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。     

电感耦合等离子体质谱法测定岩土中银的干扰分析

利用电感耦合等离子体质谱法测定土壤、水系沉积物及岩石样品中的痕量银时,Zr 、Nb与氧的复合离子对银的测定结果产生干扰,经过反复试验计算出91 Zr16 O＋对107 Ag＋的干扰系数,利用系数进行在线干扰校正,用115 In内标校正仪器漂移和基体效应。经过对4个岩石标准物质,6个土壤标准物质和8个水系沉积物标准物质进行验证,测定结果与推荐值相吻合,能够满足岩土样品分析精密度和准确度的要求,同时也可进行钨、钼等元素的测量。     

应用X射线荧光法测定铁矿石中的铁

采用Li2B4O7+LiBO2混合试剂熔融法制样,应用WD-XRF光谱仪测定铁矿石中的Fe及Si、Al、Ca、Mg、K、P、Ti、Mn等元素。试验采用理论α系数和经验系数法相结合的基体效应校正模式,主要元素铁的测定采用Co2O3做内标[1]。经标准物质检验,统计结果显示,主元素Fe的测试精密度、准确度[2]均满足要求,RSD≤0.12%(n=20)。随机选择30件样品,与滴定法测铁的数据吻合较好。     

193 nm ArF准分子激光剥蚀等离子体质谱法测定熔融玻璃中微量铌和钽

建立了一种利用193 nm ArF准分子激光剥蚀-等离子体质谱法直接测定岩石熔融玻璃中Nb和Ta的分析方法。采用常规的碱熔法熔融样品,以29Si为内标、玻璃标准参考物质NIST SRM612为外标进行测定,方法的检出限分别为Nb0.003μg/g和Ta0.006μg/g(n=10)。分析4个不同的地质标准参考物质结果表明,Nb和Ta测定结果的相对误差(RE)和精密度(RSD,n=11)均低于10%。     

熔融制样-X射线荧光光谱法测定高磷铁矿中主量元素

采用熔融制样,加入钴元素(Co Kα)作为铁的内标元素,建立了熔融制样-波长色散X射线荧光光谱法测定高磷铁矿中主量元素的分析方法。用国家标准物质和人工合成标准参考物质拟合校准曲线,对熔融条件进行了研究,确定样品与复合熔剂(Li_2B_4O_7:LiBO_2:Li F=4.5:1:0.4)的熔融稀释比例为1︰25,650℃预氧化,并在1050℃温度下熔融完全,成片均匀,表面光滑,无气孔,符合测定的要求。本方法可以简单、快速、准确地测定高磷铁矿中的主量元素,满足日常生产对高磷铁矿石中的测定要求。     

封闭酸溶-电感耦合等离子体原子发射光谱法同时测定地质样品中硼砷硫

采用充氩电荷注入检测器(CID)-电感耦合等离子体原子发射光谱仪结合HF—HNO3-HClO4-H3PO4密封溶样法，建立了适用于多目标地质调查中土壤、水系沉积物等地质样品中B、As、S的同时测定方法。方法的特点是通过加入少量H3PO4避免了易挥发元素B的挥发损失；采用Se 196.0nm谱线为内标，对残留空气对超紫外区谱线测定中的强度漂移影响起到了很好的补偿作用；该方法还可同时测定Cu、Pb、Zn、Cr、Ni、Li、Mn和V等微量元素。B、As、S的仪器检出限(3SD，μg／mL)分别为0．01、0．008、0．03，方法检出限(10SD，DF=100，μg/g)分别为2．61、3．28、9，58。用国家标准物质土壤GBW 07401-07408，水系沉积物GBW 07309-07312验证了测定B、As、S的准确性及精密度，允许误差范围之内，测定值与标准值接近，样品10次测定的RSD为4．34％～25．0％。     

乙醇增强—电感耦合等离子体质谱法直接测定地质样品中碲

建立了HF—HN03密封酸溶以及Na2O2熔融处理样品，乙醇增强灵敏度，电感耦合等离子体质谱直接测定地质样品中微量和超痕量碲的方法。样品溶液中加入乙醇(φ＝4％)，在0．85L/min的载气流速下，碲信号可增强2．5倍以上。碲的方法检出限(100，DF＝1000)为0．02μg/g。用土壤和水系沉积物国家一级标准物质验证了方法的准确度，标准物质的绝大多数分析结果与标准值的误差在允许范围内。分析了大洋多金属结核样品及深海沉积物样品中的微量碲，结果与其他方法相符，精密度试验RSD(n＝3)＜10％。     

敞口酸溶-电感耦合等离子体质谱法同时测定地质样品中45个元素

改进了三酸(HCl-HNO3-HF)或四酸(HCl-HNO3-HF-HClO4)溶矿对难溶元素分解不彻底及对易挥发元素测定结果不稳定的现象,建立了地质样品中15个稀土元素及其常规微量元素一次溶矿、一次测定的分析方法,提高了分析质量。采用HCl-HNO3-HF-HClO4-H2SO4混合酸一次分解样品,用50%的逆王水复溶提取后定容,以Rh为内标元素,三通在线进样方式,电感耦合等离子体质谱法同时测定地质样品中45个元素的含量。讨论了分解方法对易挥发元素、难溶元素的影响,对岩石标准物质(GBW07106)、水系沉积物标准物质(GBW07303)和土壤标准物质(GBW07429)的测定值与标准值相一致,方法精密度为0.03%～4.97%。方法准确度高,简单、快捷、实用。     

熔融制样-波长色散X射线荧光光谱法同时测定砂岩型铀矿中主量及铀、钍成分

目前,砂岩型铀矿成分的测定,一般主量元素采用常规化学法,铀、钍含量采用ICP-AES测定。本文采用熔融制样,用Axiox max型波长色散X射线荧光光谱仪一次性测定砂岩型铀矿中主量及铀、钍成分。利用玻璃熔片法可以有效地消除砂岩型铀矿样品的非均匀性及颗粒度等矿物效应。采用混合熔剂Li2B4O7-LiBO2-LiI(m/m/m=66.67/32.83/0.50)在1 050℃熔融制样,用铀矿石、岩石、砂岩等国家一级标准物质制成标准样片绘制工作曲线,用理论α系数法校正基体效应。方法经与标准物质检验对照,结果与标样值符合,其准确度、精密度均达到地质行业标准的要求。     

X射线荧光光谱熔融制样法测定钛铁矿中主次量组分

采用熔融玻璃片法制样，X射线荧光光谱法测定钛铁矿中Fe、Ti、Si、Al、Ca、Mg、Mn、P、S、V和Cr等11种主次量组分。探讨了熔融钛铁矿的有效熔剂，认为Li2B4O7和Li2CO3混合熔剂效果好。方法用于钒钛磁铁矿等国家一级标准物质的测定，结果与标准值相符，对主、次量组分方法精密度（RSD，n=10）为0．20％～9．10％。     

Assessment of trace metals contamination in stream sediments and soils in Abuja leather mining,southwestern Nigeria

This study is aimed at determining the level of environmental degradation as well as the concentration of trace elements in soil and stream sediments in order to evaluate the environmental impact of the mining operation. Twenty-five (25) soils and ten (10) stream sediment samples were collected from the study area. The physicochemical parameters were determined using appropriate instrumentation with the aid of a digital pH meter (Milwaukee meter) to measure the pH and electrical conductivity, total dissolved solids, moisture content and loss on ignition of the soil and stream sediment samples. The pH of the soil sample ranged from (6.10 to 7.19); Electrical conductivity ranged from (21.3 to 279.4 µS/cm), moisture content varied from (0.60% to 7.20%), and the LOI ranged from (2.03% to 18.62%). The results of the analysis showed that the concentrations of the trace elements in the soils and stream sediment samples were slightly higher than the background values. Plots of the trace elements in stream sediment samples show moderate, consistent decrease downstream except at points where there was mine water discharge into the main river. The pollution levels of heavy metals were examined in stream sediment and soil samples using different assessable indices, such as the enrichment factor, which showed significant-moderate enrichment for Cr, Th, Nb, Zn, Pb, Y and Zr and the geo-accumulation index, which showed practically moderate contamination with Cr, Ni and Sr based on regional background reference values. Geo-accumulation index and contamination index for soils and stream sediment revealed uncontaminated to moderate contamination. Likewise, elements with moderate contamination were Cr, Ni and Sr. The Pearson correlation showed that there were significant positive associations among selected metals in soil and stream sediment samples.     

贵州西部龙场地区水系沉积物Pt、Pd异常源地球化学示踪的初步研究

以贵州龙场地区水系沉积物中的Pt、Pd异常为研究对象，选择相容性接近的7对元素比值Cr/Ni、Nb/Ta、Pd/Pt、Rb/Cs、Sr/Ba、Th/U和Zr/Hf以及CaO、TFe2O3作为地球化学示踪指标，对龙场地区水系沉积物的物质来源组成进行了示踪探讨。结果表明：（1）龙场地区水系沉积物的物质来源主要为玄武岩风化产物，其中的高含量Pt、Pd是对玄武岩层中Pt、Pd高背景的继承和进一步浓缩富集；（2）根据对分布在灰岩区的水系沉积物物质来源的地球化学示踪研究，推测部分样品的物质来源应为玄武岩和灰岩风化产物；（3）根据对红岩村的水系沉积物物质来源的示踪研究，推断有热液活动和基性－超基性侵入体的物质成分，预测该地区具有一定的找矿远景。     

中国几个主要煤产地煤中微量元素特征

采用原煤直接溶样和使用ＩＣＰ－ＭＳ方法对我国平朔,大同,六盘水和唐山几个主要煤产地煤的微是元素进行了检测,报道了这几个主要煤产地煤中５１种微量元素含量,并对基含量特征进行了讨论,研究表明,与海水有关的过渡相沉积环境中的煤的Ｌｉ,Ｂｅ,Ｓｃ,Ｔｉ,Ｖ,Ｚｎ,Ｃｕ,Ｇａ,Ａｓ,Ｓｅ,Ｙ,Ｚｒ,Ｓｎ,Ｐｂ,Ｔｈ,Ｕ和稀土元素含量相对较高,内陆湖泊沉积环境中的煤的微量元素含量相对较低。     

An Automated Iridium-Strip Heater for LA-ICP-MS Bulk Analysis of Geological Samples

In this paper we describe a flux‐free fusion technique for the highly precise LA‐ICP‐MS bulk analysis of geological samples. For this purpose we have developed an automated iridium‐strip heater with temperature and melt time control. To optimise the homogeneity of the fused glasses and to reduce possible depletion of volatile elements during melting, we undertook experiments with basaltic rock and glass powders using different melting temperatures (1300–1700 °C) and melting times (5‐80 s). Major and trace element microanalysis was performed using EPMA and LA‐ICP‐MS. Homogeneous glasses were obtained for temperatures ≥ 1500 °C and melting times ≥ 10 s. High loss (20‐90%) of highly volatile elements (e.g., Cs, Ge, Sn, Pb) was observed for high melting temperatures (≥ 1600 °C) and long melting times (80 s). Standard melting conditions (1600 °C, 10 s) represent a compromise, as the glasses were homogeneous with respect to major and trace elements and, at the same time, were not depleted in elements with condensation temperatures (at a pressure of 10^?4 bar) higher than about 900 K (e.g., Zr, Hf, Ba, Sr, REE, U, Mo, Ni, Rb, Ga). Several international geological reference materials with SiO₂ ranging between 47% m/m and 59% m/m were prepared using our standard melting conditions (1600 °C, 10 s) and subsequently analysed by LA‐ICP‐MS. These samples also include the new Brazilian basaltic reference material BRP‐1. Matrix‐matched calibration of the LA‐ICP‐MS data was performed using the basaltic reference glasses KL2‐G, ML3B‐G, BCR‐2G and BHVO‐2G. Most analytical data agreed within uncertainty at the 95% confidence level with the GeoReM preferred values published in the GeoReM database for reference materials of geological and environmental interest. To demonstrate routine bulk LA‐ICP‐MS analyses of geochemical and cosmochemical samples using the whole rock fusion technique, we also present trace element data for ocean island basalts from Lanai (Hawaii) and of Martian meteorites.     

Geochemical Exploration on the Stream Sediments of Gabal El Mueilha Area, Central Eastern Desert, Egypt: An Overview on the Rare Metals

Abstract: El Mueilha area consists of post-collision granitic rocks intruding Pan-African metasediments, metavolcanics and granodiorites. Tin mineralization in Gabal El Mueilha is either of vein type or disseminated in the greisenized and albitized parts of the granitic rocks. Cassiterite and wolframite-bearing quartz veins also characterize a small intrusion of muscovite granite at El Mueilha tin mine area. Detailed geochemical prospecting for the rare metals Sn, Nb, Be, Li, U, Th and some other trace elements was carried out at Gabal El Mueilha area using stream sediments survey. Sixty-seven stream sediment samples were collected from the main drainage patterns of the study area. Statistical parameters were calculated for the analyzed elements. The sought elements Sn, Nb, Be and Li have relatively high background values in the studied sediments. This may reflect the role of the pathfinder elements (Nb, Be and Li) during secondary dispersion survey for Sn mineralization.
Geochemical maps were constructed to delineate anomalous areas with abnormally high rare metal contents. The anomalous Sn, Nb and Be areas are mainly encountered in the main stream draining the mineralized zones of El Mueilha tin mine and near the SW albitized parts of the post-collision granite. Correlation coefficient matrices show significant positive relation between Sn and the rare metals group (Nb, Rb and Li) at 99 % significant level. R-mode factor analysis for the concerned elements yields five factor–model.     

多向观测电感耦合等离子体发射光谱法同时测定土壤和水系沉积物中常量和微量元素

采用电感耦合等离子体发射光谱法同时测定土壤和水系沉积物样品中Al、Fe、Ca、Mg、K、Na、P、Ba、Be、Cd、Ce、Co、Cr、Cu、Li、Mn、Mo、Ni、Pb、Ti、V、W、Zn等23个常量和微量元素。各元素选择光谱干扰少、准确度高的多向观测方式(轴向、径向、轴向衰减、径向衰减),结合多元光谱拟合技术校正光谱干扰,改善方法的检出限及精密度。结果表明,方法的回收率为94.0%~103.4%,精密度(RSD,n=10)低于3.0%。方法经国家一级标准物质验证,测定值与标准值基本相符。     

Preliminary Characterisation of New Reference Materials for Microanalysis: Chinese Geological Standard Glasses CGSG‐1, CGSG‐2, CGSG‐4 and CGSG‐5

Four silicate glasses were prepared by the fusion of about 1 kg powder each of a basalt, syenite, soil and andesite to provide reference materials of natural composition for microanalytical work. These glasses are referred to as ‘Chinese Geological Standard Glasses’ (CGSG) ‐1, ‐2, ‐4 and ‐5. Micro and bulk analyses indicated that the glasses are well homogenised with respect to major and trace elements. Some siderophile/chalcophile elements (e.g., Sn, Pt, Pb) may be heterogeneously distributed in CGSG‐5. This paper provides the first analytical data for the CGSG reference glasses using a variety of analytical techniques (wet chemistry, XRF, EPMA, ICP‐AES, ICP‐MS, LA‐ICP‐MS) performed in nine laboratories. Most data agree within uncertainty limits of the analytical techniques used. Discrepancies in the data for some siderophile/chalcophile elements exist, mainly because of possible heterogeneities of these elements in the glasses and/or analytical problems. From the analytical data, preliminary reference and information values for fifty‐five elements were calculated. The analytical uncertainties [2 relative standard error (RSE)] were estimated to be between about 1% and 20%.     

The Preparation and Preliminary Characterisation of Three Synthetic Andesite Reference Glass Materials (ARM‐1, ARM‐2, ARM‐3) for In Situ Microanalysis

Three synthetic reference glasses were prepared by directly fusing and stirring 3.8 kg of high‐purity oxide powders to provide reference materials for microanalytical work. These glasses have andesitic major compositions and are doped with fifty‐four trace elements in nearly identical abundance (500, 50, 5 µg g^?1) using oxide powders or element solutions, and are named ARM‐1, 2 and 3, respectively. We further document that sector‐field (SF) ICP‐MS (Element 2 or Element XR) is capable of sweeping seventy‐seven isotopes (from ⁷Li to ²³⁸U, a total of sixty‐eight elements) in 1 s and, thus, is able to quantify up to sixty‐eight elements by laser sampling. Micro‐ and bulk analyses indicate that the glasses are homogeneous with respect to major and trace elements. This paper provides preliminary data for the ARM glasses using a variety of analytical techniques (EPMA, XRF, ICP‐OES, ICP‐MS, LA‐Q‐ICP‐MS and LA‐SF‐ICP‐MS) performed in ten laboratories. Discrepancies in the data of V, Cr, Ni and Tl exist, mainly caused by analytical limitations. Preliminary reference and information values for fifty‐six elements were calculated with uncertainties [2 relative standard error (RSE)] estimated in the range of 1–20%.     

玄武岩全岩元素含量快速、准确分析新技术:双铱带高温炉与LA-ICP-MS联用法

全岩样品主元素和微量元素的准确测试是地球科学研究的重要手段和依据.传统溶液进样ICP-MS元素测试方法制样和测试所需周期较长(两周以上).相对溶液进样法而言,激光剥蚀系统与ICP-MS联用测试全岩粉末熔融玻璃的方法可以大大地提高测试效率.在前人研究基础上,针对前人熔融制样中Pb、Zn元素的严重丢失问题,研究了Pb、Zn...     

Flux‐Free Fusion of Silicate Rock Preceding Acid Digestion for ICP‐MS Bulk Analysis

We present a new method for the decomposition of silicate rocks by flux‐free fusion in preparation for whole‐rock trace element determination (Sc, Rb, Sr, Y, Zr, Nb, Cs, Ba, rare earth elements and Hf) that is especially applicable to zircon‐bearing felsic rocks. The method was verified by analyses of RMs of mafic (JB‐1a, JB‐2, JGb‐1) and felsic rocks (JG‐3, JR‐3, JSd‐1, GSP‐2, G‐2). Pellets of powdered sample (up to 500 mg) without flux were weighed and placed in a clean platinum crucible. The samples were then fused in a Siliconit® tube furnace and quenched to room temperature. The optimum condition for the fusion of granitic rock was determined to be heating for 2–3 min at 1600 °C. The fused glass in the platinum crucible after heating was decomposed using HF and HClO₄ in a Teflon® beaker. Decomposed and diluted sample solutions were analysed using a quadrupole inductively coupled plasma‐mass spectrometer. Replicate analyses (n = 4 or 5) of the RMs revealed that analytical uncertainties were generally < 3% for all elements except Zr and Hf (～ 6%) in JG‐3. These higher uncertainties may be attributed to sample heterogeneity. Our analytical results for the RMs agreed well with recommended concentrations and recently published concentrations, indicating complete decomposition of our rock samples during fusion.