Cupferron separation for the determination of tantalum in high-purity iron and low alloy steel by ICP-AES

For the determination of Ta (> 0.0005 mass %) in iron and low-alloy steel spectrophotometric methods, e.g., after the extraction of the Ta-Victoria Blue B complex by benzene, are generally used. To avoid the application of poisonous benzene as extracting solvent and to improve the detection power, an ICP-AES method after the separation of Ta by coprecipitation with cupferron has been developed. The detection limit (3σ) of 0.6 μgTa/g is lower in comparison with spectrophotometric methods. Therefore, the method also allows the determination of Ta-concentrations in the μg/g-range in high-purity iron.     

Cupferron separation for the determination of tantalum in high-purity iron and low alloy steel by ICP-AES

For the determination of Ta (> 0.0005 mass %) in iron and low-alloy steel spectrophotometric methods, e.g., after the extraction of the Ta-Victoria Blue B complex by benzene, are generally used. To avoid the application of poisonous benzene as extracting solvent and to improve the detection power, an ICP-AES method after the separation of Ta by coprecipitation with cupferron has been developed. The detection limit (3σ) of 0.6 μgTa/g is lower in comparison with spectrophotometric methods. Therefore, the method also allows the determination of Ta-concentrations in the μg/g-range in high-purity iron. Received: 26 February 1998 / Revised: 4 May 1998 / Accepted: 10 May 1998     

Trace characterization of tantalum by NAA involving pre- and post-irradiation separations

Three different methods for pre-irradiation separation of the tantalum matrix combined with preconcentration of trace elements for NAA were developed. They involve selective extraction of tantalum with diantipyrylmethane, and anion- and cation-exchange from hydrofluoric acid medium. The role of the blank as the limiting factor for limits of detection and accuracy was one of the main aspects of this investigation. A conventional radiochemical NAA based on post-irradiation separation of the matrix radionuclides was also applied. The trace elements considered were Ag, Ba, Ce, Co, Cr, Cu, Eu, Hf, K, La, Mn, Mo, Na, Rb, Re, Sc, W, Y, Zn, Zr. The methods were used for the analysis of tantalum materials of different purity grades. The advantages and disadvantages of each technique are discussed and the achievable limits of detection are given.     

The separation and determination of niobium and tantalum by partition chromatography

A procedure is outlined for the separation and determination of niobium and tantalum by paper chromatography. A mixture of methyl isobutyl ketone and hydrofluoric acid was used as solvent and the metals were detected by means of 8-hydroxyquinoline. The minimum amount of each element detectable is 20 μg.

The procedure was applied successfully to the quantitative determination of small amounts of niobium and tantalum in a steel.     

用ICP-AES法测定首饰金的成分

本文报道采用ICP-AES法直接同时测定首饰金中合金无素及主要杂质元素含量,通过计算求得金含量。确定了仪器的最佳工作条件,进行了干扰试验。方法适用于18k～99.99%成色的首饰金。测定的RSD为<0.01%(对于高纯度金祥n=10)～0.2%(对于10k金样n=10)之间,分析结果表明,方法准确、快速、简便且样品消耗量少。     

ICP—AES法测定镍基合金中合金元素含量

ＩＣＰ ＡＥＳ法灵敏度高 ,线性范围宽 ,并同时测定多种元素 ,已成为现代分析测试技术中一个重要的检测手段 ,广泛地应用在各个领域。由于核电用材镍基合金焊丝及焊带是以镍作为基体 ,硅、锰、铬、铁等元素含量较高 ,而钛、铝的含量却很低 ,其基体较复杂 ,各元素含量相差又较悬殊 ,所以给分析工作带来困难。本文采用ＰＳ 6型ＩＣＰ多道真空光谱仪 ,通过对镍基合金试样的溶解方法、等离子体发射光谱仪的工作参数、共存元素的干扰、离峰分析校正等进行了研究 ,从而制定了相应准确有效的方法 ,解决了生产检测的困难 ,结果满意[1] 。1　试验部分…     

Spectrophotometric determination of tantalum in ores and mill products with brilliant green after separation by methyl isobutyl ketone extraction of tantalum fluoride

A method for determining ~ 0.001% or more of tantalum in ores and mill products is described. After fusion of the sample with sodium carbonate, the cooled melt is dissolved in dilute sulphuric-hydrofluoric acid mixture and tantalum is separated from niobium and other matrix elements by methyl isobutyl ketone extraction of its fluoride from 1M hydrofluoric acid-0.5M sulphuric acid. The extract is washed with a hydrofluoric-sulphuric acid solution of the same composition to remove co-extracted niobium, and tantalum is stripped with dilute hydrogen peroxide. This solution is acidified with sulphuric and hydrofluoric acids and evaporated to dryness, and the residue is dissolved in oxalic-hydrofluoric acid solution. Tantalum is ultimately determined spectrophotometrically after extraction of the blue hexafluorotantalate-Brilliant Green ion-association complex into benzene from a 0.05M sulphuric acid-0.5M hydrofluoric acid-0.2M oxalic acid medium. The apparent molar absorptivity of the complex is 1.19 x 10(4) l.mole(-1).mm(-1) at 640 nm, the wavelength of maximum absorption. Common ions, including iron, aluminium, manganese, zirconium, titanium, molybdenum, tungsten, vanadium, tin, arsenic and antimony, do not interfere. Results obtained by this method are compared with those obtained by an X-ray fluorescence method.     

ICP-AES determination of silver after chemical separation from uranium matrix

The separation of silver from a uranium matrix has been carried out using Cyanex-471X (triisobutylphosphine sulphide) in xylene. The effects of various parameters such as the Cyanex-471X concentration, the nitric acid molarity, the contact time and the nitrate ion concentration on the extraction of silver have been studied. The silver metal ion species extracted into the organic phase was found to be Ag(NO₃)·2S (where S is Cyanex-471X). The stripping of silver into an aqueous medium was carried out with 5% NaHSO₃, followed by its determination using ICP-AES.     

Molybdenum determination in iron matrices by ICP-AES after separation and preconcentration using polyurethane foam

A procedure is proposed for the separation and determination of molybdenum in iron matrices by a batch process. It is based on the solid-phase extraction of the molybdenum(V) ion as thiocyanate complex on polyurethane (PU) foam. The extraction parameters were optimized. Using 0.20 mol L-1 hydrochloric acid, a thiocyanate concentration of 0.10 mol L-1, 100 mg of polyurethane foam and shaking time of 10 min, molybdenum (5-400 micrograms) can be separated and preconcentrated from large amounts of iron (10 mg). Desorption was carried out instantaneously by conc. nitric acid or acetone. Distribution coefficients, sorption capacity of the PU foam and coefficients of variation were also evaluated. The effect of some ions on the separation procedure was assessed. Iron(III) should be reduced to iron(II). The proposed procedure was used to determine molybdenum in standard iron matrices such as steel and pure iron. The achieved results did not show significant differences with certified values.     

Molybdenum determination in iron matrices by ICP-AES after separation and preconcentration using polyurethane foam

A procedure is proposed for the separation and determination of molybdenum in iron matrices by a batch process. It is based on the solid-phase extraction of the molybdenum(V) ion as thiocyanate complex on polyurethane (PU) foam. The extraction parameters were optimized. Using 0.20 mol L^–1 hydrochloric acid, a thiocyanate concentration of 0.10 mol L^–1, 100 mg of polyurethane foam and shaking time of 10 min, molybdenum (5–400 μg) can be separated and preconcentrated from large amounts of iron (10 mg). Desorption was carried out instantaneously by conc. nitric acid or acetone. Distribution coefficients, sorption capacity of the PU foam and coefficients of variation were also evaluated. The effect of some ions on the separation procedure was assessed. Iron(III) should be reduced to iron(II). The proposed procedure was used to determine molybdenum in standard iron matrices such as steel and pure iron. The achieved results did not show significant differences with certified values.     

电感耦合等离子体发射光谱法测定硅铝铁合金中的多种元素

本文应用电感耦合等离子体发射光谱法(ICP—AES)对硅铝铁合金的溶解和仪器参数进行了优化,确定了适宜的硅铝铁合金中多种元素的测定条件。测定结果的RSD在0．26％～5．1％之间,加标回收率在95．5％～102．7％之间,标准样品测定结果与推荐值接近。本文方法简便、准确、快速,有应用推广价值。     

ICP-AES analysis of impurities in PuO2 after separation of Pu by TOPO impregnated XAD-4

Nuclear fuels should meet some specified characteristics to achieve their better performance in the reactor. Hence controlling and monitoring of trace level elements in the fuel materials are essential. Atomic emission spectroscopic methods are most popular for the trace level analysis. An ICP-AES procedure is described here for the trace level impurity analysis of PuO₂ produced through PUREX process. To avoid the Pu interference in the impurity analysis, initially the Pu was separated by extraction chromatography using TOPO impregnated XAD-4 resin. Magnitude of Pu interference in the impurities spectra lines was investigated. Moreover the recovery of impurity elements using the resin was established.     

Determination of ten rare-earth elements and yttrium in silicate rocks by ICP-AES without separation and preconcentration

Lanthanum, cerium, neodymium, samarium, europium, gadolinium, dysprosium, erbium, ytterbium, lutetium and yttrium have been determined in 8 international rock standards by inductively coupled plasma atomic emission spectrometry (ICP-AES) without prior ion-exchange separation and preconcentration. The results for La, Ce, Nd, Eu, Dy, Yb and Y were in good agreement with the reported values, whereas those for Sm, Gd, Er and Lu were less accurate. However, the results for Sm, Gd, Er and Lu can also be used for studies of petrogenesis.     

ICP-AES法测定硅铝钡钙合金

硅铝钡钙合金是炼钢常用的复合脱氧剂[1] ,它具有较强的脱氧能力和使夹杂物变质的能力 ,同时还能脱硫[2 ] 。硅铝钡钙合金目前既无国家标准分析方法 ,又无较成熟的化学分析方法 ,本文研究了用ＩＣＰ发射光谱仪测定硅铝钡钙合金的方法。本法采用基准物质配制标准系列绘制工作曲线 ,并用回收试验和试样精密度试验来证实方法的可靠性。1　试验部分1.1　仪器与试剂美国ＰＥ公司的ＯＰＴＩＭＡ330 0型全谱直读电感耦合等离子体发射光谱仪铝、钡、锶、锰、钙、磷、铁标准溶液 :用光谱纯金属氧化物或基准物质分别配置成 1ｍｇ·ｍｌ-1的储备液 ,使…     

Determination of analytes at trace level in uranium matrix by ICP-AES without chemical/physical separation

Determination of trace metallic constituents in nuclear materials e.g. U, Pu, Am, Zr etc. by Atomic Emission Spectroscopy requires the separation of the major matrix without the loss of analytes at trace level. For DC Arc carrier distillation technique, carrier is used to separate the matrix physically according to the volatility of the analytes while appropriate extractant in suitable diluent is used for chemical separation in inductively coupled plasma atomic emission spectroscopy (ICP-AES). In the present study an attempt was made to develop a methodology for the determination of B, Cd, Mg, Zn, Al, Sr and Sc at trace level (up to 0.1 μg/mL) in uranium matrix without any chemical or physical separation. It involves identification of suitable analytical lines of uranium for its ICP-AES determination; study the spectral interference of uranium to choose interference free analytical lines, optimization of instrumental and experimental parameters etc. The method was validated using synthetic samples.     

Determination of boron in high-purity tantalum materials by on-line matrix separation/inductively coupled plasma mass spectrometry

A method for the determination of ultratrace amounts of boron in high-purity tantalum materials [tantalum metal, tantalum(v) oxide, tantalum pentachloride and tantalum pentaethoxide] is described. On-line anion-exchange matrix separation combined with inductively coupled plasma mass spectrometry (ICP-MS) was employed for the determination of boron at the ng g(-1) level. Tantalum materials were dissolved using HF and/or HNO3 prior to analysis. The loss of boron in the sample preparation procedure was examined as the recovery of boron by adding a definite amount of boron to each tantalum material sample before decomposition, and it was almost negligible. In an anion-exchange method using 0.1 M HF carrier solution, tantalum and boron in the sample solution were first adsorbed on a strongly basic anion-exchange resin. Next, boron was eluted from the resin with 5 M HCl, whereas tantalum was retained strongly adsorbed. The eluted boron was introduced directly into the ICP-MS system for quantitative analysis at m/z 10 and 11. Because of the long elution time of boron, the transient signal was integrated in the time range 70-300 s on the chromatogram. Although the elution of boron in the time range was ca. 40% of total boron in the sample solution injected, the determination limits (10sigma) obtained by the present method were 30, 25, 15 and 13 ng g(-1) for tantalum metal, tantalum(v) oxide, tantalum pentachloride and tantalum pentaethoxide, respectively. The method was applied to the determination of boron in commercially available high-purity tantalum materials and it was found that the concentrations of boron were in the ng g(-1)-microg g(-1) range.     

Analysis by means of atomic-absorption spectroscopy,using a tantalum boat

Summary A technique for flameless atomic absorption with a tantalum boat method is described. Detection limits for 13 elements were determined and a special analysis procedure for mercury was worked out. The study of this technique also included a detailed investigation of some important parameters, namely heating rate, argon flow and sample volume. Interferences were studied for Cu, Mn and Pb and the results showed less interferences from some common salts than the carbon rod technique does. A brief study of applications to trace element determination in milk samples is also reported. Three different atomic-absorption instruments were used in this work. One of them had microwave-excited electrodeless discharge lamps instead of hollow-cathode lamps. Detection limits are comparable with other flameless techniques. The analysis time is very short (about 1 min for 10-l samples) and the boat needs no water-cooling. The equipment used is of simple construction and is considerably less expensive than the commercially made flameless accessories.

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Zusammenfassung Die Messung der Atomarabsorption ohne Flamme mit Hilfe eines Tantal-Schiffchens wurde beschrieben. Die Nachweisgrenzen für 13 Elemente wurden bestimmt und eine besondere Arbeitsvorschrift für Quecksilberanalysen ausgearbeitet. Außerdem wurden einzelne wichtige Versuchsparameter untersucht: die Geschwindigkeit des Erhitzens, die Argonströmung und das Probenvolumen. Die Störungen bei Cu, Mn und Pb wurden geprüft, wobei sich ergab, daß der störende Einfluß einiger üblicher Salze geringer ist als bei dem Kohlestab-Verfahren. Die Anwendung auf die Bestimmung von Spurenelementen in Milchproben wurde ebenfalls erörtert. Drei verschiedene Atomarabsorptionsgeräte wurden verwendet. Eines davon war an Stelle der Hohlkathodenlampen mit elektrodenlosen Entladungslampen ausgerüstet, die mit Mikrowellen angeregt wurden. Die Nachweisgrenzen sind mit denen anderer flammenloser Arbeitsweisen vergleichbar. Die Analysendauer ist sehr kurz (etwa 1 min. für 10-l-Proben). Das Schiffchen bedarf keiner Wasserkühlung. Die verwendete Ausrüstung ist einfach und billiger als handelsübliche Geräte.

     

Dissolution of niobium and tantalum matrix and their separation from trace elements by means of extraction with diantipyrylmethanes

Summary The separation of niobium and tantalum as matrices from other elements that appear as trace impurities was systematically examined by extraction with diantipyrylmethane and hexyl-diantipyrylmethane. The decomposition of the matrices in the HF/HNO₃ mixture was optimised by using the smallest possible quantities of nitric acid, because the presence of nitric acid hindered the efficiency of the separation. For the same reason the elimination of nitric acid from the sample solution by evaporation and also by decomposition with formic acid and urea was examined.Also taken into account in the examination was the behaviour of the trace elements to be determined during the decomposition of the samples and the removal of nitric acid. Arsenic, selenium and noble metals proved to be critical trace elements for which special measures are needed.The separation was undertaken under both static and dynamic conditions. For the elements Ag, Be, Cd, Co, Cr, Cu, Fe, Hf, Ir, K, La, Mo, Mn, Na, Ni, Se, Sc, Sn, Pa, V, W, Y, Zn and Zr, the separation yields are between 93% and 100% whereas in the case of the elements As, Au, Pd, Pt, Re and Sb a significant co-extraction takes place.

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Auflösung von Niob- und Tantalmatrix und ihre Abtrennung von Spurenelementen durch Extraktion mit Diantipyrylmethanen

Zusammenfassung Die Abtrennung von Niob und Tantal als Matrices von anderen als Spurenverunreinigungen vorkommenden Elementen durch Extraktion mit Diantipyrylmethan und Hexyl-Diantipyrylmethan aus HF-Medium wurde systematisch untersucht. Da die Anwesenheit von Salpetersäure die Effizienz dieses Trennverfahrens hemmt, wurde der Aufschluß der Matrices im HF/HNO₃-Gemisch optimiert und die Eliminierung von HNO₃ aus der Probelösung durch Eindampfen sowie durch Zersetzung mit Ameisensäure und Harnstoff überprüft.Mit einbezogen in diese Untersuchung wurde das Verhalten der zu bestimmenden Spurenelemente während des Aufschlusses und der Zersetzung von HNO₃. Arsen, Selen und die Edelmetalle haben sich dabei als kritische Spurenelemente erwiesen, für deren fehlerfreie Erfassung spezielle Maßnahmen erforderlich sind.Die Abtrennung wurde sowohl unter statischen als auch unter dynamischen Bedingungen vorgenommen.Bei den Elementen Ag, Be, Cd, Co, Cr, Cu, Fe, Hf, Ir, K, La, Mo, Mn, Na, Ni, Se, Sc, Sn, Pa, V, W, Y, Zn und Zr kann die Trennung mit einer Ausbeute zwischen 93 und 100% erreicht werden, während die Elemente As, Au, Pd, Pt, Re und Sb stark mitextrahiert werden.

     

The quantitative separation and determination of tantalum and niobium using anion exchange chromatographY

A method is described for separating .and determining niobium and tantalum in mixtures of the two. A solution of the two elements in 3M hydrochloric.0.1M hydrofluoric acid is put on a column of Deacidite FF, the niobium is rapidly eluted with 3M hydrochloric.0.1M hydrofluoric acid and the tantalum is recovered by elution with 4M ammonium chloride-M ammonium fluoride. A complete separation is obtained and the two elements are recovered as their oxides after precipitation. The effecth of some other elements have been examined.     

Determination of gold in sludge and soil by sequential ICP-AES after preconcentration and separation with thiol-cotton fibre

Summary A method is presented for the determination of gold in sludge and soil samples by sequential ICP-AES after preconcentration and separation from the common alkali and alkaline-earth metals, as well as other matrix components, e.g. iron, by a thiol-cotton fibre column. The cotton fibre, impregnated with thioacetic acid, quantitatively adsorbs gold, thus eliminating the severe spectral interferences encountered by direct ICP-AES analysis. After preconcentration and separation the results obtained at Au 242.795 nm and Au 267.595 nm agree with each other. A quantitative recovery for added spikes was obtained. The method allows the determination of gold in complex matrices such as soil or sludge samples that have been proven to be impossible by conventional ICP-AES without separation from the matrix.On leave from Shanghai Institute of Metallurgy, Academia Sinica, Shanghai 2000 50, China