A comparison of double-focusing sector field ICP-MS, ICP-OES and octopole collision cell ICP-MS for the high-accuracy determination of calcium in human serum

Human serum is routinely measured for total calcium content in clinical studies. A definitive high-accuracy and low-uncertainty method is required for reference measurements to underpin medical diagnoses. This study presents a novel octopole collision cell ICP-MS, high-accuracy, methodology and comparison of that technique with double-focusing sector field ICP-MS and an ICP-OES method. Double-matched isotope dilution mass spectrometry (IDMS) was employed for ICP-MS techniques and an exact matching bracketing technique using scandium as an internal standard was used for ICP-OES analysis. Medium resolution mode was utilised for double-focusing sector field ICP-MS analysis to resolve the dominant interferences on the ⁴⁴Ca/⁴²Ca isotope pair. Hydrogen reaction gas was employed to chemically resolve a number of polyatomic interferences predominantly through charge transfer reactions in the octopole collision cell. Comparison data presented for NIST CRM 909b human serum analysis from all three techniques demonstrates highest accuracy (99.6%) and lowest uncertainty (1.1%) for octopole collision cell ICP-MS. Data from ICP-OES using a non-IDMS technique produces comparably accurate data and low-uncertainties. The much higher total expanded uncertainties for double-focusing sector field ICP-MS compared with octopole collision cell data are explained by lower precision on the measurement of the ⁴⁴Ca/⁴²Ca isotope ratio. Data for octopole collision cell ICP-MS submitted for an international blind trial comparison (CCQM K-14) demonstrated excellent agreement with the mean of all participants with a low expanded uncertainty.     

Determination of Li, Na, Mg, K, Ca and Fe with ICP-MS using cold plasma conditions

Some important analytes in ICP-MS are interfered by plasma argon or argon species, such as ArO⁺ and ⁵⁶Fe, ⁴⁰Ar and K or Ca. One approach to overcome this interference is the use of reduced forward power and a metal shield inserted between torch and load coil. These so called cold plasma conditions reduce the background caused by argon species and the formerly interfered analytes can be easily detected in the ng/g-range. Other elements in the lower mass region also profit from these conditions even when they are not interfered in normal plasma mode. The limits of detection are improved due to reduced background noise level and enhanced ion transmission. On the other hand, the reduced power fed to the plasma lowers the analytical performance and makes it susceptible to matrix effects. Elements of higher mass generally show higher detection limits compared to normal plasma mode.     

Determination of Li, Na, Mg, K, Ca and Fe with ICP-MS using cold plasma conditions

Some important analytes in ICP-MS are interfered by plasma argon or argon species, such as ArO⁺ and ⁵⁶Fe, ⁴⁰Ar and K or Ca. One approach to overcome this interference is the use of reduced forward power and a metal shield inserted between torch and load coil. These so called cold plasma conditions reduce the background caused by argon species and the formerly interfered analytes can be easily detected in the ng/g-range. Other elements in the lower mass region also profit from these conditions even when they are not interfered in normal plasma mode. The limits of detection are improved due to reduced background noise level and enhanced ion transmission. On the other hand, the reduced power fed to the plasma lowers the analytical performance and makes it susceptible to matrix effects. Elements of higher mass generally show higher detection limits compared to normal plasma mode. Received: 30 November 1998 / Revised: 4 February 1999 / Accepted: 8 February 1999     

原子吸收光谱法测定营养品中钙钾镁铁的含量

对藕粉、豆粉、芝麻糊、核桃粉中无机营养元素的含量进行考察.采用高氯酸-硝酸（1＋4）混酸消解的方法将样品在低温下消解,用镧盐作为钙、镁的释放剂以消除共存元素P的化学干扰,火焰原子吸收光谱法定量.实验测得Ca、K、Mg、Fe工作曲线的相关系数r〉0.991,加标回收率在99.31%-103.70%,相对标准偏差在2.06%以下.实验方法简单、快速、定量准确,测得各营养品中无机元素含量丰富,可作为无机营养元素的来源.     

稀释法快速测定人体血液和尿液中多种重金属元素

利用电感耦合等离子体质谱(ICP-MS),建立了直接稀释测定人体血液和尿液中Cr、Mn、As、Se、Cd、Hg、Pb等7种重金属元素含量的方法。利用甲醇,异丙醇,正丁醇,1,4-丁二醇4种不同有机溶剂作为碳元素来源,改善实际样品和标准溶液之间的基体匹配。结果表明,稀释液(0.1%HNO3,0.1%2-巯基乙醇,0.1%Triton-X100)直接稀释血液和尿液,标准溶液中补偿体积分数1.5%的1,4-丁二醇作基体匹配后,ICP-MS测定,分析结果与标准参考值吻合,Se,Hg等元素加标回收率在90%～120%之间。该方法各元素检出限在0.01～0.1ng/mL之间;标准曲线线性相关系数大于0.9999;测量结果RSD3%。     

Simple,fast, and low-contamination microwave-assisted digestion procedures for the determination of chemical elements in biological and environmental matrices by sector field ICP-MS

A simple and convenient method for the digestion of animal tissues, lichens, and plants for 33 metals measured by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) was described. Microwave-assisted acid digestions were performed at atmospheric pressure by means of a multi-samples rotor designed for processing a large number of samples at once in screw-capped disposable polystyrene liners. The digested samples were filled up to final volume directly in the polystyrene liners ready for elemental quantification. Seven certified reference materials, namely BCR 184 (bovine muscle), BCR 186 (pig kidney), DORM-2 (dogfish muscle), BCR 422 (cod muscle), BCR 62 (olive leaves), BCR 100 (beech leaves), and BCR 482 (lichen) were analysed to verify the accuracy of the method. The linearity range, limit of quantification, precision, and recovery by addition of non-certified elements were also assessed. All elements, with the exception of Hg in BCR 184 and As in BCR 186, were above the quantification limit and blank concentrations, and good agreement existed between found and target values in bovine muscle, pig kidney, and cod muscle. Significant deviations were observed for Al, Co, Cr, Mn, and Ni in dogfish muscle and for Ca, Cr, Fe, and Hg in lichens and plants. The proposed digestion procedure offers a low contamination risk, simplicity, speed, low cost, and applicability in routine analysis, and the SF-ICP-MS method allowed metals from a fraction of ng?g^?1 to hundreds of µg?g^?1 to be quantified in one analytical run.     

Quantitation of Si,B, Ca,Mg, Ba,and Zr in Complex-Alloyed Nickel Alloys by ICP-MS

The possibility of the use of a collision and reaction cell is shown and the optimum parameters for its adjustment are selected for the determination of Si, B, Ca, Mg, Ba, and Zr in a complex-alloyed nickel alloy via inductively coupled plasma mass spectrometry (ICP-MS). The procedure of sample dissolution and its preparation for the analysis is presented. The correctness of the obtained results is confirmed by the analysis of the certified reference standard of a nickel alloy.     

The determination of arsenic and selenium in standard reference materials using sector field ICP-MS in high resolution mode

Sector field ICP-MS was used to analyse As and Se in a range of standard reference materials (NIST 1643d Water, NIST 1573a Tomato Leaves, NIST 1566a Oyster Tissue, NIST 2704 Buffalo River Sediment and Bio-Rad Reference Urine Level 2). A spectral resolution of m/Δm = 7500 enabled ⁷⁵As and ⁷⁷Se to be separated from problematic ArCl interferences. Following microwave acid digestion, solid samples were typically diluted 1 + 99 prior to analysis, while the urine sample was diluted 1 + 9. The water sample was analysed undiluted and diluted 1 + 9. Despite near baseline spectral separation, ⁷⁵As and ⁷⁷Se were still found to be influenced by ArCl at high Cl concentrations, the effect being most pronounced for ⁷⁷Se. When necessary ⁸²Se was also monitored to determine the accuracy of the ⁷⁷Se results. Detection limits (LOD, based on 3σ of 10 replicates) for ⁷⁵As, ⁷⁷Se and ⁸²Se in ultra-pure water, 1% (w/w) HNO₃ and 1% (w/w) HCl were ～?0.1, ～?0.2 and ～?0.5 ng g^–1, respectively. Although signal intensities when using high resolution were ～?1% of that found when using low resolution mode (m/Δm = 300), measured As concentrations and certified values were found to agree to within ± 11% for all samples analysed. The concentration of Se in NIST 1566a Oyster Tissue, NIST 2704 Buffalo River Sediment and Bio-Rad Reference Urine were found to be in agreement with certified values to within ± 15– 20%, as measured by ⁷⁷Se. However, closer agreement (± 5%) was found when these samples were analysed using ⁸²Se. The Se concentration in NIST 1643d Water was found to agree to within ± 5% of the certified value (depending on dilution factor). Due to the low concentration of Se in NIST 1573a Tomato Leaves, quantitation was not possible (below LOQ, 10σ). As a consequence of the lower ion transmission when using resolution 7500, analytical precisions were found to be elevated over that normally observed using low resolution mode, typically ± 5–20% (depending on analyte concentration and isotopic abundance).     

The determination of arsenic and selenium in standard reference materials using sector field ICP-MS in high resolution mode

Sector field ICP-MS was used to analyse As and Se in a range of standard reference materials (NIST 1643d Water, NIST 1573a Tomato Leaves, NIST 1566a Oyster Tissue, NIST 2704 Buffalo River Sediment and Bio-Rad Reference Urine Level 2). A spectral resolution of m/Δm = 7500 enabled ⁷⁵As and ⁷⁷Se to be separated from problematic ArCl interferences. Following microwave acid digestion, solid samples were typically diluted 1 + 99 prior to analysis, while the urine sample was diluted 1 + 9. The water sample was analysed undiluted and diluted 1 + 9. Despite near baseline spectral separation, ⁷⁵As and ⁷⁷Se were still found to be influenced by ArCl at high Cl concentrations, the effect being most pronounced for ⁷⁷Se. When necessary ⁸²Se was also monitored to determine the accuracy of the ⁷⁷Se results. Detection limits (LOD, based on 3σ of 10 replicates) for ⁷⁵As, ⁷⁷Se and ⁸²Se in ultra-pure water, 1% (w/w) HNO₃ and 1% (w/w) HCl were ∼ 0.1, ∼ 0.2 and ∼ 0.5 ng g^–1, respectively. Although signal intensities when using high resolution were ∼ 1% of that found when using low resolution mode (m/Δm = 300), measured As concentrations and certified values were found to agree to within ± 11% for all samples analysed. The concentration of Se in NIST 1566a Oyster Tissue, NIST 2704 Buffalo River Sediment and Bio-Rad Reference Urine were found to be in agreement with certified values to within ± 15– 20%, as measured by ⁷⁷Se. However, closer agreement (± 5%) was found when these samples were analysed using ⁸²Se. The Se concentration in NIST 1643d Water was found to agree to within ± 5% of the certified value (depending on dilution factor). Due to the low concentration of Se in NIST 1573a Tomato Leaves, quantitation was not possible (below LOQ, 10σ). As a consequence of the lower ion transmission when using resolution 7500, analytical precisions were found to be elevated over that normally observed using low resolution mode, typically ± 5–20% (depending on analyte concentration and isotopic abundance). Received: 28 December 1998 / Accepted: 9 February 1999     

Molybdenum determination in human serum (plasma) by ICP-MS coupled to a graphite furnace

A method for the Mo-determination in human serum or plasma is described, employing ICP-MS coupled with graphite furnace atomization. Because of severe differences between the slopes of an aqueous calibration function and the signals produced in native serum samples, the standard addition method has to be used. Seventy serum samples from healthy individuals in the age between 2 and 60 years have been investigated. The mean value for the Mo-concentration found was 0.58±0.34 g/l.     

The flame photometric determination of Li,Na, K,Ca, Mg,and Sr in natural and mineral waters

Summary A method for rapid, sensitive and accurate flame photometric analysis of Li, Na, K, Mg, Ca and Sr in various kinds of waters is described. Anionic interferences are eliminated by anion-exchange to give the chlorides of the elements and mutual inter-elemental effects are eliminated by applying the dilution and standard-addition techniques. Very high sensitivities are obtained by using a monochromator which provides high line-to-background ratios. Spectral lines or bands are used which give linear calibration curves. The variation of the standard error of determination with change in the analyte concentration was studied. The overlap interference of strontium with lithium is discussed, and the possibility of its mathematical elimination suggested.

---

Zusammenfassung Ein Verfahren zur raschen, empfindlichen und genauen flammenphotometrischen Bestimmung von Li, Na, K, Mg, Ca und Sr in Wässern wurde beschrieben. Störungen durch Anionen werden durch Austausch gegen Chlorid vermieden, während interelementare Störungen mit Hilfe der Verdünnungstechnik bzw. innerer Standards umgangen werden.Sehr hohe Empfindlichkeiten erzielt man mit einem Monochromator infolge günstiger Schwärzungs-Hintergrundverhältnisse. Es wurden Spektrallinien bzw. Banden verwendet, die lineare Eichkurven geben. Die Varianz des Standardfehlers bei Bestimmung verschiedener Konzentrationen wurde untersucht. Die Überlappung von Strontium und Lithium wurde diskutiert und die Möglichkeit ihrer rechnerischen Eliminierung empfohlen.

---

Résumé On décrit un procédé pour le dosage rapide, sensible et exact du Li, Na, K, Mg, Ca et Sr, par photométrie de flamme, dans l'eau. On évite les interférences avec les anions en échangeant avec le chlorure, tandis que les interférences inter-éléments sont éliminées par emploi de la technique de dilution ou d'étalons internes.On atteint une très haute sensibilité avec un monochromateur en raison du rapport favorable entre le fond et le noircissement. On se sert des raies ou des bandes spectrales donnant des courbes d'étalonnage linéaires. On a fait l'étude de la variation de l'erreur standard dans le cas de dosages à différentes concentrations. On discute le recouvrement du strontium et du lithium et l'on recommande la possibilité de l'éliminer par le calcul.

     

速效胃宁冲剂中钾钠钙镁含量分析

用原子吸收法测定了5批速效胃冲剂中钾,钠,钙,镁的含量,结果表明,该药物中钾,钠,钙,镁的含量均较丰富,本结果为探讨速效胃宁冲剂中宏量元素及疗效的关系提供了有用数据。     

Isotopes and concentrations of Zn in human blood and serum by ICP-MS

The double focusing-Jeol Inductively Coupled Plasma Mass Spectrometer PLASMAX2 is used at different resolving powers, for the separation between zinc isotopes and their interfering ions. NIST standard solution samples of zinc as single and multielements are used in the analysis. Variation of different Zn isotopic abundances and their interfering ions are studied as a function of concentrations at low and high resolutions. The precision for different isotopic ratios in multielement solutions, after taking the experimental considerations, at high resolution are calculated and found to have a value between 0.19 and 0.42. While the accuracy for the isotopes can reach a value between 0.27 and 1.17, blood and serum samples in human are used as an application for this method in the biological samples. The obtained results are compared with that obtained by using flame atomic absorption spectrometer and it is found in the same range of concentration.     

Precise and accurate isotope ratio measurements by ICP-MS

The precise and accurate determination of isotope ratios by inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) is important for quite different application fields (e.g. for isotope ratio measurements of stable isotopes in nature, especially for the investigation of isotope variation in nature or age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, quality assurance of fuel material, for reprocessing plants, nuclear material accounting and radioactive waste control, for tracer experiments using stable isotopes or long-lived radionuclides in biological or medical studies). Thermal ionization mass spectrometry (TIMS), which used to be the dominant analytical technique for precise isotope ratio measurements, is being increasingly replaced for isotope ratio measurements by ICP-MS due to its excellent sensitivity, precision and good accuracy. Instrumental progress in ICP-MS was achieved by the introduction of the collision cell interface in order to dissociate many disturbing argon-based molecular ions, thermalize the ions and neutralize the disturbing argon ions of plasma gas (Ar+). The application of the collision cell in ICP-QMS results in a higher ion transmission, improved sensitivity and better precision of isotope ratio measurements compared to quadrupole ICP-MS without the collision cell [e.g., for 235U/238U approximately 1 (10 microg x L(-1) uranium) 0.07% relative standard deviation (RSD) vs. 0.2% RSD in short-term measurements (n = 5)]. A significant instrumental improvement for ICP-MS is the multicollector device (MC-ICP-MS) in order to obtain a better precision of isotope ratio measurements (with a precision of up to 0.002%, RSD). CE- and HPLC-ICP-MS are used for the separation of isobaric interferences of long-lived radionuclides and stable isotopes by determination of spallation nuclide abundances in an irradiated tantalum target.     

Elemental fingerprinting of gypsum drywall using sector field ICP-MS and multivariate statistics

Outgassing of volatile sulphur compounds from gypsum drywall from some sources has resulted in odours, corrosion of wiring and metals and health problems for homeowners. Infrared spectroscopy has been the primary analytical tool to identify ‘problematic’ drywall. In this paper, we demonstrate that elemental fingerprinting using inductively coupled plasma mass spectrometry and multivariate statistics is an effective alternative. The approach also showed potential in determining the geographic source of gypsum. Nineteen elements (Al, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, Mg, Mn, Ni, Pb, Rb, Sr, Tl, U, V and Zn) were measured in 20 samples of drywall, half of which were classified as positive for contamination by Fourier Transform Infrared Spectroscopy. Gypsum from three different mines and a flue gas desulphurisation plant were also analysed. Principal component analysis and multivariate analysis of variance of the elemental data showed significant differences between the problematic and non-problematic drywall and between sources of gypsum. Strontium averaged 1800 ± 500 µg/g in problematic drywall compared to 400 ± 100 µg/g in non-problematic drywall (p < 0.0001).     

X射线荧光光谱仪快捷、准确测定水玻璃主次量元素

本方法介绍了采用X射线荧光光谱仪测定液体水玻璃中的Al2O3、CaO、MgO、Fe2O3、K2O、Na2O、SiO2的含量。研究了适合直接测定液态水玻璃的制样方式、仪器分析参数,建立了工作曲线并录入数据库中。将该方法对未知样品的测定结果与化学法、ICP-AES法对比分析,证实具有良好的准确度,精密度试验显示RSD在0.38%~14.26% 之间。结果显示本方法的准确度、精密度完全可以满足对水玻璃中上述元素的测定要求。     

Selected isotope ratio measurements of light metallic elements (Li, Mg, Ca, and Cu) by multiple collector ICP-MS

The unique capabilities of multiple collector inductively coupled mass spectrometry (MC-ICP-MS) for high precision isotope ratio measurements in light elements as Li, Mg, Ca, and Cu are reviewed in this paper. These elements have been intensively studied at the Geological Survey of Israel (GSI) and other laboratories over the past few years, and the methods used to obtain high precision isotope analyses are discussed in detail. The scientific study of isotopic fractionation of these elements is significant for achieving a better understanding of geochemical and biochemical processes in nature and the environment.     

干灰化–离子色谱法测定木耳标准物质中的钾、钙、镁

采用离子色谱法对木耳标准物质中的K,Ca,Mg进行测定,对样品消解以及离子色谱分离条件进行了优化。在优化实验条件下,该法对木耳中K,Ca,Mg 3种元素测定结果的相对标准偏差小于1.0%(n=7)。采用该方法对NIST西红柿叶标准物质(SRM1573a)进行测定,测定结果与标准值相符,同时与ICP–OES方法比较验证,两者测定结果一致。对该方法测定结果的不确定度进行了评定,K,Ca,Mg测定结果的相对扩展不确定度(k=2)分别为2.3%,3.3%,1.9%。该方法准确可靠,能够满足标准物质定值的要求。     

Die automatische Schnellanalyse von Ca, K, Mg und P in Bodenextrakten

Ohne Zusammenfassung     

Die flammenphotometrische Bestimmung von Na, K, Mg und Ca in Weinen

Ohne Zusammenfassung