无内标-多外标校正激光剥蚀等离子体质谱法测定磁铁矿微量元素组成

激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)常用于磁铁矿原位微量元素分析,按照校正策略不同,主要分为内标法和无内标法。内标法需要用电子探针(EMPA)预先测定磁铁矿中内标元素Fe的含量,过程较繁琐,且待测元素含量会受到内标元素含量测定的影响。本文采用铁含量较高的玄武质玻璃BCR-2G、BIR-1G、BHVO-2G和GSE-1G作为外标,避免了内标元素含量的测定,建立了无内标-多外标校正LA-ICP-MS测定磁铁矿微量元素组成的分析方法。利用该方法测定了科马提岩玻璃GOR-128g和自然岩浆磁铁矿BC 28的微量元素组成以评估方法的可靠性。结果表明,科马提岩玻璃的测定结果与推荐值及前人内标法的测定值一致,多数元素的相对标准偏差RSD5%;自然岩浆磁铁矿的测定结果与推荐值相比,多数元素的RSD7%,低于前人内标法的RSD(15%)。由此说明无内标-多外标法可以实现富铁硅酸岩或磁铁矿微量元素含量的准确校正,克服了基体效应的影响。因此,无内标-多外标法是一种原位测定磁铁矿微量元素含量的快速、准确方法,具有一定的应用潜力。     

CGSG系列标准物质元素分馏效应及主量微量元素单元内均匀性探究

探究CGSG系列标准物质(CGSG-1、CGSG-2、CGSG-4、CGSG-5)的元素分馏效应及均匀性问题有助于开展其质量评估和应用推广。本文采用电子探针(EMPA)和激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)研究了CGSG标准物质中的元素分馏效应、主量和微量元素单元内均匀性,并报道了主量和微量元素分析数据。结果表明,在50μm激光束斑下,CGSG系列标准物质的元素分馏效应可忽略不计。EMPA均匀性指数结果显示,CGSG标准物质主量元素的单元内均匀性满足要求;以MPI-DING标准物质为参照,LA-ICP-MS测试CGSG标准物质中的大多数微量元素的单元内均匀性良好。与已报道的数据相比,本文报道的EMPA主量元素数据偏差在2%以内;LA-ICP-MS主量元素数据偏差在5%以内,微量元素数据基本匹配,少数元素由于分析不确定度较大等原因,如Cr、Ge、Cd、As、Tl等与已报道数据偏差较大。总体上,本文报道的分析数据可为CGSG定值数据库提供进一步的补充。     

古代玻璃材料LA-ICP-MS组分分析及产源研究

古代玻璃及玻璃质材料的定量分析对于研究其制作年代及产地、原料的来源以及制作工艺有着重要的参考意义。与电子探针(EMPA)、能谱扫描-电子显微镜(EDX-SEM)等分析方法相比,LA-ICP-MS能够快速且准确地提供样品主次量及微量元素信息。本文对LA-ICP-MS古代玻璃元素定量分析中的影响因素进行研究认为:在193nm激光下玻璃标准NIST610和康宁玻璃标准之间基体差异造成的影响较小,而采用玻璃标准NIST610为外标结合基体归一化法的校正策略测定康宁标准结果表明,该策略能够准确反映不同类型古代玻璃材料中成分组成;实验中不同剥蚀模式的研究,有助于不同实验条件的建立,从而满足不同研究的需要。本次研究对出土样品进行了分析,为该制品的产源研究提供了数据支持。     

橄榄石中Ni、Ca、Mn含量的电子探针与激光等离子体质谱准确分析

镁铁-超镁铁岩浆岩中的橄榄石斑晶是示踪玄武岩原始岩浆组成, 进而示踪地幔源区组成和演化的最重要矿物.本研究利用电子探针和激光等离子质谱两种方法对橄榄石斑晶中Ni、Ca、Mn等具有重要成因指示意义的少量-微量元素进行准确分析.采用的电子探针方法较常规电子探针分析方法可使元素的检出限降低3~18倍, 并且激光等离子质谱方法对4个国际标准MPI-DING玻璃(KL2-G (玄武岩)、ML3B-G (玄武岩)、StHs6/80-G (安山岩) 和T1-G (石英闪长岩)) 中Mg、Al、Ca、Ti、Cr、Mn、Fe、Co和Ni含量的分析结果与其推荐值大多数相差在±5%之内.两种方法对费县和四合屯同一样品获得的Ca、Ni、Co、Cr、Mg和Fe的含量相差绝大多数情况下小于10%, 表明利用研究建立的电子探针和激光等离子体质谱两种方法均可准确分析橄榄石中的上述元素含量.      

193nmLA-ICPMS对国际地质标准参考物质中42种主量和微量元素的分析

本文采用配备有 193nm Ar F准分子 (excimer)激光器的 Geo L as2 0 0 M剥蚀系统和 Elan6 10 0 DRC ICP- MS对 4个美国地质调查所 (USGS)玻璃标准参考物质以及 3个美国国家标准技术研究院 (NIST)人工合成硅酸盐玻璃标准参考物质中几乎覆盖整个质量数范围 (从 7L i到 2 38U)的 38个微量和 4个主量 (Na、Mg、Ti和 Mn)元素进行了分析。分析结果表明 ,无论是对 USGS还是 NIST玻璃 ,元素分析的相对标准偏差 RSDs和分析值与参考值之间的相对偏差 (RDs)一般优于 10 % ,RSD和RD较大的元素主要出现在含量很低或不均匀样品中。稀土元素的 RSD显示 ,除 AGV- 2 G可能存在不均匀现象外 ,其它所测样品在 6 0 μm尺度上 ,元素分布是均匀的。本研究证明 ,由于 ICP- MS具有 10 8cps(每秒计数 )的动态线性范围 ,本实验室的L A- ICPMS系统可定量分析含量在百分之几的主量元素及微量元素。分析精密度和准确度可与常规溶液雾化进样 ICP- MS方法相媲美     

ODP 1144站钻孔沉积物中微玻璃陨石的元素地球化学特征

利用电子探针和激光探针等离子体质谱方法分析了取自南海北部的ODP1144钻孔沉积物中的微玻璃陨石和取自邻近的广东省湛江和吴川玻璃陨石的主元素和微量元素组成。结果显示，这些微玻璃陨石属于亚洲-澳大利亚散落区的普通微玻璃陨石。从成分上看，这些微玻璃陨石存在两种不同的类型，其中的绝大部分Al2O3含量在19.0%以上，属于高Al类型，相应的难熔微量元素含量也比较高；个别微玻璃陨石Al2O3含量（13.0%)和难熔微量元素含量较低，微量元素含量和特征比值都与邻近的广东省湛江和吴川的玻璃陨石相近。元素地球化学特征意味着，这些微玻璃陨石来源于同一靶源区，但靶区的物质组成并不均一。     

激光剥蚀电感耦合等离子体质谱-电子探针分析白山堂铜矿中的黄铁矿成分

通过激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)获得被测物相中痕量元素的丰度值是目前原位分析矿物物相的技术之一。黄铁矿作为斑岩铜矿中的重要矿物,其主量、微量元素的特征能为成矿过程提供重要信息。本文建立了应用LA-ICP-MS测定黄铁矿微区微量元素组成、电子探针(EMPA)测定主量元素的方法,并将该方法应用到白山堂斑岩铜矿区。LA-ICP-MS实验采用60μm的激光束对分析样品进行斑点式剥蚀,以氦气作载气,重复频率5 Hz,激光能量约6 J/cm~2;单点分析时间60 s,分析数据以Fe作内标,用MASS-1黄铁矿标样进行校正,多数元素分析精度好于10%。针对黄铁矿与毒砂光学性质相似,容易混淆的问题,可以利用二者物理性质的差异进行区分。测试结果显示:矿区黄铁矿的主量元素呈亏硫高铁的特征,指示其为热液成因;微量元素特征表明其形成深度为中部,属与火山作用有关的中低温热液型黄铁矿。此结论对白山堂铜矿的成因类型、成矿流体来源等提供了相应的证据,对矿区的勘查具有理论指导意义。     

电子探针对含Be矿物绿柱石的定量分析

绿柱石是最常见的含有超轻元素Be的硅酸盐矿物,其准确定量测试一直是电子探针微束分析领域的一大难点。本文总结了超轻元素微区测试的特点和难点,使用电子探针并结合全元素测试的思路对含Be矿物绿柱石进行微区化学成分分析,获得了令人满意的结果。结果同时表明,全元素测试方法可用于硅酸盐矿物中氧元素测试。此外,应用此方法对于含水或是变价元素矿物可得到更为理想的元素定量结果。     

锍镍试金技术制备含铂族元素硫化物微区分析标准样品的可行性

激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)适合于直接分析硫化物矿物中痕量元素的含量及空间分布,但硫化物矿物的激光剥蚀特性与硅酸盐及氧化物不同,受到的干扰也更严重,且由于硫化物标准物质(尤其是含铂族元素、Au、Ag等贵金属元素标准物质)极度缺乏,限制了LA-ICP-MS技术在硫化物微区分析中的广泛应用。本文以贵金属标准样品GPT-9和矿石标准物质为原料合成锍镍试金扣,并封入真空管中重熔,利用背散射电子图像和LA-ICP-MS分析元素分布的均匀性,探讨真空重熔锍镍试金扣制备硫化物原位微区分析标准样品的可行性。背散射电子图像(BSE)显示真空重熔后锍镍试金扣由单相S、Ni化合物组成。LA-ICP-MS线扫描和点扫描分析表明,锍镍试金扣中S、Ni、Cr、Co、Cu、Pb、Sb、Cd、Bi等主量及微量元素分析精密度(RSD)均小于10%,均匀分布;在镍扣制备过程中Zn相对于Cu、Pb、Sb更难进入硫化物相;贵金属元素Au、Ag、Pt均一性较好,其余贵金属元素由于含量低、仪器波动及质谱干扰等影响因素造成分析数据的RSD相对较大,但可通过提高原料中贵金属元素含量、降低熔融样品淬火温度等方法进一步提高其均匀性。锍镍试金扣的组成元素对铂族元素分析的质谱干扰研究表明,重铂族元素(Os、Ir、Pt)和Au受到的干扰可忽略不计;轻铂族元素(Ru、Rh、Pd)受金属氩化物干扰较为严重,需进行干扰校正。研究认为,真空重熔技术可有效提高锍镍试金扣中各元素(包括贵金属)的均一性,达到硫化物原位微区分析标准样品的要求,利用真空重熔锍镍试金扣制备LA-ICP-MS原位微区痕量及贵金属硫化物分析标准样品具可行性。     

高温熔融研制安山岩玻璃标准物质初探

地质标准玻璃物质在激光剥蚀等离子体质谱技术应用中发挥着重要的作用,目前国内对于地质标准玻璃物质合成方法研究还较少,一定程度上限制了该技术的高精度应用。本文对国家一级安山岩粉末标准物质(GSR-2)采用高温熔融法合成安山岩玻璃标准物质(GSR-2G),探讨了熔融温度、时间、淬火方式对安山岩玻璃均一性的影响。实验确定了在熔融温度1300℃、熔融时间4 h的最佳条件下,采用液氮淬火合成的安山岩玻璃标准物质GSR-2G均一性较好,可作为微区分析的内部标准物质。利用193 nm ArF准分子激光剥蚀-四极杆等离子体质谱(LA-Q-ICPMS)分析合成的GSR-2G中35个微量元素和10个主量元素,精密度(RSD)均优于10%。GSR-2G的7Li～238U共35个微量元素,化学法分析测定值与LA-Q-ICPMS测定值的相对偏差优于10%;23Na～56Fe共10个主量元素,电子探针分析测定值与LA-Q-ICPMS测定值一致。利用LA-Q-ICPMS法分析GSR-2G中40个元素,获得的平均测定值可作为初步参考值。     

Chemical Characterisation of the USGS Reference Glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G Using EPMA, ID-TIMS, ID-ICP-MS and LA-ICP-MS

The USGS reference glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G were investigated by different analytical techniques. All these materials have a geological (basaltic) matrix and are therefore useful in igneous geochemistry as matrix-matched reference materials for microanalytical techniques. The new GS glasses have trace elements in groups at concentration levels of about < 0.01, 5, 50 and 500 μg g^-1. Their major element compositions have been determined by EPMA, and trace elements have been analysed by LA-ICP-MS and two isotope dilution techniques using TIMS and ICP-MS. EPMA and LA-ICP-MS analyses indicated that the USGS reference glasses are homogeneous at the μm to mm scale with respect to major (variations < 1-2%) and most trace elements (variations 1-4%). Trace element data obtained from the different analytical techniques agreed within an uncertainty of 1-5%, indicating that between method results are comparable. Therefore, the preliminary working values for the four USGS GS glasses calculated from these data have a low level of uncertainty.     

A Flux‐Free Fusion Technique for Rapid Determination of Major and Trace Elements in Silicate Rocks by LA‐ICP‐MS

A simple flux‐free fusion technique was developed to analyse major and trace element compositions of silicate rocks. The sample powders were melted in a molybdenum capsule sealed in a graphite tube to make a homogenous glass in a temperature‐controlled one‐atmosphere furnace. The glass was then measured for both major and trace element concentrations by LA‐ICP‐MS using a calibration strategy of total metal‐oxide normalisation. The optimum conditions (i.e., temperature and duration) to make homogeneous glasses were obtained by performing melting experiments using a series of USGS reference materials including BCR‐2, BIR‐1, BHVO‐2, AGV‐1, AGV‐2, RGM‐1, W‐2 and GSP‐2 with SiO₂ contents from 47 to 73% m/m. Analytical results of the USGS reference materials using our method were generally consistent with the recommended values within a discrepancy of 5–10% for most elements. The routine precision of our method was generally better than 5–10% RSD. Compared with previous methods of LA‐ICP‐MS whole‐rock analyses, our flux‐free fusion method is convenient and efficient in making silicate powder into homogeneous glass. Furthermore, it limits contamination and loss of volatile elements during heating. Therefore, our new method has great potential to provide reliable and rapid determinations of major and trace element compositions for silicate rocks.     

Multi-Element Isotope Dilution Sector Field ICP-MS: A Precise Technique for the Analysis of Geological Materials and its Application to Geological Reference Materials

We present a multi-element technique for the simultaneous determination of twelve trace elements in geological materials by combined isotope dilution (ID) sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) following simple sample digestion. In addition, the concentrations of fourteen other trace elements have been obtained using the ID determined elements as internal standards. This method combines the advantages of ID (high precision and accuracy) with those of SF-ICP-MS (multi-element capability, fast sample processing without element separation) and overcomes the most prevailing drawbacks of ICP-MS (matrix effects and drift in sensitivity). Trace element concentration data for BHVO-1 (n = 5) reproduced to within 1–3% RSD with an accuracy of 1–2% relative to respective literature values for ID values and 2–3% for all other values. We have applied this technique to the analysis of seventeen geological reference materials from the USGS, GSJ and IAG. The sample set also included the new USGS reference glasses BCR-2G, BHVO-2G and BIR-1G, as well as the MPI-DING reference glasses KL2-G and ML3B-G, and NIST SRM 612. Most data agreed within 3–4% with respective literature data. The concentration data for the USGS reference glasses agreed in most cases with respective data of the original rock powder within the combined standard uncertainty of the method (2–3%), except the U concentration of BIR-1G, which showed a three times higher concentration compared to BIR-1.     

Determination of Trace Elements in Calcite Using Solution and Laser Ablation ICP-MS: Calibration to NIST SRM Glass and USGS MACS Carbonate, and Application to Real Landfill Calcite

We report new data on the trace element concentrations of Mg, Cr, Mn, Co, Ni, Cu, Zn, Sr, Cd, Ba, La, Ce, Nd, Pb and U in USGS carbonate reference materials (MACS-1 and MACS-2) and compare solution ICP-MS and LA-ICP-MS trace element determinations on landfill calcites using calibration to different reference materials (MACS-1 and MACS-2 carbonate and NIST SRM 612 glass). Very good agreement (differences below 10% relative) was found between laser ablation and solution ICP-MS data for MACS-1 with higher concentrations of trace elements (values between 100 and 150 μg g⁻¹), with the exception of Cu and Zn. Similarly good agreement was found for MACS-2 with lower trace element concentrations (units to tens of μg g⁻¹), with the exception of Cr, Co and Zn. The MACS-1 reference material for calibration of LA-ICP-MS was found to be extremely useful for in situ determination of trace elements in real-world carbonate samples (landfill calcites), especially those present in calcite in higher concentrations (Mn, Sr, Ba; < 5% RSD). Less accurate determinations were generally obtained for trace elements present at low concentrations (∼ units of μg g⁻¹). In addition, good agreement was observed between the instrument calibration to MACS and NIST SRM 612 glass for in situ measurements of trace elements in landfill calcites K-2, K-3 and K-4 (differences below 15% relative for most elements). Thus, the application of MACS carbonate reference materials is promising and points to the need for the development of new carbonate reference materials for laser ablation ICP-MS.     

主编絮语

自2011年第2期起,我刊推出"主编絮语"这个栏目,目的在于及时表达我刊的办刊思想和办刊动态,推介重点文章,加强与读者、作者和各位编委的信息沟通和交流。正如在本卷卷首语中指出的,文章质量是刊物的生命线。因此,如何提高发表在我刊文章的质量,是本届编委会的第一要务和工作重点。编委会将通过多种途径,从     

GeoReM: A New Geochemical Database for Reference Materials and Isotopic Standards

We have developed a new database named GeoReM ( http://georem.mpch-mainz.gwdg.de ) for reference materials and isotopic standards of geochemical and mineralogical interest. Reference samples include rock powders originating from the USGS, GSJ, GIT-IWG, synthetic and natural reference glasses originating from NIST, USGS, MPI-DING, as well as mineral (e.g., 91500 zircon), isotopic (e.g., La Jolla, E&A, NIST SRM 981), river water and seawater reference materials. GeoReM is a relational database, which strongly follows the concept of the three EARTHCHEM databases. It contains published analytical and compilation values (major and trace element concentrations, radiogenic and stable isotope ratios), important metadata about the analytical values, such as uncertainty, uncertainty type, method and laboratory. Sample information and references are also included. Three different ways of interrogating the database are possible: (1) sample names or material types, (2) chemical criteria and (3) bibliography. Some typical applications are described. GeoReM currently (October 2005) contains more than 750 geological reference materials, 6000 individual sets of results and references to 650 publications.     

Trace Element Analysis of Fused Whole-Rock Glasses by Laser Ablation-ICP-MS and PIXE

The concentrations of fifty trace elements, including relatively volatile elements and transition metal elements, in fused glasses of Geological Survey of Japan rock reference materials GSJ JR-2, JA-1, JA-2, JB-1a, JB-3, JGb-1 and JF-1 were determined by particle (proton) induced X-ray emission (PIXE) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The fused glasses were prepared by rapid fusion and subsequent quenching in welded platinum capsules and were found to be homogeneous for major elements and for trace elements with concentrations of more than 1 μg g^-1 within the observed precision (± 10% mean) on a 70 μm sampling scale. The values obtained by PIXE and LA-ICP-MS for the transition elements (Cr, Mn, Fe, Ni and Cu), the relatively volatile elements (Zn, Ga, Rb and Pb) and the refractory elements (Y, Zr, Nb and Th) with concentrations greater than a few μg g^-1 showed good agreement (within 10 % relative difference). The values for almost all the elements detected at concentrations higher than 1 μg g^-1 as determined by LA-ICP-MS also agreed well with the reference values (mean relative difference < ± 10%), except for B and Cu. The good agreement confirmed the appropriateness of the NIST SRM 600 series glass calibration reference material for LA-ICP-MS analysis of glasses with variable major-element compositions for almost all elements. The concentrations of Cu in all the samples were lower than the reference values, which was attributed to adsorption of the transition metals onto the platinum capsule during preparation.     

Multi-Elemental Analysis of ATHO-G Rhyolitic Glass (MPI-DING Reference Material) by Femtosecond and Nanosecond LA-ICP-MS: Evidence for Significant Heterogeneity of B,V, Zn,Mo, Sn,Sb, Cs,W, Pt and Pb at the Millimetre Scale

This paper reports on the application of variants of LA-ICP-MS – including infrared femtosecond laser ablation (fs-LA) inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS) and nanosecond laser ablation (ns-LA) coupled with single-collector sector-field (SF-) ICP-MS – to the in situ determination of trace elements in different splits of the reference material (RM) ATHO-G (MPI-DING). Analyses of the materials performed by fs- and ns-LA-ICP-MS demonstrated the efficiency of the techniques with typical accuracy at a level of ≤ ± 20%. One ‘anomalous’ split, however, displayed a significant discrepancy from the reference concentrations for B, V, Zn, Mo, Sn, Sb, Cs, W and Pb. Three- to six-fold enrichment of V, Mo, Cs and Pt relative to the reference contents in this split is likely to have been due to direct contact of the silicate melt with Pt crucible walls and ceramics. Boron, Zn, Sn, Sb, W and Pb depletion relative to the reference concentrations is probably due to siderophile element adsorption by the Pt walls and/or related to the formation of volatile-depleted compositional cords during the preparation process. Our results imply that additional precautions should be taken against volatile/siderophile element heterogeneity in marginal/surface layers (≤ 10 mm) during the preparation of RMs by the fusion technique.     

STDGL3, a Reference Material for Analysis of Sulfide Minerals by Laser Ablation ICP-MS: An Assessment of Matrix Effects and the Impact of Laser Wavelengths and Pulse Widths

A new reference material, STDGL3, for the calibration of in situ analyses of sulfide minerals by LA-ICP-MS has been developed and characterised. It represents a lithium-borate-based glass containing a mixture of Zn- and Fe-sulfide concentrates doped with several chalcophile elements as well as Zr, Gd, Hf and Ta required for assessing common interferences on Ag, Au and Pt. STDGL3 has a wider range of elements and a better homogeneity compared with existing reference materials for LA-ICP-MS analysis of sulfides. Compositional variations for most elements are below 3% RSD, below 5% RSD for Ag, Au and Pt, and below 7% RSD for Se, when performing spot analyses with a 50 μm beam size. Its preparation recipe is reproducible allowing for multiple batches to be made. Use of STDGL3 significantly improves accuracy of sulfide mineral analysis by LA-ICP-MS when compared with use of other available reference materials. Performance of STDGL3 was evaluated using several different laser systems. No significant change was observed between 193 nm ArF excimer lasers with 5 and 20 ns pulse widths, but use of 213 and 248 nm lasers displays more systematic differences, especially when analysing galena. Correction coefficients are needed for some elements (Zn and Cd in particular) when analysing sulfide minerals using STDGL3 as a calibration reference material.     

High Sensitivity Analysis of Trace Element-Poor Geological Reference Glasses by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS)

Fifty-two trace elements in NIST SRM 614, 616 and MPI-DING BM90/21-G glass reference materials as well as in NIST SRM 612, USGS BCR2-G and other MPI-DING reference glasses (KL2-G, GOR132-G, GOR128-G, ATHO-G, Tl-G, StHs6/80-G and ML3B-G) were determined by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Accurate ultra-low trace element abundances in the NIST SRM 614, 616 and BM90/21-G reference glasses down to lower ng g⁻¹ levels were determined with relative standard deviations (RSD) of less than 10%. Limits of detection using He as carrier gas were up to two times lower than with Ar and were 0.004 to 0.12 μg g⁻¹ for elements of lower mass numbers (amu < 85) and 0.002 to 0.06 μg g⁻¹ for elements having amu < 85. The measured concentrations generally agree within 15% with previous studies except for B in NIST SRM 614 and 616, which appears to be heterogeneously distributed, and Co, Zn, Ga and Ag in NIST SRM 616 for which the existing data set is too small to evaluate the discrepancies. New values for As (0.593 μg g⁻¹), Ag (0.361 μg g⁻¹) and Cd (0.566 μg g⁻¹) in NIST SRM 614 and new values for Na (94864 μg g⁻¹) and As (0.276 μg g⁻¹) in NIST SRM 616 are reported.