Analysis of leaves by using the laser ICP-MS with isotope dissolution method

The use of laser ablation inductively coupled mass spectrometry (laser ICP-MS), in combination with a calibration procedure involving the addition of enriched isotopes, for the determination of trace elements in birch leaves and their ashes is described. Samples are pressed into pellets without binder materials and analyzed using the ICP-MS spectrometer ELAN 5000 with the laser sampler type 320 (Perkin Elmer). The analytical results obtained by two methods are compared with the values obtained after digestion of the same samples and analysis of the resulting solutions by ICP-MS. The results are discussed in terms of precision, accuracy and limits of detections.     

Elemental composition of laser ablation aerosol particles deposited in the transport tube to an ICP

The element ratios in aerosol particles produced by laser ablation (λ=266 nm, pulse length: 5 ns) of brass and steel in Ar and He and deposited in different segments of the transport tube to an ICP have been measured by ICP-MS. The data are compared with the ratios obtained by a corresponding bulk analysis. For brass, the element compositions of the aerosol particles deposited in different parts of the tube deviated from the bulk and varied along the tube. For steel, moderate agreement of the element ratios in the aerosols and the bulk was found. It is also shown that elemental ratios measured on-line by laser ablation ICP-MS with the laser-produced aerosol should not be calibrated by elemental ratios obtained with wet aerosols from aqueous solutions of the bulk.     

A study of laser ablation and slurry nebulisation sample introduction for the analysis of geochemical materials by inductively coupled plasma spectrometry

Summary The performances of two alternative sample introduction methods for use with Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) have been evaluated for the analysis of the same sample material. The laser ablation sample introduction system is based on a Nd:YAG laser to which an x-y-z translational sampling head had been added. A study has been made of a number of parameters which affect the performance of the system to find the optimum operating conditions. The slurry introduction system involved aspirating the slurries into the plasma using a de Galan nebuliser and a Scott-type spray chamber arrangement. A study has been made of the parameters which control the production of stable homogeneous slurries. Initial particle size measurements have been carried out on the slurried samples to show how this affects this method of sample introduction. Results are presented for the analysis of a South African reference material rock sample (SARM 5) by ICP-OES with both laser ablation and slurry nebulisation sample introduction and some preliminary results for the analysis by ICP-MS with laser ablation introduction. Semi-quantitative results are obtained for laser ablation ICP-OES as only one matrix matched standard is used. However, the agreement between the results obtained for slurry nebulisation and the certificate value is poor. It is suggested by comparison with previous studies that this may be due to particle size effects. Encouraging results were obtained for the determination of trace elements by laser ablation ICP-MS.     

A new laser ablation system for quantitative analysis of solid samples with ICP-MS.

The laser ablation (LA) method is an effective technique for quantitative analysis. In the present work, a new LA system was developed for the high-sensitivity analysis of metal materials using inductively coupled plasma mass spectrometry (ICP-MS). This system consists of a high-frequency Q-switched laser and 2 scanning mirrors for scanning the ablation spot in an adequately large area of the specimen without vacant spaces. The influence of elemental fractionation (non-stoichiometric generation of vapor species) can be eliminated by repetitive irradiation of this pattern on the same area. Particles generated with an average laser power of 0.6 W with the developed LA system gave intensity and stability substantially similar to that of a 500 microg/ml solution steel sample in solution ICP-MS. The analytical performance of the developed LA-ICP-MS was compared with that of a solution ICP-MS using NIST steel SRMs. The performance of the newly-developed system is comparable to that of conventional solution ICP-MS in both accuracy and precision. The correlation coefficients between the contents and the intensity ratios to Fe were over 0.99 for most elements. The relative standard deviation (RSD) obtained by LA-ICP-MS revealed that this system can analyze iron samples with good precision. The results of ultra trace level analysis of high-purity iron showed that developed LA-ICP-MS is capable of analyzing ppm concentration levels with a 20 - 30 ppb level standard deviation. The detection limit was on the order of 10 ppb for most elements.     

Application of laser ablation inductively coupled mass spectrometry (LA-ICP-MS) for the determination of major, minor, and trace elements in bark samples

The large surface area of barks from many tree species enables the effective accumulation of pollutants. Therefore, the analysis of bark material will provide useful information about the degree of pollution of a certain region. The determination of main, minor, and trace elements (Al, Ca, Cd, Ce, Cr, Cu, Fe, Mn, P, Pb, S, Ti and Zn) in bark was performed with an Nd:YAG laser coupled to an ICP-MS system. Bark standards for the calibration by laser ablation ICP-MS were prepared from different bark layers which differ for some relevant elements in concentrations. Four digestion procedures for the decomposition of the standard pellets, the numbers of laser shots per sample and of samples per region necessary have been investigated. Representative results were obtained for 5 or more samples taken from different individuals of one species of a sampling area and the averaged element concentrations of 10 separately placed laser shots for each sample. Laser ablation ICP-MS was applied for the characterization of real bark samples from different regions with high and low pollution burden. It was shown that the method is well suited to characterize different degrees of environmental impact. Anthropogenic sources were responsible for the higher concentrations of most of the elements under investigation.     

Application of laser ablation inductively coupled mass spectrometry (LA-ICP-MS) for the determination of major, minor, and trace elements in bark samples

The large surface area of barks from many tree species enables the effective accumulation of pollutants. Therefore, the analysis of bark material will provide useful information about the degree of pollution of a certain region. The determination of main, minor, and trace elements (Al, Ca, Cd, Ce, Cr, Cu, Fe, Mn, P, Pb, S, Ti and Zn) in bark was performed with an Nd:YAG laser coupled to an ICP-MS system. Bark standards for the calibration by laser ablation ICP-MS were prepared from different bark layers which differ for some relevant elements in concentrations. Four digestion procedures for the decomposition of the standard pellets, the numbers of laser shots per sample and of samples per region necessary have been investigated. Representative results were obtained for 5 or more samples taken from different individuals of one species of a sampling area and the averaged element concentrations of 10 separately placed laser shots for each sample. Laser ablation ICP-MS was applied for the characterization of real bark samples from different regions with high and low pollution burden. It was shown that the method is well suited to characterize different degrees of environmental impact. Anthropogenic sources were responsible for the higher concentrations of most of the elements under investigation. Received: 26 April 1999 / Revised: 24 August 1999 / /Accepted: 28 August 1999     

Frontiers in elemental analysis by mass spectrometry

New developments in inductively coupled plasma mass spectrometry (ICP-MS) and laser desorption-time-of-flight mass spectrometry (LD-TOF-MS) for inorganic analysis are described. These include fundamental studies of the ion extraction, process in ICP-MS, development of a highly efficient nebulizer, isotope tracer studies, measurement of elemental speciation by liquid chromatography with ICP-MS detection and characterization of the structures of solids by ion association. The possibilities of determining inorganic species in solutions by electrospray MS are also described.     

Trace element analysis of synthetic mono- and poly-crystalline CaF2 by ultraviolet laser ablation inductively coupled plasma mass spectrometry at 266 and 193 nm

The analytical figures of merit for ultraviolet laser ablation-inductively coupled plasma mass spectrometry (UV-LA-ICP-MS) at 266 nm with respect to the trace element analysis of high-purity, UV-transmitting alkaline earth halides are investigated and discussed. Ablation threshold energy density values and ablation rates for mono- and poly-crystalline CaF₂ samples were determined. Furthermore, Pb-, Rb-, Sr-, Ba- and Yb-specific analysis was performed. For these purposes, a pulsed Nd:YAG laser operated at the fourth harmonic of the fundamental wavelength (λ=266 nm) and a double-focusing sector field ICP-MS detector were employed. Depending on the background noise and isotope-specific sensitivity, the detection limits typically varied from 0.7 ng/g for Sr to 7 ng/g in the case of Pb. The concentrations were determined using a glass standard reference material (SRM NIST612). In order to demonstrate the sensitivity of the arrangement described, comparative measurements by means of a commercial ablation system consisting of an ArF excimer laser (λ=193 nm) and a quadrupole-type ICP-MS (ICP-QMS) instrument were carried out. The accuracy of both analyses was in good agreement, whereas ablation at 266 nm and detection using sector-field ICP-MS led to a sensitivity that was one order of magnitude above that obtained at 193 nm with ICP-QMS.     

电感耦合等离子体质谱(ICP-MS)法测定高钨基体样品中稀土元素的含量

准确测定钨矿和钨酸盐晶体等高钨基体样品中稀土元素的含量有助于开展矿床地球化学特征研究及钨酸盐激光晶体材料的制备和性质研究。在高钨基体样品电感耦合等离子体质谱法（ICP-MS）分析时,为了考察高钨及高含量阳离子等基体组成对分析结果的影响,实验针对Na2WO4、CaWO4、NaY(WO4)2、MnWO4和(Fe,Mn)WO4等高钨基体样品,采用硝酸和氢氟酸高压密闭消解,加入稀土元素并用2% HNO3溶液稀释定容配制成稀土元素浓度为1 ng·g-1的基体匹配标准溶液;同时,直接用2% HNO3溶液配制稀土元素浓度相同的非基体匹配标准溶液以对比系统考察两种基体溶液中稀土元素的相对灵敏度系数（RSC）差异。结果显示,基体匹配溶液与2% HNO3溶液中稀土元素的RSC相对偏差基本小于15%,表明基体效应的影响可以忽略不计。进而,为了准确测定常见高钨基体样品中稀土元素的含量,实验建立了基于ICP-MS的高钨基体样品中稀土元素准确定量分析方法,该方法线性关系好（R2 ? 0.9997）,检出限低（0.5 ~ 27.9 pg·g-1）,准确度理想（相对误差-6.25 ~ 10.74%）。采用该方法测定了钨酸钙单晶实际样品中稀土元素的含量并将其与基体匹配法的测定结果进行比对,结果显示两者相对偏差为0.80 ~ 12.75%,说明本文所建立的分析方法可靠,能用于定量测定高钨基体样品中稀土元素的含量。     

基于大气压下介质阻挡放电抑制LA-ICP-MS分析中元素分馏效应研究

采用自制的大气压下介质阻挡放电装置串联在激光剥蚀池与ICP炬管之间, 对激光剥蚀产生的气溶胶进行预电离. 结果表明, 元素瞬时信号轮廓的平滑度得以改善, 元素分析信号精密度(RSD, n=3)可提高2.55％. 在ArF准分子激光(193 nm)和Nd∶YAG 固体激光(213 nm)两种不同波长的激光剥蚀系统中, 元素分馏因子均比常规模式下更接近于1, 表明采用介质阻挡放电对气溶胶预电离后元素分馏效应得以有效抑制. 相比两种不同波长的激光剥蚀系统, 介质阻挡放电对213 nm固体激光的元素分馏效应改善作用明显.     

Determination of Pt from coke samples by ICP-MS after microwave assisted digestion and microwave assisted cloud point extraction

Platinum in coke samples was determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted sample digestion and temperature controlled microwave assisted cloud point extraction (MW-CPE). Interferences due to hafnium (¹⁷⁹Hf¹⁶O) were successfully eliminated using MW-CPE with 2-MBT prior to the determination of platinum by ICP-MS. The validity of the method was studied by spike recovery tests and by analyzing certified reference material (BCR-723 street dust). The results obtained for platinum in the BCR-723 were generally in good agreement with the certified values. Furthermore, the preliminary platinum results obtained for coke sample by ICP-MS after MW-CPE were compared to those obtained by a reference method (NiS-Fire Assay preconcentration/Te coprecipitation and ICP-MS determination).     

Application of laser ablation ICP-MS to elemental analysis of glasses

A technique involving the coupling of laser ablation and inductively coupled plasma mass spectrometer has been used for semi-quantitative analysis of glasses without sample dissolution. The characteristic features of this technique is low detection limit and accuracy between a few % up to 20%. An NIST glass standard (SRM 612) was dissolved and then analysed by ICP-MS in semi-quantitative mode. The results were in close agreement with the certified values for elements such as Mn, Sr, Y, Ti...Abbreviations AA atomic absorption - ICP-OES inductively coupled plasma optical emission spectroscopy - ICP-MS inductively coupled plasma mass spectrometry - LA laser ablation     

激光剥蚀-电感耦合等离子体质谱 (ICP-MS)法测定纯钌中19种杂质元素

建立了激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)法测定纯钌中Mg、Al、Fe、Ni、Cu、Zn、Rb、Rh、Pd、Mo、Ag、Cd、Sn、Ba、Ir、Pt、Au、Pb和Si等19种杂质元素的分析方法.优化了仪器参数,给出了激光能量为60％,剥蚀孔径为110μm,扫描速率为50μm/s,脉冲频率为10 Hz,载...     

Calibration strategies for quantifying the Mn content of tooth and bone samples by LA-ICP-MS

There is a growing interest in using biomonitoring of tooth and bone specimens to assess human exposure to manganese (Mn). Information on historical exposure to Mn can be obtained through micro-spatial analysis of such specimens by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The principal aim of this study was to compare several calibration strategies for determining Mn content in tooth and bone by LA-ICP-MS including: (a) a six-point calibration curve based on synthesized hydroxyapatite (HA) materials, and single-point calibrations based on (b) NIST SRM 1400 Bone Ash, (c) NIST SRM 1486 Bone Meal, and (d) NIST SRM 612 Trace Elements in Glass. Performance was similar between different ICP-MS platforms (quadrupole ICP-MS, dynamic reaction cell ICP-MS, and sector field ICP-MS). Data based on calibration using the ⁵⁵Mn count rate were compared to that based on using the ⁵⁵Mn/⁴³Ca count rate ratio to obtain results as the Mn mass fraction. Reasonable performance was obtained by calibration using either SRM 612 or SRM 1400, in combination with the ⁵⁵Mn/⁴³Ca count rate ratio and using either the synthesized HA standards or SRM 1400 as calibrators, combined with ⁵⁵Mn count rate. By contrast, calibration based on SRM 1486 resulted in a systematic low bias. While there are several options for quantifying the Mn content of tooth and bone using LA-ICP-MS, users should be aware of the potential for strong matrix effects that may affect results. Overall, determining the ⁵⁵Mn/⁴³Ca count rate ratio, rather than the mass fraction, may represent a better approach for reporting the content of Mn in tooth and bone by LA-ICP-MS.     

电感耦合等离子体质谱技术在环境领域的应用

综述电感耦合等离子体质谱技术在环境监测和环境科学研究领域的应用.介绍了电感耦合等离子体质谱技术在环境监测中的分析优势,环境研究领域中稳定同位素比值测定技术及其与色谱、激光烧蚀、流动注射技术联用分析技术应用的进展.     

Development of a procedure for the multi-element determination of trace elements in wine by ICP-MS

An inductively coupled plasma mass spectrometric (ICP-MS) procedure has been developed for the determination of trace elements in wine. The procedure consists in simple 1+1 dilution of the wine and semi-quantitative analysis (without external calibration) using In as internal standard. Thirty-one elements at concentrations ranging from 0.1 mg mL(-1) to 0.5 ng mL(-1) can be determined by ICP-MS analysis with and without digestion. It was investigated whether a matrix effect observed for EtOH in the wine matrix can be overcome by application of a micro-concentric nebulizer with a membrane desolvator (MCN 6000). The results obtained for the MCN 6000 are compared with those obtained by use of a conventional Meinhard nebulizer. It is shown that the observed matrix effect can only be compensated by use of an internal standard for the Meinhard nebulizer, but not for the MCN 6000. Results for ICP-MS are compared with those obtained by total reflection X-ray fluorescence spectrometry (TXRF).     

Double-pulse laser ablation inductively coupled plasma mass spectrometry

This paper describes the use of double-pulse laser ablation to improve ICP-MS internal (temporal relative standard deviation, %TRSD) and external (%RSD) precision. The first laser pulse is used to ablate a large quantity of mass from the sample surface. The second pulse is applied with a variable time delay after the first pulse to break the ablated mass into a finer aerosol, which is more readily transported to and digested in the ICP-MS. A factor of two improvement in %TRSD and factor of five in %RSD are demonstrated.     

Laser ablation and arc/spark solid sample introduction into inductively coupled plasma mass spectrometers

Sample introduction using laser ablation and arc and spark ablation is reviewed. Few references were found in the literature on the use of spark or arc ablation as a sample introduction technique into the ICP-MS and emphasis is therefore placed on the use of laser ablation sampling, particularly for Inductively Coupled Plasma Mass Spectrometry (ICP-MS) detection; however, many of the principles can also be applied to optical emission detection. The applications of the techniques are described, with particular emphasis on micro-sampling of geological materials.     

Investigations on cluster and molecular ion formation by plasma mass spectrometry

The formation of molecular and cluster ions of different inorganic materials in plasma mass spectrometry – spark source mass spectrometry (SSMS), radiofrequency glow discharge mass spectrometry (rf GDMS), laser ionization mass spectrometry (LIMS), inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) – was investigated and compared. Similar abundance distributions of cluster ions were observed for a graphite sample, for boron nitride/ graphite and for metal oxide/graphite mixtures using different plasma mass spectrometric methods. A correlation of intensities of metal argide ions in ICP-MS with their bond dissociation energies was used to estimate unknown dissociation energies of molecular ionic species. For the elements of the 2nd or 3rd period in the periodic table, the intensities of most argon molecular ions (ArX⁺) measured by ICP-MS rise with increasing atomic number in a similar manner to the theoretically calculated bond dissociation energies of argon molecular ions.     

Sample Preparation for Determination of Rare Earth Elements in Geological Samples by ICP-MS: A Critical Review

The presence of rare earth elements (REE) in geological materials provides important information about the formation and the geochemical processes that rocks undergo. Therefore, there is a constant necessity for accurate data and reliable and fast analytical methods. However, the low concentrations of these elements typically found in rocks require quantification by sufficiently sensitive techniques, such as Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The preparation of these samples to the introduction in ICP-MS is a critical part of the process. Traditional wet dissolution methods, such as acid digestion or alkaline fusion followed by dissolution are mostly employed. The acid digestion requires a mixture of strong acids due to the presence of low soluble constituents common in rock samples, such as silicates or clays. The alkaline fusion is fast and efficient, but the dissolution of the melted material results in solutions with a high amount of total dissolved solids (TDS), which can be a problem due to the possibility of deposition in parts of the ICP-MS. Other instrumental approaches have been spread rapidly, as the coupling of a laser ablation accessory or an electrothermal vaporizer to the ICP-MS, as they can allow the direct sample introduction, or at least with minimum preparation. This paper presents a review of sample preparation methods, aimed at the quantification of rare earth elements by ICP-MS and focusing on works published in the last decade.