Rapid isolation of plutonium in environmental solid samples using sequential injection anion exchange chromatography followed by detection with inductively coupled plasma mass spectrometry

This paper reports an automated analytical method for rapid determination of plutonium isotopes (²³⁹Pu and ²⁴⁰Pu) in environmental solid extracts. Anion exchange chromatographic columns were incorporated in a sequential injection (SI) system to undertake the automated separation of plutonium from matrix and interfering elements. The analytical results most distinctly demonstrated that the crosslinkage of the anion exchanger is a key parameter controlling the separation efficiency. AG 1-×4 type resin was selected as the most suitable sorbent material for analyte separation. Investigation of column size effect upon the separation efficiency revealed that small-sized (2 mL) columns sufficed to handle up to 50 g of environmental soil samples. Under the optimum conditions, chemical yields of plutonium exceeded 90% and the decontamination factors for uranium, thorium and lead ranged from 10³ to 10⁴. The determination of plutonium isotopes in three standard/certified reference materials (IAEA-375 soil, IAEA-135 sediment and NIST-4359 seaweed) and two reference samples (Irish Sea sediment and Danish soil) revealed a good agreement with reference/certified values. The SI column-separation method is straightforward and less labor intensive as compared with batch-wise anion exchange chromatographic procedures. Besides, the automated method features low consumption of ion-exchanger and reagents for column washing and elution, with the consequent decrease in the generation of acidic waste, thus bearing green chemical credentials.     

Ion exchange chromatography coupled to inductively coupled plasma mass spectrometry for the study of Pt electro-dissolution

There is an ongoing debate regarding the mechanism of Pt electrochemical dissolution. However, only off-line methods have so far been used, where separation of Pt species is performed separately from their detection. In this study, ion exchange chromatography coupled to inductively coupled plasma mass spectrometry was used for the first time to separate and detect Pt species generated by the electro-dissolution of a Pt electrode in 0.5 M aqueous H₂SO₄ solution. Because these species are either neutral or cationic, they were converted to chloro-complexes using 0.1 M KCl to enable their separation by anion exchange chromatography. Chloro-aqua complexes were observed in addition to the two predominant species, namely PtCl₄²⁻ and PtCl₆²⁻. A good linear relationship was observed between the sum of peak areas for all complexes of a given Pt oxidation state and the Pt concentration, with a detection limit of 0.1 μg L⁻¹ being reached for Pt(II) and Pt(IV). Application of this speciation analysis method to real samples generated by potential cycling using cyclic voltammetry (CV) revealed that, in general, at least 80% of Pt was present as Pt(II), irrespectively of the cyclic potential range or of temperature (up to 60 °C). Still, quantitative spike recovery was achieved after adding known amounts of Pt(II) or Pt(IV) to a sample prepared by CV, which demonstrated that no significant species inter-conversion took place.     

Capillary electrophoresis inductively coupled plasma mass spectrometry

Chemical speciation (extraction of elemental information and identification of molecular environment for an analyte in a complex sample) has been a long sought after goal for analytical chemists. Recently, because of successful developments in more sensitive element-specific detectors and gentle separation schemes, which preserve the true chemical information in a real sample, routine speciation experiments are becoming a common occurrence in the scientific literature. For many reasons, the combination of capillary electrophoresis (for separation of different chemical species) with inductively coupled plasma mass spectrometry (for element and isotope specific detection) has emerged as the method of choice for these analyses. In this article the basic principles of capillary electrophoresis inductively coupled plasma mass spectrometry are discussed. Design consideration for instrument interface, anticipated difficulties with speciation experiments and applications for specific matrices and analytes are also presented in this article.     

Online anion exchange column preconcentration and high performance liquid chromatographic separation with inductively coupled plasma mass spectrometry detection for mercury speciation analysis

A hyphenated method for mercury speciation analysis by the coupling of high performance liquid chromatography and inductively coupled plasma mass spectrometry with the online strong anion exchange column (SAX) preconcentration was developed. The Hg analytes (Hg⁺, MeHg, EtHg and Hg²⁺) were absorbed on the SAX column preconditioned with sodium 3-mercapto-1-propanesulfonate, and then rapidly eluted (less than 16 s) by 5 μL 3% (v/v) 2-mercaptoethanol. The enrichment factors of 1025 for Hg⁺, 1084 for MeHg, 1108 for EtHg and 1046 for Hg²⁺ were obtained using 6 mL sample in a 1.5-min enrichment procedure. Rapid separation of the four mercurial compounds was achieved within 5 min on a 50-mm C₁₈ column using 0.5% (v/v) 2-mercaptoethanol as the mobile phase. The detection limits for Hg⁺, MeHg, EtHg and Hg²⁺ were 0.015, 0.010, 0.009 and 0.016 ng L⁻¹, each, and the relative standard deviations of peak height and peak area (5 ng L⁻¹ for each Hg species) were all below 5%. Mercury speciation in three freshwater, two drinking water and two seawater samples were then analyzed by the proposed method. MeHg and Hg²⁺ concentrations down to 0.14 and 0.56 ng L⁻¹ were detected in the drinking waters.     

Determination of rare-earth elements in uranium-bearing materials by inductively coupled plasma mass spectrometry

A novel and simple analytical procedure has been developed for the trace-level determination of lanthanides (rare-earth elements) in uranium-bearing materials by inductively coupled plasma sector-field mass spectrometry (ICP-SFMS). The method involves a selective extraction chromatographic separation of lanthanides using TRU™ resin followed by ICP-SFMS analysis. The limits of detection of the method proposed is in the low pg g⁻¹ range, which are approximately two orders of magnitude better than that of without chemical separation. The method was validated by the measurement of reference material and applied for the analysis of uranium ore concentrates (yellow cakes) for nuclear forensic purposes, as a potential application of the methodology.     

电感耦合等离子体质谱(ICP-MS)法测定锆钛矿中的铪

锆钛矿组成成分复杂,存在耐高温的锆、钛化合物,不易分解,且铪以类质同象进入锆矿物,导致锆钛矿中的铪含量不均,因此完全分解锆钛矿并准确测定其中含量不同的铪成为一个难题。本文建立了碳酸钠-硼砂高温熔融,以178Hf为分析同位素及50 ng/mL185Re为内标,使用电感耦合等离子体质谱法（ICP-MS）测定锆钛矿中铪的新方法,可准确锆钛矿中含量不均的铪。实验研究了锆钛矿成分及其熔融方法,结果表明碳酸钠-硼砂高温熔融效果最好,可完全溶解耐高温难分解的锆钛矿,当碳酸钠-硼砂质量配比为2:1时熔融效果最佳。电感耦合等离子体质谱法具有检出限低、灵敏度高、线性范围宽等优势,可用于测定锆钛矿中含量不均的铪,ICP-MS蠕动泵转速为45 rpm、雾化流量为1.06 L/min时雾化效率最优。在选定的实验条件下,HfO2质谱强度与其质量浓度在0.01～250 ng/mL范围内呈良好的线性关系,相关系数为0.9997,背景等效浓度为0.029 ng/mL,方法检出限为0.0032 ng/mL。按实验方法对中国国家标准物质中的HfO2进行测定,测定值与认定值一致,相对标准偏差在1.6%~3.2%之间。按实验方法对锆钛矿样品中的HfO2进行测定并进行加标回收率实验,测定结果的相对标准偏差（RSDs,n=9）在0.9～3.4%之间,加标回收率在96%～106%之间,满足国家地质矿产行业标准DZ/T 0130—2006的要求。     

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。     

Method optimization for the determination of four mercury species by micro-liquid chromatography-inductively coupled plasma mass spectrometry coupling in environmental water samples

A method based on the coupling microHPLC-microneb-ICPMS has been developed for Hg(II), MeHg⁺, EtHg⁺ and PhHg⁺ species. Gradient elution using methanol and l-cysteine at pH 3.0 allowed the chromatographic separation of all species in less than 13 min (total analysis time 15 min). The direct coupling of microLC to ICPMS through a Micromist nebulizer permits the analysis of environmental water without sample pretreatment and derivatization steps. Nebulizer type, organic modifier and column length were the main parameters tested. The methanol content and pH of the mobile phase greatly affected the retention time and sensitivity of the method. Key factors to obtain high signal to noise ratio, at concentrations below 1 μg L⁻¹, were found to be the nebulization step and traces of Hg present in the complexing agent. A detailed optimization of carrier and make up gas flow rates have enabled the nebulization of the methanol gradient elution with good mass transport efficiency, low organic solvent loading into the plasma and excellent precision.The performance of the microHPLC-microneb-ICPMS method developed was evaluated on a surface water sample filtered (0.22 μm) and spiked with 0.5 μg L⁻¹ (as Hg) of each species. Precision (R.S.D., n = 6) for all species of Hg varied from 0.5 to 2.1%. Detection limit, defined as three times the standard deviation (n = 6), ranged from 8 ng L⁻¹ for EtHg⁺ to 32 ng L⁻¹ for PhHg⁺ and was noticeably lower than those reported in previous LC-based methods. Accuracy was suitable with recoveries ranging from 85 to 100% when tested at two levels (0.5 and 10 μg L⁻¹) in groundwater samples. Recovery was matrix affected when water samples of high salinity (depurated wastewater and seawater) were used.     

电感耦合等离子体-质谱法测定高纯硫粉末中17种痕量杂质

建立电感耦合等离子体-质谱(ICP-MS)法测定高纯硫粉中Si、P、V、Cr、Mn、Ni、Co、Cu、As、Zn、Zr、Cd、In、Sb、Te、Pb、Bi等17种痕量金属杂质含量的方法。样品用HClO4溶解后挥发硫基体,使样品中杂质元素得到富集,各杂质元素的方法检出限为0.1～50ng/g。方法加标回收率为83%～117%。各杂质元素均为10ng/mL的混合标准溶液平行7次测定的相对标准偏差均小于5%。该方法能够满足纯度为99.999%～99.9999%的高纯硫样品中杂质测定的需要。     

Lead determination in whole blood by laser ablation coupled with inductively coupled plasma mass spectrometry

This work describes a simple procedure for blood lead level determination. The proposed method requires little sample pretreatment and subsequent direct analysis of a dried blood spot on a filter membrane using laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS). In general, LA-ICP-MS studies are somewhat limited by the lack of matrix-matched standards for calibration purposes. Here we describe aqueous standard calibration and matrix-matched calibration methods. This method was validated by analysis of the reference materials. With the matrix-matched calibration method, the recovery ranged from 97.8% to 112.8%, while the aqueous standard calibration method ranged 90.4% to 122.4%. The lower detection limit was estimated as 0.1 ng mL⁻¹. The determination precision, expressed as the relative standard deviation (RSD), was not worse than 10% for all results. A sample throughput of approximately 5 min per sample made it possible to rapidly screen a large number of samples.     

Selenium speciation analysis in a sediment using strong anion exchange and reversed phase chromatography coupled with inductively coupled plasma-mass spectrometry

An analytical procedure for selenium speciation of analysis of selenourea (SeU), selenoethionine (SeE), selenomethionine (SeM), Se(VI), Se(IV), dimethylselenide (dMeSe) and dimethyldiselenide (dMedSe) was developed, based on two complementary liquid chromatography (LC) techniques coupled with inductively coupled plasma-mass spectrometry (ICP-MS). Specifically, strong anion exchange (SAX) chromatography coupled with ICP-MS was used for the separation and quantification of all the earlier mentioned Se compounds, except for the two methyl selenides, which could be separated and determined by reversed phase chromatography coupled with ICP-MS. This procedure was applied to a soil sample from the warm springs area of Thermopyles (Greece). For leaching the Se species from the soil sample, four extraction methods, using water at ambient temperature, hot water, methanol and 0.5 M HCl, were tested for their efficiency of extracting the different Se species. The speciation results obtained by the LC-ICP-MS methods were compared with those obtained by voltammetric techniques. The determination of total selenium in the sample was achieved by graphite furnace atomic absorption spectrometry, as well as by ICP-atomic emission spectrometry, after suitable digestion of the sediment sample.     

电感耦合等离子体质谱(ICP-MS)法测定锰矿冶炼烟尘中多种重金属元素

为了准确测定锰矿冶炼烟尘中重金属元素的含量,为锰矿冶炼过程中监测和评价环境影响提供有力的数据支撑,采用HCl+HNO₃+HClO₄+HF消解体系对试样进行前处理,通过选用合适的内标溶液消除测定中的非质谱干扰,采用碰撞池模式和编辑校正方程消除质谱干扰,从而建立了电感耦合等离子体质谱法测定锰矿冶炼烟尘中的Cr、Ni、Cd、Tl、Pb等多种重金属元素的方法。实验结果表明,各元素标准曲线的线性相关系数均大于0.999 9,方法检出限为0.007～0.094 mg/kg,样品测定的相对标准偏差(RSD,n=11)在0.43%～4.9%,样品加标回收率为93.8%～107%。方法具有操作简便、线性范围宽、检出限低、精密度高等优点,满足锰矿冶炼烟尘中Cr、Ni、Cd、Tl、Pb等多种重金属元素同时测定的要求。     

Comparative study of atomic fluorescence spectroscopy and inductively coupled plasma mass spectrometry for mercury and arsenic multispeciation

Mercury and arsenic are two elements of undoubted importance owing to their toxic character. Although speciation of these elements has been developed separately, in this work for the first time the speciation of As and Hg using two atomic fluorescence detectors in a sequential ensemble is presented. A coupling based on the combination of high-performance liquid chromatography (where mercury and arsenic species are separated) and two atomic fluorescence detectors in series, with several online treatments, including photooxidation (UV) and hydride generation, has allowed the determination of mercury and arsenic compounds simultaneously. The detection limits for this device were 16, 3, 17, 12 and 8 ng mL^–1 for As^III, monomethylarsinic acid, As^V, Hg²⁺ and methylmercury, respectively. This coupling was compared with an analogous one based on inductively coupled plasma–mass spectrometry (ICP-MS) detection, with detection limits of 0.7, 0.5, 0.8, 0.9 and 1.1 ng mL^–1, respectively. Multispeciation based on ICP-MS exhibits better sensitivity than the coupling based on tandem atomic fluorescence, but this second device is a very robust system and exhibits obvious advantages related to the low cost of acquisition and maintenance, as well as easy handling, which makes it a suitable system for routine laboratories.     

电感耦合等离子体质谱(ICP-MS)法测定土壤中的有效钼

准确快速测定土壤中的有效钼,是评价土壤肥力的重要指标,对指导作物生产有重大意义。本文采用草酸-草酸铵溶液浸提土壤样品,待测浸提液稀释5倍后通过电感耦合等离子体质谱法在氦气模式下测定土壤中有效钼的含量,建立了土壤中有效钼高灵敏度分析的检测方法。选择103Rh为内标元素,校正仪器在测定过程中引起的信号飘移。对两种前处理方式进行比较,确定了震荡30 min、放置过夜的浸提方法浸提效果更好且更利于大批量样品的分析。使用震荡30 min、放置过夜的浸提方法对5个土壤标准物质有效钼进行前处理,其测定值均在标准值范围内;分别在无气体模式和氦气模式下比较了浓度为0mg/L、1mg/L、2mg/L、5mg/L、10mg/L、50mg/L的Mn对5ug/L 95Mo测定浓度的影响,结果表明氦气模式下的动能歧视可有效去除95Mo测定过程中的多原子离子的干扰,氦气模式测定有效钼明显优于无气体模式;分别对待测溶液稀释5倍和未稀释的内标回收率趋势进行监测,发现未稀释的样品内标回收率随着测量样品数的增多呈下降趋势,而稀释5倍对基体干扰的消除有显著效果。对5个土壤样品分别重复测定6次,其RSD均小于4.1%;线性相关系数为1.0000;方法检出限为0.0012 mg/kg。综上,该方法测定土壤有效钼结果准确,重现性好,灵敏度高,且适合大批量样品的分析。     

Capillary electrochromatographic separation of metal ion species with on-line detection by inductively coupled plasma mass spectrometry

A bonded phase capillary column containing macrocyclic polyamine, [28]ane-N₆O₂ functional groups was used for the electrophoretic separation of arsenic, chromium and selenium species. A simple device interfacing this capillary electrochromatography (CEC) systems to an inductively coupled plasma mass spectrometer (ICPMS) is described. The dimension of the capillary column was 160 cm×100 μm i.d. To accommodate this electrophoretic separation, an auxiliary capillary was used with nitric acid (0.05 M) as makeup liquid. With the electrokinetic method at –20 kV, 20 s and a nebulizer gas flow rate of 1 l min⁻¹, the sample injected was analyzed with an applied potential of −20 kV. The background electrolyte buffer for the separation of CrO₄²⁻–Cr³⁺ was phosphate (20 mM, pH 6.5). That for HAsO₄²⁻–Ph₄As⁺ was pyromellitate (20 mM, pH 6.0) and for SeO₄²⁻–SeO₃²⁻ was acetate (20 mM, pH 6.0). The role of the buffer’s anion was also discussed. The separation efficiency of the bonded phase was compared with the bare fused silica. Concentration detection limits for these metal ions were in the low ppb range. In addition, the matrix effect of the established system with the bonded phase was found smaller than that with the bare fused silica.     

电感耦合等离子体质谱法测定血液和精液中的硼

采用HNO3-H2O2和氨水-甘露醇两种方法处理样品,电感耦合等离子体质谱法（ICP-MS）测定血液和精液中的硼。Be作内标补偿基体效应,并用标准加入法验证了方法的可靠性,标准加入法与外标法测定结果相吻合。在测定B的同时,还可进行Cr、Cu、Cd、Ba、Sr、Mn、Co、Tl、Li、Pb、Zn、Sc、Ti、V、As等多元素测定。两种样品处理方法的测定值呈显著正相关（r=0.99919）。方法检出限为0．11ng／mL（氨水-甘露醇法）,0.06ng／mL（HNO3-H2O2）。已用于测定某硼矿区血液和精液样品中的硼。     

微波消解法-电感耦合等离子体质谱(ICP-MS)法测定韭菜中11种元素

为快速、准确测定韭菜中多元素含量,采用微波消解法对韭菜中样品进行消解处理,优化了前处理方法、ICP-MS工作条件和检测方法,利用微波消解-电感耦合等离子体质谱法测定韭菜中Pb、Cd、Se、As、Zn、Cu、Ni、Fe、Cr、Ca、K等11种元素含量。结果表明,在硝酸-双氧水(7:1)体系中,消解功率1550W,温度梯度为120℃-160℃-195℃,总时长为45min,赶酸温度选择150℃,可将韭菜完全消解,并且ICP-MS射频功率设为1550W,运用在线内标的检测方式降低非质谱干扰。11种元素回归系数R₂^{均大于0.999,方法检出限为}0.002～0.100μg/kg,方法定量限为0.006～0.300μg/kg。方法回收率88.0%～102.7%,相对标准偏差为1.8%～4.6%,可以满足韭菜中多种元素同时测定的需求。方法具有灵敏度高、线性范围宽、准确性高等特点,可为韭菜样品的多元素同时测定提供可靠的方法支撑。     

Determination of picomolar beryllium levels in seawater with inductively coupled plasma mass spectrometry following silica-gel preconcentration

A robust and rapid method for the determination of natural levels of beryllium (Be) in seawater was developed to facilitate mapping Be concentrations in the ocean. A solid-phase extraction method using a silica gel column was applied for preconcentration and purification of Be in seawater prior to determination of Be concentrations with inductively coupled plasma mass spectrometry (ICP-MS). Be was quantitatively adsorbed onto silica gel from solutions with pH values ranging from 6.3 to 9, including natural seawater. The chelating agent ethylenediamine tetraacetic acid was used to remove other ions in the seawater matrix (Na, Mg, and Ca) that interfere with the ICP-MS analysis. The reproducibility of the method was 3% based on triplicate analyses of natural seawater samples, and the detection limit was 0.4 pmol kg⁻¹ for 250 mL of seawater, which is sufficient for the analysis of seawater in the open ocean. The method was then used to determine the vertical profile of Be in the eastern North Pacific Ocean, which was found to be a recycled-type profile in which the Be concentration increased with depth from the surface (7.2 pmol kg⁻¹ at <200 m) to deep water (29.2 pmol kg⁻¹ from 3500 m to the bottom).     

Applications of inductively coupled plasma mass spectrometry and laser ablation inductively coupled plasma mass spectrometry in materials science

Inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) have been applied as the most important inorganic mass spectrometric techniques having multielemental capability for the characterization of solid samples in materials science. ICP-MS is used for the sensitive determination of trace and ultratrace elements in digested solutions of solid samples or of process chemicals (ultrapure water, acids and organic solutions) for the semiconductor industry with detection limits down to sub-picogram per liter levels. Whereas ICP-MS on solid samples (e.g. high-purity ceramics) sometimes requires time-consuming sample preparation for its application in materials science, and the risk of contamination is a serious drawback, a fast, direct determination of trace elements in solid materials without any sample preparation by LA-ICP-MS is possible. The detection limits for the direct analysis of solid samples by LA-ICP-MS have been determined for many elements down to the nanogram per gram range. A deterioration of detection limits was observed for elements where interferences with polyatomic ions occur. The inherent interference problem can often be solved by applying a double-focusing sector field mass spectrometer at higher mass resolution or by collision-induced reactions of polyatomic ions with a collision gas using an ICP-MS fitted with collision cell. The main problem of LA-ICP-MS is quantification if no suitable standard reference materials with a similar matrix composition are available. The calibration problem in LA-ICP-MS can be solved using on-line solution-based calibration, and different procedures, such as external calibration and standard addition, have been discussed with respect to their application in materials science. The application of isotope dilution in solution-based calibration for trace metal determination in small amounts of noble metals has been developed as a new calibration strategy. This review discusses new analytical developments and possible applications of ICP-MS and LA-ICP-MS for the quantitative determination of trace elements and in surface analysis for materials science.     

Matrix effects in inductively coupled plasma mass spectrometry: a review

Fundamental research on non-spectroscopic interferences, also known as matrix effects, in inductively coupled plasma (ICP) mass spectrometry with sample introduction using nebulization is critically and exclusively examined in this review, starting with fundamental processes that may be a source of matrix effects during sample introduction, ion generation in the ICP, ion extraction through the interface, and ion transport through the ion optics to the detector. Various methods for attenuating matrix effects are then reviewed and illustrated with some examples. Instead of exhaustively reviewing the literature, representative references are used to comprehensively describe the main issues, several of which are also common to ICP optical emission spectrometry.