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微波消解-电感耦合等离子体质谱仪法测定三七粉中重金属元素 被引量:13
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作者 李伟 吴英婷 郝晶晶 《分析仪器》 CAS 2019年第1期36-39,共4页
目的:建立微波消解-电感耦合等离子体质谱仪法(ICP-MS)测定中药三七粉中Cr、Cu、As、Cd、Sn、Pb等金属元素含量的测定方法。方法:微波消解法前处理三七粉样品,分别以Sc,Ge,In,Lu为内标,采用优化后ICPMS同时测定上述8种金属元素含量。结... 目的:建立微波消解-电感耦合等离子体质谱仪法(ICP-MS)测定中药三七粉中Cr、Cu、As、Cd、Sn、Pb等金属元素含量的测定方法。方法:微波消解法前处理三七粉样品,分别以Sc,Ge,In,Lu为内标,采用优化后ICPMS同时测定上述8种金属元素含量。结果:实验结果表明各元素线性关系良好,相关系数在0.9991~0.9998之间。方法检出限0.0106~0.1464μg/L,相对标准偏差(RSD)为4.48~9.86%,加标回收率在91.99~109.22%之间。结论:该方法满足三七粉中金属元素测定的检测要求,操作简单,准确,灵敏度高。 展开更多
关键词 三七粉 重金属元 ICP-MS
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海南岛西部农用地表层土壤重金属富集研究 被引量:10
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作者 赵志忠 王鹏 +1 位作者 赵广儒 王军广 《生态环境学报》 CSCD 北大核心 2012年第1期136-139,共4页
对海南岛西部农业用地表层土壤进行了7种重金属元素含量测定,重金属元素的富集指数计算和相关性分析。结果表明:海南岛西部农业用地表层土壤中重金属元素富集程度大小依次为As>Pb>Zn>Cu>Ni>Cd>Cr。各采样点Cr、Cd和C... 对海南岛西部农业用地表层土壤进行了7种重金属元素含量测定,重金属元素的富集指数计算和相关性分析。结果表明:海南岛西部农业用地表层土壤中重金属元素富集程度大小依次为As>Pb>Zn>Cu>Ni>Cd>Cr。各采样点Cr、Cd和Cu元素处于贫乏状态,As和Pb元素达到严重富集,可能与当地农业活动密切相关。相关性分析表明,研究区土壤表层中重金属As与Pb元素可能存在复合富集与复合污染,应引起高度重视。 展开更多
关键词 土壤重金属元 富集 相关性 农用地 海南岛
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化学分析法对大气颗粒物重金属的检测
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作者 李栋 《中国石油和化工标准与质量》 2018年第8期38-39,共2页
在现代化科技创新领域蓬勃发展的时期,各行各业的各类需求都在不断增加,工业污染排放、交通污染排放等问题仍然是一直萦绕我们的重大问题,现如今,大气污染问题在日益突出。大气污染中,大气环境中的重金属成为了空气中的重要污染物,重金... 在现代化科技创新领域蓬勃发展的时期,各行各业的各类需求都在不断增加,工业污染排放、交通污染排放等问题仍然是一直萦绕我们的重大问题,现如今,大气污染问题在日益突出。大气污染中,大气环境中的重金属成为了空气中的重要污染物,重金属在大气中的含量对人们的生命安全健康构成了一定的威胁。根据数据报告表明,中国在全年的重金属污染物的排放量高达上万吨,其中,对空气污染造成比较重大影响的行业类型有重工业,化生行业等行业领域,这些都是造成重金属严重污染的源头行业。冶炼行业以及燃煤行业所排放的废气,对大气环境造成十分严重的影响,添增了大气中的重金属含量用度。除此之外,轮胎的摩擦,尾气的释放等也是增大了空气中的悬浮颗粒物的含量。因此,对大气中的重金属进行检测,并降低含量有着重要意义。 展开更多
关键词 化学分析法 重金属元 素含量 大气颗粒物 重金属占值
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Determination of Heavy Metals in Dendrobium candidium Wall.ex Lindl.by ICP-MS 被引量:3
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作者 郑龙 杨春亮 +1 位作者 苏子鹏 叶剑芝 《Agricultural Science & Technology》 CAS 2015年第12期2592-2595,共4页
[Objective] This research aimed to establish an inductively coupled plasma mass spectrometry (ICP-MS) method for determination of five kinds of heavy metals (Pb, Cd, Cu, As and Hg) in Dendrobium candidium Wall. ex... [Objective] This research aimed to establish an inductively coupled plasma mass spectrometry (ICP-MS) method for determination of five kinds of heavy metals (Pb, Cd, Cu, As and Hg) in Dendrobium candidium Wall. ex Lindl. [Method] The samples were digested in HNO3-H202 acids system by closed vessel microwave di- gestion. At the same time, internal standard was added to avoid the matrix effect. [Result] The five kinds of heavy meals all showed good linear relationships, and the correlation coefficients ranged from 0.998 2 to 0.999 9. The detection limits of the five kinds of heavy metals were in the range of 0.008-0.750 μg/L, while the stan- dard recovery rates were in the range of 90.4%-96.9%. The relative standard devi- ations ranged from 1.6% to 8.2%. The heavy metals in the Ginseng and Astragalus national standard samples were determined by the established ICP-MS method, and the results were in conformity with the standard values. [Conclusion] The established method has simple and convenient operation and accurate and reliable results, and it meets the requirements by determination of heavy metals in Dendrobium candididium Wall. ex Lindl. 展开更多
关键词 Dendrobium candidium Wall. ex Lindl. Heavy metals Microwave diges- tion: ICP-MS
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The Determination of Heavy Metal Elements in Sipunculs nudus by MWD-ICP-AES 被引量:1
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作者 陈文 王湘君 +5 位作者 赵阳 苏利兴 张哲 莫兰发 欧阳敏 黄梁 《Agricultural Science & Technology》 CAS 2014年第5期724-728,共5页
In order to develop a method for measuring of elements in Sipunculus nudus, the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were determined by actively coupled plasma atomic emission spectrometry (MWD) and microwa... In order to develop a method for measuring of elements in Sipunculus nudus, the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were determined by actively coupled plasma atomic emission spectrometry (MWD) and microwave digestion (ICP-AES). The results showed that correlation coefficients al kept higher than 0.999 and the recovery rates of sample added standard solutions were in 98%-114%. The results indicated that the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were 17.119, 3.781, 0.695, 7.351, 1997.982, 0.620, 0.144, 4.249 mg/kg respectively. The contents of Mn exceeded national limit by hundredfold, Cd sevenfold, Pd fourfold, Cd three-and-a-half-fold, and As onefold. Sipunculs nudus became seriously pol uted. Therefore, it is necessary to formulate robust policies to fol ow closely and pay close attention to coastal areas pol ution around Dongfang City. 展开更多
关键词 Sipunculs nudus ICP-AES MWD Heavy metal ELEMENT
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Influence of Soil Geochemistry to the Quality of Winter Jujube in Zhanhua 被引量:1
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作者 高宗军 王敏 +1 位作者 庞绪贵 刘中业 《Agricultural Science & Technology》 CAS 2010年第9期209-212,216,共5页
[Objective] The aim was to investigate the effects of soil geochemistry on the quality of winter jujube.[Method]Based on the data of ecological geochemical survey in lower Yellow River Basin,the relevance of the geoch... [Objective] The aim was to investigate the effects of soil geochemistry on the quality of winter jujube.[Method]Based on the data of ecological geochemical survey in lower Yellow River Basin,the relevance of the geochemistry environment in top soils and the quality of winter jujubes was analyzed.[Result]Cd,Ni and other heavy metals in the soil more obviously affected the nutrition of winter jujubes.[Conclusion]B,Mn,MgO,Cd,Zn,K2O and other elements in the root soil played an important role in the enrichment of Cr and Hg of winter jujube fruit.And the absorption of heavy metals in winter jujube root could be interfered by improving fertilization method,to reduce the enrichment of harmful elements in jujube fruit. 展开更多
关键词 Zhanhua winter jujube Ecological geochemical environment Heavy metal element
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Effects of Different Lead Compounds on Growth and Heavy Metal Uptake of Wetland Rice 被引量:13
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作者 CHENHUAI-MAN ZHENGCHUN-RONG 《Pedosphere》 SCIE CAS CSCD 1991年第3期253-264,共12页
Effects of different lead compounds, PbCl2, Pb(NO3)2 and Pb(OAc)2, on the rice growth and uptake of lead and some microelements by wetland rice were studied. The results showed that the seed germination, rice seedling... Effects of different lead compounds, PbCl2, Pb(NO3)2 and Pb(OAc)2, on the rice growth and uptake of lead and some microelements by wetland rice were studied. The results showed that the seed germination, rice seedling growth, chlorophyl content, grain yield and uptake of Pb, Cu, Zn, Fe and Mn by rice plant were affected by the chemical forms of Pb compounds added in soil to a certain degree. The germination rate and the amount of chlorophyl decreased remarkably with increasing Pb concentration, the root extension was restrained obviously by the presence of Pb, and the effect of PbCl2 was more evident than that of Pb(NO3)2 or Pb(OAc)2. The pot incubation test with yellow brown soil and red soil showed that there was no significant regularity in effect of Pb on grain yield, but the difference in the influence of various Pb compounds on yield was clearer. The effect on the amount of Pb in straw and brown rice was in the sequence of Pb(NO3)2> Pb(OAc)2> PbCl2. In case the content of Pb in brown rice was 0.5 mg/ kg, the relative loading capacities of yellow brown soil for Pb added as PbCl2, Pb(OAc)2 and Pb(NO3)2 were 100, 90 and 60 respectively. Pb uptake by wetland rice was closely related to the chemical species of Pb in soil, but there was no comparability among chemical forms of different Pb compounds in the same soil. The uptake of Cu, Zn, Fe and Mn by wetland rice was markedly affected by the addition of Pb, and different Pb compounds varied in their impacts on the uptake of other metals by different organs of wetland rice, e.g. the concentration of Fe in root increased significantly (r = 0.92), while opposite was true for Fe in brown rice (r =-0.92) due to the application of Pb(OAc), in soil. These results demonstrate that the effect of accompanying anions of Pb on the physiological and biochemical processes of wetland rice was rather complex. 展开更多
关键词 ANION loading capacity of soil microelement PB RICE
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SPATIAL-TEMPORAL VARIATION OF HEAVY METAL ELEMENTS CONTENT IN COVERING SOIL OF RECLAMATION AREA IN FUSHUN COAL MINE 被引量:5
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作者 YUJun-bao LIUJing-shuang 《Chinese Geographical Science》 SCIE CSCD 2002年第3期268-272,共5页
Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp le... Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp les are taken at different locations,inclu ding three kinds of covering soil,th ree different depths of soil layers a nd four different covering ages of covering soil.The s patial-temporal variation of heavy metal element content in reclamatio n soil is stud-ied.The results indicate that the co ntent of heavy metal elements is decreasing year after year;the determin ant reason why the content of heavy metal elemen ts at 60cm depth layer is higher than t hat at 30cm depth layer and surface is fertiliz-er and manure application;the metal elements mainly come from external environment;there is no metal pollut ion coming from mother material(coal mining wastes)in plough layer of covering soil. 展开更多
关键词 covering soil heavy metal elements spatial-temporal variation RECLAMATION fushun coal mine
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Nuclear ?eld shift effects on stable isotope fractionation: a review 被引量:7
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作者 Sha Yang Yun Liu 《Acta Geochimica》 EI CAS CSCD 2016年第3期227-239,共13页
An anomalous isotope effect exists in many heavy element isotope systems (e.g., Sr, Gd, Zn, U). This effect used to be called the "odd--even isotope effect" because the odd mass number isotopes behave differently ... An anomalous isotope effect exists in many heavy element isotope systems (e.g., Sr, Gd, Zn, U). This effect used to be called the "odd--even isotope effect" because the odd mass number isotopes behave differently from the even mass number isotopes. This mass-indepen- dent isotope fractionation driving force, which originates from the difference in the ground-state electronic energies caused by differences in nuclear size and shape, is cur- rently denoted as the nuclear field shift effect (NFSE). It is found that the NFSE can drive isotope fractionation of some heavy elements (e.g., Hg, T1, U) to an astonishing degree, far more than the magnitude caused by the con- ventional mass-dependent effect (MDE). For light ele- ments, the MDE is the dominant factor in isotope fractionation, while the NFSE is neglectable. Furthermore, the MDE and the NFSE both decrease as temperatures increase, though at different rates. The MDE decreases rapidly with a factor of 1/T2, while the NFSE decreases slowly with a factor of 1/T. As a result, even at high temperatures, the NFSE is still significant for many heavy element isotope systems. In this review paper, we begin with an introduction of the basic concept of the NSFE, including its history and recent progress, and follow with the potential implications of the inclusion of the NFSE into the kinetic isotope fractionation effect (KIE) and heavy isotope geochronology. 展开更多
关键词 Isotope fractionation Mass-dependent effect.Nuclear field shift effect. Mass-independent fractionation Nuclear volume effect Nuclear shape effect
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Application of NaHCO_3/ DTPA Extractant-ICP Spectrometry Technique in Soil Test for Availability of Nutrients and Heavy Metals 被引量:4
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作者 CHEN TONG-BINBeifng Agroecosystem Experimental Station, Institute of Geography, Chinese Academy of Sciences, Beifng 100101 (China) 《Pedosphere》 SCIE CAS CSCD 1993年第4期377-382,共6页
Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertiliz... Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test. 展开更多
关键词 calcareous soil elemental availability ICP spectrometry NaHCO3/ DTPA extractant soil test
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Characteristics of heavy metals in soils under different land use in a typical karst area, Southwest China 被引量:3
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作者 Yang Tang Guilin Han 《Acta Geochimica》 EI CAS CSCD 2017年第3期515-518,共4页
This study investigated the distribution of six pollutant elements(Cr, Cu, Pb, Zn, Cd, and As), and their relationship to soil organic carbon(SOC) in five soil profiles in the Puding area. Results show SOC content dec... This study investigated the distribution of six pollutant elements(Cr, Cu, Pb, Zn, Cd, and As), and their relationship to soil organic carbon(SOC) in five soil profiles in the Puding area. Results show SOC content decreased exponentially to the depth of soil profiles; the vertical distribution patterns of SOC in soil profiles were partially controlled by land use. The concentrations of these pollutant elements in most soils were lower than background values, indicating that the local soil was less likely to be contaminated by foreign inputs. Geo-accumulation index values of these elements in most soil samples were less than 1, suggesting that the soil of this area may not be polluted. The concentrations of Cr, Cu, As, and Zn in soils from all land use types were significantly negatively correlated with SOC contents. Geochemical approaches confirmed that the soil of this area was less influenced by pollutant elements. 展开更多
关键词 Heavy metals Soil organic carbon Land use KARST Southwest China
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Distribution of heavy metals and nutrients in rainwater in coastal regions between the southern Yellow Sea and East China Sea 被引量:1
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作者 刘昌岭 张国森 +1 位作者 任宏波 张经 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2005年第2期230-237,共8页
Rainwater samples were collected in series in Qianliyan Island (southern Yellow Sea) and Shengsi Archipelago (East China Sea) between May 2000 and May 2002, chemical analysis for pH values, concentrations of heavy met... Rainwater samples were collected in series in Qianliyan Island (southern Yellow Sea) and Shengsi Archipelago (East China Sea) between May 2000 and May 2002, chemical analysis for pH values, concentrations of heavy metals (Cu, Pb, Zn and Cd) and nutrients (NH4+, NO3-, PO43-, SiO32-) were performed. Results indicate that concentrations of most of the heavy metals and nutrients in rainwater show clear seasonal variation, i.e. high level in winter and low level in summer. Regionally, concentrations are higher in the southern Yellow Sea than in the East China Sea, but the annual input of heavy metals into oceans by wet deposition is similar in both stations. However, the input of nutrients by wet deposition in the East China Sea is 2–3 times higher than that in the southern Yellow Sea. In individual, Pb and PO43- are input to the sea mainly by dry deposition; whereas Cu, Zn, Cd and N compounds are input dominantly by wet deposition, the N/P ratios in the rainwater from two stations are much higher than those in seawater, showing a significant impact of atmospheric wet deposition on marine production and biogeochemical circulation of nutrients in these sea regions. 展开更多
关键词 southern Yellow Sea East China Sea RAINWATER heavy metals nutrient elements
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Species Transformation of Trace Elements and Their Distribution Prediction in Dyestuff Residue Incineration 被引量:4
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作者 谭中欣 李海滨 +2 位作者 王小亮 蒋旭光 严建华 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第2期268-275,共8页
The release of heavy metals from the combustion of hazardous wastes is an environmental issue of in-creasing concern.The species transformation characteristics of toxic heavy metals and their distribution are consid-e... The release of heavy metals from the combustion of hazardous wastes is an environmental issue of in-creasing concern.The species transformation characteristics of toxic heavy metals and their distribution are consid-ered to be a complex problem of mechanism.The behavior of hazardous dyestuff residue is investigated in a tubular furnace under the general condition of hazardous waste pyrolysis and gasfication.Data interpretation has been aided by parallel theoretical study based on a thermodynamic equilibrium model based on the principle of Gibbs free en-ergy minimization.The results show that Ni,Zn,Mn,and Cr are more enriched in dyestuff residue incineration than other heavy metals(Hg,As,and Se)subjected to volatilization.The thermodynamic model calculation is used for explaining the experiment data at 800℃ and analyzing species transformation of heavy metals.These results of species transformation are used to predict the distribution and emission characteristics of trace elements.Although most trace element predictions are validated by the measurements,cautions are in order due to the complexity of incineration systems. 展开更多
关键词 hazardous waste INCINERATION thermodynamic equilibrium model heavy metals species transformation PREDICTION
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Recent Foraminifers from Oman Coast
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作者 Abdul Razak Siddiq A1-Sayigh Moza Muhanna A1 Jahdhami Ahmed Mohamed Muftah 《Journal of Environmental Science and Engineering(A)》 2015年第3期137-142,共6页
This study presents the first documentation work on recent benthic foraminifers of Oman coasts, especially of the northern part of Sultanate at Sawadi and the southern part at Janoof Tidal Creek near Taqah-Salalah bea... This study presents the first documentation work on recent benthic foraminifers of Oman coasts, especially of the northern part of Sultanate at Sawadi and the southern part at Janoof Tidal Creek near Taqah-Salalah beach. Eleven samples were collected from both localities. Twenty-nine species of benthonic Foraminifera belonging to 20 genera are retrieved, identified and illustrated herein. The study areas show the interaction in land and sea. Lagoons with normal marine hypersaline inhabited with sea grass and Mangrove-swamps. Mainly calcareous porcellaneous and hyaline walled foraminifers are abundant. Environmentally, the Janoof Tidal Creek shows better condition than Sawadi Tidal Creek as reflected by the more diverse and high abundance of foraminiferal taxa at the former locality. Both water bodies are free of toxic-heavy elements as evidenced by the lack of any abnormal foraminiferal test. 展开更多
关键词 MANGROVE FORAMINIFERA tidal creek sawadi muscat.
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Determination of Selected Toxic Elements in Apples from Organic Farming 被引量:1
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作者 Michaela Zeiner Iva Juranovic Cindric +1 位作者 Ivona Krizman Gerhard Stingeder 《Journal of Chemistry and Chemical Engineering》 2011年第7期577-582,共6页
Due to the elevated ecological awareness nowadays the consumption of products of organic agriculture is increasing. Organic farming means excluding the use of synthetic inputs, such as synthetic fertilizers and pestic... Due to the elevated ecological awareness nowadays the consumption of products of organic agriculture is increasing. Organic farming means excluding the use of synthetic inputs, such as synthetic fertilizers and pesticides or genetically modified organisms, but there are only a few regulations regarding heavy metal concentrations in soils. Thus a not negligible uptake of metals from the soil where the apple trees are grown may occur. Furthermore inorganic copper compounds being traditional fertilizers for apple trees are not considered as synthetic fertilizers, thus they are still used in organic apple farming for soil or foliar application. Thus also apples produced by organic agriculture may contain toxic elements, such as cadmium, chromium, copper, and lead. The concentrations of these elements were determined in whole apples, as well as in the flesh and peel in order to estimate the possible risk for human health. Prior to analysis using ICP-AES samples underwent a microwave assisted digestion. The LODs obtained are below the recommended maximum levels in vegetables/fruits by WHO. In all samples no Cu, Cr, and Pb could be detected. Only Ca was found in the peel of about a third of samples investigated in concentrations between LOD and LOQ (1-3 μg/g). 展开更多
关键词 Apples CADMIUM CHROMIUM copper LEAD organic farming.
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Statistical Approach to Identify Environmental Factors in Controlling Heavy Metal Concentrations in Sediment
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作者 Hassan Alshemmari Eqbal Al-Enezi +1 位作者 Lulwa Ali Ali. AI-Dousari 《Journal of Environmental Science and Engineering(A)》 2012年第8期1025-1035,共11页
Surface sediment samples were collected from 35 locations in Sulaibikhat Bay, Kuwait. Co, Cr, Cu, Ni, Pb and Zn concentrations were determined. Grain sizes, TOC (total organic carbon), carbonate, mineralogical and e... Surface sediment samples were collected from 35 locations in Sulaibikhat Bay, Kuwait. Co, Cr, Cu, Ni, Pb and Zn concentrations were determined. Grain sizes, TOC (total organic carbon), carbonate, mineralogical and environmental data were also determined. Multiple linear regression is applied to the data from the sediment sequential extractions to assess the relative importance of mineralogical and sedimentological factors in controlling heavy metal concentrations in individual chemical fractions (exchangeable, reducible, oxidizable, residual) under different environmental conditions. The analysis shows that grain size, TOC, calcium carbonate and minerals clearly influence heavy metal concentrations. For the exchangeable fraction, clay, grain size and the mineral pyrite are the main factors, whereas for the reducible fraction, TOC is the main factor influencing concentrations ofZn, Pb, Ni, Cu and Cr. For the oxidizable fraction, modelling shows that TOC is the main factor influencing Zn, Ni, Cu, Cr and Co concentrations. The residual fraction concentrations of Zn, Ni, Cr and Co were best predicted by the abundance of sand, with sand content having a negative effect on heavy metal concentrations in this fraction. The statistical techniques in environmental data interpretation are quite useful in cutting down the volume of the data and identifying identical classes which are statistically distinct. 展开更多
关键词 Metals SEDIMENTS MINERALOGICAL CLAY sequential extraction sedimentological.
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Determination of the major metal elements including heavy metals in Saffron from Tibet and Henan by ICP-AES or ICP-MS
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作者 贾凌晗 刘一 李玉珍 《Journal of Chinese Pharmaceutical Sciences》 CAS 2011年第3期297-301,共5页
A quick and sensitive method was developed for the determination of 19 metal elements in Saffron,a traditional Chinese medicinal herb,collected from Tibet Autonomous Region and Henan Province of China using inductivel... A quick and sensitive method was developed for the determination of 19 metal elements in Saffron,a traditional Chinese medicinal herb,collected from Tibet Autonomous Region and Henan Province of China using inductively coupled plasma atomic emission spectrometry(ICP-AES)or inductively coupled plasma mass spectrometry(ICP-MS).The determined 19 metals in Saffron include Ca,Fe,Mg,P,Sr,Al,Mn,Zn,V,Cr,Se,Co,Ni,Mo,and heavy metals As,Cu,Cd,Hg and Pb.For all the analyzed elements,the correlative coefficients of the calibration curves were no less than 0.9938.This proposed method was accurate,and the relative standard deviations of the measurements were lower than 5.25%.It can be used for the quality control of metal elements in Saffron. 展开更多
关键词 ICP-AES/ICP-MS Element analysis Heavy metals SAFFRON
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Risk Assessment of Heavy Metal Pollution in Sediments of the Fenghe River by the Fuzzy Synthetic Evaluation Model and Multivariate Statistical Methods 被引量:13
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作者 YANG Yang ZHOU Zhengchao +2 位作者 BAI Yanying CAI Yimin CHEN Weiping 《Pedosphere》 SCIE CAS CSCD 2016年第3期326-334,共9页
Concentrations of heavy metals in 74 sediment samples from the Fenghe River, which originates from the north of the Qinling Mountains and flows through Xi'an, Shaanxi Province, China, were characterized by employi... Concentrations of heavy metals in 74 sediment samples from the Fenghe River, which originates from the north of the Qinling Mountains and flows through Xi'an, Shaanxi Province, China, were characterized by employing geographic information system(GIS)mapping, fuzzy synthetic assessment, and multivariate statistical analysis to determine the enrichment characteristics of heavy metals as well as their potential risks of pollution to sediments. Al, Cd, and Co were the major pollutants, with a high enrichment factor(EF) value. Heavy metal concentrations from samples near the paper plant were maintained at a high level. Significant enrichment of Al, Ba, Cr, Ni, Pb, and Co was found in the midstream and downstream, while high concentration of Cu occurred in the headwater stream. Based on the cluster and principal component analyses, sediment metals mainly came from the paper plants, agronomic practices, natural sources, and tourism, with a contribution of 51.59%, 23.01%, 14.21%, and 9.88%, respectively. Sediment pollution assessment explored using fuzzy theory based on the entropy method and toxicity coefficient showed that 26, 32, and 11 sites fell into Class III(slightly polluted), Class IV(moderately polluted), and Class V(heavily polluted), respectively, and their scores of membership degree in the polluted level were on the rise, suggesting a relatively high degree of sediment metal pollution in the study area. Closely related to the excessive industrial and agricultural applications, metal pollution in sediment is necessary to be addressed in the Fenghe River. 展开更多
关键词 fuzzy theory risk analysis river ecosystem sediment pollution spatial analysis
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Investigating the abundance enrichment pattern of heavy elements in the only observed CEMP-r/s star J004441.04-732136.4 of the SMC
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作者 CUI WenYuan ZHANG Bo ZHAO Gang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第6期1201-1205,共5页
The post-AGB star J004441 is the first and the only one CEMP-r/s star found in SMC. Herein, we investigate the observed abun- dance pattern of the heavy elements using our parametric model. A consistent fitting result... The post-AGB star J004441 is the first and the only one CEMP-r/s star found in SMC. Herein, we investigate the observed abun- dance pattern of the heavy elements using our parametric model. A consistent fitting results was obtained for the sample star. Based on the low r = 0.08, the s-process nucleosynthesis occurred in the interior is supposed to belong to the single neutron-exposure v9 ,1/2 mbarn-1 supports a higher efficiency of the s-process nucleosynthesis relative to event. The median value of τ0 =0.44(T9/0.348)mbarn-1 supports a higher efficiency of the s-process nucleosynthesis relative to J004441 than that of the solar system, however, the value is not sufficiently high to favor the formation of a lead star. Thus, J004441 does not belong to lead star group. The large Cs value of J004441 supports the intrinsic characteristic of the s-enrichment. The Cr value is similar with that found in halo CEMP-r/s stars, which indicates that the r-process contributions is critical during heavy element enrichment. This star has a metallicity of [Fe/H] = -1.34, which is larger than that of Galaxy halo CEMP-r/s stars. The reason may be because of the different history of metallicity enrichment between the SMC and the Galaxy halo. 展开更多
关键词 stellar nucleosynthesis ABUNDANCES chemically peculiar stars
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