30 resultados para Paläoklima, LA-ICP-MS, Ostrakoden, Stalagmit
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
Metabolic profiles caused by rare earth complex were investigated using NMR and ICP-MS techniques. Male and female Wistar rats were treated orally with Changle (A kind of rare earth complex applied in agriculture to raise the production of crops) at dose of 2, 5 and 20 mg (.) kg(-1) body weight/day respectively for 90 d. Urine and serum samples are collected on 90 d. The relative concentrations of important endogenous metabolites in urine and serum are determined from H-1 NMR spectra and the contents of the four rare earth elements ( La, Ce, Pr and Nd) constituting Changle in the serum samples are measured by ICP-MS technique. Changle-induced renal and liver damage in rats is found based on the increase in the amounts of the amino acids, trimethylamine N-oxide, N, N-dimethyglycine, dimethylamine, succinate, aketoglutarate and ethanol as well as rare earth concentrations. The similarities and differentiations are found in the alteration patterns of metabolites and rare earth concentrations in serum.
Resumo:
本论文分为两部分:1. 综述部分(第一章和第二章),评述了悬浮进样方式在电感耦合等离子体发射光谱法(ICP-OES)中的研究与应用;电感耦合等离子体质谱(ICP-MS)中碰撞/反应池技术研究的新进展。2. 实验部分(第三章至第九章),内容包括针对不同性质的样品悬浮液选择适当的稳定剂和悬浮雾化ICP-OES的校准方法研究;以混合碰撞/反应气体解决难度较大的高纯氧化钕中稀土杂质测定的干扰问题;以及浊点萃取-石墨炉原子吸收法测定环境样品中痕量镉、氢化物发生-原子荧光光谱法测定铅基合金中砷和植物样品中锗等实用性强的分析方法研究。 ICP的传统进样方式是将样品转化成水溶液形式,以溶液方式进样。然而大多数样品是以固态形式存在,许多样品相当难溶或难熔。采用直接固体进样方法对这些样品进行分析,是分析工作者追求的目标之一。悬浮液进样是一种固体直接进样方法,除了具有其它固体进样技术的优点外,其最大优点是可以像溶液雾化一样用标准水溶液校准。本研究针对实际分析工作中遇到的具体样品,对悬浮进样ICP-OES技术进行了比较深入的研究,成功解决了样品处理繁琐和样品难以处理等困难。对特殊地质样品和激光晶体材料(Nd:YAG)的悬浮进样分析进行了探索。主要工作为:①建立分析地质样品中主量和微量元素的方法,标准水溶液可以成功地用于校准。优点是可以同时对地质样品中的Si和其它元素进行分析,避免了传统分析时需分别处理样品的麻烦。②探索了分析铌钽矿中铌和钽的应用。由于铌和钽具有强抗化学腐蚀性,所以溶液进样分析时样品处理过程复杂。结果表明,以标准水溶液校准时,只要样品研磨时间延长至5 h,即可获得悬浮进样的满意的回收率。③研究了分析掺钕钇铝石榴石(Nd:YAG)中钕掺杂量的可行性。研究表明,加入适量聚丙烯酸作分散剂并调节pH为6,可以得到稳定悬浮液;以通用标准加入法(GSAM)校准可以得到满意的结果。 我国的稀土资源占世界的80%以上,高纯稀土氧化物是高科技领域中的重要材料。碰撞/反应池技术是目前四极杆ICP-MS消除干扰的先进技术,可以选择性地减少某些基体干扰,使背景和检测限得到显著的改进。本实验选择氧化钕(有7个同位素)作为研究对象,采用碰撞/反应池技术重点解决四极杆ICP-MS方法对高纯Nd2O3中稀土杂质进行测定时,基体Nd对Tb、Dy和Ho严重的氧化物或氢氧化物干扰难题。研究结果如下:①在四极杆高分辨率模式下,可以消除Nd对Pr的相邻峰的拖尾干扰;②采用碰撞/反应池技术,设计了10% O2-10% Ar-80% He混合气体作为碰撞/反应气,将Tb、Dy和Ho分别转化为相应的氧化物离子进行测定,成功地消除了基体Nd对Ho的干扰;Nd对Tb和Dy造成干扰的表观浓度显著降低。本方法可直接测定纯度为6N的高纯Nd2O3中的Ho;对纯度为6N的高纯Nd2O3中的Tb和Dy进行扣除,可以分析纯度达5N的高纯Nd2O3中的Tb和Dy。与文献报道的其它消除基体Nd干扰的方法相比较,此方法能够对纯度更高的Nd2O3进行直接分析,且操作简便。此方法也可进一步拓宽,有望解决其它轻稀土氧化物对中重稀土检测的质谱干扰问题。 论文的7~9章的工作包括:浊点萃取-GFAAS测定环境样品中痕量镉、HG-AFS分析铅基合金中砷和植物样品中锗的研究。针对实际分析工作中的具体困难,以上工作分别解决了分析元素含量低、测定干扰严重及样品处理的问题,建立了实用性强、准确度高的分析方法,具有实际应用价值。
Resumo:
A method was developed for the determination of trace and ultratrace amounts of REE. Cd. In. Tl. Th. Nb, Ta. Zr and Hf in soils and sediments. With NaOH-Na2O2 as the flux. Ti(OH)(4)-Fe(OH)(3) co-precipitation as the preconcentration technique and inductively coupled plasma mass spectrometry (ICP-MS) for measurement, the whole procedure was concise and suitable for batch analysis of multi-element solutions. An investigation was carried out of the Ti(OH)(4)-Fe(OH)(3) co-precipitation system, and the results obtained showed that the natural situation of Ti tightly coexisting with Nb. Ta, Zr and Hf in geological samples plays a very important role in the complete co-precipitation of the four elements. The accuracy of this procedure was established using six Chinese soil and sediment certified reference materials (GSS and GSD). and the relative errors between the found and certified values were mostly below 10%.
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A method was developed for the determination of lanthanum in the cytoplasm of human erythrocytes after they were incubated in lanthanum nitrate or citrate solutions. The lanthanum concentration in the cytoplasm of incubated erythrocytes is much higher than that in normal erythrocytes. It is suggested lanthanum can transport through the membrane of erythrocyte in vitro. Solutions containing chelator are unsuitable to be washing buffer in the investigation.
Resumo:
An off-line chelation system combined with ICP-MS technique was developed for the quantitative determination of trace elements in seawater, namely V, Co, Ni, Cu, Zn, Mo, Cd, Pb, U and rare earth elements(REEs). The system was built based on an ion chromatography equipped with MetPac((R)) CC-I chelation columns which had a strong selective chelation to these target elements within a pH range 5.2-5.6. Acidified seawater samples and NH4Ac(2 mol/L) were blended to meet suitable pH before being injected into the chelation column, thus target elements were retained while alkali and alkaline metals were excluded. Then chelated elements were eluted by HNO3 (1 mol/L) and samples were collected for ICP-MS analysis. Varying the ratio of input( gen. 200 mL) to output( gen. 5 mL), the target elements which were concentrated as 40 times as their concentrations were far beyond instrumental quantification limits. At last, a certificated seawater CASS-4 was introduced and our detected values were in good agreement with those certified values.
Resumo:
Based on previous studies, boron can be separated from aqueous samples with Amberlite IRA-743 resin. Experiments on the elute temperature, elute volume and the dynamic resin exchange capacity have been performed in this study. Results show that the dynamic exchange capacity of the resin is 4.2mg B/g and at room temperature, boron fixed on the resin within this capacity level can be extracted quantitatively by using 5ml 2%HNO3. A new procedure has been developed for the measurement of boron isotope ratios in water samples using a Neptune MC-ICP-MS, after resolving the memory effect, which is a key problem, and investigating the impacts of mass bias and Si matrix effect. Using this method, it usually takes 20 min to perform one measurement on 0.1ppm boron solution with a precision of 0.23‰ (SD). If the relative deviation between a sample and the standard is large, the washout time needs to be doubled to achieve a higher precision. δ11B values of water samples from Yangbajing geothermal field vary from -10.53 to -9.13‰. Owing to the large difference B concentration and the small B isotope difference between deep geothermal water and surface water, B isotope ratios of the shallow geothermal fluids are dominated by the deep end member rather than the shallower one in the mixing process. As a consequence, δ11B-B relation is indicative basically of a dilution process. Vapor-liquid separation and calcite scaling also greatly influence B isotope fractionation. δ11B values of water samples from Dagejia geothermal field are from -15.98‰ to -11.67‰. Boron in Changma River near the field has two sources, freshwater lakes (Dajiamang Lake and Canke Lake) and geothermal waters. Finally, a preliminary discussion is included on boron geochemical characteristics of the salt lakes in Shuanghu area and other geothermal fields, to provide information for future studies on boron isotope geochemistry of geothermal systems and salt lakes in Tibet.
Resumo:
Over past ten years, a great development has been made in the Lu-Hf isotopic system with the advent of MC-ICP-MS. Based on a comprehensive review of available references in the related field, a novel analytical protocol of three exchange chromatographies after one mixed acid attacking geological samples was developed in this work, which not only avoids common multiple sample treatments for natural inhomegeneous samples, but also is useful for Rb-Sr, Sm-Nd and Lu-Hf isotopic system simultaneously, especially for the garnet- and apatite-bearing rocks for the Sm-Nd and Lu-Hf geochronology. An analytical procedure for the Lu and Hf concentration in geological samples determined by by ID-MC-ICP-MS was detailedly investigated. The Hf yield is > 90 % and total procedural blank is less than. 50 pg for Hf and 10 pg for Lu, respectively. The developed method was successfully applied to the determination of Lu and Hf concentrations for USGS geological materials. A one-column procedure for Hf purification in geological samples using common anion exchange chromatography and its isotopic analyses by MC-ICP-MS were also established. Multiple analyses of Standard Reference Materials demonstrate that this method was simple, time-saving, cheap and efficient, especially suitable for the Hf isotopic compositions of young samples. Finally, the measurements of Sr and Nd isotopic compositions using Neptune MC-ICP-MS were described briefly, which indicates that Neptune MC-ICP-MS can precisely measure Sr and Nd isotopic compositions as the TIMS does, even more efficient and less time-consuming than the TIMS method. The Hf isotopic characteristics of typical volcanic rocks (Cenozoic Changle-Linqu basalts, Mesozoic Fangcheng basalts, Mesozoic Jianguo basalts, Mesozoic Wulahada high-Mg andesite, Cenozoic Fanshi, Zuoquan and Xiyang-Pingding basalts of the Taihang Mountains, Paleozoic diamondiferous Menyin and Fuxian Kimblites) from the North China Craton were firstly studied in this work. Coupled with Nd isotopic compositions, it shows that the Hf isotopes could be a better tracer for mantle sources than the Nd isotopes. Individual kimberlite fields from both the Mengyin and Fuxian regions have quite uniform Hf isotopic compositions, similar to the situation for the Nd isotopes.
Resumo:
针对目前最常用的液- 液萃取、ICP- M S 测定法检测表生水体中微量稀土元素方法, 研究了不同pH值条件下, 酸性膦(65%HDEHP 和35%H2M EHP) 自表生水体中萃取稀土元素(REEs) 的回收率。结果表明, 在pH1~ 4 的范围内, 不同性质的水体(湖泊、河流、地下水) 有不同的REEs 回收率。其中湖水在pH 118~ 317 有90% 以上的回收率, 最高回收率为93164%; 河水在pH 211~ 315 范围内有90% 以上的回收率, 最高回收率为95152%; 地下水仅在pH 113~ 115 时回收率超过90% , 最高回收率为97161%。说明在萃取不同表生水体中稀土元素时, 需要调到特定的pH 值才能得到最好的萃取效果。
Resumo:
一定元素的同位素组成被认为是该元素特有的“指纹”,同位素组成测量是地球化学、生命科学、环境化学、地质科学和核科学等领域重要的研究手段。利用同位素技术开展生命过程,地球系统中的物理、化学、生物过程及其资源、环境与灾害效应,资源勘探,污染物溯源等方面的研究,既是该技术的前沿研究主题,也使相关领域的研究更加“精细量化”,从而在新的科学纵深揭示出更加清晰的规律。 1992年多接收电感耦合等离子体质谱仪(MC-ICP-MS)的问世,为同位素分析提供了一种强有力的技术手段,与传统的热电离同位素质谱相比,MC-ICP-MS具有测量速度快、操作简便、灵敏度高等优点。而且,由于等离子体源产生的高温,在理论上能测量所有的金属元素和一些非金属元素,并已很好地解决了一些高电离电位元素同位素测量的难题(如Se, Zn, Hf等),用MC-ICP-MS准确、精密测量各种元素同位素组成的方法正在逐渐得到发展和完善。目前,MC-ICP-MS比较成熟的方法主要是针对核和地质科学研究中应用较多的U, Pb, Sm, Nd, Sr, Hf, B, Li等,在硒和锌同位素测量方法学的研究还相对较少(尤其是硒),对一些测量中受各种干扰较为严重的、原子量小于80 的元素同位素的测量技术还有待进一步深入探索和研究。锌、硒元素不仅与人类健康息息相关,而且随着质谱分析技术的发展,使其在环境地球化学、生命科学等领域有着广泛的应用前景。准确测量生物、食品、环境、地质等样品中的锌、硒元素含量、各种形态及其同位素组成受到越来越多的关注。锌、硒同位素准确测量的方法学研究,不仅可以广泛应用于各相关领域,也为锌和硒同位素基、标准物质研制奠定技术基础,从而为锌、硒元素含量和同位素测量提供量值溯源保障。 本工作针对锌和硒元素同位素组成以及生物、环境等样品中成分量准确测量存在的问题,通过使用六极杆碰撞室MC-ICP-MS进行准确测量锌和硒元素同位素的技术研究,结合在化学计量研究中的长期实践及相关文献,从方法学角度和应用方面得出以下结论: 1.MC-ICP-MS仪器测量主要参数,如炬管轴向位置、载气流量、碰撞气流量、仪器稳定性等对测量结果影响很大,要获得高精度的测量结果,须优化和固定参数设置,保持仪器的稳定状态。在六极杆碰撞室MC-ICP-MS测量锌同位素时,高纯氩气碰撞气模式是较为理想的模式,64Zn/66Zn、67Zn/66Zn、68Zn/66Zn同位素丰度比测量精度达到0.002-0.008%,70Zn/66Zn 测量精度达到0.01%;在高纯氢气和氩气碰撞气按一定比例混合的模式下, 76Se/80Se、77Se/80Se、78Se/80Se、82Se/80Se同位素丰度比测量精度达到0.004-0.005%。 2.采用高纯、高浓缩64Zn和66Zn配制了8个校正样品 (64Zn/66Zn:0.6-2.2);用高纯、高浓缩同位素76Se和82Se配制了16个校正样品(76Se/82Se: 0.05-11.8),用这些样品分别测量并计算了仪器系统误差校正系数K,这些校正样品的K64/66 和 K76/82的相对标准偏差分别为0.034%和0.03%,均在仪器的测量不确定度范围内,说明在校正样品同位素变化范围内,仪器测量同位素丰度比的校正系数没有发生明显变化。 3.在硒同位素丰度比值测量中,氢气碰撞气的使用是SeH产生的重要原因之一,Ar/H在2-7之间都可以满足硒同位素比值测量的要求,即保证较高的硒灵敏度、较小的SeH生成比例、稳定的同位素比值测量结果。本工作建立了SeH的校正计算公式,在对测量结果的质量歧视进行校正时,77Se和78Se的校正更为复杂,因为它们除自身产生的SeH外,还分别受到了来自76SeH和77SeH的影响,故校正质量偏移时应首先对SeH进行校正。对于不同的SeH生成比例,经过校正后,硒的同位素丰度比校正值是一致的,并不受SeH生成比例变化影响。 4.通过对IDMS过程中的关键技术研究,明确了如何正确使用该方法以获得准确测量结果。IDMS方法在测量步骤中引入的不确定度影响因素相对于其它化学分析方法较少,并且可以被明确地表达出来,测量结果可直接溯源到国际单位,因此,该方法对化学计量学研究具有十分重要的意义。 5.建立了适用于ICP-MS测量血清、大豆粉、金枪鱼等多种复杂基体中锌和硒元素的样品前处理方法,建立了锌和硒的ICP-IDMS测量方法。将建立的方法应用于人血清标准物质研制、国家计量院之间的国际比对和合作研究中,取得的优异成绩验证了所建方法的可靠性和可比性。IDMS方法在样品前处理上不怕样品损失和高精度同位素丰度比测量的优点,使其在复杂基体中硒、锌的准确测量方面较其它分析方法具有独特的优势,可在生物、临床、环境、食品等方面的分析研究中广泛应用。
Resumo:
自然界锂同位素分馏强烈,这使得它在很多方面都得到了应用,如地球化学、天体化学和核工业等。所有这些领域都要求精确的测定6Li/7Li的比值。但由于锂是微量元素,而且在测试过程中还存在明显的干扰,因此在进行锂同位素比值测定之前必须对样品进行分离和富集。本文以锂元素标准样品和钾、钠、钙、镁元素标准样品的混合溶液为主要研究对象,采用阳离子交换树脂AG-50W-X8来分离富集锂,探索在不同淋洗介质条件下锂分离纯化的最佳介质条件。初步得出以下结论: 1、本次研究建立了相对简单、高效的锂同位素分离方法。用单一的柱子分离、提纯样品锂;用低浓度的盐酸(0.15M HCl)直接作为淋洗介质,操作过程简单。 2、对锂同位素比值测定产生潜在影响因素,如基体效应、回收率、流程空白等进行了实验研究,证实这些影响因素对于本次研究所建立的方法来说都是可以忽略不计的。 3、用MC-ICP-MS测定样品的锂同位素组成,分析结果的准确度和精度与现阶段所报道数据相同。测定海水的锂同位素组成(+31.6±1.0‰,2σ)与Tomoscak 等(+31.8±1.9‰,2σ)的分析值相近。 4、该方法也适用于低含量的样品。我们分离并测定了不同类型样品的锂同位素组成,样品锂含量在0.064µg/g和132µg/g之间,说明该方法也同样适用于低含量地质样品的分析测定。
Resumo:
Tazhong-Bachu region is located in the Western Tarim basin.The early Permian magmatic rocks occur in the earth surface of Tazhong-Bachu region are mainly distributed in Kepintag,Mazhartag and Wajilitag region. There are a lot of wells, in which researchers found the early Permian magmatic rocks,in desert cover area.Most magmatic rocks are basic rocks, a few of which are ultrabasic rocks and intermediate-acid magmatic rocks.The ultrabasic rocks are are mainly occur in the Cryptoexplosive Breccia Pipes ,which is located in the volcanic complex body of Wajilitag region.The basic rocks can be divided into three rock types:The first type of the magmatic rocks in Tazhong-Bachu region is volcanic rock ,which occurs in the Lower Permian Kupukuziman Formation and Kaipaizileike Formation. Most Volcanic rocks are basalts,a few of which are volcanic breccias and pyroclastic rocks.The basalts are distributed in stratiform occurrences and interbeded the clastic rocks in Kepintag region.The attitudes of the basalts are nearly horizontal.Columnar Joints, gas pore textures and amygdaloidal structure are to develop in basalts.The second type of the magmatic rocks in Tazhong-Bachu region is diabase,which occurs in Mazhartag region.Diabase dike swarms occur in the stratums of Silurian, Devonian, Carboniferous and Lower Permian.They make from NNW direction to SSE direction, the obliquity of stratum is greater than 60°, and the dike thickness is form several cm to several meters. Diabasic texture is found in the rocks .The first type of the magmatic rocks in Tazhong-Bachu region are gabbro- pyroxenite rocks ,which occur in the Wajilitag igneous complex body. The intermediate-acid magmatic rocks, which are mainly syenites, are located in Mazhartag and Wajiltag region. But they are small in the whole Tazhong-Bachu region.There are intermediate-acid magmatic rocks,which are mainly dacite,in the northeast part of the wells in Tazhong-Bachu region.But ,it is not found in earth surface.Through systematical geochemical research of early Permian magmatic rocks,which are distributed in Kepintag,Mazhartag, Wajilitag region and the wells such as F1 well、Z1 well、Z13 well、TZ18 well、H3 well、H4 well et al., the focus on the geochronologic characteristics, the main element,trace element and REE geochemistry, the mineralogic characteristics, the Sr-Nd and Pb isotopic characteristics are put forward. The main points are: 1、A combined study of CL imaging and LA-ICP-MS U-Pb dating were carried out for zircon grains of the magmatic rocks in the Tazhong-Bachu region from the Tarim basin.The results of the systematic zircon LA-ICP-MS U-Pb dating reveal 272±6Ma to 291±10Ma for the magamatic rocks. It indicated that Early Permian is an important period of magmatic acvivity in the Tazhong-Bachu region. 2、There are a big hunch in the curves of primitive mantle-normalized trace element concentrations in the early Permian magmatic rocks from Kepintag, Mazhartag, Wajilitag region and the 14 wells. Light rare earth elements are comparatively rich and heavy rare earth elements are comparatively poor. The slope rates are same between light rare erath elements and heavy rare earth elements. It is not like the curves of the basalts in the convergent margin of plate , in which the slope rates of light rare erath elements is bigger than the alope rates of heavy rare erath elements, and the curves of heavy rare earth elements are comparatively flat. The magmatic rocks of Tazhong-Bachu region rarely have the characteristics of the basalts in the convergent margin of plate, which is that Tantalum, Niobium and Titanium are much poor, and Zirconium, Hafnium and Phosphorus are moderately poor. The magamatic rocks are mostly alkaline, which is indicated by the dots of the (Na2O+K2O)-SiO2 identification diagram. All of these indicate that the early Permian magmatic rocks were formed in an extension environment of intraplate. 3、The Thorium abundance is high and Tantalum abundance is low in most magmatic rocks from Tazhong-Bachu reguion, which is formed for crustal contamination.In the Th/Yb-Ta/Yb identification diagram,most dots are in the region, which means active continental margin, but a few dots are in the region, which means mantle source. It indicated the feeding of continental crust materials. 4、The magnesium content of the olvines from Wagilitag region is richest, and the olvines from Kepintag region is poorest in the tree region. 5、Through the the Sr-Nd and Pb isotopic study of the basalts and diabases from the F1 well core, Z1 well core, Z13 well core,TZ18 well core, and the basalts,gabbros, diabases(diabase-prophyrites) and pl-peridotites from Kepintag,Mazhartag, Wajilitag region , it indicated that all isotopic data is similar and close to enriched mantle.