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1.
Palaeosols and soils of early Holocene (9,000–10,000 yr BP) and Neoglacial (<1200 yr BP) ages from three sections in the Okstindan Mountains in central Norway were analyzed to determine their geochemical compositions. Four buried horizons and a surface sample all had significant water/organic contents. The highest Br (and also Th, U and possibly the REEs) contents were associated with the highest water/organic contents. From the rare earth and other elemental concentration variations, it appears that the three sections were formed from three parent materials, different horizons of which have been affected by weathering and plants. 相似文献
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Fluorescence characterization of the natural organic matter in deep ground waters from the Canadian Shield,Ontario, Canada 总被引:1,自引:0,他引:1
François Caron Karen Sharp-King Stefan Siemann D. Scott Smith 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(3):699-705
Deep groundwater samples from a deep borehole in the Canadian Shield, Ontario, Canada, have been analyzed by fluorometry, to determine the difference in character of the natural organic matter (NOM) with depth. This work was done to obtain a set of geochemical characteristics of deep groundwaters at the site. The fluorescence signal is a complex signature of excitation and emission of light from fluorescent molecules which are part of all natural waters. Fluorescent components have characteristic excitation/emission components, defined as a humic-like (C1), fulvic-like (C2), and protein-like (C3); these are found in various proportions in natural samples. Changes in relative fluorescence intensities of these components have been used in the past to determine the origin and/or processes of the NOM between sampling locations. In this work, six samples were taken at different depths, from ~108 to 650 m below the surface in the borehole. The fluorescence signals of the samples showed three main patterns: (1) the shallower samples (~108, 139 and 285 m) had a pattern similar to that of surface groundwaters, dominated by components C1 and C2; (2) the samples in deep groundwaters (~620 and 650 m) had a weak overall signal, dominated by component C3; finally (3) the mid-depth sample (~503 m) had a component pattern intermediate between the shallower and deeper zones. This set of data is consistent with other data for the groundwaters from this borehole, such as chlorinity, suggesting that the three sampling intervals represent three different types of groundwaters. 相似文献
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This paper presents the first application of mammal tooth enamel carbonate stable isotope analysis for the purpose of investigating late Pleistocene–early Holocene environmental change in an Australian archaeological context. Stable carbon (δ13C) and oxygen (δ18O) isotope ratios were analyzed from archaeological and modern spectacled hare wallaby (Lagorchestes conspicillatus) and hill kangaroo (Osphranter robustus) tooth enamel carbonates from Boodie Cave on Barrow Island in Western Australia. δ18O results track the dynamic paleoecological history at Boodie Cave including a clear shift towards increasing aridity preceding the onset of the Last Glacial Maximum and a period of increased humidity in the early to mid-Holocene. Enamel δ13C reflects divergent species feeding ecology and may imply a long-term shift toward increasing diversity in vegetation structure. This study contributes new data to the carbonate-isotope record for Australian fauna and demonstrates the significant potential of stable isotope based ecological investigations for tracking paleoenvironment change to inter-strata resolution. 相似文献
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M. S. Nagra B. S. Pallah G. P. S. Sahota Harjinder Singh H. S. Sahota 《Journal of Radioanalytical and Nuclear Chemistry》1992,162(2):283-288
Instrumental neutron activation analysis was performed on scalp hair and fingernail samples collected randomly from a group of heavily exposed healthy male industrial workers living in the cities of Hamilton and Toronto (Ont.), Canada. The concentrations of trace elements (Ag, Au, Br, Cd, Co, Cr, Cs, Fe, Hg, Lu, Mn, Mo, Rb, Ru and T3) were evaluated and compared for scalp hair and fingernails. Various trace elements show similar variations in the two kinds of samples. The results have also been compared with those for normal subjects from USA (scalp hair) and Canada (fingernails). 相似文献
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L. Sha M. Yamamoto K. Komura K. Ueno 《Journal of Radioanalytical and Nuclear Chemistry》1991,155(1):45-53
This paper gives the first data on239,240Pu and241Am in Chinese soils. Surface soil samples with a set of 0–5 cm and 5–20 cm depth were collected from Beijing, Taiyuan, Shijiazhuang and Jinang of China in 1990, and239,240Pu,241Am and137Cs, including naturally occurring radionuclides, in these samples were measured to evaluate their present levels and distributions. From these results, the average accumulated depositions were estimated roughly to be 24±13 MBq/km2 for239,240Pu, 10±5 MBq/km2 for241Am and 1.2±0.7 GBq/km2 for137Cs. The activity ratios of239,240Pu/137Cs and241Am/239,240Pu ranged from 0.016 to 0.026 with a mean value of 0.020±0.004 and 0.35 to 0.49 with a mean value of 0.43±0.05, respectively. 相似文献
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Scazzola R Avezzù S Biancotto R Chiamenti E Chiozzotto E Gerotto M Palonta M Roiter S 《Annali di chimica》2003,93(4):465-470
The main aim of this project was to assess background levels of heavy metals in soil in the inland coastal area of Venice, Italy. The pilot study area is located near the industrial area of Porto Marghera, considered of national interest in terms of contaminated soil remediation (Environmental Ministerial Decree n. 471/1999). The Decree under consideration emphasises the importance of the assessment of background values in soil remediation. Results will show cases (As and Sn) in which background values are greater than concentration limit standards given by legislation. 相似文献
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Analyses of fish and other environmental samples (clams, macrophytes, sediments and waters) from areas upstream and downstream from two alkyllead manufactures beside the St Lawrence and St Clair Rivers, Ontario, show a clear indication of elevated alkyllead levels in samples near the industries. Most species of fish contained alkyllead compounds with tetraethyllead and triethyllead as the predominant forms. Most fish from the contaminated areas contained 50–75% of total lead as alkylleads. Carp, yellow perch and white sucker were generally the most contaminated species while pike, alewife and rock bass were the least contaminated. Average alkyllead levels varied from year to year but declined steadily after 1981. For example, the geometric mean of alkyllead compounds in carp from the St Lawrence River decreased from 4207 μg kg?1 in 1981 to 2000 μg kg?1 in 1982 and to 49 μg kg?1 in 1987, reflecting the reduction of alkylleads in the effluents and the closure of one of the manufactures in 1985. Alkyllead levels were consistently lower in muscle and carcass samples in comparison with whole fish containing fatty intestines. However, muscle levels were generally equal to carcass levels. The concentrations of alkyllead compounds were generally low in clams, macrophytes, sediments and waters except from the immediate vicinity of the manufactures' final effluent discharges. 相似文献
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海南岛南渡江近岸河口沉积物稀土元素地球化学 总被引:2,自引:0,他引:2
用电感耦合等离子体(ICP-MS)测定了海南岛南渡江近岸河口11个站位沉积物中的稀土元素(REEs)以及U,Th,Ti,Sr,Mn等元素的含量,探讨了沉积物中REE分布模式和变化规律,推断沉积物的来源及演化过程。结果表明,研究区沉积物ΣREE平均含量为124.94 mg.kg-1,河口沉积物ΣREE含量低于滨浅海沉积物。虽然各站ΣREE含量存在较大差别,但分布模式相似,均为轻稀土富集型和Eu负异常,为陆壳型沉积。沉积物中REE与U,Th,Ti和Zr有显著的正相关性,与Sr,CaO相关性较弱,表明沉积物主要来源是花岗岩陆源物质,其次是生源碳酸盐物质。 相似文献
10.
Gas chromatography-mass spectrometry (GC/MS) was employed for the determination of 30 widely used pesticides including various
transformation products and alkylphenols in water and agricultural soils with the aim of assessing the impact of these compounds
in agricultural soils and the underlying aquifer. The extraction, clean-up, and analytical procedures were optimized for both
water and soil samples to provide a highly robust method capable of determining target analytes at the ppb–ppt level with
high precision. For water samples, different solid-phase extraction cartridges and conditions were optimized; similarly, pressurized
liquid extraction conditions were tested to provide interference-free extracts and high sensitivity. Instrumental LODs of
3–4 pg were obtained. The multi-residue extraction procedures were applied to the analysis of groundwaters and agricultural
soils from the Ebro river basin (NE Spain). Most ubiquitous herbicides detected were triazines but some acetanilides and organophosphorus
pesticides were also found; the pesticide additive tributylphosphate was found in all water samples. Levels varied between
0.57 and 5.37 μg/L in groundwater, whereas nonylphenol was the sole compound detected in soil. Alkylphenols are used as adjuvants
in pesticide formulations and are present in sludges employed as soil fertilizers. Occurrence was found to be similar to other
environmental studies. 相似文献
11.
R. G. V. Hancock W. C. Mahaney 《Journal of Radioanalytical and Nuclear Chemistry》1991,148(2):285-294
A stratigraphic and geochemical study of alpine soils, which formed in later Pleistocene (late glacial) and Neoglacial deposits in the Wind River Mountains of western Wyoming, indicates that these soils have been affected by air-fall influx of inorganic pollutants. Arsenic, bromine, and antimony appear to have been deposited in surface soils by incorporation of aeolian materials which were presumably transported by prevailing winds from industrial sources, including coal-burning operations. Because vanadium was not found in surface soils at concentrations above site-specific background levels, oil-fired energy generating stations were not deemed to be significant sources of surface soil pollution in the region. Acid-rain effects were not observed in the soils. 相似文献
12.
Majumder Ratan Kumar Das Sudeb Chandra Rasul Md. Golam Khalil Mohammad Ibrahim Dina Nafisa Tamannaya Kabir Mohammad Zafrul Deeba Farah Rajib Mohammad 《Journal of Radioanalytical and Nuclear Chemistry》2021,329(1):265-277
Journal of Radioanalytical and Nuclear Chemistry - The study investigates the measurement of radon concentration in soils and rocks as a natural tracer for exploring uranium mineralization, first... 相似文献
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Arsenic (As) in soils and hair collected from schools in Ron Phibun district, Nakhon Si Thammarat province, Thailand, where former tin mining operation were located, was determined by hydride generation atomic absorption spectrophotometry. The relationship between As content in soils and hair with distance from secured landfill was also investigated. Soil and hair samples were collected from 6 schools in summer (February) and rainy season (July). For soils, silt+clay (<45 µm) fraction and sand (45 µm–2 mm) fraction were analyzed. The average concentrations of arsenic in soils during summer (21.70 ± 16.79 mg/kg) and rainy season (22.45 ± 14.17 mg/kg) were at the same concentration level. The average arsenic content in hair samples was 2.24 ± 0.05 mg/kg in rainy season which was higher than 1.05 ± 0.04 mg/kg in summer. It was found that arsenic contents in hair and soils are correlated with the distance from the secured landfill. Most importantly, a positive relationship between arsenic content in hair and soil was obtained for rainy season, which indicated that arsenic in soil corresponded to arsenic in hair. The cancer risk from soils ranged from 4.48 × 10?7 to 2.06 × 10?6 indicating low carcinogenic risk to school children. 相似文献
17.
Jianzhong Zhu Yunlong Jin Jingqi Xue 《Fresenius' Journal of Analytical Chemistry》1992,344(1-2):42-46
Summary A simple and fast analytical method for the simultaneous determination of the herbicides isoproturon (N-(4-isopropylphenyl)-N'N'-dimethyl-urea),
dichlorprop-p ((+)-2-(2,4-dichlorophenoxy)-propionic acid), bifenox (methyl-5-(2,4-dichlorophenoxy)-2-nitro-benzoate), and
its main metabolite bifenox acid (5-(2,4-dichloro-phenoxy)-2-nitro-benzoic acid) in soils is described. The herbicides differ
substantially in their physical and chemical properties. The soil extraction with a mixture of CH2Cl2, C2H5OH, and acetone, followed by an isocratic RP-HPLC determination yields high, reproducible recoveries for all compounds. The
method can be used for different soil moisture and pH conditions. The detection limits range from 0.01 to 0.03 mg active compound/kg
dry soil. An additional clean-up using size exclusion techniques can improve the detection limits to 0.003 to 0.007 mg active
compound/kg dry soil. The method is suitable for routine residue analyses and applicable to other herbicides as well. 相似文献
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Determination of arsenic species in water, soils and plants 总被引:8,自引:0,他引:8
Mattusch J Wennrich R Schmidt AC Reisser W 《Fresenius' Journal of Analytical Chemistry》2000,366(2):200-203
Ion chromatographic separation coupled with ICP-MS was used to determine arsenic species in plant and soil extracts. A scheme for growth, harvesting, sample pre-treatment and analysis was developed for the arsenic species to enable determination. Preliminary results obtained with ten herb plants grown on arsenic-contaminated soil compared to non-contaminated soil show a heterogeneous pattern of accumulation rate, metabolization and detoxification mechanisms in monocots and dicots. Arsenite appears to be the major component in plants with good growth. Organic arsenic species were even detected at very low concentrations (< 150 microg kg(-1) (dry mass)). 相似文献
20.
Based on data from palynology, paleosols, paleolimnology, ice core, archeology, sea levels, etc. , we reconstructed climates and environments of the Holocene Megathermal maximum (7. 2-6. 0 ka B. P. ), particularly vegetation zones, temperatures, precipitation and sea-level fluctuations. Annual mean temperature during that period was estimated at 1 ℃ higher than today for South China, 2 ℃ higher for the Changjiang River Valley, about 3℃ higher for North China, Northeast China and Northwest China and up to 4 - 5 ℃ higher for southern Qinghai-Xizang Plateau. Relative winter temperatures increased much more than average annual temperatures. The centennial-scale warming was accompanied by the expansion of summer monsoon and recession of winter cold currents as well as northward and westward shift of vegetation zones. Higher lake levels registered in all inland lakes of Inner Mongolia, Xinjiang, Qinghai and Xizang indicated that precipitation increased to a certain extent. The Holocene highest sea level i 相似文献