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1.
The water and bed-sediment pollution status of the Padma River was determined by analysis of representative samples for selected metals and ions. Water and bed-sediment samples were collected at a T-dam, Rajshahi, Bangladesh, for 7 months. Water and silt-metal content analysis was performed using atomic absorption spectrophotometry or other analytical methods. The data showed the variation of the metal ion-levels in water as follows: Ca 17.11–48.37 ppm, Na 17.51–20.09 ppm, K 1.00–3.60 ppm, Cr 2.80–7.00 ppm, and SO4 4.17–5.48 ppm; in bed sediment, the levels were Cr 35–1050 ppm and Pb 12–48 ppm. The occurrence of Na, K and Ca was in the normal range (US EPA permissible limit), but the levels of Cr in water were much higher than the permissible limit. The SO4 ion content was well below the pollution level. The concentration of Pb in the bed sediment was within the permissible limit for the standard International Atomic Energy Agency (IAEA) Soil-5a, but the concentration of Cr in the bed sediment was significantly higher than the permissible limit for the standard IAEA Soil-5a. Thus the Padma river water was polluted with Cr. The occurrence of some ions showed a monthly variation. Received: 19 August 1999 · Accepted: 12 October 1999  相似文献   

2.
The beryllium and zirconium contents of 45 geochemical reference samples have been determined by inductively coupled plasma after fusion of the samples with lithium metaborate and dissolution of the melt in dilute nitric acid. The method described here is rapid and sample preparation straightforward. Good agreement is shown with previously published results for these two elements. A correction has to be made for an interference due to vanadium in determining the beryllium content, and there is a slight interference due to yttrium in the determination of zirconium. The detection limit for beryllium is about 0.2 μg g-1 and for zirconium about 15 μg g-1 in the sample.  相似文献   

3.
The contents of total carbon, hydrogen, nitrogen and sulfur in twenty-seven geological reference materials, issued by five producer organisations (USGS, CCRMP, ANRT, NIST and GSJ) were determined using an automated simultaneous elemental analyser following combustion. In order to complete gasification of C and N in some geological materials, the combustion temperature needed to be greater than 1150 °C. The calibrator prepared from known amounts of reagent material was not adopted for more than 1.2% m/m of H. Unrealistically high values in certain materials supposed to contain less than 1000 μg g−1 S may be due mainly to memory effects. The limit of detection was 50 μg g−1 for C and N, 500 μg g−1 for H and 1000 μg g−1 for S. Although the blank value of C and N was always stable and less than one third of the detection limit, it had a slightly higher value for N and S. By repeating long-term analysis, high reproducibility for each of the four elements was verified. The method has been applied satisfactorily to a variety of geological reference materials, and recommended values for C, H and N for most of the reference materials studied have been tabulated.  相似文献   

4.
A new, simple and highly sensitive kinetic method for the determination of trace iron (III) has been developed based on the catalytic effect of iron (III) on color reaction ofp-amino-N, N-dimethylaniline dihydrochloride (p-DMA) oxidated by hydrogen peroxide. The reaction is followed spectrophotometrically by measuring the absorbance at 510 nm. The detection limit is 4.47×10−11 g/ml, and the calibration curve is linear in the range of 0–0.10μg Fe(III) /25 ml with a relative standard deviation of ±3.25%. The method has been applied to the determination of iron in tap-water, chemical reagents and human hair.  相似文献   

5.
This paper gives impact of Arsenic contaminated water on human health as well as overview of the extent and severity of groundwater arsenic contamination in Bangladesh. Scalp hair is the most important part of the human body to monitor the accumulation of this type of poison. Therefore, an experiment has been carried out by Neutron Activation Analysis (NAA) at Atomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh on human hair of corresponding tube well water users of these areas to determine the total accumulation of arsenic to their body. Hair samples collected from the region where the groundwater was found highly contaminated with arsenic. The obtained results of arsenic concentration in the lower age (Hb) categories of users (below 12 years of age users) is in the range of 0.33 to 3.29 /gmg/g (ppm) and that in the Hu categories (upper 12 years of age users) is 0.47 to 6.64 μg/g (ppm). Where as maximum permissible range is 1 ppm certified from WHO. Results show that the peoples are highly affected where the groundwater is highly contaminated with arsenic and acts as the primary source of arsenic poisoning among the peoples of those areas. The results indicate that human population is affected with arsenic locally using the contaminated water for a long time.  相似文献   

6.
The uranium content of twelve rock reference samples, five from the Canada Centre for Mineral and Energy Technology, four from the Czechoslovakian Institute of Mineral Raw Materials and three from the United States Geological Survey was determined by neutron activation followed by delayed-neutron counting. Uranium contents measured ranged from 0.20 to 560 ppm. Three of the Canadian samples have relatively well established uranium contents. Of these we agree well with two of them; our value on the third is ∼13% lower than the recommended value. Comparison of our data on the other samples with other researchers is not yet possible because (i) no determinations are yet reported on several of these samples and (ii) even when several reported values are available, the wide disparity of those values does not allow meaningful comparison.  相似文献   

7.
Selenium has been determined in sixty five geological reference materials of different origins by graphite furnace atomic absorption spectrometry. Samples were decomposed with a mixture of nitric and hydrofluoric acids. Selenium was reduced to SeIV with hydrochloric acid, and then fixed and separated from the matrix on thiol cotton. After digestion of the thiol cotton in hot nitric acid, the Se concentration was measured using palladium and magnesium nitrates as a matrix modifier. The limit of determination was 0.02 μg g−1, the precision of the results (relative standard deviation of 3 to 8 replicates) varied from 2.6 to 17.7% with an average of 7.9% in the range 0.02-42.7 μg g−1 and was similar to the value obtained for synthetic samples. Our results are in good agreement with available literature values.  相似文献   

8.
This study was carried out to assess the distribution of uranium in groundwater by using LED fluorimeter LF-2a and chemical and radiological risks associated with its consumption in Sirsa district, Haryana, India. Uranium concentration ranged between 0.93 and 290μg l-1 with an average value of 49 μg l-1. About 44% of the groundwater samples had uranium concentration above the maximum contamination level of 30 μg l-1 prescribed by the World Health Organization and United States Environmental Protection Agency and 22% of the samples exceeded the permissible limit of 60 μgl-1 prescribed by the Atomic Energy Regulatory Board, India. The average cancer morbidity and mortality risks are determined to be 1.10 × 10-4 and 7.17 × 10-5 respectively, indicating the negligible carcinogenic risk. Hazard quotient for 44% samples is greater than unity which indicates health risk due to chemical toxicity of uranium in groundwater. The associated age-dependent annual effective dose is estimated by taking the prescribed water intake values of different age groups.  相似文献   

9.
银是高纯铟的常检痕量元素,由于银含量低,一般的分析方法难以达到期望的检出限。本研究样品用硝酸溶解,强酸性阳离子交换树脂分离,试液蒸发浓缩后用石墨炉原子吸收光谱法测定高纯铟中痕量银。通过溶样方法、离子交换分离条件和仪器测定条件实验,结果表明,以0.7 mol/L硝酸作为淋洗液进行分离,样品中痕量砷、铝、铁、锡及大量的铟可被分离除去;铜、镉、镁、镍、锌、铅、硅和铊不能与银分离,但对测定无影响。方法线性范围为0～50 pg,相对标准偏差(RSD,n=8)小于10%,银的检出限为0.3 pg,测定下限为0.8ng/g,比文献方法的0.02～1μg/g中最低者低2个数量级,加标回收率为93.3%～110.0%。本方法由于分离了基体铟,避免了铟对银测定的影响,兼之将试液浓缩,有效地降低了检出限,且测定时无需使用基体改进剂,成本低,灵敏度较高,适合于高纯铟中痕量银的分析。  相似文献   

10.
Trace elements in the Geological Survey of Japan carbonate reference materials Coral JCp-1 and Giant Clam JCt-1 were determined by inductively coupled plasma-mass spectrometry after digestion with 2% v/v HNO3. A standard addition method was adopted in this determination in order to neutralise the Ca matrix effect. In addition, Sc, Y, In and Bi were used as internal standards to control the matrix effect and correct instrumental drift. Of the eighteen elements measured in JCp-1, precisions for fourteen elements, including Cu, Cd and Ba, were better than 10% RSD and concentrations ranged from 0.002 μg g-1 (Cs) to 8.02 μg g-1 (Ba). The concentrations of measured trace elements in JCt-1, except for Cu, were lower than those in JCp-1. Precisions for all elements with concentrations higher than 0.04 μg g-1 in JCt-1 were also better than 10% RSD and concentrations were found to be between 0.001 μg g-1 (Cs) and 4.84 μg g-1 (Ba). The concentrations of more than fifteen trace elements in the aragonite reference materials are reported here for the first time. Both reference materials are suitable for use in geochemical studies of environmental reconstruction based upon biogenic carbonate materials.  相似文献   

11.
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12.
Inductively coupled plasma-atomic emission spectrometry in conjunction with an ultrasonic nebulizer was employed for the determination of Sr and Ba in river waters at parts per billion (μg l−1) levels without pre-concentration. The ultrasonic nebulizer, equipped with a desolvation system, enhanced the analytical sensitivity by ten to twenty fold compared to conventional pneumatic nebulizers. The detection limits for Sr and Ba, ascertained from blanks and reference samples made in 0.05% NaCl solution, were 0.045 μg l−1 and 0.16 μg l−1 respectively. The accuracy of measurements, based on analyses of solutions of reference materials (G-2 and W-1) and multielement commercial standards (Merck®), was ± 10%. Replicate analyses of samples and reference samples showed measurement precision to be to be better than ± 5%, which is adequate considering that the concentration of Sr and Ba in river waters varies by one to two orders of magnitude.  相似文献   

13.
The determination of sulphur in rocks, soils and sediments by pyrohydrolysis/ion chromatography has been modified to reach lower detection limits of the order of 2 μg g−1. Thirty-one standard reference materials containing sulphur at levels ranging from 3 to about 900 μg g−1 have been analysed in triplicate. In general, the comparison of the results with those published is favorable. The method is also applicable to organic-rich samples as demonstrated by the analysis of NBS samples (citrus leaves, tomato leaves, bovine liver).  相似文献   

14.
A combination of EMPA, sensitive high resolution ion microprobe (SHRIMP II) and/or LA-ICP-MS techniques was used to measure the concentration of selenium (Se) in NIST SRM 610, 612, 614 and a range of reference materials. Our new compiled value for the concentration of Se in NIST SRM 610 is 112 ± 2 μg g−1. The concentration of Se in NIST SRM 612, using NIST SRM 610 for calibration, determined using LA-ICP-MS (confirmed using SHRIMP II) was 15.2 ± 0.2 μg g−1. The concentration of Se in NIST SRM 614, using LA-ICP-MS was 0.394 ± 0.012 μg g−1. LA-ICP-MS determination of Se in synthetic geological glasses BCR-2G, BIR-1G, TB-1G and the MPI-DING glasses showed a range in concentrations from 0.062 to 0.168 μg g−1. Selenium in the natural glass, VG2, was 0.204 ± 0.028 μg g−1.  相似文献   

15.
The concentrations of bromine and iodine in USGS reference material MAG-1 were determined by standard addition with secondary-source x-ray fluorescence spectrometric detection. Three determinations of bromine in the same sample yielded 311, 309 and 346 μg Br/g solid. The iodine content was found to be 380 μg I/g solid. The determination of bromine in a second bottle of MAG-1 (266 ± 9 μg Br/g) indicated that a large variation in halogen concentration may exist between samples of this reference material.  相似文献   

16.
Over the years a large number of rock samples were collected by the explorationists of Atomic Minerals Directorate for Exploration and Research (AMD), Department of Atomic Energy from Sambalpur district, Orissa, India. The variation of uranium enrichment with various types of rock in these samples was studied with an aim to help quick reviewing of toposheets in case of newly taken up areas, for uranium exploration. The radioelements U, Th and K determined for these samples are plotted in ternary diagrams for classifying them as being uraniferous or thoriferous with respect to various type of rocks, keeping the total natural content of radioelements (expressed by eUP3O8) as a parameter. In this study it is seen that samples of quartzofeldspathic breccia type are enriched in uranium irrespective of their further sub classification and eU3O8 content. Granites are enriched in thorium when eU3O8 < 100 ppm and are enriched in uranium when eU3O8 > 100 ppm. A database prepared for this purpose may be useful for reviewing toposheets in future  相似文献   

17.
A method for the selective separation of Ag, Cd, Cr, Cu, Ni, Pb and Zn in traces from solutions of calcite (CaCO3), dolomite (CaMg(CO3)2) and gypsum (CaSO4.2H2O) before their determination by inductively coupled plasma-atomic emission spectrometry (ICP-AES) is presented. The expected interferences of Ca and Mg on intensities of trace analytes were removed by collecting the elements of interest with cobalt(III) hexamethylenedithiocar-bamate, Co(HMDTC)3. The flotation of aqueous solutions (1 l) of calcite, dolomite and gypsum was performed at pH 6.0, by 1.5 mg l−1 Co and 0.6 mmol l−1 HMDTC−. To minimise the effect of the reaction between Ca/Mg, which restrains the function of the surfactant, careful selection of the most suitable foaming reagent was necessary. The accuracy of the method was established by analysing natural alkaline-earth minerals by the standard addition method as well as using the dolomite reference materials GBW 07114 and GSJ JDo-1. The ICP-AES limits of detection following flotation on different minerals were found to be 0.080 μg g−1 for Cd, 0.105 μg g−1 for Ag, 0.142 μg g−1 for Cu, 0.195 μg g−1 for Cr, 0.212 μg g−1 for Ni, 0.235 μg g−1 for Zn and 0.450 μg g−1 for Pb.  相似文献   

18.
In this paper, a method developed to determine the major, minor and trace elements, including carbon and the four halogens, in seamount phosphorite involving a modern XRF spectrometry technique is described. Ultra-fine (99% v/v < 40 μm) powder samples (4 g) were directly pressed into pellets (Φ= 30 mm). For elements having an analytical line lower in energy than the energy of Fe Kα line absorption edge, the inter-element absorption-enhancement effects were corrected using an influence coefficient method. For the other elements, the matrix effects were corrected using the ratio of element peak to Rh Kα Compton peak (for I, Rh K|3 Compton peak was used instead). The relative standard deviation was smaller than 1.0% for the major elements (except C, Na and Cl). The detection limit levels of C, F, Cl, Br and I were 30, 20, 0.8, 0.2 and 0.3 (μg g−1 respectively for 100 s count time of background. The accuracy of this method was tested by evaluating determinations on three certified reference materials. The direct analysis of major and minor elements in geological materials by pressed pellet without any chemical procedures makes XRF spectrometry a particularly environment-friendly analytical technique.  相似文献   

19.
The geochemical reference material BHVO-1 was analysed by a variety of techniques over a six year period. These techniques included inductively coupled plasma-mass spectrometry and atomic emission spectroscopy (ICP-MS and ICP-AES, respectively), laser ablation ICP-MS and spark source mass spectroscopy. Inconsistencies between the published consensus values reported by Gladney and Roelandts (1988, Geostandards Newsletter) and the results of our study are noted for Rb, Y, Zr, Pb and Th. The values reported here for Rb, Y, Zr and Pb are generally lower, while Th is higher than the consensus value. This is not an analytical artefact unique to the University of Notre Dame ICP-MS facility, as most of the BHVO-1 analyses reported over the last ten to twenty years are in agreement with our results. We propose new consensus values for each of these elements as follows: Rb = 9.3 ± 0.2 μg g-1 (compared to 11 ± 2 μg g-1), Y = 24.4 ± 1.3 μg g-1 (compared to 27.6 ± 1.7 μg g-1), Zr = 172 ± 10 μg g-1 (compared to 179 ± 21 μg g-1), Pb = 2.2 ± 0.2 μg g-1 (compared to 2.6 ± 0.9 μg g-1) and Th = 1.22 ± 0.02 μg g-1 (compared to 1.08 ± 0.15 μg g-1).  相似文献   

20.
李德春 《地质科学》1990,(3):294-301
对于含硫化物样品,用2:1逆王水分解,泡沫塑料吸附,缩短(或省去)了除硫和有机碳的灼烧时间,解决了矿石中含硫和有机碳高时,经长时间灼烧,硫、碳仍除不尽,致使金的分析结果偏低的问题。逆王水分解后的试样用泡沫塑料分离富集金,回收率在95%以上。高含量金火焰法测定,低含量金石墨炉法测定,操作极为方便快速。火焰法测定时,特征浓度为0.48ppm/l%吸收,VC为2—11%;石墨炉法测定时,绝对灵敏度为2.48×10-11g/l%吸收,VC为7.42%。  相似文献   

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