A practical approach to non-spectral interferences elimination in inductively coupled plasma optical emission spectrometry

Matrix effects and practical possibilities of reducing accompanying non-spectral interferences in inductively coupled plasma optical emission spectrometry (ICP-OES) were studied for microconcentric Micromist, concentric and V-groove nebulizers (VGN) coupled with two cyclonic spray chambers of different sizes. The effect of a wide scale of interferents and mixtures thereof in the concentration range of up to 2 mass % (Na, Ca, Ba, La, urea) or up to 20 vol. % (nitric acid) on the analysis of Cd, Cu, K, Mg, Mn, Pb and Zn was investigated in terms of their analytical recovery and Mg(II) 280.27 nm/Mg(I) 285.29 nm line intensity ratio. Recoveries of ionic lines were lower than those of atomic lines (37–102 %) depending on the matrix concentration. The Mg(II)/Mg(I) ratios were found to be 12–15 and they slightly decreased as the matrix load increased. Exceptional behavior of pure La matrix, steeply lowering the recoveries and Mg(II)/Mg(I) ratios was observed. A Micromist nebulizer coupled with a small inner volume spray chamber provided the highest recoveries (94–102 %), lowest matrix effects across the matrix loads and, compared to others, the least significant dependence without worsening of the analytical characteristics (recoveries, signal background ratios and the Mg(II)/Mg(I) ratios) across the studied matrices.     

Systems for the suppression of spectral interferences for inductively coupled plasma mass-spectrometry

This review considers the basics, principles of operation and practical application of spectral interference suppression systems based on multipole gas-filled cells.     

Fission yield measurements by inductively coupled plasma mass-spectrometry

Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. The uncertainty of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain fissioning isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry.     

Determination of vanadium by reaction cell inductively coupled plasma mass spectrometry

Recent advances in inductively coupled plasma mass spectrometry (ICP-MS) have included the addition of interference reduction technologies, such as collision and reaction cells, to improve its detection capability for certain elements that suffer from polyatomic interferences. The principle behind reaction cell (RC)-ICP-MS is to remove a particular polyatomic interference by dissociation or formation of a different polyatomic species that no longer interferes with the analyte of interest. However, some interferences cannot be removed by commonly reported reaction gases, such as hydrogen, oxygen, or methane, necessitating using more reactive and hazardous gases, such as ammonia. The current study investigates oxygen as a reaction gas in RC-ICP-MS to specifically react with vanadium analyte ions, rather than the interferents, to produce a polyatomic analyte species and thereby provide a way to analyze for vanadium in complex environmental matrices. The technique has been tested on a series of river water, tap water, and synthetic laboratory samples, and shown to be successful in vanadium analyses in high chloride and sulfate matrices. The zinc isobaric interference on the new vanadium oxide analyte at m/z 67 is also investigated, and can be corrected by using a standard mathematical correction equation. The results of this study further increase the utility of RC-ICP-MS analytical techniques for complex environmental matrices.     

Combination of cool plasma and collision-reaction interface for correction of polyatomic interferences on copper signals in inductively coupled plasma quadrupole mass spectrometry

Inductively coupled plasma mass spectrometry (ICP-MS) is an important instrumental technique for elemental analysis. However, some elements suffer from spectral interferences caused by ions derived from argon plasma gas and matrix components. The determination of copper isotopes is affected by ⁴⁰Ar²³Na⁺ and ⁴⁰Ar²⁵Mg⁺. The performance of an ICP-MS with a collision reaction interface (CRI) and cool plasma conditions for correction of spectral interferences was evaluated here. The efficiency of the CRI was studied introducing H₂ or He through sampler and skimmer cones. Gas introduction through the sampler cone was ineffective. Complete elimination of spectral interferences was reached when introducing 60 or 80 mL min⁻¹ of H₂ in the skimmer cone, but sensitivity losses were as large as 99%. Further, the effect of interferences was checked when the argon plasma was operated under cool plasma conditions. The effects of the applied radiofrequency (0.6, 0.8, 0.9, and 1.0 kW), sampling depth (5.5, 8.5 and 11.5 mm), and dwell time (25 and 50 ms) were studied considering interference reduction and sensitivities. Best conditions were reached at 0.8 kW. Subsequently, both CRI and cool plasma conditions were combined to evaluate their performance on reduction of polyatomic Na and Mg argide interferences. Spectral interferences were eliminated using a CRI with 20 mL min⁻¹ H₂ introduced through the skimmer cone, cool plasma conditions at 0.8 kW and sampling depth of 8.5 mm. This work demonstrated the feasibility of combining CRI and cool plasma for circumventing some spectral interferences on Cu determination by ICP-QMS.     

KED碰撞模式-电感耦合等离子体质谱（ICP-MS）法测定多种煤中磷

煤是重要的工业生产和生活能源燃料,磷元素又是煤中主要的有害微量元素之一,磷元素极易进入大气、水体和土壤,对环境和生态造成严重污染,为快速准确测定不同煤质样品中磷元素的含量,建立了混合酸消解-KED碰撞模式-电感耦合等离子体质谱法（ICP-MS）测定多种煤中磷的方法。讨论了样品灰化温度、灰化时间、消解试剂等对磷元素测定结果的影响,试样经箱式电阻炉在815 ℃,灼烧1.5 h灰化后,采用盐酸-硝酸-氢氟酸-高氯酸体系进行酸解,王水提取,以磷元素特定质量数31 (质荷比,m/z )定性,以磷元素和103Rh内标元素质谱信号的强度比值与磷元素的浓度成正比进行定量分析,向碰撞反应池中通入碰撞混合气,与相同质量数的多原子离子物质的发生有效碰撞使其质荷比发生变化,从而降低氧化物产率、消除双电荷产生的质谱干扰,准确测定试样中磷的含量。磷标准溶液浓度在0.5～50 μg/mL范围内呈现良好的线性关系,磷校准曲线方程为y=3985x-226.23,相关系数(R2) =0.9998。方法检出限为0.96 μg/g。选用17种不同种类国家一级标准物质进行验证,测定值与认定基本一致,相对标准偏差(RSD)均≤9.6%,(n=12),相对误差(RE) 均≤4.6%,各种标准物质磷元素测定t值均小于2.20（t 0.05,11值）,该方法测定结果与标准物质认定值具有较好的一致性,且无显著性差异,该方法可用于不同煤质样品中磷元素的测定。     

电感耦合等离子体质谱技术最新进展

对1998年以来电感耦合等离子体质谱技术（ICP－MS）的最新进展作一简要回顾。内容包括同位素比值分析、双聚焦扇形磁场高分辨ICP－MS、多接收器磁扇形等离子体质谱仪（MC－ICP－MS）、飞行时间等离子体质谱仪（ICP－TOF－MS）、“冷”等离子体及屏蔽炬技术以及动态碰撞／反应池技术等进展。     

Spectral interferences in the determination of trace elements in environmental materials by inductively coupled plasma atomic emission spectrometry

This paper deals with spectral interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES) encountered with environmental materials. These samples normally contain high concentrations of aluminium, calcium, magnesium, iron, titanium, potassium and sodium. The investigations cover: (a) spectral data for Al, Ca, Mg, Fe, Ti, K and Na as interferents for 200 pm wide windows centred (±100 pm) around the prominent lines of As, B, Ba, Be, Cd, Cr, Cu, Hg, Mn, P, Pb, Sb, Se, Sn, Tl, U and Zn; (b) a data base of Q-values for line interference [Q_Ij(λ_a)] and Q-values for wing background interference [Q_Wj(Δλ_a)] for two values of the excitation temperature 6200 K and 7200 K. The lines free or negligibly influenced by line interference were selected for analyte determination. Q-values were used for calculation of correction factors under a spectral line without the measurement of a reference blank at the wavelength of the prominent analysis lines. The accuracy of ICP-AES with the Q-concept as a basic methodology is checked by the analysis of a certified reference material IAEA/Sediment SD-N-1/2/. The precision of the method is characterised by an RSD of 0.6–1.7%. Extraction of trace elements soluble in aqua regia was used as a decomposition method. This article is an electronic publication in Spectrochimica Acta Electronica (SAE), a section of Spectrochimica Acta, Part B (SAB). The hardcopy text is accompanied by an electronic archive, stored on the SAE homepage at http://www.elsevier.nl/locate/sabe. The archive contains the tabular material of this article in electronic form.     

蒸气发生-电感耦合等离子体质谱法测定碘

建立了一种在线化学蒸气发生-电感耦合等离子体质谱测定碘的方法。利用碘负离子的还原性,采用氧化还原手段,将碘负离子氧化为碘单质;然后通过碘单质的易挥发特点,将碘蒸气直接导入等离子体。该方法可以提高传输效率,改善样品利用率,使检测灵敏度得到极大的提高。方法的检出限为0.22μg/L,样品加标回收率在87.4%~97.75%之间,RSD(n=11)在3%以内。实验中预先将正5价碘还原成碘负离子,然后加入氧化剂将碘负离子氧化成碘单质进行检测;对碘的形态化学蒸气发生法进行了尝试。     

Spectral diagnostics of inductively coupled RF discharge plasma

Results of UV spectral measurements in low-pressure (30–65 Pa) and atmospheric-pressure inductively coupled radiofrequency discharges at different power inputs and gas compositions typical for that of industrial processing regimes are reported. Isolated molecular bands have been observed in the spectra; by analyzing the unresolved rotational temperature of these bands, the rotational temperature of the upper emission state can be found.     

电感耦合等离子体质谱法测定镁合金中的多种元素

用电感耦合等离子体质谱(ICP-MS)法测定了镁合金中的Be、Al、Ca、Fe、Mn、Ni、Cu、Zn、Ag、Cd、Sn、La、Ce、Pb14种元素,进行了稳定性实验以及Cu、Zn、Ni、Mg、Al基体实验,考察了共存元素的干扰.镁合金标准物质测定值与参考值符合较好,方法检出限为0.0002～0.3346 μg/g,相对标准偏差RSD＜10%.     

Investigation of matrix-induced interferences in mixed-gas helium-argon inductively coupled plasma mass spectrometry

The effects of various matrix constituents, Cd, Co, Pb, and synthetic ocean water, on analyte ion signal were investigated in He-Ar plasma source mass spectrometry. Analyte ion signal suppressions and enhancements were observed in the presence of varying concomitants. The method used for optimizing analyte ion lens signal determined whether suppression or enhancement was encountered. Tuning on a nitric acid standard solution results in a suppressed signal, whereas tuning on the analyte in the presence of the matrix results in signal enhancement, relative to that obtained with no concomitant present. The heavier mass lead concomitant had the greatest effect on the ion signal. Additionally, lighter analyte elements were affected to a greater extent than heavier analytes in the presence of high concomitant concentrations.     

电感耦合等离子体质谱测定地质样品中多种元素

用电感耦合等离子体质谱(ICP-MS)测定了地质样品中多种元素。考察了测量过程中的基体效应及质谱干扰,利用In内标,补偿由于基体效应的影响所引起的测量偏差,建立校正公式校正质谱干扰。方法的检出限为0.06~250ng/L,精密度为1.7%~3.2%,加标回收率为91%~108%,方法适于批量地质样品分析。     

萃取分离-ICP-MS测定高纯铝中痕量元素

利用吡咯烷二硫代氨基甲酸铵(APDC)-CHCl_3萃取分离体系结合ICP-MS对高纯铝中的Co、As、Mo、In、Sn、Sb、Cd、Ag、Pd、Au进行测定,建立了测定高纯铝中痕量元素的方法.实验分别考察了仪器工作参数,萃取酸度,络合剂用量对于杂质元素测定结果的影响,选择了最佳实验条件.各元素的回收率在77.6%～112.2%之间,检出限0.02～0.6 ng/mL,RSD为1.6%～7.2%.     

Removal of spectral interferences and accuracy monitoring of trace cadmium in feeds by dynamic reaction cell inductively coupled plasma mass spectrometry

In the direct ICP-MS determination of Cd in feed samples, significant spectral interferences caused by high concentrations of Mo can play an important role. In the present study, Mo based oxide or hydroxide polyatomic interferences were eliminated by dynamic reaction cell (DRC) with O₂ as reaction gas. Some other oxide or hydroxide interferences (i.e. Zr and Ru) were simultaneously reduced by this technology. These potentially interfering polyatomic ions ⁹⁵Mo¹⁶O⁺, ⁹⁴Mo¹⁶OH⁺, ⁹⁴Zr¹⁶OH⁺, ⁹⁸Mo¹⁶O⁺, ⁹⁸Ru¹⁶O⁺ and ⁹⁷Mo¹⁶OH⁺ on ¹¹¹Cd⁺ and ¹¹⁴Cd⁺ were oxidized to higher oxides MoO₂⁺, MoO₃⁺, MoO₄⁺, RuO₃⁺, RuO₄⁺, MoO₂H⁺, MoO₃H⁺, ZrO₂H⁺ and ZrO₃H⁺. The rejection parameter q (RPq) of DRC and the flow rate of O₂ were optimized and set at 0.75 and 2.0 ml min^{− 1}, respectively. In addition, the residual isobaric interference of ¹¹⁴Sn on ¹¹⁴Cd was corrected using a mathematical correction equation. The limit of quantitation (LOQ) for ¹¹¹Cd or ¹¹⁴Cd was 0.8 or 1.0 ng g^{− 1} and the analysis results of NIST 1567a wheat flour and 1568a rice flour standard reference materials were in good agreement with the certified values. As the routine cadmium monitoring method in our laboratory, the proposed method was applied to the accuracy determination of 562 pig feed samples for the Monitoring of Central Meat Reserves (CMR) of China.     

Determination of long-lived radionuclides in concrete matrix by laser ablation inductively coupled plasma mass spectrometry

A laser ablation system using a Nd:YAG laser was coupled both to a quadrupole inductively coupled plasma (ICP) mass spectrometer and to a double-focusing sector field ICP mass spectrometer. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied for the determination of long-lived radionuclides in a concrete matrix. The investigated samples were two laboratory standards with a concrete matrix, which we doped with different long-lived radionuclides (e.g. ⁹⁹Tc, ²³²Th, ²³³U, ²³⁷Np) from the ng g⁻¹ to μ g⁻¹ concentration range and an undoped concrete material (blank). Detection limits for long-lived radionuclides in the 10 ng g⁻¹ range are reached for LA-ICP-MS using the quadrupole mass spectrometer. With double-focusing sector field ICP-MS, the limits of detection are in general one order of magnitude lower and reach the sub ng g⁻¹ range for ²³³U and ²³⁷Np. A comparison of mass spectrometric results with those of neutron activation analysis on undoped concrete sample indicates that a semiquantitative determination of the concentrations of the minor and trace elements in the concrete matrix is possible with LA-ICP-MS without using a standard reference material.     

Direct determination of 226Ra in environmental matrices using collision cell inductively coupled plasma mass-spectrometry

Direct determination of ²²⁶Ra in complex environmental matrices (biological and uranium ore samples) by collision-cell inductively coupled plasma mass-spectrometry was investigated. Possible polyatomic interferences were studied and their effects on ²²⁶Ra measurements were determined. The instrumental conditions for optimal signal-to-noise ratio for ²²⁶Ra were found. Concentrations of ²²⁶Ra in certified reference samples were measured using both external calibration and standard addition approaches. The best precision was obtained by applying standard additions. The absolute detection limit for ²²⁶Ra was 1 fg with optimal gas flow rates for the collision cell of 7 ml^.min^-1 for helium and 4 ml^.min^-1 for hydrogen.     

Spectral interpretation and interference correction in inductively coupled plasma mass spectrometry

To tackle the several problematic polyatomic interferences in inductively coupled plasma mass spectrometry (ICP-MS), we have developed a software approach based on data reduction of the measured total mass spectrum through multicomponent analysis (MCA). The approach leans on a working knowledge of interferents that are likely to be encountered in a sample matrix, which composition is known by virtue of the total mass spectrum and knowledge of applied solvents. The full isotopic patterns for all elements and expected interferents are used in the modelling MCA matrix of 250 masses × 105 species at maximum. Polyatomic abundances are calculated by the software. Since all species are modelled fundamentally through their known natural abundances, the MCA matrix can be manipulated and reprocessed until interpretation of the mass spectrum and, hence, interference correction are optimal. The optimum is attained by use of the bar graph and calculation modes of the PC software and criteria for properly found isotopic patterns. With optimized models stored in the data base, the user may routinely process samples in one go, and operate the ICP-MS system in a true all-element mode. Use of elemental equations or measurement of large multivariate calibration sets and pure component solutions are superfluous. Data reduction is solely based on the information about the isotopic patterns, present in the measured mass spectrum itself. As a result, in the case of interferences, detection limits may be lowered by one to two orders of magnitude. The approach is illustrated with an industrial example of Hf determined in NdFeB, and with an environmental example. Here, a suite of elements over the 50–82 amu mass range has been determined in different salt matrices in ground water.     

王水提取-电感耦合等离子体质谱法同时测定地质样品中微量银、镉、铋

样品用水浴加热、王水提取预处理,采用电感耦合等离子体质谱法同时测定了土壤、水系沉积物及岩石等地质样品中的痕量Ag、Cd和Bi。在样品预处理阶段,主要干扰元素Zr和Nb只有少量被溶出,而分析元素Ag、Cd和Bi的溶出趋于完全,这样在样品预处理阶段就完成了分析元素与干扰元素的有效分离,减小了多原子离子93Nb16O ,92Zr16OH ,92Mo16OH 对109Ag的干扰和95Mo16O ,94Zr16OH ,94Mo16OH 对111Cd的干扰。方法对实际样品的检出限(10σ,DF=300)Ag,Cd和Bi的质量分数分别为5.1,4.3和10.5ng/g。对不同含量样品7次测定的RSD为8.7%~1.8%。用该方法对土壤、水系沉积物及岩石等国家一级标准物质进行分析,分析数据均在标准推荐值的允许误差范围内。