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本文采用PMBP树脂定量分离富集微量稀土元素,提出加入少量苯甲酰丙酮,可使微量稀土元素被PMBP树脂定量吸附,用0.1N盐酸溶液又可使稀土元素定量洗脱。进而拟定了岩石矿物中微量稀土元素总量的测定手续。对于含量为0.171%、0.320%的稀土样品测得标准偏差分别为0.0062、0.0044,变动系数分别为3.64%、1.24%。 相似文献
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本文采用PMBP树脂定量分离富集微量稀土元素,提出加入少量苯甲酰丙酮,可使微量稀土元素被PMBP树脂定量吸附,用0.1N盐酸溶液又可使稀土元素定量洗脱。进而拟定了岩石矿物中微量稀土元素总量的测定手续。对于含量为0.171％、0.320％的稀土样品测得标准偏差分别为0.0062、0.0044,变动系数分别为3.64％、1.24％。 相似文献
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青藏高原新生代埃达克质岩的厘定及其意义 总被引：34，自引：2，他引：34
常量、微量及Sr-Nd-Pb同位素研究表明,青藏高原藏北石水河—浩波湖—多格错仁北部分布的一套新近纪(9.4～26.9 Ma)安山质-英安质-流纹质火山岩具有埃达克岩的地球化学特征。岩石ω(SiO_2)>58％,ω(Sr)>350×10~(-6),低Y和Yb,高La/Yb比,无铕异常。岩石N(~(87)Sr)/N(~(86)Sr)=0.706 365～0.708 156,N(~(208)Pb)/N(~(204)Pb)=38.955～39.052,N(~(207)Pb)/N(~(204)Pb)=15.651～15.672,N(~(206)Pb)/N(~(204)Pb)=18.679～18.839,N(~(143)Nd)/N(~(144)Nd)=0.512 411～0.512 535,ε(Nd)=—2.01～—4.43,充分表明它们为一套典型的壳源中酸性火山岩系,源自高原加厚陆壳下部的一个榴辉岩质源区的部分熔融。 相似文献
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本文用作者合成的新试剂——钒金试剂做指示剂莫尔盐容量法测定微量金,终点突跃明显,操作简便,测定金范围宽。岩石矿物经磷酸——王水溶样,聚氨酯泡塑富集分离后测金较王水溶样回收完全。测金范围在0.0003—100g/t。试样测定的变动系数在21.6—1.62％范围。 相似文献
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Xuli Pu Chaozhang Huang Bin Hu Zucheng Jiang 《Geostandards and Geoanalytical Research》2006,30(2):97-105
Nanometre-sized alumina was chemically modified with gallic acid (GA) and used as a solid phase adsorption material for the determination of trace amounts of V, Nb and Ta in natural water, soil and stream sediment samples by inductively coupled plasma-mass spectrometry. The effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analytes were investigated. The results showed that V, Nb and Ta could be adsorbed at pH 4.0 and recovered with 1 ml of 2.0 mol l-1 HCl. Under optimised conditions, the adsorption capacity of GA-modified nanometre-sized Al2 O3 was found to be 7.0, 8.9, 13.3 mg g-1 for V, Nb and Ta, respectively. The limits of detection were as low as 0.25, 0.24 and 0.66 ng l-1 for V, Nb and Ta, respectively with a concentration factor of fifty. The recovery of V, Nb and Ta for spiked water samples was between 85.7 and 116%. The developed method has also been applied to the determination of trace V, Nb and Ta in soil and stream sediment certified materials, and the determined values were in a good agreement with the certified values. 相似文献
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ICP-MS分析用地质样品制备过程中Nb、Ta等元素的特殊化学行为 总被引：2，自引：0，他引：2
常规PTFE对瓶亚沸蒸馏HF时,Nb、Ta等部分高场强元素提纯效果较差,甚至适得其反,暗示Nb、Ta在HF蒸馏过程中存在“挥发”作用。然而,高温、高压酸溶法溶解岩石样品时,Nb、Ta等并没有表现出类似的“挥发”作用。对Nb、Ta等在高温、高压酸溶法溶样过程不同实验阶段的行为进行了详细研究。研究结果表明岩石样品中的AJ、Fe、Mg、Ca等主元素基体会影响Nb、Ta等元素在溶液中的存在形式和稳定性。当基体元素与Ta含量比值达到1×10^4以上时,Nb、Ta在稀硝酸介质中可以稳定存在,Ta回收率达到100％。进一步的研究结果表明,在HF中加入Al、Fe等基体,可以明显降低HF蒸出液中Ta浓度,增强HF中Ta等元素的提纯效果。在用于ICP—MS分析的样品化学制备过程中Nb、Ta表现出了不同的化学行为,在以稀硝酸为介质的Nb、Ta溶液中Ta的水解聚合程度和可能性远远大于Nb。因此,除了在样品提取前使样品溶液中保留足够的HF介质外,要获得准确的Nb／Ta比值应充分延长Ta的积分时间或者采用时间分辨分析信号平均值。 相似文献
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铌、钽在氢氟酸介质中能够形成稳定的溶液,使用耐氢氟酸进样系统的电感耦合等离子体发射光谱(ICP-OES)有利于提高分析的准确性。本文采用模块化的小罐型、多罐体组合(70罐/组)酸溶罐体的微波消解溶样模式,结合ICP-OES仪器的耐氢氟酸进样系统,建立了测定铌钽矿中铌、钽的分析方法。本方法加快了酸溶的溶样速度,溶样时间从原来的48 h减少至1 h,且在氢氟酸介质中测定,避免了高含量铌、钽在低酸度介质中容易水解的影响。方法检出限为铌5.58 μg/g,钽5.87 μg/g。本方法应用于测定铌钽精矿(19%Nb2O5,27%Ta2O5)的分析结果与碱熔方法一致,能够测定Nb2O5含量在42 μg/g~19%和Ta2O5含量在86 μg/g~27%高低品位的铌钽矿,尤其对于铌、钽在百分含量以上的铌钽矿具有优势。 相似文献
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Determination of REE, Y, Nb, Zr, Hf, Ta, Th and U in Geological Reference Materials LSHC-1 and Amf-1 by Solution and Laser Ablation ICP-MS 总被引：1，自引：0，他引：1
Elena V. Smirnova Belinda Flem Elena A. Anchutina Irina N. Mysovskaya Valeriy I. Lozhkin Lev L. Petrov † 《Geostandards and Geoanalytical Research》2010,34(1):49-65
This paper presents data on REE and Y, Nb, Zr, Hf, Ta, Th and U abundances for two candidate reference materials (RMs), spinel lherzolite LSHC-1 and amphibole Amf-1, being currently developed at the Institute of Geochemistry SB RAS, Irkutsk. To determine the contents of these elements inductively coupled plasma-mass spectrometry was applied with: (i) solution nebulisation (solution ICP-MS) and (ii) laser ablation (LA-ICP-MS) of fused glass disks. The precision of results obtained by both techniques was better than 6% RSD for most elements. Accuracy was assessed by using the geochemical RMs JB-2, JGb-1 (GSJ) and MAG-1 (USGS). The trace element results by solution ICP-MS for JGb-1 and JB-2 agree with reference values presented by Imai et al. (1995, this Journal) within 1–10%. Significant differences were found for Nb and Ta determinations. The accuracy of LA-ICP-MS results evaluated by RM MAG-1 was within 4%, except for Eu (about 10%). The analytical results obtained for LSHC-1 and Amf-1 by solution ICP-MS and LA-ICP-MS were in good agreement with each other and with INAA and XRF data presented for the certification of these RMs. They can be considered as the indicative values for assigning certified values to the above-mentioned RMs. 相似文献
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S. Z. Smirnov V. G. Thomas V. S. Kamenetsky O. A. Kozmenko R. R. Large 《Petrology》2012,20(3):271-285
Consideration of the existence of hydrosilicate liquids (HSL) in nature can help in understanding the accumulation and transport of some mineral- and ore-forming components at the transition from magmas to hydrothermal fluids. We studied the experimental formation of HSL using a base system Na2O-SiO2-H2O with addition of NaF, NaCl and metallic Ta. The interaction between quartz and aqueous solution, performed at 1.5 kbar and 600°C and followed either by cooling or by quench, showed that the formation of HSL occurred when initial Na2O exceeded 2 wt %. Neither NaF nor NaCl have a significant effect on the formation of HSL. The HSL concentrates F, whereas Cl partitions into the aqueous fluid. With addition of Ta to the system, the HSL becomes metal-enriched. Natural analogs of experimental HSL can be found among ??melt/fluid?? inclusions entrapped in quartz and other minerals of miaroles in granite pegmatites and raremetal granites. The HSL is a novel medium enabling extreme concentrations of lithophile ore metals at the magmatic-hydrothermal transition. 相似文献
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The key role of mica during igneous concentration of tantalum 总被引：2，自引：0，他引：2
Aleksandr Stepanov John A. Mavrogenes Sebastien Meffre Paul Davidson 《Contributions to Mineralogy and Petrology》2014,167(6):1-8
Igneous rocks with high Ta concentrations share a number of similarities such as high Ta/Nb, low Ti, LREE and Zr concentrations and granitic compositions. These features can be traced through fractionated granitic series. Formation of Ta-rich melts begins with anatexis in the presence of residual biotite, followed by magmatic crystallization of biotite and muscovite. Crystallization of biotite and muscovite increases Ta/Nb and reduces the Ti content of the melt. Titanium-bearing oxides such as rutile and titanite are enriched in Ta and have the potential to deplete Ta at early stages of fractionation. However, mica crystallization suppresses their saturation and allows Ta to increase in the melt. Saturation with respect to Ta and Nb minerals occurs at the latest stages of magmatic crystallization, and columbite can originate from recrystallization of mica. We propose a model for prediction of intrusion fertility for Ta. 相似文献
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A method for the determination of Ge, As, Se and Te in silicate samples using isotope dilution-internal standardisation (ID-IS) octopole reaction cell (ORC) ICP-QMS by normal sample nebulisation was developed. The method does not involve either hydride generation or ion exchange. Germanium, Se and Te were determined by isotope dilution (ID), and As was determined by ID-IS. A silicate sample with an added Ge-Se-Te spike was digested with an HF-HNO3 -HBr mixture, dried, re-dissolved with HF and the supernatant liquid was directly aspirated into an ORC-ICP-QMS instrument with He or H2 gas. No matrix effects were observed down to a dilution factor (DF) of ∼ 70 for Ge, Se and Te and DF of ∼ 1000 for As, which resulted in 3s detection limits in silicates of 2, 1, 0.1 and 4 ng g−1 , respectively. Advantages of the method are the simple sample introduction as well as a capability of determining S, Ti, Zr, Nb, Mo, Sn, Sb, Hf and Ta by ID-IS-ICP-QMS/SFMS from the same solution. Furthermore, the total sample solution consumption was only 0.253 ml with DF = 2000. Therefore, only a 0.13 mg test portion was required. To demonstrate the applicability of this technique, Ge, As, Se and Te in eight silicate reference materials were determined, as well as S, Ti, Zr, Nb, Mo, Sn, Sb, Hf and Ta in four carbonaceous chondrites. 相似文献
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We have developed a rapid and accurate method to determine Zr, Nb, Hf and Ta (denoted as HFSE) in geological samples by inductively coupled plasma-mass spectrometry fitted with a flow injection system (FI-ICP-MS). The method involves sample decomposition by HF followed by HF dissolution of HFSE coprecipitated with insoluble M and Ca fluoride residues formed during the initial HF attack. This HF solution was directly nebulized into an ICP mass spectrometer. An external calibration curve method and an isotope dilution method (ID) were applied for the determination of Nb and Ta, and of Zr and Hf, respectively. Recovery yields of HFSE were > 96% for peridotite, basalt and andesite compositions, apart from Zr and Hf for peridotite (> 85%). No matrix effects for either signal intensities of HFSE or isotope ratios of Zr and Hf were observed in basalt, andesite and peridotite solutions down to a dilution factor of 100. Detection limits in silicate rocks were 40, 2, 1 and 0.1 ng g-1 for Zr, Nb, Hf and Ta, respectively. This technique required only 0.1 ml of sample solution, and thus is suitable for analysing small and/or precious samples such as meteorites, mantle peridotites and their mineral separates. We also present newly determined data for the Zr, Nb, Hf and Ta concentrations in USGS silicate reference materials DTS-1, PCC-1, BCR-1, BHVO-1 and AGV-1, GSJ reference materials JB-1, -2, -3, JA-1, -2 and -3, and the Smithsonian reference Allende powder. 相似文献
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George Pavlovich Zaraisky Valentina Korzhinskaya Nataliya Kotova 《Mineralogy and Petrology》2010,99(3-4):287-300
It is well established that the fractionation of Li–F granitic magmas at depth leads to the accumulation of flux elements such as F and Li, and metal cations such as Ta and Nb in residual melts. However, it remains to be determined whether magmatic fractionation is sufficient to concentrate Nb and Ta into economically significant quantities, and what role hydrothermal–metasomatic processes play in the formation of such ore deposits. In the literature, reliable data about the solubility of Ta and Nb in hydrothermal solutions is missing or incomplete. This study provides a quantitative experimental estimation of the possible contribution from hydrothermal processes in Ta enrichment in cupolas of albitized and greisenized Li–F granite. Experimental studies of Ta2O5 and columbite–tantalite (Mn,Fe)(Nb,Ta)2O6 solubility were carried out in fluoride solutions consisting of HF, NaF, KF, and LiF. At low fluoride concentrations (0.01 and 0.1 m), Ta2O5 solubility at 550°C and 100 MPa under Co–CoO oxidizing conditions is low (near 10?5–10?4 m) in all fluoride solutions (HF, NaF, KF, LiF). At high fluoride concentrations (1 and 2 m) the highest Ta2O5 concentrations (10?1 m) were detected in HF solutions. In KF, NaF, and LiF solutions, the Ta2O5 solubility is also high (10?3–10?2 m). The dependence of columbite–tantalite (Nb2O5-59 wt. %, Ta2O5-18 wt. %) solubility as a function of solution composition, T, and P has also been investigated. Tantalum and Nb concentrations have the highest values in HF solutions at reduced conditions (up to 10?3 to 10?2 m Ta in 1 m HF). In 1 m NaF solutions, the concentrations of Nb and Ta are, respectively, 2.5 and 3 orders of magnitude less than those in the 1 m HF solutions. Solubility of Ta and Nb in KF solutions has intermediate values. It is established that in NaF and KF solutions the dependence of solubility on pressure is distinctly negative. The Nb and Ta contents increase with increasing concentrations of HF and KF in solution, however, they do not change with increasing NaF concentration. In NaHCO3, Na2CO3, and HCl solutions columbite–tantalite solubility is low. Even in 1 m chloride solutions the content is within the limits of 10?5 m for Nb and 10?6 to 10?8 m for Ta. We conclude that hydrothermal transport of Ta and Nb is possible only in concentrated fluoride solutions. 相似文献