Trace analysis of high-purity graphite by LA-ICP-MS

Laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been established as a very efficient and sensitive technique for the direct analysis of solids. In this work the capability of LA-ICP-MS was investigated for determination of trace elements in high-purity graphite. Synthetic laboratory standards with a graphite matrix were prepared for the purpose of quantifying the analytical results. Doped trace elements, concentration 0.5 microg g(-1), in a laboratory standard were determined with an accuracy of 1% to +/- 7% and a relative standard deviation (RSD) of 2-13%. Solution-based calibration was also used for quantitative analysis of high-purity graphite. It was found that such calibration led to analytical results for trace-element determination in graphite with accuracy similar to that obtained by use of synthetic laboratory standards for quantification of analytical results. Results from quantitative determination of trace impurities in a real reactor-graphite sample, using both quantification approaches, were in good agreement. Detection limits for all elements of interest were determined in the low ng g(-1) concentration range. Improvement of detection limits by a factor of 10 was achieved for analyses of high-purity graphite with LA-ICP-MS under wet plasma conditions, because the lower background signal and increased element sensitivity.     

Trennung von Spurenelementaktivitäten aus Neutronenbestrahltem Selen mit Hilfe der Gegenstrom-Ionenwanderung

For the determination of trace elements in neutron irradiated, selenium by gamma-ray spectrometry the separation of the matrix activity is often necessary. In model experiments the decontamination of cation and anion impurities from the matrix solution was investigated by the counter current ion migration. After a processing of 3 hrs the trace activities of Co, Cr, Ga, Na and Zn were decontaminated from Se with a factor of >10³. For the trace elements As and Te representing the anionic constituents, a decontamination factor of 3·10² was obtained.     

Studies of LA-ICP-MS on quartz glasses at different wavelengths of a Nd:YAG laser

The capability of LA-ICP-MS for determination of trace impurities in transparent quartz glasses was investigated. Due to low or completely lacking absorption of laser radiation, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) proves difficult on transparent solids, and in particular the quantification of measurement results is problematic in these circumstances. Quartz glass reference materials of various compositions were studied by using a Nd:YAG laser system with focused laser radiation of wavelengths of 1064 nm, 532 nm and 266 nm, and an ICP-QMS (Elan 6000, Perkin Elmer). The influence of ICP and laser ablation conditions in the analysis of quartz glasses of different compositions was investigated, with the laser power density in the region of interaction between laser radiation and solid surface determining the ablation process. The trace element concentration was determined via calibration curves recorded with the aid of quartz glass reference materials. Under optimized measuring conditions the correlation coefficients of the calibration curves are in the range of 0.9-1. The relative sensitivity factors of the trace elements determined in the quartz glass matrix are 0.1-10 for most of the trace elements studied by LA-ICP-MS. The detection limits of the trace elements in quartz glass are in the low ng/g to pg/g range.     

血液中某些必需微量元素与高血压的关系探讨

为探讨人全血中微量元素与高血压的关系,用电感耦合等离子体质谱仪测定了47例高血压患者和3 2例健康对照者全血中钒(V)、铬(Cr)、锰(Mn)、钴(Co)、铜(Cu)、锌(Zn)、钼(Mo)、锶(Sr)八种必需微量元素的含量。结果表明,高血压组患者全血中除锰元素外,其余微量元素均显著低于对照组(P <0 0 5 )。提示这些必需微量元素可能在高血压的发生和发展中起着一定的作用     

Studies of LA-ICP-MS on quartz glasses at different wavelengths of a Nd:YAG laser

The capability of LA-ICP-MS for determination of trace impurities in transparent quartz glasses was investigated. Due to low or completely lacking absorption of laser radiation, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) proves difficult on transparent solids, and in particular the quantification of measurement results is problematic in these circumstances. Quartz glass reference materials of various compositions were studied by using a Nd:YAG laser system with focused laser radiation of wavelengths of 1064 nm, 532 nm and 266 nm, and an ICP-QMS (Elan 6000, Perkin Elmer). The influence of ICP and laser ablation conditions in the analysis of quartz glasses of different compositions was investigated, with the laser power density in the region of interaction between laser radiation and solid surface determining the ablation process. The trace element concentration was determined via calibration curves recorded with the aid of quartz glass reference materials. Under optimized measuring conditions the correlation coefficients of the calibration curves are in the range of 0.9–1. The relative sensitivity factors of the trace elements determined in the quartz glass matrix are 0.1–10 for most of the trace elements studied by LA-ICP-MS. The detection limits of the trace elements in quartz glass are in the low ng/g to pg/g range.     

Abtrennung von Spurenelementen aus Meerwasser durch Adsorption und ihre Bestimmung durch Neutronenaktivierungsanalyse

The possibilities of trace element adsorption on different adsorbents are investigated. Three procedures are described' (a) adsorption on activated charcoal at pH 8.5, (b) adsorption on activated charcoal in presence of dithizone at pH 8.5 and (c) adsorption on activated charcoal in presence of sodium diethyldithiocarbaminate at pH 5.5. Of the 23 elements which have been investigated in detail using standardised samples of water the following are determined quantitatively within an error of 10% according to procedure (a) and (b) Au, Cr, Eu, Hg, La, Sc, U and Zn, according to procedure (b) also Cd. The elements Ag, As, Ce, Fe and Se are adsorbed according to procedure (a) and (b) with yields between 60 and 90%, according to procedure (b) also Co. Mo is adsorbed by procedure (c) quantitatively. Cu is not detected after a decay time of 3 days. Sb is adsorbed by all procedures with low yields between 18 and 56%. The elements Br, Ca, Cl, K and Na remain mainly in the solution. The decontamination factors for these elements range between 10² and 10⁶ (Na). Water from the North Sea is analysed by procedure (b).      

Use of chelating resins and inductively coupled plasma mass spectrometry for simultaneous determination of trace and major elements in small volumes of saline water samples

For some saline environments (e.g. deeply percolating groundwater, interstitial water in marine sediments, water sample collected after several steps of fractionation) the volume of water sample available is limited. A technique is presented which enables simultaneous determination of major and trace elements after preconcentration of only 60 mL sample on chelating resins. Chelex-100 and Chelamine were used for the preconcentration of trace elements (Cd, Cu, Pb, Zn, Sc) and rare earth elements (La, Ce, Nd, Yb) from saline water before their measurement by inductively coupled plasma mass spectrometry. Retention of the major elements (Na, Ca, Mg) by the Chelamine resin was lower than by Chelex; this enabled their direct measurement in the solution after passage through the resin column. For trace metal recoveries both resins yield the same mass balance. Only Chelex resin enabled the quantitative recovery of rare earth elements. The major elements, trace metals and rare earth elements cannot be measured after passage through one resin only. The protocol proposes the initial use of Chelamine for measurement of trace and major elements and then passage the same sample through the Chelex resin for determination of the rare earth elements. The detection limit ranged from 1 to 12 pg mL(-1). At concentrations of 1 ng mL(-1) of trace metals and REE spiked in coastal water the precision for 10 replicates was in the range of 0.3-3.4% (RSD). The accuracy of the method was demonstrated by analyzing two standard reference waters, SLRS-3 and CASS-3.     

ICP-MS分析马莲花中的10种元素

目的 对马莲花中的微量元素进行分析.方法 采用微波消解法处理样品,利用电感耦合等离子体质谱法（ICP-MS）对马莲花中钾、钠、钙、镁、铜、铁、锌、锰、钼、镍等10种元素进行测定.所测元素校准方程的相关系数均大于0.999 0,回收率范围为90.2％ ～107.0％,相对标准偏差为1.54％～7.57％.结果 马莲花中含有丰富的钾、钙、镁等元素.结论 该法简便、快速、准确,灵敏度高,可用于马莲花中10种元素的同时测定.     

Trace analysis of high-purity graphite by LA–ICP–MS

Laser-ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) has been established as a very efficient and sensitive technique for the direct analysis of solids. In this work the capability of LA–ICP–MS was investigated for determination of trace elements in high-purity graphite. Synthetic laboratory standards with a graphite matrix were prepared for the purpose of quantifying the analytical results. Doped trace elements, concentration 0.5 μg g^–1, in a laboratory standard were determined with an accuracy of 1% to ± 7% and a relative standard deviation (RSD) of 2–13%. Solution-based calibration was also used for quantitative analysis of high-purity graphite. It was found that such calibration led to analytical results for trace-element determination in graphite with accuracy similar to that obtained by use of synthetic laboratory standards for quantification of analytical results. Results from quantitative determination of trace impurities in a real reactor-graphite sample, using both quantification approaches, were in good agreement. Detection limits for all elements of interest were determined in the low ng g^–1 concentration range. Improvement of detection limits by a factor of 10 was achieved for analyses of high-purity graphite with LA–ICP–MS under wet plasma conditions, because the lower background signal and increased element sensitivity. Received: 4 January 2001 / Revised: 27 March 2001 / Accepted: 28 March 2001     

Use of chelating resins and inductively coupled plasma mass spectrometry for simultaneous determination of trace and major elements in small volumes of saline water samples

For some saline environments (e.g. deeply percolating groundwater, interstitial water in marine sediments, water sample collected after several steps of fractionation) the volume of water sample available is limited. A technique is presented which enables simultaneous determination of major and trace elements after preconcentration of only 60 mL sample on chelating resins. Chelex-100 and Chelamine were used for the preconcentration of trace elements (Cd, Cu, Pb, Zn, Sc) and rare earth elements (La, Ce, Nd, Yb) from saline water before their measurement by inductively coupled plasma mass spectrometry. Retention of the major elements (Na, Ca, Mg) by the Chelamine resin was lower than by Chelex; this enabled their direct measurement in the solution after passage through the resin column. For trace metal recoveries both resins yield the same mass balance. Only Chelex resin enabled the quantitative recovery of rare earth elements. The major elements, trace metals and rare earth elements cannot be measured after passage through one resin only. The protocol proposes the initial use of Chelamine for measurement of trace and major elements and then passage the same sample through the Chelex resin for determination of the rare earth elements. The detection limit ranged from 1 to 12 pg mL^–1. At concentrations of 1 ng mL^–1 of trace metals and REE spiked in coastal water the precision for 10 replicates was in the range of 0.3–3.4% (RSD). The accuracy of the method was demonstrated by analyzing two standard reference waters, SLRS-3 and CASS-3.     

石嘴山电厂煤中微量元素的迁移释放行为

应用电感耦合等离子体质谱（ICP-MS）和原子荧光光谱（AFS）对中国西北部石嘴山电厂的原煤、底灰和飞灰中Hg、As、Se、Pb、Cr、Cd、Mo、Ni、Co、U和Th 11种微量元素的含量进行了测定。根据底灰和飞灰的产率, 结合微量元素在底灰和飞灰中的含量计算了电厂燃煤过程中微量元素的挥发性。结果表明, Hg、Cd、Se、As四种元素在燃煤过程的挥发率均在50%以上, 最高可达70%。通过对底灰和飞灰在酸性介质下的柱淋滤实验研究了底灰和飞灰中微量元素在60h内的迁移释放行为。Mn、Ni、Co、As四种元素的最大淋出率均超过2.0%, 最高接近10.0%, 并且还未达到淋滤平衡。根据微量元素的挥发和淋滤释放特性建立了电厂煤中有害微量元素在燃烧和淋滤过程中的释放分配模型。结果显示, 燃煤过程中的挥发是微量元素释放的主要形式, 部分元素的淋滤释放也可对周围水环境造成污染。
     

Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide

The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry.     

Bestimmung von Elementspuren im ng- und pg-Bereich durch optische Emissionsspektrometrie mit He-MIP-Anregung nach elektrolytischer Abtrennung im Graphitrohr und nach-folgender elektrothermischer Atomisierung

This article deals with the determination of traces of elements in the ng and pg range by emission spectroscopy with a He-MIP excitation after electrolytic preconcentration in a graphit tube followed by electrothermal atomization. A multi-stage combined procedure is described for the sensitive and reliable determination of trace elements in high-purity metals. Electrolytically depositable elements such as noble metals, copper, as well as bismuth, cadmium, iron, cobalt, zinc, and others are preconcentrated from acidic solutions with concentrations ? 0.05 ng ml^?1 after the decomposition of the sample if the matrix elements are not deposited. The electrolyte is cycled through a small cylindrical cathode of pure graphite on the inner wall of which the elements are deposited. The graphite tube is coupled directly to the quartz capillary of a microwave induced helium plasma (MIP). After electrothermal atomisation the trace elements are determined by emission spectrometry. Different types of MIP excitation sources are investigated. The MIP with the TM₀₁₀ microwave resonator shows optimal properties. For the determination of the trace elements in niobium and beryllium detection limits near 1 ng g^?1 and relative standard deviations between 6.5 and 15% are obtained.     

Untersuchungen zur adsorptiven Anreicherung von Elementspuren an Adsorberharzen

Summary The adsorption behaviour of trace amounts of As(III), As(V), Fe(II), Hg(II), Pd(II), Pt(IV), Sb(V), Sn(II), Sn(IV) and Tl(III) from hydrochloric and hydrobromic acid solutions on Amberlite XAD-4 and XAD-7 resins by use of a chromatographic method was investigated. As expected, in certain acid concentrations, all of the elements are adsorbed partly or quantitatively. Furthermore, the adsorbability of 23 elements from sulphuric or hydrochloric acid solutions containing iodide or thiocyanate was examined. In accordance with analogous results for chloro- and bromocompounds it was found that the distribution behaviour of iodo- and thiocyanato-compounds is similar to that of corresponding solvent extraction systems. The adsorbed species of the trace compounds were estimated by comparison of the dependence of sorption rate on ligand concentration with the species distribution in the solution. The similarity of adsorbable and extractable species was discussed.

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Teil II: Fresenius Z Anal Chem (1988) 331:588     

Anreicherung von Spurenelementen durch fraktionierte Extraktion des Hauptbestandteils

Zusammenfassung Es wird ein Verfahren zur Anreicherung zahlreicher Spurenelemente in Wismut angegeben. Durch selektive fraktionierte Extraktion des Wismuts aus jodidhaltiger Lösung mit Cyclohexanon erhält man ein Spurenkonzentrat, in dem die für eine Reinheitskontrolle im unteren ppm-Bereich wichtigen Elemente mit Hilfe photometrischer (Fe, Cu), polarographischer (Pb, M, Zn) und voltammetrischer (Zn, Pb) Verfahren bestimmt werden. Arsen wird elektrolytisch zu Arsin reduziert, abdestilliert und photometrisch als Molybdänblau bestimmt. Die relativen Standardabweichungen liegen bei 5–10%.

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Summary A procedure is described for the enrichment of several trace elements in bismuth. The residue of the trace elements is obtained by a selective fractional extraction of the bismuth content with cyclohexanone from an iodide containing solution. The elements most important for a purity control in the lower ppm range are determined with photometric (Fe, Cu), polarographic (Pb, Ni, Zn) and voltammetric (Zn, Pb) procedures. Arsenic is determined by photometry as molybdenum blue after electrolytic reduction to arsine and distillation. The relative standard deviations are in the order of 5–10%.

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II. Mitteilung: diese Z. 206, 269 (1964).     

Mikrowellenaufschluss zur Bestimmung von Spurenelementen in Pflanzenmaterial

(Microwave digestion of plant material for trace element determination.) A digestion method utilizing a mixture of nitric acid, hydrofluoric acid and hydrogen peroxide in closed vessels with a microwave system was developed for the determination of trace elements in plant materials and was tested on NIST standard reference materials [Citrus Leaves (SRM 1572) and Pine Needles (SRM 1575)] for Al, As, Ba, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Rb, Sr and Zn. Analyses were done by d.c. plasma atomic emission spectrometry. The results showed high reproducibility and good agreement with the certified values. Rapid ashing and dissolution of plant material, reduced sources of contamination and the simplicity of the system make the microwave digestion system suitable for routine laboratory application.     

Multielemental Analysis of Yew,Pine and Spruce Needles by ICP-AES

Abstract

Concentrations of 22 trace and nutritional elements in yew, pine and spruce needles collected from urban and industrial areas were determined by inductively coupled plasma atomic emission spectrometry. Dependence of concentrations of trace elements in conifers species on sampling site was investigated. Various procedures of sample digestion (different acids, conventional hot plate and microwave digestion methods, dry ashing) were examined and discussed.     

Elemental analysis of a single-wall carbon nanotube candidate reference material

A material containing single-wall carbon nanotubes (SWCNTs) with other carbon species, catalyst residues, and trace element contaminants has been prepared by the National Institute of Standards and Technology for characterization and distribution as Standard Reference Material SRM 2483 Carbon Nanotube Soot. Neutron activation analysis (NAA) and inductively coupled plasma mass spectrometry (ICP–MS) were selected to characterize the elemental composition. Catalyst residues at percentage mass fraction level were determined with independent NAA procedures and a number of trace elements, including selected rare earth elements, were determined with NAA and ICP–MS procedures. The results of the investigated materials agreed well among the NAA and ICP–MS procedures and good agreement of measured values with certified values was found in selected SRMs included in the analyses. Based on this work mass fraction values for catalyst and trace elements were assigned to the candidate SRM.     

Determination of Trace Elements in Super Alloy by ICP-MS

 A method is described for determination of 14 trace elements in super alloy certified reference material. Inconel 718 by ICP-MS. The interferences were investigated in detail. By using appropriate settings of the operational parameters and correcting interferences the elements without interference free isotopes were also analyzed. Non-spectral interference to the analytes was studied. No matrix separation or any other sample pretreatment but acid dissolution was made. 14 trace elements (B, Sc, Ga, Ge, In, Sn, Sb, Te, Hf, Ag, Ce, Tl, Pb and Bi) were analyzed by matrix matched standard solution calibration and using Rh as internal standard. Good agreement was achieved between the found levels and the certified values for most of the elements. The RSD (n = 4) of the determination values of Ce was lower than 20%, and RSD of the other 13 elements was lower than 10%. Received July 21, 2000. Revision May 29, 2001.     

MPT-AES法同时测定航空润滑油中铁、银和镍

用微波等离子体炬原子发射光谱法(MPT-AES)同时测定未使用过的航空润滑油中铁、银和镍的方法。详细考察了微波功率、载气流量、工作气流量、氧屏蔽气压力等实验参数对铁、银和镍发射强度的影响,并进行了系统优化。测得铁、银和镍的检出限分别为21.94ng/mL0、.36ng/mL9、.82ng/mL,线性范围分别为0.1~100μg/mL、0.001~8μg/mL、0.05~8μg/mL,各元素测定结果的相对标准偏差均小于3.95%,回收率在93.1%~107.4%之间。