首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
SR-XRF studies are performed on samples of altered and unaltered fresh host rocks and bottom sediments from mud pots collected at the Mutnovsky volcano. Four groups of elements are identified according to their mobility: inert (Ga, Ge, and Sr); partially mobilized into the altered rocks (Cs, Rb, Mo, Nb, Cd, and Pb); partially leached during alteration of the host rocks (Cu, Zn, Sn, Ag, and Ni); and transitional (I, Br, As, Sb, Se, and Te). It is shown that the movement of thermal fluids through the host rock alters both. The concentrations of Rb, Cu, Zn, and V in the solution could partly be due to leaching from the host rocks.  相似文献   

2.
采用ICP-MS法对国内市场常用的13种采血管中铝、钒、铬、锰、铁、钴、镍、铜、锌、砷、硒、钼、镉、锡、锑、钡、钨、汞、铊和铅元素进行测定。通过对采血管的纯水浸出液和10%硝酸浸出液进行20种微量元素含量分析,得到了13种采血管中20种微量元素的含量。根据近年发表的文献中有关人体血清、血浆和全血微量元素含量参考范围,详细分析了各种采血管适用的微量元素检测种类。分析结果表明:最适用于血清分析的为采血管1,该采血管适用于18种血清微量元素的分析;最适用于血浆分析的为采血管6,该采血管适用于15种血浆微量元素的分析;最适用于全血分析的为采血管13,该采血管适用于17种全血微量元素的分析。但是,值得注意的是,采血管1中的锑和钨元素,采血管6中的钒、铬、镍和锑元素,以及采血管13中的铝,锑和钨元素,其纯水浸出液中这几种微量元素的含量与正常人血液(血清、血浆、全血)中微量元素含量处于同一数量级,可能会对血液微量元素的测量结果造成影响。该研究也对比了采血管1和采血管3对实际血清样本检测结果的影响,结果表明,采血管1的检测结果中几乎所有微量元素含量都低于采血管3的检测结果,尤其是铝,钒,铬,锰,砷,锡,锑等几种元素,说明在实际采血过程中,采血管的选择对微量元素检测结果影响很大。  相似文献   

3.
以云浮黄铁矿矿石作原料的某硫酸厂堆渣场土壤剖面为研究对象, 应用ICP-MS同时测定了污染元素和部分参考元素的含量,快速找出各元素的相关性,用富集因子评价了土壤的污染状态,并指出了污染元素的背景选择问题。结果表明:V已呈显著及高度污染,Co呈中度污染,并有显著污染的倾向,Cr, Mo和Cd在轻度和中度污染之间,Zn和Sb呈轻度污染,并有中度污染的潜在危险,Cu呈轻度污染。富集的高位点V和Cr在土壤剖面的上部(4.0~10. 5 cm)和深部(44.0~75. 5 cm),Co和Mo集中在土壤剖面表面(0~5.0 cm)、中上部(9.5~10.5 cm)和中部(29.5~46.0 cm),Cd和Cu集中在土壤剖面中部(29.5~46.0 cm)。高富集点的污染来自于以花岗岩为母质的亚热带强风化红壤的残余金属离子的淋溶淀积和堆渣场废渣中释放的金属元素在土壤中的迁移累积相互叠加的结果。其中V污染主要为土壤母质贡献,其次是硫酸生产过程失活催化剂挥发引入废渣的V淋溶淀积。  相似文献   

4.
An activation measuring complex containing a W–Be photoneutron source of neutrons and a lowbackground gamma spectrometer is designed at the Russian Academy of Sciences Institute for Nuclear Research. The photoneutron source is mounted on the beam of a LUE-8 industrial electron linear accelerator with an electron energy of 7–8 MeV and contains a tungsten bremsstrahlung target, a photoneutron beryllium target, and a fast neutron moderator. The measuring component of the complex includes a detector made from high purity germanium, positioned inside a low-background chamber with active-passive protection. Neutron-activation analysis (NAA) is used to determine the content of microimpurities in a substance. A procedure for measuring ultralow contents of elements in aerosol filters is developed. Contents of Au, As, Sb, Mn, Fe, W, and other elements are measured in a variety of samples. The limits of detecting microimpurities in materials are estimated.  相似文献   

5.
ICP-OES/ICP-MS测定葵花子中28种无机元素   总被引:2,自引:0,他引:2  
建立了葵花子中微量元素组成的分析方法。采用HNO3+H2O2混合酸为消解体系经微波消解葵花子样品,电感耦合等离子体发射光谱(ICP-OES)法测定葵花子中Al,B,Ca,Fe,K,Mg,Na,Si,P和S,电感耦合等离子体质谱(ICP-MS)法测定葵花子As,Ba,Cd,Co,Cr,Cu,Li,Mn,Mo,Ni,Pb,Rb,Sr,Sn,Sb,Ti,V和Zn。采用国家一级标准物质大米(GBW10045)验证了方法的准确性,结果表明,标准物质的测定结果与参考值基本一致,葵花子中Ca,K,Mg,P,S的含量较高。该方法具有良好的准确性和精密度。  相似文献   

6.
Strontium isotope ratios and Ca2+, Na+, K+, Mg2+, Cl-, SO4(2-), NO3- and Sr2+ concentrations were measured in rainwater samples collected in four stations in France (Brest, Dax, Orleans and Clermont-Ferrand) over a period of 1 year. Each sample represented a monthly series of rain events. The chemical composition and the 87Sr/86Sr ratios of the rainwater samples varied considerably. Using Na concentrations as an indicator of marine origin, the proportion of marine and crustal elements was estimated from elemental ratios. Strontium isotopes were used to characterize the different sources using data from the four stations and the literature. Such sources include sea salts, crustal sources (carbonates, silicates and volcanic rocks) and anthropogenic sources (fertilizers, automobile exhausts, incinerators and urban heating).  相似文献   

7.
SR scanning XRF is used to analyze the annual elemental layers of bottom sediments from Lake Teletskoye. Scanning is conducted with a pitch of 0.1 mm at energies of 16, 24, and 38 keV. The content of more than 15 elements are determined: K, Ca, Ti, Mn, Fe, V, Cr, Ni, Cu, Zn, As, Rb, Sr, Y, Zr, Cd, Sn, I, and Ba (range of concentrations, 0.005–10%). A cross section containing (1) the upper part of an underlying layer, (2) the total annual layer, (3) one more complete layer, and (4) the lower part of an overlapping layer is measured. Geochemical indicators reflecting the rhythm of annual precipitation are found.  相似文献   

8.
龚姣丽  刘劲松  褚政  杨振刚  王可嘉  姚建铨 《中国物理 B》2016,25(10):100203-100203
The nonlinear radiation responses of two different n-doped bulk semiconductors: indium antimonide(In Sb) and indium arsenide(In As) in an intense terahertz(THz) field are studied by using the method of ensemble Monte Carlo(EMC)at room temperature. The results show that the radiations of two materials generate about 2-THz periodic regular spectrum distributions under a high field of 100 k V/cm at 1-THz center frequency. The center frequencies are enhanced to about 7 THz in In Sb, and only 5 THz in In As, respectively. The electron valley occupancy and the percentage of new electrons excited by impact ionization are also calculated. We find that the band nonparabolicity and impact ionization promote the generation of nonlinear high frequency radiation, while intervalley scattering has the opposite effect. Moreover, the impact ionization dominates in In Sb, while impact ionization and intervalley scattering work together in In As. These characteristics have potential applications in up-convension of THz wave and THz nonlinear frequency multiplication field.  相似文献   

9.
采用电感耦合等离子体质谱(ICP-MS)技术结合化学计量学分析技术对采自云南南部的四种特色蜂蜜中的23种矿物元素进行了分析。结果表明:ICP-MS技术测定蜂蜜中多种矿物元素含量的稳定性、精确度较好,回收率较高;23种矿物元素中有21种元素(Na,Mg,K,Ca,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,As,Se,Sr,Mo,Cd,Sb,Ba,Tl,Pb)在不同蜂蜜品种间存在显著差异;主成分分析结果显示,前4个主成分的累积方差贡献率达到77.74%,第一主成分中的Mg,Ca,Mn,Co,Sr,Cd,Ba 七种元素包含大部分蜂蜜信息;通过逐步判别分析,Mg, K, Ca, Cr, Mn, Sr, Pb共七种元素被筛选出来并用于建立判别函数模型,对所建模型进行回代检验和交叉检验,正确判别率分别为90%和86.7%,表明多元素指标对云南南部四种特色蜂蜜植物源的判别效果较好。鉴于所采蜂蜜样品都来自云南南部,气候和土壤等环境条件类似,四种蜂蜜中矿质元素的差异主要与对应的蜜源植物有关,因此,利用矿质元素差异鉴别蜂蜜植物源具有可行性。  相似文献   

10.
Aerosol samples were collected at an urban background site in Skopje, Former Yugoslavic Republic of Macedonia, during four measurement campaigns from December 2006 to October 2007. An impactor was used to collect particulate matter (PM2.5) aerosol particles and the samples were analyzed for the concentrations of particulate mass, black carbon (BC), and 17 elements. The 12‐h average PM2.5 concentrations varied in the range 10–140 µg m?3 with the highest concentrations measured during wintertime pollution episodes and during the summer period. Pair‐wise correlations and crustal enrichment were studied and the data set was analyzed by factor analysis and positive matrix factorization. Major aerosol components were identified as mineral dust (main observed tracers Si, K, Ca, Ti, Fe, Sr, and Rb), combustion (BC, S, K, V, and Ni), traffic‐related aerosol (Pb and Zn), and secondary sulfate combined with mineral dust. Combustion sources dominated during wintertime and were likely due to heavy oil combustion, biomass burning, and other industrial activities within the city area. Mineral dust was observed throughout the year, but the concentrations peaked during the unusually hot and dry summer of 2007. It is concluded that Skopje suffers from serious air pollution due to central and residential heating, the transport sector, and industrial activities within the city, and contributions from mineral dust increase the PM2.5 concentrations under dry periods. Topography and meteorological conditions aggravate the problems and make the air quality comparable with the conditions in other highly polluted cities in Southern Europe and worldwide. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

11.
Interest in studying leaching of toxic (in)organic contaminants such as antimony (Sb) and phthalate esters into drinking water increased because of the ever growing market of water bottled in polyethylene terephthalate (PET) packaging material. Possible contamination sources of drinking water contained in PET bottles are hereby reviewed. Instrumental analytical methods suitable for Sb and phthalate ester determination in drinking water and PET material are also presented. Outcomes on leaching of Sb and phthalate esters into drinking water are grouped according to storage time, exposure to heat/light, sample pH, and PET bottle volume. Methods for estimation of toxicological activity of water in PET bottles are also compiled. Normally, Sb and phthalate ester concentrations in drinking water do not exceed the health limit values in force. Although excellent detection limits can be achieved for phthalate ester determination, due to their ubiquity, results are primarily affected by laboratory cross-contamination. Recent investigations suggest that drinking water stored in PET bottles does not possess either genotoxic or estrogenic activity.  相似文献   

12.
密封消解ICP-AES和ICP-MS测定中日两国茶叶中23种矿质元素   总被引:18,自引:4,他引:14  
收集了13种中国茶叶和6种日本茶叶,在进行密封消解后,采用电感耦合等离子体发射光谱法(ICP-AES)和电感耦合等离子体质谱法(ICP-MS)测定了茶叶中Al,Ba,Ca,Cd,Ce,Co,Cr,Cs,Cu,Fe,La,Mg,Mn,Na,Ni,Pb,Rb,Sb,Sr,Th,U,Y和Zn等23种矿质元素的含量,并用茶叶标准参考物质(GBW07605)评价了分析方法的准确度。研究结果表明:密封消解有助于获得较为准确的茶叶中矿质元素含量的分析结果;与日本茶叶相比,中国茶叶中Cd,Co,Cr,Cs,Fe,Pb,Rb,Sb,Th,U和Zn等元素含量显著偏高(P<0.05),预示大气重金属污染程度中国较日本严重。另外,还发现茶叶中一些矿质元素含量之间有很强的线性相关性。  相似文献   

13.
采集了石河子城区32个站点的道路尘土样本,测定了样品中10种非常规监测微量元素(B,Be,Bi,Co,Ga,Li,Sb,Sn,Tl,V)的含量。并采用地积累指数法、元素相关性分析和主成分分析法对尘土中的微量元素污染程度和来源进行了分析。结果表明:道路尘土中微量B,Be,Bi,Co,Ga,Li,Sb,Sn,Tl和V的平均含量分别为41.11,1.68,0.52,13.58,36.26,24.91,3.37,3.64,0.42,72.66 mg·kg-1。其中,Co,Li和Tl的平均含量均低于新疆土壤元素背景值,B,Be和V的平均含量和新疆土壤元素背景值相似,Bi,Ga,Sb和Sn的平均含量高于新疆和世界土壤元素背景值。地积累指数计算结果表明:B,Be,Co,Ga,Li,Tl和V污染级数为0,说明无污染,而Sb,Bi和Sn污染较为严重(污染等级分别为2,1,1)。元素相关性分析和主成分分析多元统计方法计算结果表明,Bi,Co,Sb和Tl主要是人为来源,B,Be,Li和V主要是自然来源,而Ga和Sn可能受自然因素和人为因素的共同影响。  相似文献   

14.
ICP-AES法测定广西中药白花丹不同部位常量及微量元素   总被引:2,自引:0,他引:2  
采用电感耦合等离子体发射光谱法(ICP-AES) 分析广西中药白花丹根、茎、叶3个部位的20种常量及微量元素。结果显示,白花丹中除了含人体必需的常量元素K,Ca,Na,Mg外, 还有Zn,Fe,Mn, Cr,Co等必需的微量元素和其他元素Mo, Sb,Bi,Cd, Sr,Pb,Cd,As等。各元素的含量在白花丹的根,茎,叶中分布不同, 在叶和根中的含量比较丰富,与白花丹的抗菌, 抗肿瘤及抗氧化活性的药用有效部位在根部和叶部的结果一致,如Na,K,Ca,Zn,Fe,Mn,Sr,Cu,Co等含量在叶中含量最高,根次之。在许多抗癌中药中,Zn,Mn,Fe的含量通常比较高,Cr,Sr,Cu的含量也至关重要,作为传统抗癌中药的白花丹中就含有丰富的Zn,Mn,Fe和一定量的Sr,Cr,Cu元素,测定结果为探讨中草药中常量、微量元素与生物活性之间的相互协同关系提供了有用的数据,也为更好地开发和利用白花丹药用资源提供理论依据。  相似文献   

15.
Trace elements were determined in hippuran and the corresponding radiopharmaceutical preparation, labelled with 131I by using nondestructive radioactivation analysis.

The presence of Cr, Hg, Au, Sb, Sc, Fe, Co, Na, Zn and Br in the above compounds has been proved and their concentrations determined  相似文献   

16.
Heavy metal analysis around Iskenderun Bay in Turkey   总被引:1,自引:0,他引:1  
The heavy metal analysis around Iskenderun Bay in Turkey was carried out using mosses, soils, mussels, and sediments. This region is one of the most industrial areas of Turkey, including iron–steel plants, beverage, liquefied petroleum gas (LPG) plants, and oil transfer docks. Energy dispersive X‐ray fluorescence spectrometry (Epsilon 5, PANalytical, Almelo, The Netherlands) was used to analyze all samples. V, Cr, Mn, Fe, Ni, Cu, Zn, As, and Pb elements were observed in all samples studied. Although Ce was detected in some mosses and soils, Sn was detected only in some moss samples. Pb concentrations in the moss samples are higher than the soil, the mussel, and the sediment samples. This can be attributed to the mosses that absorb heavy metals such as Pb easily from the air. As the aim of this study was to analyze heavy metals, the evaluation of these elements with their potential hazards for ecology and humans is briefly discussed. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

17.
The possible Beta-Delayed neutron precursors in the elements Tl,Hg,and Au were predicted following a systematic research for the known Beta-Delayed neutron precursors.The masses of the unknown nuclei and neutron emission probabilities were calculated.  相似文献   

18.
《X射线光谱测定》2003,32(6):452-457
Convenient x‐ray fluorescent spectrometry was developed for the determination of V, Cr, Co, Ni, Ge and Sb in plastic materials. The calibrating standards were prepared by casting of polyurethane or polyester including a xylene solution of organometallic compounds as a standard. The calibrating disk had a homogeneous elemental distribution and excellent durability. The calibration curves of six elements showed a good linearity of less than 50 mass ppm for V and Ni, 100 mass ppm for Co and Ge, 200 mass ppm for Cr, and 400 mass ppm for Sb. The lower limits of detection (3σ) of the present method were 0.19 mass ppm for V, 0.42 for Cr, 0.24 for Co, 0.18 for Ni, 0.066 for Ge, and 2.1 for Sb. The proposed method has been applied to several different industrial plastics. The quantitative results are in good agreement with those obtained by the AAS method and x‐ray fluorescent spectrometry using the fundamental parameter calculation method. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

19.
Due to the remarkable increasing of the mass concentrations of suspended particulate matter (SPM) as an air pollution indicator in Greater Cairo‐Egypt, regular sampling during autumn 2014 and winter 2014/2015 seasons has been performed from industrial and residential areas. It was found that the average mass concentrations of the SPM collected from residential and industrial areas are equal to 531 ± 198 and 912 ± 230 μg/m3, respectively. These quantities are much higher than the maximum allowance level, especially for the industrial area. By utilizing three secondary targets, energy dispersive x‐ray fluorescence working under vacuum environment was used for elemental analysis of 19 elements namely; Na, Al, Si, S, Cl, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, Pb, Se, Br, Rb, and Sr. The present optimized selective excitation energy dispersive x‐ray fluorescence analysis has considerably enhanced the analytical range with respect to our previous similar studies, including low Z elements such as Na, Al, S, and Cl and attaining lower detection limits in the range of ng/m3. Remarkable high elemental concentrations were determined for most of the detected elements from the industrial area samples, strongly indicating the influence of the industrial and anthropogenic activities. The average percentages of the mass concentration of the detected inorganic elements account only for 3.2% and 10.5% of the total mass concentration collected from the residential and industrial areas, respectively, thus directly indicating that the content of organic pollutants in SPM is the dominant contribution.  相似文献   

20.
开展了一种用电感耦合等离子体质谱仪(ICP-MS)结合主成分分析(principle component analysis)和判别分析(discrimination analysis)识别蜂蜜品种的研究。实验选取三种不同品种的蜂蜜:洋槐蜜,葵花蜜和油菜蜜,经湿法消解等预处理后,利用ICP-MS分别测得蜂蜜样品中20种矿质元素的含量。结果表明电感耦合等离子体质谱法的精密度,准确度以及回收率等满足要求,洋槐蜜在主成分得分图上呈现一定的聚集趋势, 而葵花蜜和油菜蜜的聚集趋势不明显,Na,Mg,K,Ca,Sr,Ba,V,Fe,Ni,Sb等十种矿质元素能够成为鉴别蜂蜜品种的特征元素;通过逐步判别分析筛选出Mg,Sr,Ba,Ni,Sb,Cr和Na等七种矿质元素,并利用贝叶斯判别对这些元素建立线性判别函数,其中洋槐蜜的判别率为100%,葵花蜜的判别率为80.8%,有两个葵花蜜样品误判为油菜蜜,油菜蜜的判别率为 90.9%,有一个油菜蜜样品误判为洋槐蜜,模型交叉验证总判别率为90.3%,说明矿质元素对蜂蜜品种鉴别具有良好的分类和鉴别效果,能够为研究蜂蜜品种与矿质元素之间的关系提供理论依据,该方法具有简单、准确、稳定等特点, 可作为蜂蜜品种鉴别的可靠方法。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号