Determination of Major/ Minor and Trace Elements in Silicate Samples by ICP-QMS and ICP-SFMS Applying Isotope Dilution-Internal Standardisation (ID-IS) and Multi-Stage Internal Standardisation

A method for the determination of major, minor and trace elements in silicate samples by ICP‐QMS and ICP‐SFMS applying isotope dilution‐internal standardisation (ID‐IS) and multi‐stage internal standardisation has been developed. Samples with an enriched isotope of ¹⁴⁹Sm (spike) were decomposed by a HF/HCIO₄ mixture and stepwise drying and finally diluted. In ID‐IS for trace element analyses by Q‐pole type ICP‐MS (ICP‐QMS), the Sm concentration was determined by ID, while other trace elements (Li, Be, Rb, Sr, Y, In, Cs, Ba, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Tl, Pb, Bi, Th and U) were determined using the ¹⁴⁹Sm intensity as an internal standard. Major and minor elements were determined by multi‐stage internal standardisation, with Na, Mg, Al, P, Ca, V, Mn, Fe and Co measured by sector magnetic field type ICP‐MS (ICP‐SFMS) at middle resolution (MR; M/AM =～ 3000) using Sr determined by ICP‐QMS in the sample as the internal standard. Potassium, Sc, Ni, Cu, Zn and Ga were measured at high resolution (HR; M/ΔM ～ 7500) using the Sr concentration obtained by ICP‐QMS or the Mn concentration obtained by ICP‐SFMS at MR as internal standard. The merit of ID‐IS is that accurate dilution of the sample is not required. Matrix effects on elemental ratios down to a dilution factor (DF) of 600 were not observed in either types of mass spectrometry. Pseudo‐flow injection (FI), where transient signals were integrated, was used in ICP‐QMS, while conventional continuous sample introduction was used in ICP‐SFMS, resulting in total required sample solutions of 0.026 ml and 0.08 ml, respectively. Detection limits were low enough to determine these elements in depleted ultramafic rocks, and typical reproducibilities for basalts were 3% (Li‐Be), 1% (Rb‐U), 5% (In, Tl and Bi), 7% (Sc‐Ga) and 3% (major elements). Carbonaceous chondrites including Orgueil (Cll), Murchison (CM2) and Allende (CV3), as well as reference materials, JB‐1, ‐2, ‐3, JA‐1, ‐2, ‐3 and JP‐1 (GSJ), BHVO‐1, AGV‐1, PCC‐1 and DTS‐1 (USGS), were analysed to show the applicability of this method. Une méthode permettant la détermination des éléments majeurs, mineurs et en trace dans les echantillons silicates par ICP‐QMS et ICP‐SFMS a été développée. Elle combine la standardisation interne par dilution isotopique (ID‐IS) et la standardisation interne en deux étapes. Les échantillons, auxquels est ajouté un spike enrichi en ¹⁴⁹ Sm, sont décomposés par une mixture HF/HCIO_4′ séchés progressivement puis dilués. Dans la phase de standardisation interne par dilution isotopique avec un ICP‐MS à quadrupôle (ICP‐QMS), la concentration en Sm est déterminée par dilution isotopique tandis que les autres éléments en trace (Li, Be, Rb, Sr, Y, In, Cs, Ba, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Tl, Pb, Bi, Th et U) sont déterminés en utilisant le signal de ¹⁴⁹ Sm comme standard interne. Les éléments majeurs et mineurs sont déterminés par standardisation interne par étapes, avec Na, Mg, Al, P, Ca, V, Mn, Fe et Co mesurés par ICP‐MS à secteur magnétique (ICP‐SFMS) en résolution intermédiaire (MR; M/ΔM =～ 3000 en utilisant Sr, mesuré par ICP‐QMS comme standard interne. Les éléments K, Sc, Ni, Cu, Zn et Ga sont mesurés en Haute Résolution (M/ΔM ～ 7500) en utilisant comme standard interne, soit la concentration en Sr obtenue par ICP‐QMS soit la concentration en Mn obtenue par ICP‐SFMS en résolution moyenne. La technique de ID‐IS a l'avantage de ne pas nécessiter la connaissance exacte du facteur de dilution de l'Schantillon. Aucun effet de matrice sur la mesure de rapports élémentaires n'a été observé sur l'un ou l'autre des spectromètres de masse, ceci jusqu'à un facteur de dilution (DF) de 600. Les analyses par ICP‐QMS ont été effectuées par pseudo injection de flux (Fl) et intégration d'un signal transitoire tandis que les analyses par ICP‐SFMS l'ont été avec un système conventionnel d'introduction. Le volume total de solution d'échantillon nécessaire etait de 0.026 ml et 0.08 ml respectivement. Les limites de détection étaient suffisamment basses pour permettre la détermination de ces éléments dans des roches ultrabasiques et les reproductibilités pour les basaltes étaient de l'ordre de 3% (Li‐Be), 1 % (Rb‐U), 5% (In, Tl et Bi), 7% (Sc‐Ga) et 3% (tous les éléments majeurs). Des chondrites carbonées dont Orgueil (Cll), Murchison (CM2) et Allende (CV3) ainsi que des matériaux de référence JB‐1, ‐2, ‐3, JA‐1, ‐2, ‐3 et JP‐1 (GSJ), BHVO‐1, AGV‐1, PCC‐1 et DTS (USGS) ont été analysés pour démontrer l'applicabilité de la méthode.     

电感耦合等离子体质谱法同时测定地质样品中锗硒碲

锗、硒、碲三个元素的分析需要分别采用硝酸-氢氟酸-高氯酸-磷酸、硝酸-氢氟酸-高氯酸两种溶样体系,原子荧光光谱（AFS）、电感耦合等离子体质谱（ICP-MS）两种仪器进行测定,对于大批量地质样品的分析成本高、测试效率低。本文建立了在同一份溶液中用ICP-MS同一种仪器测定锗、硒、碲三元素的方法。样品用硝酸-氢氟酸-硫酸一种体系分解,试液以50%硝酸提取,3%乙醇定容,避免乙醇在复溶时的挥发损失,保证了试样溶液中的乙醇浓度均为最佳增敏作用所需值。试样分解过程中没有使用盐酸,避免了氯离子存在给锗、碲造成的损失。在3%硝酸-3%乙醇介质中硒、碲的灵敏度提高了2.2倍、3.7倍。同时克服了ICP-MS测定硒、碲难电离、灵敏度低的问题,保证了方法稳定性;CCT碰撞池技术消除了氩的多原子离子对硒测定干扰,提高了方法准确度。本方法通过分析国家一级标准物质进行验证,测定值与标准值基本一致,相对标准偏差（RSD,n=4）小于5%,样品前处理过程简单,分析效率高。     

Boron Determination in Twenty One Silicate Rock Reference Materials by Isotope Dilution ICP-MS

The concentration of boron was determined in twenty one geochemical reference materials (silicate rocks) by isotope dilution inductively coupled plasma-mass spectrometry. Boron was extracted from the rocks using HF digestion, suppressing boron volatilisation through boron-mannitol complexation. Sample solutions, in a diluted HCl matrix, were analysed by ICP-MS without any separation of boron from the matrix elements. The results obtained were in agreement with the literature data and indicate that using the described procedure, trace amounts of boron can be very easily determined in complex matrices with rapidity and precision. With the instrumentation and reagents used in this study, this procedure can be used for the determination of 0.5 μg g⁻¹ boron in a 15 0 mg silicate rock sample. Replicate analyses of the twenty one geochemical reference materials (GRM), ranging in boron concentration from 1.35 to 15 7 μg g⁻¹, yielded precisions (relative standard deviation) varying between 0.9 and 9.8%.     

微波消解电感耦合等离子体质谱法测定地球化学样品中钒铬镍锗砷

地质样品中多种元素的分析,通常采用高压密封消解电感耦合等离子体质谱法(ICP-MS),而应用于测定地球化学样品中的V、Cr、Ni、Ge、As等元素,影响分析准确度的主要原因有:样品前处理方面,高压密封罐会释放Cr和Ni污染样品,同时Ge和As属于易挥发元素容易造成损失;质谱测定方面,多原子分子离子会产生干扰。本文针对两方面的干扰因素,对比了微波消解硝酸提取、微波消解王水提取、高压密封硝酸复溶、高压密封王水复溶四种前处理方法中待测元素的溶出效果以及污染或损失情况。结果表明,采用微波消解替代高压密封罐消解可消除引入的Cr、Ni污染,避免了Ge、As挥发损失,同时微波消解的时间短。而采用硝酸提取,由于避免了氯的引入,分析效果优于王水提取。且使用八极杆ICP-MS氦气碰撞模式消除了样品基体中的氯多原子分子离子干扰(如37Cl14N对51V干扰,35Cl16OH对52Cr干扰,35Cl37Cl对72Ge干扰以及40Ar35Cl对75As干扰等)。应用微波消解硝酸提取、ICP-MS测定岩石、水系沉积物和土壤国家标准物质,V、Cr、Ni、Ge、As的检出限分别为1.09、0.19、0.55、0.02、0.50μg/g,精密度(RSD)4%,而采用高压密封消解、ICPMS测定V、Cr、Ni的检出限为3.48、13.09、21.67μg/g(Ge和As由于挥发无法用此法检测)。运用微波消解硝酸提取-ICP-MS氦气碰撞模式测定地球化学样品中V、Cr、Ni、Ge、As,简化了分析流程,样品消解时间仅2 h,相比于高压密封方法(消解时间48 h)具有消解快速、多元素同时测定、检出限低的特点。     

液相色谱-原子荧光光谱联用法测定土壤砷铬锑硒元素价态

土壤重金属污染物的环境效应与其无机价态有密切的关系。As、Cr、Sb和Se元素的价态测定意义重大,但由于价态之间易发生转化使测定工作存在较大难度,标准化程度较低。地质行业标准DD2005-3推荐使用离子交换树脂分离,原子荧光光谱差减法测定As、Sb、Se价态及石墨炉原子吸收光谱法（GFAAS）测定Cr价态。这些方法前处理操作繁琐,测定次数多,工作量大,其他元素形态的存在还会导致结果出现误差。为满足地质调查和评价的需要,本文建立了一套适用于测定土壤水溶态和离子交换态提取液中As、Cr、Sb、Se价态的方法。样品在50℃水浴振荡加热浸提30min,采用液相色谱-原子荧光光谱法（LC-AFS）分离并测定As、Sb、Se价态,一次进样元素的两种无机价态按顺序出峰,同时测定,简便易行,结果更可靠。为了避免了某些离子交换提取剂的屏蔽和干扰,作为补充建立了AFS选择性测定Sb、Se价态的方法,设备成本较低。对于Cr价态的测定,建立了阳离子交换树脂分离-电感耦合等离子体质谱（ICP-MS）的方法,比推荐的GFAAS测定法灵敏度高。As、Cr、Sb和Se的检出限≤0.02μg/g,RSD为3.8%~10.7%,加标回收率为91.0%~106.0%。应用色谱方法对采集的土壤样品进行检测,各项指标满足规范DD2005-3质量要求,与非色谱法相比,实现多组分同时测定。同时初步研究表明,土壤中元素价态含量不高,与土壤总量不存在相关性,采用价态含量作为环境风险评估指标更为合适。     

Determination of Te,As, Bi,Sb and Se (TABS) in Geological Reference Materials and GeoPT Proficiency Test Materials by Hydride Generation‐Atomic Fluorescence Spectrometry (HG‐AFS)

The study of Te, As, Bi, Sb and Se (TABS) has increased over the past years due to their use in the development of low‐carbon energy technologies. However, there is a scarcity of mass fraction values of TABS in geological reference materials. This underlines the difficulty in undertaking routine determinations of these elements. The mass fractions of TABS were determined in geological reference materials using hydride generation‐atomic fluorescence spectrometry (HG‐AFS), calibrated with standard solutions. Comparisons with literature values were used to validate the method. Samples from the GeoPT proficiency test were also analysed. For most elements, there are no assigned or even provisional values for many of the GeoPT and reference materials because of the wide range of results reported. For mass fractions above the quantification limit of the method, our results are in good agreement with the median of GeoPT results. Thus, we propose GeoPT median values as informational values for these elements. In contrast, at mass fractions < 0.5 µg g^?1 median values of Se from GeoPT are systematically higher than our results. Our Se results are in agreement with the reference materials down to 0.02 µg g^?1, which suggest that many of the results for Se reported in GeoPT testing are too high.     

ICP-MS测定土壤中的As、Cr、Pb、Se、Cu和Zn

本文用电感耦合等离子质谱法(ICP-MS)测定了土壤的As、Cr、Pb、Se、Cu和Zn6种微量元素的质量分数,以In作为内标进行基体效应的补偿,方法快速灵敏,回收率为92.4%～106.8%,相对标准偏差小于5.0%,结果达到国家标准要求。     

Determination of Chromium, Nickel, Copper and Zinc in Milligram Samples of Geological Materials Using Isotope Dilution High Resolution Inductively Coupled Plasma-Mass Spectrometry

A simple and accurate method for the determination of Cr, Ni, Cu and Zn at μg g^?1 levels in milligram‐sized bulk silicate materials is reported using isotope dilution high‐resolution inductively coupled plasma‐mass spectrometry (HR‐ICP‐MS) with a flow injection system. Silicate samples with Cr, Ni, Cu and Zn spikes were digested with HF‐HBr and Br₂, and subsequently decomposed at 518 K in a Teflon bomb. In this procedure, all sulfides and chromite, major hosts of these elements, were completely decomposed, thus allowing for isotope equilibration between the sample and spike. Magnesium and Al fluorides formed after the digestion of the sample were removed by centrifugation, and the supernatant was directly aspirated into a HR‐ICP‐MS at a mass resolution of 7500, where interfering oxide ions, ArO⁺, CaO⁺, TiO⁺, CrO⁺ and VO⁺, were separated from Cr⁺, Ni⁺, Cu⁺ and Zn⁺. No matrix effects were observed down to a dilution factor of 50. Detection limits for these elements in silicate samples were < 0.04 μg g^?1. The effectiveness of the technique was demonstrated by the analysis of 13 to 40 mg test portions of USGS and GSJ silicate reference materials with a major element composition ranging from andesite to peridotite, in addition to 8‐23 mg of the Smithsonian reference Allende. Both the reproducibility and the deviation from the reference value for most reference materials of various rock types were < 9%, and thus confirm that the method gives accurate analytical results for small sample sizes over a wide range of Cr, Ni, Cu and Zn contents. This method is, therefore, suitable for analysing small and/or precious bulk samples, such as meteorites, mantle peridotites and mineral separates, and for the characterisation of silicate and sulfide minerals for use as calibration samples in secondary ion mass spectrometry or laser ablation ICP‐MS.     

恩施富硒茶叶中Se含量与对应土壤中Se及重金属元 As、Cd、U的关系

采用氢化物—原子荧光分光光度法(AFS)对恩施芭蕉地区玉露茶园不同坡度的茶叶、土壤样品中的Se及重金属元素Cd、U的质量分数分别进行了测试.研究了恩施富硒茶叶中的Se与As质量分数的关系以及其Se质量分数与其种植土壤中的Se质量分数和重金属元素Cd、U质量分数的关系,旨在为恩施富硒茶叶的种植提供依据.研究表明:在w(S...     

Comparison between Nickel-Sulfur Fire Assay Te Co-precipitation and Isotope Dilution with High-Pressure Asher Acid Digestion for the Determination of Platinum-Group Elements,Rhenium and Gold

The accurate determination of platinum-group elements (PGE), rhenium and gold is important in both fundamental research and ore deposit studies. Questions have been raised by some authors as to whether the nickel-sulfur fire assay technique (NiS-FA) efficiently collects all the PGE. On the other hand, most isotope dilution (ID) techniques can only treat small test portion masses (2 g was used for high-pressure asher digestion; HPA) and this makes them more vulnerable to nugget effects. We determined PGE concentrations in ten reference materials with the aim of comparing the performance characteristics of the two methods. Both methods determine Ru, Pd, Os, Ir and Pt and we found that there were no significant systematic differences in the recovery. The advantages of NiS-FA were that: (a) it is capable of determining Rh and Au; (b) the relatively large test portion mass (15 g) reduces the nugget effect and (c) it is faster and less expensive than HPA-ID. The advantages of HPA-ID were that: (a) it determined Re and (b) it had low level blanks, lower detection limits and hence better precision in low-level homogeneous samples. Each technique had advantages and limitations; they should be considered as complementary rather than competing techniques.     

原子荧光光谱法测定地球化学样品中的砷、锑和汞的方法改进

在原子荧光光谱法中，通过改进地球化学样品的分解条件，预还原条件及测定条件，使砷、锑和汞能在同一介质中测定，而且实现了砷与汞的双道同时测定。方法的检测出限、准确度及精密度均能达到行业要求。     

原子荧光光度法测定地质化探样品中的砷、锑、铋

原子荧光光度法分析As、Sb、Bi已被广泛应用，但由于仪器没有色散系统，所以干扰因素较多。阐述了原子荧光光度分析法中常见的干扰及其消除方法。方法简单、快速、灵敏、低耗。     

双毛细管雾化器氢化物-火焰原子吸收法测定地质样品中痕量硒和碲

本文研究了双毛细管雾化器氢化物-火焰原子吸收法测定地质样品中痕量Se和Te的方法。测定Se、Te的灵敏度分别为0.012μg/ml和0.0088μg/ml(1％吸收);对含1.6ppm Se与0.42ppm Te的样品测定,其RSD(n=6)分别为3.3％和5.5％。方法简单、灵敏、实用。用GSS及GSD系列部分标样验证了方法的可靠性,可以测定一般地质样品中0.0001％以上的Se和0.0000x％以上的Te。     

氢化物发生-原子荧光光谱法测定植物样品中汞硒砷

植物样品经硝酸-高氯酸一次湿法消解后,用氢化物发生-原子荧光光谱法同时测定汞、硒、砷。测定时加入消泡剂磷酸三丁酯,可有效消除泡沫,降低记忆效应,提高精密度。方法精密度(RSD,n=12)为汞2.96%,硒0.96%,砷2.49%。经加标回收试验和国家一级标准物质验证,测定结果与标准值吻合。     

High Pressure Asher Digestion and an Isotope Dilution-ICP-MS Method for the Determination of Platinum-Group Element Concentrations in Chromitite Reference Materials CHR-Bkg, GAN Pt-1 and HHH

New concentration data for Ru, Rh, Pd, Re, Os, Ir and Pt are presented for three chromitite reference materials. A simple and very effective procedure was applied for the measurements. Samples were spiked with enriched isotopes and digested in a HNO₃/HCl (5+2) acid mixture at 300 °C and 125 bar (1.25 × 10⁷ Pa) pressure in a high pressure asher (HPA-S, Anton Paar). The programme settings were changed as a function of mass (0.5, 1, 2 and 4 g) and time (5 and 15 hours). Complete chromitite dissolutions for three digestions at each setting were monitored using XRD analyses of the amorphous residue after digestion. The osmium concentration was determined by sparging the OsO₄ that was formed during digestion into a quadrupole ICP-MS. After drying and re-dissolution of the remaining residue, the other PGEs were separated on-line from their matrix in a simple cation-exchange column that was coupled to the ICP-MS. The concentrations were determined through isotope dilution and external calibration (Rh). By using the on-line separation, we were able to control interference effects (isobaric and molecular), which resulted in highly reproducible data. Replicate measurements of the reference material CHR-Bkg (SARM CRPG-CNRS) with sample masses ranging from 0.5 to 4 g showed very small standard deviations compared to the results from the initial collaborative trials and published data (e.g., 3.2% RSD vs. 32% RSD for Ru). Results for platinum showed the largest scatter, which is currently attributed to the small size of the test portion. In addition to CHR-Bkg, the first results for two chromitite reference materials "platinumore" GAN Pt-1 and "chromiumore" HHH issued by the Central Geological Laboratory of Mongolia are presented.     

Determination of Zirconium, Niobium, Hafnium and Tantalum at ng g-1 Levels in Geological Materials by Direct Nebulisation of Sample HF Solution into FI-ICP-MS

We have developed a rapid and accurate method to determine Zr, Nb, Hf and Ta (denoted as HFSE) in geological samples by inductively coupled plasma-mass spectrometry fitted with a flow injection system (FI-ICP-MS). The method involves sample decomposition by HF followed by HF dissolution of HFSE coprecipitated with insoluble M and Ca fluoride residues formed during the initial HF attack. This HF solution was directly nebulized into an ICP mass spectrometer. An external calibration curve method and an isotope dilution method (ID) were applied for the determination of Nb and Ta, and of Zr and Hf, respectively. Recovery yields of HFSE were > 96% for peridotite, basalt and andesite compositions, apart from Zr and Hf for peridotite (> 85%). No matrix effects for either signal intensities of HFSE or isotope ratios of Zr and Hf were observed in basalt, andesite and peridotite solutions down to a dilution factor of 100. Detection limits in silicate rocks were 40, 2, 1 and 0.1 ng g-1 for Zr, Nb, Hf and Ta, respectively. This technique required only 0.1 ml of sample solution, and thus is suitable for analysing small and/or precious samples such as meteorites, mantle peridotites and their mineral separates. We also present newly determined data for the Zr, Nb, Hf and Ta concentrations in USGS silicate reference materials DTS-1, PCC-1, BCR-1, BHVO-1 and AGV-1, GSJ reference materials JB-1, -2, -3, JA-1, -2 and -3, and the Smithsonian reference Allende powder.     

Determination of the "Difficult" Elements Ag, B, Ge, Mo, Sn, Tl and W in Geochemical Reference Samples and Silicate Rocks of the GeoPT Proficiency Testing Series by DC Arc Atomic Emission Spectrometry

Reference samples of rocks from the Institute of Geochemistry, Irkutsk (IGI) and the Research Institute of Applied Physics, Irkutsk University (RIAP) and silicate rocks from the GeoPT proficiency testing series were analysed with the aim of determining Ag, B, Ge, Mo, Sn, Tl and W abundances by an atomic-emission method with air-stabilized D.C. arc excitation. Many of the results reported are without recommended or assigned values. The results are compared with compilation data from the literature and, where possible, with assigned values for samples of the Geo PT series.     

Mass Fractions of S,Cu, Se,Mo, Ag,Cd, In,Te, Ba,Sm, W,Tl and Bi in Geological Reference Materials and Selected Carbonaceous Chondrites Determined by Isotope Dilution ICP‐MS

Mass fractions of S, Cu, Se, Mo, Ag, Cd, In, Te, Ba, Sm, W and Tl were determined by isotope dilution sector field ICP‐MS in the same sample aliquot of reference materials using HF‐HNO₃ digestion in PFA beakers in pressure bombs and glassy carbon vessels in a high‐pressure asher (HPA‐S) for comparison. Additionally, Bi was determined by internal standardisation relative to Tl. Because isobaric and oxide interferences pose problems for many of these elements, efficient chromatographic separation methods in combination with an Aridus desolvator were employed to minimise interference effects. Repeated digestion and measurement of geological reference materials (BHVO‐1, BHVO‐2, SCo‐1, MAG‐1, MRG‐1 and UB‐N) gave results with < 5% relative intermediate precision (1s) for most elements, except Bi. Replicates of NIST SRM 612 glass digested on a hot plate were analysed by the same methods, and the results agree with reference values mostly within 2% relative deviation. Data for the carbonaceous chondrites Allende, Murchison, Orgueil and Ivuna are also reported. Digestion in a HPA‐S was as efficient as in pressure bombs, but some elements displayed higher blank levels following HPA‐S treatment. Pressure bomb digestion yielded precise data for volatile S, Se and Te, but may result in high blanks for W.     

Determination of Cr,Cu, Ni,Sn, Sr and Zn Mass Fractions in Geochemical Reference Materials by Isotope Dilution ICP‐MS

Isotope dilution (ID) mass spectrometry is a primary method of analysis suited for the accurate and precise measurement of several trace elements in geological matrices. Here we present mass fractions and respective uncertainties for Cr, Cu, Ni, Sn, Sr and Zn in 10 silicate rock reference materials (BCR‐2, BRP‐1, BIR‐1, OU‐6, GSP‐2, GSR‐1, AGV‐1, RGM‐1, RGM‐2 and G‐3) obtained by the double ID technique and measuring the isotope ratios with an inductively coupled plasma‐mass spectrometer equipped with collision cell. Test portions of the samples were dissolved by validated procedures, and no further matrix separation was applied. Addition of spikes was designed to achieve isotope ratios close to unity to minimise error magnification factors, according to the ID theory. Radiogenic ingrowth of ⁸⁷Sr from the decay of ⁸⁷Rb was considered in the calculation of Sr mass fractions. The mean values of our results mostly agree with reference values, considering both uncertainties at the 95% confidence level, and also with ID data published for AGV‐1. Considering all results, the means of the combined uncertainties were < 1% for Sr, approximately 2% for Sn and Cu, 4% for Cr and Ni and almost 6% for Zn.