

11.
A non-chromatographic method for Hg speciation in fish muscle using eco-scale thermal desorption atomic absorption spectrometry was validated according to the demands of the Decisions 2007/333/EC, 2011/836/EC and 2002/657/EC. The method is based on the determination of total Hg in solid sample and MeHg+, respectively, after double liquid–liquid extraction (47% HBr, toluene, 1% l-cysteine) according to a procedure recommended by the European Commission. The method was applied for the speciation of Hg in fish muscle to asses the weekly intake and health risk exposure to MeHg+. The method provided calibration coefficients better than 0.999, limits of detection of 0.2 µg kg?1 total Hg and 3.0 µg kg?1 MeHg+. The accuracy of the method assessed by the analysis of CRMs was 100 ± 9% for total Hg and 101 ± 13% for MeHg+ for a coverage factor k = 2. The figures of merit of the method comply with the requirements in the European legislation. Total Hg in the analyzed fish species was in the range 12–108 µg kg?1 wet mass, of which 83–97% as MeHg+. Although significant variation in total Hg was observed among fish species, no differences in terms of distribution of organic and inorganic Hg species were identified. No risk exposure to MeHg+ was ascertained from muscle fish consumption from reliable sources, since weekly intake was below 30% of provisional tolerable weekly intake of 1.6 µg kg?1 body weight. Speciation is recommended as MeHg+ is much more helpful than total Hg to evaluate the dietary risk exposure.  相似文献   

12.
An analytical method for the determination of both sulfadiazine (SDZ) and trimethoprim (TMP), and also N4-acetyl-sulfadiazine (AcSDZ), the main metabolite of SDZ, in fish muscle plus skin has been developed and validated. Dapsone was used as internal standard. The method involves extraction of the analytes from fish tissue by pressurized liquid extraction using water as extractant. Sample cleanup was carried out by solid phase extraction using Abselut Nexus cartridges. Target analytes were quantitatively determined by liquid–chromatography mass spectrometry using single ion monitoring. The developed method was validated according to the European Union requirements (decision 2002/657/EC). The limit of detection for SDZ and AcSDZ was 3.0 and 2.5 µg kg?1 for TMP. The limit of quantification (LOQ) was 10 µg kg?1 for SDZ and AcSDZ and 7.5 µg kg?1 for TMP. The recovery experiments carried out included the concentration levels of 0.5, 1 and 1.5 times the MRLs for SDZ and TMP. Concentration levels for AcSDZ were the same as SDZ. The values obtained were higher than 92.0% with coefficient of variation (CV, %) below 8.6%. The precision of the method, calculated as CV (%), ranged from 0.2 to 6.8% and from 0.8 to 8.9% for intra–day and inter–day analysis, respectively. Decision limit (CCα) was calculated as 104.3, 53.7 and 105.3 µg kg?1 for SDZ, TMP and AcSDZ, respectively. Detection capability (CCβ) was calculated as 110.0, 58.8 and 109.7 µg kg?1 for SDZ, TMP and AcSDZ, respectively. “Matrix effect” and “relative matrix effect” were also evaluated. The method was used for the analysis of fish samples purchased from local markets.  相似文献   

13.
Arsenic (As) in soil is a contaminant originated from human activities including pesticide use, mining and ore processing operations. In this work, As concentration in soil samples collected around the monazite processing facility, Pathum Thani, Thailand, was investigated. The collections of 24 soil samples were collected from the monazite processing area and 7 soil samples were collected from the control area without the processing activity of the same facility. Soils were digested with the mixture of HNO3, HClO4 and HF using a microwave digester. Inductively coupled plasma mass spectrometer (ICP-MS) equipped with an octopole reaction system (ORS) was used to determine the concentration of As in soils after the acid digestion. JB-3 (igneous rock) was the standard reference material used to check the accuracy of the method. It was found that the analytical results showed good agreement with the certified values. As concentration in soils collected from the monazite processing area ranged from 3.85 to 36.01 mg kg?1 with the mean of 13.06 mg kg?1. The concentration of As higher than the US EPA cancer soil screening level (22 mg kg?1) was observed for only one sample. The control area showed As concentration varied from 9.59 to 14.19 mg kg?1 with the mean of 11.97 mg kg?1. The obtained results from this work were compared with the contaminated soil data of Amphoe Ron Phibun, Nakhon Si Thammarat, Thailand.  相似文献   

14.
A sensitive, rapid and easy analytical method was validated for the determination of quinoid niclosamide (LDS) molluscicide in water, rice and soil using a QuEChERS extraction procedure and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection. The LDS was extracted by using acetonitrile and then cleaned up by using dispersive solid-phase extraction with florisil and C18 sorbents. The determination of the target compound was achieved in less than 3 min using an electrospray ionisation source in negative mode. The overall average recoveries for this method in water, rice and soil matrix at three fortified levels ranged from 82.54 to 99.9%, with relative standard deviations in the range of 1.51 to 4.86% (n = 5). The calculated limits of detection were lower than 0.1 µg kg?1 and quantification was 5 µg kg?1; these values were much lower than the maximum residue levels established by the Australian standard (0.01 mg kg?1). The results of the method validation confirmed that this proposed method is convenient and reliable for the determination of LDS molluscicide in water, rice and soil samples.  相似文献   

15.
《Analytical letters》2012,45(6):1015-1030
A reliable indirect competitive enzyme-linked immunosorbent assay (ELISA) based on a new specific monoclonal antibody was developed to determine olaquindox in animal feed. The influence of several physicochemical factors (nonfat dried milk solution, organic solvent, incubation time) on the immunoassay was investigated. In the optimized system, the 50% inhibition concentration was 9.66 ± 1.81 µ g L?1. The limits of detection for porcine, chicken, and fish feed were 0.28, 0.46, and 0.48 µg kg?1. The limits of quantification were 1.00 µg kg?1 for the feed samples. The recoveries from porcine, chicken, and fish feed spiked with olaquindox were 90–104%, 77–103%, and 78–107%, respectively, with coefficients of variation (CVs) between 3.8 and 14.1%. The cross-reactivity was less than 2.08% with four structurally related compounds and no recognition of five other restricted or forbidden drugs was observed. Parallel analysis of the three spiked feed samples showed comparable results between the indirect competitive ELISA and the standard high-performance liquid chromatography method in China (R2 = 0.9985 for porcine feed, R2 = 0.9896 for chicken feed, and R2 = 0.9987 for fish feed). These data suggest that the developed indirect competitive ELISA is a specific and convenient method and is suitable for olaquindox determination in animal feed.  相似文献   

16.

Densities (ρ/103kg m?3), apparent molar volume (V2/10?6m3mol?1), and viscosities (η/0.1 kg m?1s?1) for 5.0 to 60.0 millimol kg?1 (m mol kg?1) 1,3,5 triazine (melamine) at interval of 5.0 m mol kg?1 were determined. The data were regressed and extrapolated to infinite dilution (m→0) and referred to as limiting apparent molal volume (V¯2 0) and intrinsic viscosity (B) and used to calculate free energy of activation (Δµ2 0*/KJ mol?1). Such functions illustrate feasibility of micromixing of melamine with paraffin wax emulsifier+4‐nonyl phenol ethoxylate, a nonionic surfactant in aqueous solution. The Δµ2 0* decides micromixing of melamine stabilized by poly(acrylic acid) of 4500 g mol?1 molecular weight, known as superabsorber for water. Paraffin wax emulsion was stabilized by a nonyl phenol ethoxylate and wax particles observed to adhere to melamine surface due to interactions between poly(acrylic acid) dispersant and ethoxylate group of surfactant, resulting in sedimentation of mixed particles. Thus V¯2 0, B, and Δµ2 0* values conclude to ‐NH2 group interactions for micromixing and scanning electron micrograph (SEM) elucidates microstructure and uniformity of micromixing.  相似文献   

17.
Tiruchirappalli district is naturally endowed with rich building material resources which are also used in neighboring districts. Hence, measurements of activity concentrations and absorbed dose rate of primordial radionuclides (238U, 232Th and 40K) in the rock samples collected from 14 sedimentary rocks and 9 igneous rocks were carried out employing gamma ray spectrometry. In sedimentary rocks the geometric mean activity concentrations of 238U, 232Th and 40K were found to be 7.4, 29.5 and 233.6 Bq kg?1, respectively. On the other hand in igneous rocks geometric mean activity concentrations of 238U, 232Th and 40K were distinctly higher and found to be 13.1, 105.7 and 888.8 Bq kg?1, respectively. The mean radium equivalent activity (Raeq) recorded in both sedimentary (20.8 Bq kg?1) and igneous rocks (245.4 Bq kg?1) were well within the limit prescribed for dwellings (370 Bq kg?1) except Vilathupatti (689.3 Bq kg?1) and Narthamalai (371.6 Bq kg?1). The mean absorbed dose rate from igneous rock (115 nGy h?1) exceeded the prescribed limit of 55 nGy h?1. The mean indoor annual effective dose from the sedimentary rock (0.056 mSv y?1) and igneous rock (0.580 mSv y?1) did not exceed the prescribed limit (1 mSv y?1) except the igneous rock from Vilathupatti (1.51 mSv y?1). The study concludes that sedimentary and igneous rocks analyzed were radiologically safe when used as building materials except igneous rock from Vilathupatti and Narthamalai.  相似文献   

18.
《Analytical letters》2012,45(5):932-941
The heavy metal content was investigated for six mushroom species native to Jordan. Metal (Cu, Pb, Cd, Fe, Zn, Mn, Ni, and Co) content in soil substrate and their relation to metal concentrations in mushroom and underlying soil were determined by flame and graphite furnace atomic absorption spectrometry. Mushroom species and soil were collected from different places in Jordan. The highest Cu level was 51.84 µg g?1 for the species Lepista nuda; whereas, the lowest Cu level was found to be 18.51 µg g?1 in Calvatia utriformis. Among the wild mushrooms, the highest Pb level was found as 4.81 µg g?1 in Bovista plumbea, whereas the lowest Pb concentration was 2.01 µg g?1 in Calvatia utriformis. The highest Cd level was determined as 1.9 µg g?1 for Lepista nuda, whereas the lowest Cd level was 0.58 µg g?1 for the species of Polyporus frondosus. The highest Zn level was 58.77 µg g?1 for the species of Lepista nuda and the lowest Zn concentration was found 35.98 µg g?1 in Calvatia utriformis. The highest Fe level was found as 317 µg g?1 in Lepista nuda, whereas the lowest Fe concentration was 211.7 µg g?1 in Calvatia utriformis. The highest Mn content was 36.55 µg g?1 for Russula delica, whereas the lowest Mn level was 24.5 µg g?1 for the species Bovista plumbea. The highest Ni content was found as 12.65 µg g?1 for Russula delica, whereas the lowest Ni level was 0.17 µg g?1 for Bovista plumbea. The highest Co content in the tested mushrooms was found as 3.5 µg g?1 for the species of Agaricus bisporus, whereas the lowest Co level was 0.85 µg g?1 for Polyporus frondosus. The results indicated that, in general, heavy metal contents in all mushroom species were lower than the underlying soil substrates except for some mushroom species.  相似文献   

19.
The deposition flux of 7Be was measured in the range from 0.4 to 5.2 Bq m?2 d?1, with a mean value of 2.6 Bq m?2 d?1, during the period of May 31, 2009?CMay 31, 2010 in the Three Gorges Reservoir region, China. The low annual deposition flux of 7Be was probably due to the adsorption of 7Be within high altitude clouds and the Qinling-Daba Mountain??s barrier and blocking effects on the cold air during winter months. There was a seasonal trend for 7Be deposition, showing a spring maximum and winter minimum, which may be attributed to the seasonal folding of tropopause in spring and little rainfall amount in winter. A strong positive correlation (R 2 = 0.67) between 7Be deposition flux and rainfall was observed. The depth distribution of 7Be in undisturbed purple soil profiles suggested that the nuclide was mainly distributed within the top 20.0 kg m?2 (~1.5 cm) of soil in depth and the maximum concentration occurred at a depth of 3.0 kg m?2 (~0.2 cm), then the concentration declined quickly and exponentially with depth. The seasonal inventories of 7Be in soils were consistent with the values calculated from the atmospheric fluxes, which shows a great potential for using 7Be as a tracer to assess soil redistribution in purple soil areas of China.  相似文献   

20.
Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay and its also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. Sediment samples were collected from various locations of MHB to determine the concentrations of naturally occurring radionuclides like 226Ra, 228Ra and 40K which varied between 4.0 and 26.0, 5.5 and 19.9, 249.6 and 557.6 Bq kg (dry) ?1 respectively and are comparable to the worldwide average concentration. The mean value ratio of 228Ra/226Ra in sediment was found to be 1.4, indicating a relatively higher mobility of 238U compared to 232Th. The concentration of anthropogenic radionuclide 137Cs in sediment and biota ranged between 3.6 and 54.5 Bq kg (dry) ?1 , <0.08 and 0.5 Bq kg (wet) ?1 respectively. The ingestion dose to ‘General Public’ due to 137Cs intake is 0.02 μSv years?1 which is negligible compared to the internationally accepted limit of 1,000 μSv years?1 to ‘members of public’.  相似文献   

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