激光剥蚀电感耦合等离子体质谱微区分析 进展评述

激光剥蚀电感耦合(LA-ICP-MS)等离子体以其高空间分辨率、高灵敏度、多元素同时测定并可提供同位素比值信息的检测能力在原位微区分析中已得到广泛应用。现从仪器的发展、基础研究等方面评述了近年来LA-ICP-MS微区分析的进展,重点介绍了与等离子体质谱(ICP-MS)联用的激光器(纳秒和飞秒激光器)的发展、校正方法、分馏效应及其在地球科学微量元素、同位素、包裹体分析中的应用。并简要地阐述了LA-ICP-MS分析技术存在的局限和发展趋势。     

激光探针等离子体质谱法（LAM—ICPMS）用于年龄锆石U—Pb定年

利用激光探针等离子体普（ＬＡＭ－ＩＣＰＭＳ）技术对中生代锆石进行了详细的２０６Ｐｂ／＾２３８定年研究。采用线扫描（Ｌｉｎｅ ｓｃａｎ）进样法减小了传统的剥深（Ｄｅｐｔｈ ｐｒｏｆｉｌｅ）进样法所引起的激光熔蚀分异效应;优化仪器参数可三ＩＣＰ－ＭＳ对Ｐｂ和Ｕ的质量歧视效应。测得了精确的＾２０６Ｐｂ／＾２３８Ｕ比值及年龄。研究结果表明,均匀颗粒锆石的＾２０６Ｐｂ／＾２３８Ｕ比值测量精度为２％～１０％,     

Models of rock varnish formation constrained by high resolution transmission electron microscopy

Nanometre-scale transmission electron microscope imagery of manganiferous rock varnishes from Death Valley, California, Peru, Antarctica, and Hawaii confirms prior infrared mineralogy studies. The building blocks of rock varnish are clay minerals that are cemented to the rock by oxyhydroxides of manganese and iron. Rock varnish is layered on the scale of nanometres, with the basic structure defined by the subparallel alignment of detrital clay minerals. Although only a few examples of bacteria were found, possible cell-wall encrustations are ubiquitous and aligned with the clay minerals. Mn–Fe oxides appear to be mobilized from bacterial casts and then reprecipitate on clay minerals that weather into monolayers. These observations have implications for varnish dating and palaeoenvironmental techniques: K–Ar and uranium-series dating of rock-varnish oxides can only yield minimum ages; however, this small spatial scale of mobilization would not alter the signal from micron-scale microchemical laminations.     

Synthesis of PGE sulfide standards for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)

Sulfide compositions with known Re, Os, Ir, Ru, Rh, Pt, and Pd contents are synthesized to be used as standards for noble metal analysis in solid solution in sulfides. Major elements were added as metals and elemental S. The noble metals, i.e. 35 and 60 ppm each, were added as solutions by micro syringe. Following synthesis at 1 atm the sulfides were sintered at 1.5 to 2 GPa to obtain pellets with theoretical density. Aliquots of the pellets were analysed by isotope dilution ICP-MS for bulk Re and platinum-group elements (PGE). The spatial noble metal distribution was investigated with an ArF excimer laser coupled to a single collector ICP mass spectrometer. Sample homogeneity is shown to depend on the metal/S spectrum and the major element composition of the sulfide, as well as on more subtle factors like oxygen partial pressure during synthesis, run temperature, and degree of partial melting. The most homogeneous sulfide composition is a (Fe,Ni)_{1 − x} S monosulfide with 5 wt % Ni and 1-sigma variations in ³⁴S-normalized noble metal count rates of <3.6%. Nearly as homogeneous is a pure Fe_{1 − x} S monosulfide with 1-sigma variations in ³⁴S-normalized noble metal count rates of <5.8 %. A Cu-bearing Fe_{1 − x} S monosulfide with 2 wt % Cu was found to be considerably more heterogeneous, suggesting that Cu in solid solution in monosulfides promotes noble metal heterogeneity. The sulfide composition least suitable for the synthesis of noble metal sulfide standards is NiS.     

高分辨电感耦合等离子体质谱法测定植物样品中的12种元素

植物样品经逆王水体系微波消解稀释至一定体积后,直接用高分辨等离子体质谱法（HR-ICP-MS）同时测定溶液中的Cr、Mn、Co、Ni、Cu、Zn、As、Se、Mo、Cd、Hg、Pb共12种无机元素的含量。在HR-ICP-MS仪上优化选择各元素的同位素、分辨率和内标元素,有效消除测定过程中的质谱与非质谱干扰。其中,各元素的检出限在0.55～48.6 ng/g之间 (稀释因子=250) ,相对标准偏差RSD（n=12) 均＜10%。该方法经国家一级生物标准物质验证,测定结果接近标准值,方法准确可靠,适用于快速准确测定植物样品中的12种元素。     

溴、碘的半熔法-电感耦合等离子质谱(ICP-MS)测定

样品用碳酸钠和氧化锌混合熔剂半熔,用80℃～100℃水提取,用强酸型阳离子树脂分离溶液中的大量钠等阳离子,采用电感耦合等离子质谱直接测定溶液中的溴和碘。测定下限溴为0．15μg／g,碘为0．028μg／g。     

In situ measurement of Re-Os isotopes in mantle sulfides by laser ablation multicollector-inductively coupled plasma mass spectrometry: analytical methods and preliminary results

A method has been developed for the in situ determination of Re-Os isotopes in single grains of sulfides in mantle-derived peridotites using a laser ablation microprobe attached to a multicollector-induced coupled plasma mass spectrometer (MC-ICPMS). High-precision Os isotope analysis by MC-ICPMS is demonstrated by the measurement of interlaboratory Os standards. Evaluation of mass bias correction procedures shows that the exponential law provides the best fit to the Os isotope data and that the ratio of the mass fractionation coefficients for Re and Os remains constant for the range of typical instrument operating conditions. This relationship enables the accurate and precise correction of the isobaric interference of ¹⁸⁷Re on ¹⁸⁷Os for ¹⁸⁷Re/¹⁸⁸Os values up to 1.6.Results are presented for single sulfide inclusions in olivine macrocryts from kimberlites in the Siberian and Slave Cratons, and sulfides enclosed in silicates and interstitial to silicates in peridotite xenoliths from the Slave Craton and Massif Central, France. Enclosed sulfides larger than 50 μm in diameter and with Os contents ≥40 ppm give ¹⁸⁷Os/¹⁸⁸Os ratios with a precision of 0.1% (2 SE), which is equivalent to N-TIMS whole-rock data. Interstitial sulfides typically have lower Os (10 to 30 ppm) and give analyses with lower precision (∼1 to 2%) but still provide valuable information on the movement of Os within the lithosphere. The sulfide inclusions in silicates preserve significantly less radiogenic Os isotopic compositions than interstitial sulfides and accordingly produce significantly older and more realistic Re-Os age information. Whole-rock Os isotope compositions reflect the proportions of different generations of enclosed and interstitial sulfides; this calls into question the significance of many published “depletion ages.”     

Determination of hydrocarbon distributions in oils and sediment extracts by gas chromatography—high resolution mass spectrometry

The distributions of steroid and triterpenoid hydrocarbons in crude oils and sedimentary rock extracts can be routinely determined by the direct injection of the sample into a gas chromatograph coupled to a mass spectrometer (GC-MS). The mass spectrometer is operated at a resolution of about 2500 (10% valley), and only the ion intensities at selected accurate mass values, diagnostic of the structural types of interest, are monitored throughout the analysis. The distributions, so obtained, find application in the assessment of the source and thermal maturity of crude oil accumulations in the subsurface. This technique eliminates chromatographic separation steps and combines two analyses in one. Thus, more geological samples and reference mixtures may be analyzed in a given time.     

Assignment of igneous rocks to lamproite: major- and trace-element criteria and implications for the history of the Tomtor pluton (northwestern Yakutia)

The paper presents objections against assigning picritic and some other igneous rocks to lamproite as suggested by N.V. Vladykin, both in general and in particular for the case of the large Tomtor pluton of alkaline and carbonatite rocks in northwestern Sakha Republic (Yakutia). Classifying the Tomtor picrites (picritic porphyry and its breccia-like varieties) as lamproite appears to be inconsistent with their chemistry, mineralogy, and geology. Discussed are errors and poorly proven postulates in the related publications by Vladykin, which contradict the available field data.     

Determination of Sr isotopes in calcium phosphates using laser ablation inductively coupled plasma mass spectrometry and their application to archaeological tooth enamel

The determination of accurate Sr isotope ratios in calcium phosphate matrices by laser ablation multi-collector ICP-MS is demonstrated as possible even with low Sr concentration archaeological material. Multiple on-line interference correction routines for doubly-charged REE, Ca dimers and Rb with additional calibration against TIMS-characterised materials are required to achieve this. The calibration strategy proposed uses both inorganic and biogenic apatite matrices to monitor and correct for a ⁴⁰Ca-³¹P-¹⁶O polyatomic present at levels of 0.3-1% of the non-oxide peak, which interferes on ⁸⁷Sr causing inaccuracies of 0.03-0.4% in the ⁸⁷Sr/⁸⁶Sr isotope ratio. The possibility also exists for synthetic materials to be used in this calibration. After correction for interferences total combined uncertainties of 0.04-0.15% (2SD) are achieved for analyses of 13-24 μg of archaeological tooth enamel with Sr concentrations of ca. 100-500 ppm using MC-ICP-MS. In particular, for samples containing >300 ppm Sr, total uncertainties of ∼0.05% are possible utilising 7-12 ng Sr. Data quality is monitored by determination of ⁸⁴Sr/⁸⁶Sr ratios.When applied to an archaeological cattle tooth this approach shows Sr-isotope variations along the length of the tooth in agreement with independent TIMS data. The ⁴⁰Ca-³¹P-¹⁶O polyatomic interference is the root cause of the bias at mass 87 during laser ablation ICP-MS analysis of inorganic and biogenic calcium phosphate (apatite) matrices. This results in inaccurate ⁸⁷Sr/⁸⁶Sr ratios even after correction of Ca dimers and doubly charged rare earth elements. This interference is essentially constant at specific ablation conditions and therefore the effect on ⁸⁷Sr/⁸⁶Sr data varies in proportion to changes in the Sr concentration of the ablated material. Complete elimination of this interference is unlikely through normal analytical mechanisms and therefore represents a limitation on the achievable accuracy of LA-(MC-)ICP-MS ⁸⁷Sr/⁸⁶Sr data without rigorous calibration to known reference materials.     

First vanadium isotope analyses of V-rich minerals by femtosecond laser ablation and solution-nebulization MC-ICP-MS

Vanadium is a redox-sensitive trace metal that occurs in nature as V^II, V^III, V^IV, and V^V, e.g. in a variety of ore-forming minerals like vanadates (hosting V^V), sulfides (e.g., patrónite: V^IV?S₄), silicates (e.g., roscoelite, hosting V^III; cavansite, hosting V^IV), and phosphates (e.g., sincosite, hosting V^IV). Similar to other redox-sensitive metals (e.g., Fe, Cu, U), the V isotope compositions of V minerals may provide valuable information for source fingerprinting and redox-controlled processes during ore formation. The first in situ V isotope analyses of several natural V minerals (cavansite, descloizite, patrónite, sincosite, vanadinite) were performed in this study employing femtosecond-laser ablation-high resolution-MC-ICP-MS. The δ⁵¹V values are determined relative to a V metal (Alfa Aesar, 99.5% V) via standard-sample-standard bracketing, and are recast to the Oxford Alfa Aesar solution value. Mass bias was monitored by addition of an Fe standard to the sample aerosol during analyses. For comparison, aliquots of all mineral specimens were analyzed after chromatographic separation by solution-nebulization MC-ICP-MS. Our laser ablation and solution typically data agree well with each other (within 0.1‰ units), and indicate a significant variation of δ⁵¹V values between the analyzed minerals, ranging from − 0.5 to + 1.3‰ (2 s.e. per analysis typically between 0.04 and 0.06‰). This spread is significantly larger than reported for various reference rocks, and also exceeds the difference for δ⁵¹V between the bulk silicate Earth and the chondrite average. The extended range of δ⁵¹V values demonstrates that stable V isotope analyses may provide a new proxy for redox-processes in high- and low-temperature studies, including the fingerprinting of redox-induced V mobilization and enrichment processes during the formation of V-rich ores.     

甲基汞对雄性小鼠的生殖发育毒性及作用机制

对于乳粉的汞形态分析,由于基质的复杂性,有机汞非常容易与样品中蛋白质上的巯基结合,形成稳定的络合物,在前处理过程中须保证各形态提取完全且各形态之间不会发生相互转化,因此样品前处理是汞形态分析的难点;同时乳粉中汞含量极低,对方法检出限提出了更高的要求。本文通过优化样品前处理过程,建立了离子色谱-电感耦合等离子体质谱测定乳粉中三种汞形态（二价汞、甲基汞、乙基汞）的方法。实验采用多种复合酶（蛋白酶、脂肪酶、淀粉酶）对乳粉基质中的蛋白、脂肪、淀粉进行解离,采用L-半胱氨酸-盐酸-甲醇的混合溶液作为提取剂进行超声提取,样品过RP固相萃取小柱去除杂质后用C18色谱柱（5 μm,4.6 mm×150 mm）进行分离,流动相采用10 mmol/L乙酸铵-0.12% L-半胱氨酸-5%甲醇混合溶液进行淋洗,5 min内即可实现三种汞形态的基线分离。二价汞、甲基汞和乙基汞的加标回收率在79.9%~111.2%之间,检出限分别为0.5 μg/kg、0.6 μg/kg、0.9 μg/kg。实际样品分析表明,汞总量很低的乳粉,汞各形态的提取率也能达到70%以上,能够满足检测要求。本方法在样品前处理过程中采用酶解的方式解离复杂基体中的汞形态,提高了提取率至80%以上;仪器分析方面采用甲醇作为增敏剂,提高了检测灵敏度,适用于乳粉样品中痕量汞形态的检测。

     

微量岩石样品中Rb-Sr和Pb一步分离及高精度热电离质谱测试

采用30 μL Sr特效树脂微柱,一步分离微量岩石样品中Rb-Sr和Pb,其回收率均优于90％,流程试剂用量仅0.75 mL,分离时间约3h,Rb-Sr流程本底优于5 pg,Pb流程本底优于50 pg.本方法具有样品用量少、本底低、回收率高、分离效率高等优点.结合高灵敏度TIMS分析技术,可以实现微量岩石样品高精度Rb...     

电感耦合等离子体质谱法(ICP-MS)测定水系沉积物中的铌钽锆铪

建立电感耦合等离子体质谱法(ICP-MS)测定水系沉积物中铌、钽、锆、铪四种元素的分析方法。将样品与氢氧化钠、过氧化钠混合物放入高温炉中,熔融分解完全,用热水提取,过滤后弃去滤液,将滤纸及沉淀用酒石酸-盐酸溶液溶解,稀释至刻度测定。方法检出限(3s)为:LD(Nb)=0.08μg/g,LD(Ta)=0.04μg/g,LD(Zr)=0.5μg/g,LD(Hf)=0.04μg/g,精密度(RSD%,n=6)为:0.84%~4.21%。该测定方法具有灵敏度高、精密度好、分析速度快、线性范围宽、操作性强等优势。采用该方法对国家一级标准物质进行测定表明,其结果与标准值吻合。此方法已在实际地质调查样品分析中得到应用。     

Cl,Br and I analyses of metamorphic and sedimentary rocks by isotope dilution mass spectrometry

Isotope dilution mass spectrometry with negative thermal ions was applied to determine Cl, Br and I in rocks which, in part, contained less than 100 ppb of Br and I. Two sets of samples have been investigated: a) a series of Al-rich metapelites of increasing metamorphic grade from the Damara Orogen, Namibia and b) fresh and hydrothermally altered greywackes from the Pb−Zn deposit Bad Grund in Germany. It was found that regional metamorphism of Al-rich metapelites causes no strong fractionation of the halides. The Br/Cl ratios in the metapelites are similar to those of sea water. The I/Cl and I/Br ratios, however, are 500 times higher. The I depleted in the ocean most probably is associated with organic matter stored in sediments. The unaltered greywackes from near the Pb−Zn vein have about the same concentrations of halides as the metamorphic Al-rich pelites. By contrast, the hydrothemally altered greywackes contain about twice as much Cl and I, and about 2–5 times as much Br as the unaltered samples. The element ratios, however, are similar for all three categories of rocks, thereby indicating that sea water played no role in the hydrothermal system.     

Application of rock mass index (RMi) to the rock mass excavatability assessment in open face excavations

Earthwork and surface excavation activities play an important role in construction projects. Selecting the best technique to loosen the overburden material within the surface excavation in open mining and geotechnical projects is of great importance from economical and technical viewpoints. Surface excavation includes direct digging, ripping and blasting. To select the most effective method and plan for excavation, geotechnical investigation is very important. It is also a big help in avoiding conflict between contractors and clients when they do not reach mutual agreement regarding the price of rock and soil excavation. There are many engineering classification systems used to assess rock masses for excavation purposes. All of these systems consider several geotechnical parameters to assess the earth masses. This study reviews these systems and then offers a new categorization based on the Rock Mass index (RMi) classification system and block volume to assess excavation in rock masses. The original dataset was obtained from the literature review as well as the surface excavation in Upper Gotvand dam and Hydro Power Plant (HPP). The offered system was also validated through the data extracted from the surface excavation in Sardasht dam and HPP in Iran.     

电感耦合等离子体质谱法测定黑色页岩中的铂钯

对于黑色页岩中的铂钯元素,试样经过灼烧除去硫以及有机质后,用王水分解,经树脂富集,再将树脂灰化后溶解,采用电感耦合等离子体质谱仪测量,取代比色法,得到了更好的检出限,以及准确度。     

High-noble measurement of 107Ag/109Ag in native silver and gold by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS)

The MC-ICP-MS technique was used to study Ag isotope systematics in various silver and gold deposits. Owing to the correction of measured ¹⁰⁷Ag/¹⁰⁹Ag values in samples for the mass discrimination effect on the basis of the ¹⁰⁸Pd/¹⁰⁶Pd reference ratio, a precision of ±0.4? (±2SD) was achieved. The ¹⁰⁷Ag/¹⁰⁹Ag ratio was determined in native silver and gold samples from ten well-known noble-metal deposits of varying age (from the Archean to Miocene) in Europe (Kongsberg, Banska Hodrusa, Kremnica, Maiskoe, and Karabash); northeastern, central, and southern Asia (Sukhoi Log, Dukat, Aktepe, and Kolar); and North America (Kidd Creek). The ¹⁰⁷Ag/¹⁰⁹Ag values of the samples studied range from +0.9 to ?5.0 $\varepsilon _{107_{Ag} }$ . The observed range is similar to that (6.4 $\varepsilon _{107_{Ag} }$ ) reported previously (Hauri et al., 2000) for oceanic basalts and Ag ores. The ¹⁰⁷Ag/¹⁰⁹Ag ratio shows no correlation with the age of deposits and the composition of their ores and host rocks. The most probable reasons for the observed variations in Ag isotope composition are the isotope geochemical heterogeneity of Ag sources in mineral deposits and Ag isotope fractionation in ore-forming processes.     

岩体完整性指标IRMI的工程应用与分析

岩体完整性指标（IRMI）是基于钻孔成像技术的评价岩体完整性的新指标,定义为全孔孔壁图像中岩体完整特征I与孔壁岩体长度（即完整特征I与破碎特征F之和）之比的百分数,即IRMI = I / (I + F)。钻孔成像技术在青岛海湾大桥基础勘察工程中取得了成功应用,获得了大量的第一手资料。通过与钻探和其他岩石质量估算法的对比分析,得出(1) 钻孔摄像弥补了钻孔取芯的不足;(2) 全孔图像为实现准确的岩体完整性评价创造了条件;(3) IRMI能准确地反映岩体完整特征;(4）IRMI通常大于RQD。     

Analysis of bromate and bromide in drinking water by ion chromatography-inductively coupled plasma mass spectrometry

A method for the detection of bromate and bromide in drinking water by ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS) was developed. The optimized conditions of IC including pH and concentration of the effluent were studied. The results showed that the above two species of bromine were baseline separated within nine minutes under the optimized conditions. The detection limits (S/N=3) of bromate and bromide were 0.23 and 0.12 μg/L, respectively. The RSD (n=6) of the peak areas was 1.2%-3.5%. The method has been successfully applied to the determination of the type bromide in drinking water samples. The recoveries were 95%-109%. The method can be used for the regular analysis of bromate and bromide in real drinking water samples.