Trace characterization of high-purity molybdenum and tungsten by electrothermal atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry and total reflection X-ray fluorescence spectrometry involving analyte—matrix separation

A technique for the separation of 42 trace elements from up to 5 g of molybdenum and tungsten matrices was developed by means of the radiotracer technique. It is based on adsorption of the analyses on the cation exchanger Dowex 50 W x 9 from a 4% H₂O₂/0.01 mol 1⁻¹ HNO₃ solution followed by their elution with 15 ml of 4 mol I⁻¹ HNO₃ in the opposite flow direction. Both matrices were removed with a separation factor > 10⁴. The separation technique was applied to the analysis of these materials by electrothermal atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry and total reflection X-ray fluorescence spetrometry. For all the determination methods used, the limits of detection are given and compared with those of other methods. With inductively coupled plasma mass spectrometry, for 22 of the 30 assayed elements, limits of detection at the sub-ng g⁻¹ level were achieved. The results are compared with those obtained by radiochemical neutron activation analysis in this work and by glow discharge mass spectrometry, secondary ion mass spectrometry, isotope dilution mass spectrometry and by solution spectrometric methods in other laboratories.     

Determination of silicon in biological samples by ICP-OES after non-oxidative decomposition under alkaline conditions.

A non-oxidative alkaline sample digestion procedure using tetramethylammonium hydroxide and a high pressure, microwave assisted autoclave digestion system was developed. The silicon concentrations of the digested samples were measured by inductively coupled axial plasma optical emission spectrometry (ICP-OES). Details of the digestion conditions as well as the optimised instrumental parameters for ICP-OES are described. The method was developed and tested using silicon-spiked ascorbic acid and applied to samples of animal tissue and organs. The total silicon content of two different reference materials, NIST 1577b Bovine liver and BCR 184 Bovine Muscle having neither certified nor informational values for Si was determined. The results obtained are compared with the results of independent methods such as wavelength dispersive x-ray fluorescence spectrometry (WDXRF) and solid sampling electrothermal atomic absorption spectrometry (ETAAS). The method described achieves a limit of detection of 2 mg kg(-1) using 100 mg of solid biological or organic material and covers a concentration range of up to 500 mg kg(-1).     

Identification of Oil Pollution Sources by a Set of Modern Instrumental Methods

Source of contamination of the soil and water with oil can be exactly identified by a set of instrumental methods such as atomic absorption spectrometry, inductively coupled plasma mass spectrometry, atomic emission spectroscopy, X-ray fluorescence analysis, and inductively coupled plasma emission spectrometry.     

Human albumin as a reference material for trace elements

Summary An investigation through interlaboratory comparison using different analytical techniques has been carried out in order to assess the suitability of a plasma protein solution as a source for a trace element reference material in clinical analysis. Reasonable agreement was obtained for a number of elements from the range studied: Al, Ba, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Se, Sr, V and Zn. The techniques used included flame and furnace atomic absorption spectrometry (FAAS and ETA-AAS), furnace atomic emission spectrometry (ETA-AES), inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), and simultaneous multi-element atomic absorption spectrometry (SIMAAC). Results indicated that this plasma protein solution may prove useful as a source for a reference material covering trace element levels outwith the range found in normal human plasma.

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Humanalbumin als Referenzmaterial für Spurenelemente

     

Boron analysis in biological material: microwave digestion procedure and determination by different methods

Investigations were made on the determination of boron in biological material. A procedure using the microwave digestion technique was optimised. The analyses were performed by photometry with azomethine-H, fluorimetry with carminic acid, inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. The matrix interferences, the interferences caused by iron and the detection limits were investigated for these methods. Determinations were performed for plant material, wheat, milk, meat and blood plasma. Recoveries and precision of all methods were studied. To test accuracy and precision, four NBS reference materials were analysed and the results compared with the values in literature. Good recoveries were found with all methods, except the fluorimetric technique. The boron content found in the NBS standard reference materials agreed well with data reported before. Best precision was obtained for the two ICP methods. The azomethine-H method gave good results when material of high boron content was analysed. With the carminic acid method no reliable results were achieved.     

高碳铬铁中磷,硅,锰的电感耦合等离子体原子发射光谱测定方法的研究

采用过氧化钠在石墨坩埚中熔融分解样品，硝酸酸化后直接用ＩＣＰ测定。磷，硅，锰的测定范围分别为０．００５％－０．０７５％，０．３０％－６．００％，０．０３％－２．００％，相对标准偏差ＲＳＤ≤６．０％。     

On the possibilities of inductively coupled plasma mass spectrometry for analysis of archaeological bones for reconstruction of paleodiet

The possibilities of inductively coupled plasma atomic mass spectrometry for determination of elemental composition of archaeological bones for reconstruction of paleodiet are discussed. The interferences of different polyatomic ions on the determination of Fe, Cu, Mg, Mn, Zn, and Zr are investigated and evaluated. Thus, a method for the determination of Al, As, Ba, Mg, Pb, Sr, V, Zn, and Zr is proposed and is validated by analysis of IAEA-SRM-H-5 (animal bone). The applicability of the proposed procedure is demonstrated analyzing real archaeological bone samples dated to 4th century b.c. and the results are compared with the data obtained by inductively coupled plasma atomic emission spectrometry.     

ICP-AES法测定方铅矿中多元素的方法研究

采用电感耦合等离子体原子发射光谱法(ICP-AES)进行方铅矿中多元素同时测定.通过对方铅矿样品化学处理试验建立了HCl-NH4Cl-HNO3的溶矿体系.本体系采用基体匹配、背景系数和元素干扰系数校正及元素内标法确定了最佳综合实验测试条件.本实验建立的ICP-AES法同时测定方铅矿中镉、钴、铜、铁、铟、铅、锌7种元素的方法,本方法测量相对误差RE (n=8)为1.50%～7.50%,相对标准偏差RSD (n=8)为1.7%～5.7%.经国家一级标准物质GBW 07269分析验证可以满足方铅矿单矿物样品的分析要求.     

Determination of trace amounts of cadmium, lead, copper and zinc in natural waters by inductively coupled plasma atomic emission spectrometry with thermospray nebulisation, after enrichment on Chelex-100

Enrichment on Chelex-100, followed by evaporation when necessary, was used for the pre-concentration of Cd, Pb, Cu and Zn from natural waters. The measurements were carried out with inductively coupled plasma atomic emission spectrometry using a thermospray nebulisation system to reach the required sensitivity. The detection limits corresponding to three times the standard deviation of the blank (in 1% v/v HNO3) after a 30-fold enrichment are 0.02 microgram l-1 for Cd, 0.33 microgram l-1 for Pb and 0.03 microgram l-1 for Cu and Zn. Matrix effects, which are fairly serious with thermospray nebulisation, were taken into account by using the standard additions method. Results obtained for several river water samples were compared with those found by analysis of the non-enriched sample with inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry. In all instances the agreement was satisfactory.     

Sample digestion methods for the determination of traces of precious metals by spectrometric techniques.

Recent advances in digestion methods used in the analysis of precious metal samples by spectrometric techniques are reviewed. The applicability of a fire assay, a wet acid treatment, chlorination and alkaline oxidizing fusion to a quantitative recovery of metals from various materials is discussed. Data on the precious metal contents obtained by using particular digestion methods as well as UV-VIS spectrophotometry, atomic absorption spectrometry, atomic emission spectrometry and inductively coupled plasma mass spectrometry in the examination of various samples are tabulated.     

Acid interferences in atomic spectrometry: analyte signal effects and subsequent reduction

When considering elemental analysis by atomic spectrometry techniques (e.g. flame atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry), the sample is normally introduced as a solution. In many instances an acid is present in that solution, as a result of previous sample preparation steps, analyte stabilization procedures, etc. Therefore, acids are among the most common matrices involved in spectroscopic analysis. The effect of the acid on the different stages taking place during the whole analytical process has been reviewed. Attention has been paid to the three techniques mentioned above. The results summarized here reveal the crucial role that acids play in atomic spectrometry, being one of the most important sources of interferences suffered by these techniques. In the last part of this bibliographic survey, the methods found for correction of the acid effect are mentioned and briefly described.     

Determination of metals in biofluids and tissues: sample preparation methods for atomic spectroscopic techniques

Several sample preparation methods unique to each instrumental technique exist for the elemental analysis of biological specimens, but no review or book has dealt with them. The present review is an attempt to fill this void and focuses on sample preparation methods unique to atomic and X-ray spectroscopic techniques. The techniques covered are: flame and electrothermal AAS, inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF) since these are most commonly used in trace element analysis of biological materials. The intent is not to present the procedural details for the various tissues or elements, but rather to highlight the methods which are unique to each instrument. The bibliography accompanying this review should aid the analytical chemist in his/her search for the detailed preparation protocols.     

重量法-电感耦合等离子体原子发射光谱法联用测定无取向硅钢磷酸盐体系环保涂层液中二氧化硅含量

二氧化硅是无取向硅钢环保涂层液的核心成分,其含量直接影响硅钢涂层的固化工艺及涂层产品的磁性能。因此为保证涂覆过程的顺利进行,对涂层液中二氧化硅含量的检测是十分必要的。本方法采用样品中分别加入硝酸、双氧水及高氯酸,置于电热板上进行消解处理,处理后的样品经酸溶、过滤步骤,以重量法计算沉淀中二氧化硅的含量,采用电感耦合等离子体原子发射光谱（ICP-AES）仪测定滤液中可溶性硅含量,则样品中二氧化硅含量为重量法和电感耦合等离子体原子发射光谱法测定结果的合量。从而建立了重量法-电感耦合等离子体原子发射光谱法联用测定无取向硅钢磷酸盐体系环保涂层液中二氧化硅含量的方法。讨论了样品前处理用消解酸及消解温度、滤液中可溶性硅及含量、ICP-AES仪器检测时的元素干扰。结果表明：按照本实验方法测定无取向硅钢磷酸盐体系环保涂层液中二氧化硅含量,检测结果的相对标准偏差（RSD,n=12）在0.76%~1.08%之间,加标回收率在97.00%~104.0%之间。该方法可广泛应用于各检测部门对无取向硅钢磷酸盐体系环保涂层液中二氧化硅含量的监控。     

微波辅助消解-原子荧光法测定玻璃中的镉砷铅

光学玻璃中的各种元素对玻璃的光学性能有不同的影响。如加入镉可以提高玻璃折射率;砷的引入能增加玻璃的透光度,含铅玻璃具有低成本、高折射性等优点。但是镉、砷、铅均为有毒元素,玻璃加工和处理过程以及毒废弃物的处理都可能引起水、土壤、大气的污染并给人体带来一定的危害     

Determination of silicon in biological samples by ICP-OES after non-oxidative decomposition under alkaline conditions

A non-oxidative alkaline sample digestion procedure using tetramethylammonium hydroxide and a high pressure, microwave assisted autoclave digestion system was developed. The silicon concentrations of the digested samples were measured by inductively coupled axial plasma optical emission spectrometry (ICP-OES). Details of the digestion conditions as well as the optimised instrumental parameters for ICP-OES are described. The method was developed and tested using silicon-spiked ascorbic acid and applied to samples of animal tissue and organs. The total silicon content of two different reference materials, NIST 1577b Bovine liver and BCR 184 Bovine Muscle having neither certified nor informational values for Si was determined. The results obtained are compared with the results of independent methods such as wavelength dispersive x-ray fluorescence spectrometry (WDXRF) and solid sampling electrothermal atomic absorption spectrometry (ETAAS). The method described achieves a limit of detection of 2 mg kg^–1 using 100 mg of solid biological or organic material and covers a concentration range of up to 500 mg kg^–1. Received: 27 October 2000 / Revised: 31 January 2001 / Accepted: 2 February 2001     

Effect of pH of aqueous ceramic suspensions on colloidal stability and precision of analytical measurements using slurry nebulization inductively coupled plasma atomic emission spectrometry

Colloidal stability of silicon nitride, silicon carbide and boron carbide aqueous slurries used for slurry nebulization inductively coupled plasma atomic emission spectrometry has been investigated in the pH range 2–10 by electrophoretic mobility and particle size measurements, together with sedimentation tests. The mean particle size of silicon nitride and silicon carbide suspensions change with increasing pH showing a maximum at the isoelectric points (pH 7.5 and 5.5 respectively). The particle size distribution of boron carbide slurries remains practically constant and the zeta potential of suspended boron carbide particles shows a small change in the pH range investigated. The silicon nitride and silicon carbide slurries have good stability at pH below 5 and above 8, respectively. Boron carbide slurries show excellent stability in the whole pH range investigated. The time demand for stabilization of the emission line intensities from the start of nebulization strongly depends on the colloidal stability of slurries. Consequently, it is advantageous to nebulize aqueous suspensions with a pH as far from the isoelectric point of the solid as possible and with the ionic strength of the dispersion medium as low as possible. The RSD values of the line intensity measurements determined after 3 min stabilization time decrease with increasing stability of the aqueous slurries.     

Applications of mass spectrometry in the trace element analysis of biological materials

The importance of mass spectrometry for the analysis of biological material is illustrated by reviewing the different mass spectrometric methods applied and describing some typical applications published recently. Though atomic absorption spectrometry is used in the majority of analyses of biological material, most mass spectrometric methods have been used to some extent for trace element determination in biomedical research. The relative importance of the different methods is estimated by reviewing recent research papers. It is striking that especially inductively coupled plasma mass spectrometry is increasingly being applied, partly because the method can be used on-line after chromatographic separation, in speciation studies. Mass spectrometric methods prove to offer unique possibilities in stable isotope tracer studies and for this purpose also experimentally demanding methods such as thermal ionization mass spectrometry and accelerator mass spectrometry are frequently used.     

Determination of vanadium in petroleum and petroleum products using atomic spectrometric techniques

Vanadium is recognized worldwide as the most abundant metallic constituent in petroleum. It is causing undesired side effects in the refining process, and corrosion in oil-fired power plants. Consequently, it is the most widely determined metal in petroleum and its derivatives. This paper offers a critical review of analytical methods based on atomic spectrometric techniques, particularly flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ET AAS), inductively coupled plasma optical emission spectrometry (ICP OES), inductively coupled plasma mass spectrometry (ICP-MS). In addition an overview is provided of the sample pretreatment and preparation procedures for vanadium determination in petroleum and petroleum products. Also included are the most recent studies about speciation and fractionation analysis using atomic spectrometric techniques.     

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.     

Determination of selenium and cadmium dopants in nanocomposites based on zinc and indium oxides by high resolution continuous source electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

An approach is proposed to the determination of selenium and cadmium dopants in new nanocomposites based on zinc and indium oxides. The approach is based on a combination of highly efficient high resolution continuous source electrothermal atomic absorption spectrometry (ETAAS) for the analysis of suspensions and inductively coupled plasma mass spectrometry for the analysis of solutions. A procedure is developed for the determination of Se and Cd dopants and matrix components based on Zn and In in nanocomposite solutions by inductively coupled plasma mass spectrometry. Stabilizing agents for the preparation of suspensions are studied for the ETAAS analysis of powders without their decomposition. The results of determination of CdSe dopants by high resolution ETAAS are validated by inductively coupled plasma mass spectrometry.