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1.
岩石中硼的提取分离及同位素组成的测定 总被引：4，自引：1，他引：3
介绍了一种用Ｎａ２ＣＯ３＋Ｋ２ＣＯ３混合熔剂对石样品进行分解,用硼特效树脂和阴、阳混合离子交换树脂相结合进行岩石样品中硼的纯化分离的方法。采用该方法从岩石样品中提取、分离出来的硼能满足硼同位素质谱法测定的需要,不产生硼同位素分馏,硼同位素测定精度大多优于０．０５％。 相似文献
2.
河水样品中硼的分离及其同位素组成测定 总被引：1，自引：0，他引：1
对河水样品中低含量硼的分离方法及硼同位素组成的测定进行了研究。将约1000mL河水样品分别用硼特效树脂，混合树脂富集和纯化后，紫外灯照射去除有机质，蒸发浓缩至小体积，采用正热离子质谱法进行硼同位素组成的测定。全流程回收率在95％以上，同位素稀释法测得全流程空白为41ng。经该方法处理后的样品能满足同位素质谱测定的需要。不产生同位素分馏，测试精度基本在0.6‰以内。 相似文献
3.
硼是生物样品(牙齿或骨骼)中重要的微量元素,其含量和同位素组成可以指示宿主的食物摄入、迁移和健康信息,因此生物样品中的硼同位素是重要的环境示踪剂。但生物样品中钙含量较高(90%),无法采用常规的硼特效树脂分离流程进行硼同位素的分离富集。本文采用醋酸-醋酸铵缓冲液(pH=6.0)替代以往使用的氨水作为树脂再生溶液,将硼特效树脂吸附硼的pH值从8～9降至6.0,从而避免了富含钙的生物样品在碱性条件下(pH=8～9)容易生成沉淀的难题,只需一步离子交换就能富集生物样品中的硼。样品经分离后其中的硼同位素采用多接收电感耦合等离子体质谱(MC-ICP-MS)的"标准-样品-标准"交叉法进行测定。结果表明:采用一步离子交换法分离富集,MC-ICP-MS测定生物样品(牙齿)中硼同位素的测试精度小于0.42‰,达到与其他分离和测试方法相同的水平。该方法不仅适用于牙齿和骨骼等高钙生物样品的硼同位素示踪,且为高钙土壤和海洋沉积物样品的分析提供了借鉴。 相似文献
4.
利用MC-ICPMS对水样中硼同位素比值的测定 总被引：2，自引：0，他引：2
采用Amberlite IRA-743硼特效树脂进行水溶液中硼的分离,对洗脱液温度、体积以及树脂动态交换容量等进行了实验.它的动态交换容量为4.2 mg/g,在室温条件下,用5 mL 2%HNO3可定量从树脂柱上洗脱被吸附的硼.采用Neptune型MC-ICPMS进行硼同位素组成的测定,1 μg/g浓度的硼标准溶液获得放大的信号强度约为0.7V,硼的化学分离过程有效避免了质量歧视效应.实验结果表明,MC-ICPMS对硼存在严重的记忆效应,通过采用5%HNO3-(1%HNO3 0.1%HF)-H2O-20%NH3H2O-H2O的交替清洗方法,可在约1 h内消除硼的记忆效应.在最佳仪器条件下,对含有250 ng硼的水样,可以快速测定硼的同位素组成,占δ11B测定的绝对偏差为0.4‰-0.5‰(SD). 相似文献
5.
硼具有两种稳定同位素10B和11B,其在自然界的丰度分别是19.90%和80.10%。自然界硼同位素组成变化很大, δ11B变化可达90‰以上(－30‰～＋60‰)。硼同位素的分析精度优于0.2‰,因此被广泛应用于多种地质过程的示踪研究。近年来,硼元素的提取、分离纯化和仪器测定技术均取得了可喜的进展,分析精度不断提高,为硼同位素地球化学研究奠定了良好的基础。本文从样品分解、化学分离和仪器测定等方面对硼同位素分析测试方法进行了归纳总结。 相似文献
6.
少量AG1-X4阴离子交换树脂分离地质标样中的铁及铁同位素测定 总被引：1，自引：0，他引：1
报道了利用少量AG1-X4阴离子交换树脂分离地质样品中Fe及测定Fe同位素的方法。对少量AG1-X4和AG MP-1树脂的分离效果进行了比较,测定了经过AG1-X4分离后的地质标样BCR-2、BHVO-2、BIR-1a、AGV-2、W-2、GSP-2、COQ-1、DTS-2b、JB-2、Jsd-1、GBW07105和GBW07267的Fe同位素组成,其结果与文献参考值在误差范围内一致。这些数据的发表对于地质样品Fe的化学分离和同位素测定提供了参考依据。此方法可以大大减少化学试剂用量,是一种快速有效分离铁的方法。 相似文献
7.
直接熔融热电离质谱法测定硼酸盐矿物中的硼同位素组成 总被引：1，自引：0，他引：1
为简化一些硼同位素样品的前处理过程,本文用直接熔融法,即待测样品直接在电离带上进行熔融后测定其硼同位素值。本文测定了柱硼镁石、电气石、钠硼解石、碳化硼、硼化硅等几种含硼化合物中的硼同位素组成,并与传统的溶样方法进行了比较。结果表明,直接熔融法可以快速且高精度测定上述几种化合物中硼同位素组成,相对内精度小于0.05‰,为此类含硼化合物的硼同位素测定提供了一种新的测试方法。 相似文献
8.
MC-ICP-MS测定积累植物中Cu、Zn同位素的化学分离方法研究 总被引：2，自引：0，他引：2
多接收器等离子体质谱仪(MC-ICP-MS)高精度同位素组成的准确测定,依赖于对样品中待测元素的分离纯化.本研究比较了两种溶样方法对有机样品积累植物海州香薷的消解效果,检测了AG MP-1阴离子交换树脂对样品中Cu、Zn的分离效果,并测定了样品中的Cu、Zn同位素组成.结果表明:①两种不同溶样方法均能有效地破坏累植物海州香薷样品中的有机质;②AG MP-1树脂能有效分离纯化植物中的Cu、Zn,经过AG MP-1树脂一次交换分离和二次交换分离的植物根样品的Cu接收液基体元素的去除基本没有差别,经过一次交换分离的Zn溶液,基体元素也基本除去,可以用于MC-ICP-MS对Cu、Zn同位素组成高精度的测定;③Cu、Zn同位素组成测定误差不大于仪器的长期重现性,表明样品的化学处理过程、各离子交换树脂柱分离交换过程和仪器测试过程均有很好的重现性,符合样品测定的要求. 相似文献
9.
硼特效树脂离子交换法分离B的研究 总被引：4，自引：0，他引：4
本文对Amberlite IRA 743 硼特效树脂交换分离B的特征及其影响因素进行了研究。它适用于各种地质样品中B的分离提取，特别是在B同位素地球化学研究时必须进行B纯化的场合。 相似文献
10.
硼特效树脂分离分光光度法测定岩石矿物中痕量硼 总被引：3，自引：0，他引：3
本文将国产D_(564)硼特效树脂用于岩石矿物中痕量硼的富集分离。研究了大量铁、铝等元素存在时在碱性介质中硼的吸附行为和洗脱的最佳条件。硼以铍试剂Ⅲ光度法测定,所拟定的方法用于地质标准参考试样、铝土矿、锰结核和硫化矿物中硼的测定结果满意。 相似文献
11.
《Chemical Geology》2002,182(2-4):323-334
An optimized procedure for the separation of boron from natural river samples and an improved mass spectrometry determination of boron isotopic ratio are presented. The chemical procedure, based on the use of the boron-specific resin Amberlite IRA 743, is especially efficient in separating boron from natural organic matter-rich samples like river waters.The properties of Amberlite IRA 743 have been investigated. The two factors important in determining the boron affinity for the resin are: the pH value and the ionic strength of the solution from which B is to be extracted. A logarithmic relationship between B partition coefficients and pH values is found. High ionic strength significantly lowers the fixation of B onto the Amberlite resin.The knowledge of the factors controlling the affinity of the resin Amberlite IRA 743 for boron enables us to design a simple and miniaturized chemical separation procedure characterized by (i) three chromatographic steps using, respectively, 50, 10 and 3 μl of resin, (ii) no evaporation step between each column, and (iii) final separation of boron from residual organic matter by sublimation of boric acid at 75 °C.Boron isotopic ratios are measured using an improved cesium metaborate technique, with graphite and mannitol. Adequate loading conditions enable us to obtain typical signal intensities of 5×10−12 A for 250 ng of boron. No in-run isotopic fractionation is observed, the external reproducibility for standards processed through the entire chemical procedure, as well as for samples, corresponds to 0.35‰ (±2σ). According to this precision, a slight, but reproducible isotopic fractionation of 0.4‰ is observed for standards processed through the entire chemical procedure whose origin is discussed, but is still unclear. 相似文献
12.
ZHANG Yanling XIAO Yingkai MA Yunqi ZHUGE Qin LIU Zhiqi HE Maoyong LUO Chongguang MA Haizhou 《中国地球化学学报》2013,32(2):203-211
The procedures of sample preparation for isotopic determination of boron in clay sediments is very cumbersome, by far, there haven’t been relevant reports on that. In order to establish an effective method for sample preparation, a series of experiments were carried out. In this paper, boron in clay sediments was extracted with HCl solution and purified by two-step ion exchange method. Extracted HCl solution should be adjusted to alkalescency before passing through the Amberlite IRA 743 resin column due to the fact that Amberlite IRA 743 resin absorbs boron only from alkalescent solution. However, a mass of hydroxides of Al and Fe will be precipitated when the extracted HCl solution becomes alkalescent. Hydroxides of Al and Fe have a strong adsorption capacity for boron, which can cause boron isotope fractionation. To treat precipitated hydroxides of Al and Fe, four procedures, namely direct ion exchange (DRIE), decationizing ion exchange (DCIE), once sedimentation ion exchange (OSIE) and repeated sedimentation ion exchange (RSIE) were used and assessed. The influences of the four procedures on separation and extraction and isotopic composition of boron in experimental solutions and clay sediments were also discussed. According to the results, the DRIE, DCIE and OSIE are improper. The result of sample determination indicates that when extracting boron via RSIE, with the increase of precipitation times, there’s an obvious decrease in boron content in the precipitated hydroxides while a sharp increase in recovery of boron and it is favorable for weakening the influence of boron isotope fractionation. But the process of RSIE is time consuming and it may introduce boron. It needs further research to establish a more effective sample preparation method for isotopic deter- mination of boron in clay sediments. 相似文献
13.
海洋浮游有孔虫中的硼同位素能够反映海水酸碱度的变化,从而为重建大气二氧化碳浓度的变化提供了一种新的手段,有望提供目前极地冰心记录所无法企及的百万年甚至千万年时间尺度上的大气二氧化碳浓度的变化。最近,海洋浮游有孔虫硼同位素的研究在实验分析技术(负热电离质谱法)、实验室偏差、同位素分馏系数、海水硼同位素长期变化以及各种次要因素等方面都取得了长足的进步,尤其是全蒸发负热电离质谱法的建立使硼同位素分析的样品需求量降到纳克级以下。不过,尽管海洋浮游有孔虫中的硼同位素作为大气二氧化碳浓度的替代指标很具有潜力,但还需要进行更加深入地研究。 相似文献
14.
Yuki Hibiya Tsuyoshi Iizuka Katsuyuki Yamashita Shigekazu Yoneda Akane Yamakawa 《Geostandards and Geoanalytical Research》2019,43(1):133-145
Combined determination of Cr and Ti isotopes of planetary materials offers a means with which to investigate their genetic relationship and the evolution of the protoplanetary disk. Here, we report the new sequential chemical separation procedure for combined Cr and Ti isotope ratio measurements. It comprises three steps: (a) Fe removal using AG1‐X8 anion exchange resin, (b) Ti separation using TODGA resin and (c) Cr separation using AG50W‐X8 cation exchange resin (with one additional step of Ti purification using AG1‐X8 anion exchange resin for samples having high Cr/Ti and Ca/Ti ratios). We applied the proposed procedure to terrestrial and meteorite samples with various compositions. Typical recovery rates of 90–100% were achieved with total procedural Cr and Ti blanks of 3–5 and 2–3 ng, respectively. We measured the Cr and Ti isotope compositions of the separated samples using thermal ionisation mass spectrometry and multiple collector‐inductively coupled plasma‐mass spectrometry, respectively. Our Cr and Ti isotope data were found to be consistent with those of previous studies of individual Cr and Ti isotopic compositions of the meteorites. These results demonstrate the capability of our separation method when applied to combined high‐precision Cr and Ti isotope analyses for single digests of planetary materials. 相似文献
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16.
Nancy Healy-Williams 《地学学报》1992,4(6):693-700
The stable isotopic composition of planktonic foraminifera plays a paramount role in interpretations of past oceanographic and environmental conditions; thus an accurate understanding of the factors which influence their isotopic composition is essential. In order to increase the palaeoceanographic utility of the high-latitude planktonic foraminifera Neogloboquadrina pachyderma , its shape and oxygen and carbon isotopic variability are quantitatively described in this study. Over 8200 specimens of N. pachyderma from 36 gravity and piston core tops from surface sediments of the North Atlantic and southern Indian Oceans were digitized and analysed via Fourier series in closed form. The morphological results are presented in detail elsewhere and are utilized in this study to select specimens for isotopic analyses. Significant isotopic differences exist between morphological variants of this important high-latitude speaes. Specimens become depleted in both oxygen and carbon isotopes as the test shape becomes more pentagonal and less quadrate. The isotopic differences cannot be attributed to test thickening nor to size or coiling direction. This observation has important implications in the use of this speaes as a tracer in high-latitude palaeoceanographic investigations. In particular, future isotopic investigations utilizing this species should analyse single forms to allow for clear interpretation of palaeoceanographic signals. 相似文献
17.
Jie Li Xi‐Rong Liang Li‐Feng Zhong Xuan‐Ce Wang Zhong‐Yuan Ren Sheng‐Ling Sun Zhao‐Feng Zhang Ji‐Feng Xu 《Geostandards and Geoanalytical Research》2014,38(3):345-354
A novel preconcentration method is presented for the determination of Mo isotope ratios by multi‐collector inductively coupled plasma‐mass spectrometry (MC‐ICP‐MS) in geological samples. The method is based on the separation of Mo by extraction chromatography using N‐benzoyl‐N‐phenylhydroxylamine (BPHA) supported on a microporous acrylic ester polymeric resin (Amberlite CG‐71). By optimising the procedure, Mo could be simply and effectively separated from virtually all matrix elements with a single pass through a small volume of BPHA resin (0.5 ml). This technique for separation and enrichment of Mo is characterised by high selectivity, column efficiency and recovery (~ 100%), and low total procedural blank (~ 0.18 ng). A 100Mo‐97Mo double spike was mixed with samples before digestion and column separation, which enabled natural mass‐dependent isotopic fractionation to be determined with a measurement reproducibility of < 0.09‰ (δ98/95Mo, 2s) by MC‐ICP‐MS. The mean δ98/95MoSRM 3134 (NIST SRM 3134 Mo reference material; Lot No. 891307) composition of the IAPSO seawater reference material measured in this study was 2.00 ± 0.03‰ (2s, n = 3), which is consistent with previously published values. The described procedure facilitated efficient and rapid Mo isotopic determination in various types of geological samples. 相似文献
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19.
Determination of Boron Concentration in Geochemical Reference Materials Extracted by Pyrohydrolysis and Measured by ICP‐MS 
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下载免费PDF全文 Agnès Michel Johanna Noireaux Mickaël Tharaud 《Geostandards and Geoanalytical Research》2015,39(4):489-495
This article presents new boron concentrations for nine geochemical reference materials (GS‐N, FK‐N, GL‐O, BX‐N, DT‐N, AN‐G, GH, Mica‐Fe, Mica‐Mg). After extraction by a modified pyrohydrolysis technique, boron concentrations were measured by ICP‐MS. The blank levels for the whole procedure were 0.091 ± 0.020 ng ml?1 or 14 ± 5 ng of boron in total. The method was first validated by measuring nine reference materials with known boron concentrations. The determined boron concentrations are all within the range of recommended or published values, which means that the yields were 100%, and show precisions below 10% for samples containing over 2 μg g?1 of boron. 相似文献
20.
离子交换树脂法分离沉积物中锶和钕的影响因素研究 总被引：3，自引：3，他引：0
Sr和Nd同位素是地质学研究中经典的同位素定年和示踪体系。传统沉积物中Sr和Nd分离方法通常是利用AG50W-X8树脂分离Sr与稀土元素(REEs),再用Sr和Ln特效树脂分别对Sr和Nd纯化,但对于Fe元素含量较高的沉积物样品,该方法对REEs的洗脱率偏低,仅有50%。另外,AG50W-X8树脂高度、洗脱酸种类、Sr特效树脂淋洗酸体积以及Ln特效树脂过柱方式对Sr和Nd分离都有影响。为分析上述因素对Sr和Nd分离效果的影响,本文以水系沉积物标准物质GBW07309为例进行了研究,结果表明:(1)高含量的Fe会显著影响Sr和Nd的分离效果,而AG1-X8树脂可以有效去除Fe;(2)当AG50W-X8树脂高度为1 m L,硝酸作为洗脱酸时,Sr和REEs的分离效果较好;(3)Sr特效树脂淋洗酸中硝酸淋洗体积达到15 m L时可以有效分离Sr和Rb;(4)Ln特效树脂采用重力过柱方式时Sr和Nd分离效果较好,没有拖尾现象。本研究解决了Fe对分离Sr和Nd的干扰,K、Na、Ca、Mg、Fe、Rb、Sm去除率达到99%以上,完全满足Sr和Nd同位素分析的要求,为离子交换树脂法分离沉积物中Sr和Nd提供了较详细的前处理经验数据。 相似文献