Determination of the Rare Earth Elements in Thirteen GSJ Silicate Rock Reference Samples by Secondary Ion Mass Spectrometry

Rare earth elements were determined by secondary ion mass spectrometry (SIMS) for 12 igneous rocks and one feldspar separate from the new rock reference samples of the Geological Survey of Japan. The study presents an expanded application of the SIMS facility.     

Ultra-Trace Element Analysis of NIST SRM 616 and 614 using Laser Ablation Microprobe-Inductively Coupled Plasma-Mass Spectrometry (LAM-ICP-MS): a Comparison with Secondary Ion Mass Spectrometry (SIMS)

The microanalytical capability of laser ablation microprobe-inductively coupled plasma-mass spectrometry (LAM-ICP-MS) to determine ultra trace elemental concentrations has been demonstrated by the analysis of two low concentration glass standard reference materials, NIST SRM 614 and 616. Results for fifty two elements at concentrations in the low ng g^-1 range are compared with those determined using secondary ion mass spectrometry (SIMS). Both techniques provide results at these concentrations that generally agree within 95% confidence limits, demonstrating the accuracy for ultra-trace level of in situ determinations by the two techniques. At concentrations of less than 20 ng g^-1 in NIST SRM 616, an accuracy and precision of better than 10% has been obtained for most mono-isotopic rare earth elements, when a spot size of 50 μm is used. Limits of detection for selected elements were as low as 0.5 ng g^-1.     

Determination of rare earth and refractory trace element abundances in early solar system objects by ion microprobe

Experimental and analytical procedures devised for measurement of rare earth element (REE) abundances using a secondary ion mass spectrometer (ion microprobe) are described. This approach is more versatile than the conventional techniques such as neutron activation analysis and isotope dilution mass spectrometry by virtue of its high spatial resolution that allows determination of REE abundances in small domains (10-20 micron) within individual mineral phases. The ion microprobe measurements are performed at a low mass-resolving power adopting the energy-filtering technique (Zinner and Crozaz 1986) for removal and suppression of unresolved complex molecular interferences in the REE masses of interest. Synthetic standards are used for determining various instrument specific parameters needed in the data deconvolution procedure adopted for obtaining REE abundances. Results obtained from analysis of standards show that our ion microprobe may be used for determining REE abundances down to ppm range with uncertainties of ∼ 10 to 15%. Abundances of rare earth and several other refractory trace elements in a set of early solar system objects isolated from two primitive carbonaceous chondrites were determined using the procedures devised by us. The results suggest that some of these objects could be high temperature nebular condensates, while others are products of melting and recrystallization of precursor nebular solids in a high temperature environment.     

Effect of melt composition on the partitioning of trace elements between titanite and silicate melt

Isobaric and isothermal experiments were performed to investigate the effect of melt composition on the partitioning of trace elements between titanite (CaTiSiO₅) and a range of different silicate melts. Titanite-melt partition coefficients for 18 trace elements were determined by secondary ion mass spectrometry (SIMS) analyses of experimental run products. The partition coefficients for the rare earth elements and for Th, Nb, and Ta reveal a strong influence of melt composition on partition coefficients, whereas partition coefficients for other studied monovalent, divalent and most quadrivalent (i.e., Zr, Hf) cations are not significantly affected by melt composition. The present data show that the influence of melt composition may not be neglected when modelling trace element partitioning.It is argued that it is mainly the change of coordination number and the regularity of the coordination space of trace elements in the melt structure that controls partition coefficients in our experiments. Furthermore, our data also show that the substitution mechanism by which trace elements are incorporated into titanite crystals may be of additional importance in this context.     

Determination of Rare Earth Elements and Yttrium in Nine Geochemical Reference Samples Using a Novel Group Separation Procedure Involving Mixed-Acid Elution Ion-Exchange Chromatography

Rare earth data for nine well-known geochemical reference samples were obtained using a rapid and efficient cation exchange chromatographic separation procedure. It involves the use of a mixed-acid eluent (HCI and HNO3) on a 15 x 1 cm column of Bio-Rad AG50–X8 (200–400 mesh) to remove matrix and many trace elements from rock solutions. The rare earth elements are removed from the column using 60 ml 7M HNO3. The pre-concentration procedure described is routinely used in this laboratory for the determination of the rare earth elements by mass spectrometry-isotope dilution, and has been satisfactorily used for their determination using inductively-coupled plasma-source atomic emission spectrometry.     

Potential Orthopyroxene,Clinopyroxene and Olivine Reference Materials for In Situ Lithium Isotope Determination

Over 1400 electron probe and 700 ion probe microanalyses were performed on eleven mineral separates to evaluate their potential as reference materials for in situ Li isotopic determination. Our results suggest the homogenous distributions of major elements, Li and its isotopes for each sample. Hence, these samples are suitable to be used as reference materials for in situ measurements of Li abundance and Li isotopes by secondary ion mass spectrometry (SIMS) or laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS). These samples have the advantage of mitigating probable matrix effects during calibration owing to the wide range of compositions. The effect of composition on the δ⁷Li of olivine measured by SIMS is a linear function of composition, with δ⁷Li increasing by 1.0‰ for each mole per cent decrease in forsterite component.     

电感耦合等离子体质谱法测定地质样品中稀土元素

采用酸溶一敞开溶矿技术,等离子体质谱法测定地质样品中的稀土元素。该方法选用高氯酸和硫酸,试验发现,硫酸的溶矿效果明显优于高氯酸,且硫酸的存在有利于消除Ba对稀土元素的质谱影响。用该方法对地质样品三类国家一级标样（GBW07401、GBW07103、GBW07309）：进行验证,准确率达95％～105％,结果令人满意。     

稀土稀有稀散元素现代仪器测试全新方法的建立

本文系统总结了自2011年以来在三稀矿产实验测试方面取得的新进展。重点介绍了离子相稀土单元素浸泡提取实验研究、稀土原产地Nd同位素与微量元素示踪技术研究、离子吸附型稀土样品野外现场快速定性定量手持X射线荧光(XRF)分析研究成果。结果表明,采用25%硫酸铵浸泡提取,电感耦合等离子体光、质谱(ICP- AES、ICP- MS)测定,可以清晰反映出各稀土元素的浸泡提取率;采用高精度多接收电感耦合等离子体质谱仪(MC- ICP- MS)进行稀土矿石中Nd143/Nd144同位素比值测定,其比值差异可以示踪不同稀土矿石产地;通过精确测试分析不同产地稀土精矿样品中的稀土和其他微量元素含量,并进行数据相关性分析和数据分类分析,通过Y、Be和Bi三种元素含量的比较,可以判断稀土精矿来源;野外现场快速分析,20分钟可完成1件样品测试,不仅可定性判断是否为离子吸附型稀土,同时可定量各离子相稀土单元素含量,与室内精确分析结果符合性良好,可为我国离子吸附型稀土矿床的找矿快速筛查提供技术支撑。 同时介绍了混合酸微波分解样品- 电感耦合等离子体光、质谱(ICP- AES、ICP- MS)同时测定钨矿石、钼矿石、铌钽矿石中的多种稀有稀散稀土元素含量的方案。该方案的特点在于采用了耐氢氟酸体系,尤其对高含量W、Nb、Ta样品更具优势,否则易产生水解,导致测定结果系统偏低。同时梳理总结了我国常见三稀矿石地质样品的特点,针对不同矿种、不同矿床样品类型与基体特点,以及所测试元素种类的不同,研究建立了专门针对“稀有、稀散、稀土元素”现代仪器分析的10个全新的配套方法及其相应的技术指标(准确度、精密度、检出限),可满足地质矿产实验室测试质量管理的规范要求,而且为我国三稀金属矿产资源的战略调查、国家重点研发计划“深地锂资源探测”和四川甲基卡等地找矿突破做出了贡献。     

飞行时间二次离子质谱(TOF-SIMS)在矿物包裹体研究中的应用

矿物包裹体的化学成分研究在地质学、矿床学和油气勘探等方面具有重要意义。目前对包裹体化学成分分析的主要分析方法有激光烧蚀电感耦合等离子体质谱(LA-ICP-MS)、电子探针(EPMA)、显微激光拉曼光谱(LRS)、傅里叶变换红外光谱(FTIR)、质子诱发X射线光谱分析(PIXE)、同步辐射X射线荧光光谱(SXRF)和(传统的)二次离子质谱分析(SIMS)等。本文在对上述方法的分析特点进行简单介绍的基础上,重点阐述了对于矿床学样品表征具有广泛应用潜力的飞行时间二次离子质谱(TOF-SIMS)的原理、特点和技术优势,总结了国内外学者应用TOF-SIMS对矿物包裹体化学成分分析的研究进展与存在问题,并做了相关领域的展望。     

西太平洋海山富钴结壳稀土元素(REE)组成原位LA-ICPMS测定

利用激光剥蚀电感耦合等离子体质谱(LA-ICPMS)微区原位分析方法,对采自西太平洋海山具完整三层结构的富钴结壳样品进行了稀土元素(REE)含量测定,结果表明, 虽然均产于西太平洋海山且均具有明显的三层结构,富钴结壳化学组成受地理位置和沉积环境影响很大。绝大多数西太平洋富钴结壳具有高ΣREE、高LREE/HREE、δCe正异常和δEu基本无异常或微弱正异常的特点, 显示它们主要由正常海水沉积形成。结壳不同层圈之间REE组成有较大的区别, 其原因主要在于其形成环境和矿物组成不同。样品0327稀土元素总量(∑REE)由亮煤层到疏松层到外层逐渐升高,且亮煤层δCe和Y/Ho变化非常大,最大值分别为38.61和105.5,显示该层生长环境较为氧化且相对动荡,而样品0346中三层结构的∑REE都非常高,且变化趋势与0327正好相反,从亮煤层到致密层∑REE有降低的趋势。 亮煤层形成时海水相对较氧化的环境有利于铁锰氧化物的形成和Ce⁴⁺等稀土元素的吸附,导致其中ΣREE较疏松层和外层为高,而后期磷酸盐化导致REE元素的迁移和亏损。在结壳生长剖面上,由最外层到疏松层和亮煤层,δCe呈明显上升趋势,且变化范围趋大,说明该结壳所处的海水环境在由老至新的生长过程中由相对动荡和氧化变为相对平静和还原。     

电感耦合等离子体发射光谱法同时测定土壤样品中54种组分

用高氯酸-氢氟酸-硝酸消解样品,样品中的难溶组分被有效浸取,电感耦合等离子体发射光谱法测定土壤样品中稀土元素及稀散元素等54种组分。通过筛选分析谱线、合理设置背景扣除位置及干扰元素校正系数,改善了光谱干扰。方法经国家一级土壤标准物质分析验证,结果与标准值吻合,相对标准偏差低于6.0%。方法可测组分多,试剂用量少,简便快速,劳动强度低,能够满足基体组成复杂的区域土壤地球化学调查样品分析的要求,也为其他地球化学样品中相关组分的分析提供借鉴。     

川西甲基卡锂资源富集区根系土壤重金属含量水平及时空分布特征

锂能源金属的战略地位不断提高,与锂矿床及锂金属相关的研究也在不断跟进,锂矿区土壤重金属污染近年来持续受到关注,其含量分布情况值得深入研究。本文对亚洲最大的锂矿区——川西甲基卡根系土壤环境进行重金属含量监测,调查和评价锂矿区土壤重金属含量水平及其安全性。2016—2018年于川西甲基卡锂资源富集区采集根系土壤样品68件,采用电感耦合等离子体质谱法(ICP-MS)测定根系土壤Cd、As、Pb、Cr、Cu、Ni、Zn含量。测试结果表明,甲基卡矿区根系土壤Cd、As、Pb、Cr、Cu、Ni、Zn含量平均值分别为0.13、15.31、25.47、60.57、16.12、23.59、66.83mg/kg,与2018年8月最新颁布的农用地土壤标准对比,无一超标,均低于风险筛选值及管制值。常见矿床的尾矿库区土壤一般存在严重的重金属污染,而甲基卡尾矿库土壤重金属含量均低于环境标准限值,且矿业活动停止的三年期间尾矿库区根系土壤中Cd、As、Cr含量明显呈逐年下降趋势。本研究认为,选矿厂房及尾矿库周边根系土壤重金属由于人为源的存在有一定的富集现象,但不构成危害,废弃物对环境污染小。     

碱熔沉淀分离-电感耦合等离子体质谱法测定伴生重晶石稀土矿中的稀土元素

采用电感耦合等离子体质谱法(ICP-MS)测定伴生重晶石轻稀土矿中的稀土元素时,Ba以及轻稀土元素La、Ce、Pr、Nd、Sm等对中重稀土造成严重的质谱重叠干扰,因此在保证矿石完全消解的同时,若能选择合适的前处理方法实现目标元素与基体的有效分离,将有利于减少质谱干扰。本文采用过氧化钠-碳酸钠熔融分解伴生重晶石的稀土矿样品,熔融物用三乙醇胺溶液提取,将沉淀过滤去除硅、铁、锰、铝等大量基体元素,而稀土元素与钡、锶、钙等留存于沉淀中,沉淀经盐酸溶解后再用氨水进行二次沉淀,将稀土元素与伴生的高含量钡、锶、钙等元素分离,分离率超过96%,从而极大地降低了由钡的氧化物和氢氧化物对~(153)Eu等元素质量数的质谱干扰。轻稀土元素对中重稀土元素的干扰则通过测定高浓度的单元素标准溶液在m/z 138～175处的表观浓度来计算干扰校正系数,对干扰量进行扣除校正。该方法通过稀土矿石标准物质GBW07187、GBW07188验证,测定值与认定值的相对误差10%;应用于伴生重晶石稀土矿石实际样品分析,相对标准偏差(RSD,n=12)为0.5%～4.6%,证明了本方法可用于分析高钡矿石中的稀土元素。     

AN ION PROBE CONTRIBUTION TO RARE EARTH ELEMENT INVESTIGATION OF GABBRO GOG-1 USING SECONDARY ION MASS SPECTROMETRY

An updated REE measurement of Gabbro GOG-1 was carried out by means of secondary ion mass spectrometry (SIMS). The availability of high amount of rock powder allowed the sample to be well ground and homogenized before analysis. Fused glass pellets were employed for SIMS investigations. REE data were compared with new ICP-AES and NAA analyses. REE results from all employed analytical techniques show good agreement and are consistent with in-situ SIMS measurements of REE in major mineral phases forming GOG-1. Extensive homogeneity tests seem to confirm the possibility to using this rock as a reference material for earth sciences.     

江西赣南风化淋滤型稀土矿床中的粘土矿物研究

对江西赣南6个地区风化淋滤型稀土矿中全风化层的粘土矿物进行了研究,为进一步了解粘土矿物对该类型稀土矿中稀土元素分异的影响奠定了基础。X射线衍射自然定向片、甲酰胺片、饱和乙二醇片和加热片、红外光谱及扫描电镜观察结果表明该区粘土矿物以片状高岭石和针管状7埃洛石为主,其中坳背塘、长坑屋、上堡、杨村样品主体为高岭石,足洞样品中发育大量埃洛石,而石排样品中高岭石与埃洛石比例相当。电感耦合等离子体质谱分析表明稀土元素在粘土矿物中大量富集,其稀土元素配分不仅受到原岩的影响,而且受到粘土矿物本身性质的影响。Ce元素在足洞和石排样品的粘土矿物中表现出正异常,而在其他样品粘土矿物中表现为负异常,可能与其中发育的埃洛石密切相关。Ce元素可能以方铈矿胶膜的形式包裹在针状埃洛石中,和/或以离子形式被选择性吸附于埃洛石表面。     

Determination of Nickel in GSJ Standard Rock Samples Using Secondary Ion Mass Spectrometry

Trace level determination of nickel in silicate rock samples has been achieved using secondary ion mass spectrometry (SIMS) with kinetic energy filtering. Standard rock references, issued by the Geological Survey of Japan, were fused into glass and used as standards for the SIMS analysis. Due to interferences from the glass matrix, the secondary ion of mass 60 was only useful for Ni, although the secondary ion was interfered mainly by CaO+. The contributions of these molecular ions were deconvolved by a least squares regression. Good linear correlation between results after the deconvolution and the Ni concentration in the glass standards was obtained. The uncertainties of the SIMS analysis depend strongly on the degree of contribution of CaO+ molecular ion. Such a method of SIMS analysis is especially useful to study the detailed behavior of Ni on a micro-scale in Ca-poor materials.     

Further Characterisation of the 91500 Zircon Crystal

This paper reports the results from a second characterisation of the 91500 zircon, including data from electron probe microanalysis, laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS), secondary ion mass spectrometry (SIMS) and laser fluorination analyses. The focus of this initiative was to establish the suitability of this large single zircon crystal for calibrating in situ analyses of the rare earth elements and oxygen isotopes, as well as to provide working values for key geochemical systems. In addition to extensive testing of the chemical and structural homogeneity of this sample, the occurrence of banding in 91500 in both backscattered electron and cathodoluminescence images is described in detail. Blind intercomparison data reported by both LA-ICP-MS and SIMS laboratories indicate that only small systematic differences exist between the data sets provided by these two techniques. Furthermore, the use of NIST SRM 610 glass as the calibrant for SIMS analyses was found to introduce little or no systematic error into the results for zircon. Based on both laser fluorination and SIMS data, zircon 91500 seems to be very well suited for calibrating in situ oxygen isotopic analyses.     

Mass Fractions of Forty‐Six Major and Trace Elements,Including Rare Earth Elements,in Sediment and Soil Reference Materials Used in Environmental Studies

Development of new techniques, enabling simultaneous determination of large numbers of elements in environmental samples, can force analysts to use certified reference materials that do not contain all the elements of interest. In this paper, the mass fractions of forty‐six major and trace elements, including rare earth elements (REE), are presented in one soil (NCS DC 77302 also known as GBW 07410) and five sediment (Metranal‐1, IAEA 405, MESS‐3, NCS DC 73309 also known as GBW 07311 and NCS DC 75301 also known as GBW 07314) certified reference materials determined by high resolution inductively coupled plasma‐mass spectrometry. The selected certified materials represent a spectrum of geological matrices often analysed in environmental studies. Measured elements include certified elements, elements listed with information values as well as new elements absent from certificates, including REEs and some other elements. REE + Y mass fractions in the river sediment reference material Metranal‐1 are reported for the first time. The results obtained are in agreement with available certified or information values.     

Strategies towards robust interpretations of in situ zircon oxygen isotopes

Oxygen isotopes are a versatile tool to address a wide range of questions in the Earth sciences. Applications include geothermometry, paleoclimatology, tracing of geochemical reservoirs, fluid-rock interaction, magmatic petrogenesis, and identification of extra-terrestrial materials. Zircon arguably provides one of the most robust records of primary magmatic O isotope ratio due to low diffusion rates in crystalline grains. The ability to correlate zircon O isotopes with temporal and petrogenetic information (e.g. U-Pb geochronology, Lu-Hf isotopes, and trace elements) makes this mineral a key archive for understanding Earth’s crustal evolution. Consequently, zircon O isotope geochemistry has found widespread usage to address fundamental questions across the earth and planetary sciences. The general apparent ease of O isotopic acquisition through the advancement of rapid in situ techniques (i.e. secondary ion mass spectrometry; SIMS) and associated dedicated national laboratories has led to the generation of large O isotopic data sets of variable quality, highlighting the importance of a coherent workflow for data collection, reduction, and presentation. This paper presents a set of approaches for measurement, assessment, and reporting of zircon O isotope data. The focus in this contribution is on in situ analysis via secondary ion mass spectrometry using large geometry instruments, but other commonly used techniques are briefly reviewed for context. This work aims to provide an analytical framework necessary for geologically meaningful interpretation of O isotope data. In addition, we describe inherent geological (e.g. radiation-induced disturbance of the zircon O isotopic system) and analytical (e.g. fractionation due to sample topography effects) challenges and outline means to identify and avoid such issues as a prerequisite to the generation of robust primary O isotopic signatures for geological interpretation.     

赣南峰山离子型稀土矿床成矿机理探讨

以赣南大埠岩体西部峰山钻孔风化壳剖面为研究对象,在风化壳剖面各层地质特征研究的基础上,对风化壳剖面各层中含稀土矿物开展了扫描电镜和电子探针分析,探讨了风化壳剖面各层主、微量（包括稀土）元素和离子相稀土元素特征。研究表明,风化壳中稀土元素呈“弓背式”分布,矿体位于风化壳剖面2~9 m,w(REE)平均为516.8×10^-6,离子相稀土元素浸出率为51%~84%,离子相与全项稀土元素总量分布特征一致。风化壳中稀土元素主要以离子吸附态形式和独立矿物（次生方铈矿和风化残余的磷钇矿、褐钇铌矿）形式存在,以离子吸附态形式为主。峰山风化壳离子吸附型稀土矿为轻、重稀土元素共生型稀土矿,以重稀土元素占主导,矿体上部相对富集轻稀土元素,下部相对富集重稀土元素。风化壳剖面中稀土元素的富集分异主要受轻重稀土元素地球化学行为的差异性、风化程度和黏土矿物含量联合控制。