The atomic absorption spectrometric determination of arsenic,bismuth, lead,antimony, selenium and tin with a flame-heated silica t-tube after hydride generation

A modified technique with a simple T-tube for atomisation held above conventional atomic absorption burners is described. The absolute sensitivities are in the range 0.3–11 ng and the r.s.d. is usually below 5%. It is confirmed that prior oxidation of lead markedly increases the sensitivity.     

Interferences of hydride forming elements and of mercury in the determination of antimony, arsenic, selenium and tin by hydride-generation AAS

Summary By means of the radiotracer technique supplemented by conventional absorption measurements, the interferences of As, Bi, Hg, Pb, Sb, Se, Sn and Te in amounts between 10 g and 1 mg with the determination of As, Sb, Se and Sn by hydride generation AAS using heated quartz tube were investigated during the hydride-generation and the atomization stages. Amounts up to 100 g of Hg and Pb do not cause any detectable interference. The interference of Bi and Te is dominant in the hydride-generation stage and that of As, Se, Sb and Sn in the atomization stage. Tin is retained to a considerable extent in the quartz tube and the resulting memory effect makes the determination of As, Sb, and Se impossible. In the absence of interfering elements, the efficiency of the formation of hydrides of As, Sb, Se and Sn was close to 100%. However, a reduction of Sb(V) to Sb(III) prior to the hydride-generation is necessary for which an improved procedure was developed.

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Störungen von Hydridbildnern und von Quecksilber bei der Bestimmung von Antimon, Arsen, Selen und Zinn durch die Hydrid-AAS

Zusammenfassung Mittels der Radiotracertechnik und Atomabsorptionsspektrometrie wurde der Störeinfluß unterschiedlicher Mengen (10–1000 g) von As, Bi, Hg, Pb, Sb, Se, Sn und Te auf die Bestimmung von As, Sb, Se und Sn mit der Hydrid-AAS untersucht. Durch diese Verfahrenskombination war es möglich, das Ausmaß der Störungen durch diese Elemente sowohl im Hydrierungs- als auch im Atomisierungsschritt zu bestimmen sowie zum großen Teil auch die Gründe für ihr Auftreten aufzuklären. Keine nachweisbare Störung verursachen Hg und Pb bis zu jeweils 100 g. Die Störung durch Bi und Te tritt hauptsächlich im Hydrierungsgefäß auf, hingegen die durch As, Sb, Se und Sn im wesentlichen in der Quarzabsorptionszelle. Bei Zinn wurde ein starker Memoryeffekt festgestellt, der aus der Ablagerung dieses Elements in der Quarzküvette resultiert und der die Bestimmung von As, Sb und Se völlig unmöglich macht. Ohne diese Störelemente liegen die Hydrierungsausbeuten für As, Sb, Se und Sn bei nahezu 100%. Bei Antimon ist allerdings eine vorherige Reduktion von Sb(V) zu Sb(III) notwendig, für die ein verbessertes Verfahren vorgeschlagen wurde. Denn durch die Radiotracertechnik konnte nachgewiesen werden, daß die während der Alterung von Sb(V)-Lösungen durch Kondensationsprozesse entstehenden Polysäuren nicht mehr hydriert werden können.

     

Determination of arsenic, antimony, bismuth, selenium and tin in biological and environmental samples by continuous flow hydride generation ICP-AES without gas-liquid separator

Summary A simple continuous flow hydride generation system without conventional gas-liquid phase separator was developed for the determination of As, Se, Sb, Bi and Sn in biological and environmental samples by sequential ICP-AES with 1.5 kW power. The interchange of operating mode from normal solution nebulization to hydride generation or vice versa can easily be done without interrupting the plasma in this system.Two digestion methods were compared, i.e. the pressurized digestion with HNO₃ in a closed vessel and HNO₃/HClO₄/H₂SO₄ acid digestion in an open system. It was found that further treatment is necessary after normal pressurized digestion for As determination in marine samples, e.g. mussel. Interferences, especially by copper and nickel were examined and completely eliminated up to 10 g/ml by using a mixed reductant (3% NaBH₄ and 2% KI) with lower flow rate as well as the sample solution media of 30% HCl (v/v) and 20% HNO₃ (v/v). The effect of KI on the elemental oxidation states of As, Se and Sb is discussed. The accuracy of the method was validated by the analysis of a number of biological and environmental SRM's of NIST, BCR and NIES. Most results were in agreement with the certified values or reference values. The detection limits for these elements were in the range of 0.x ng/ml.On leave from Shanghai Institute of Metallurgy, Academia Sinica, Shanghai, China 200050     

Determination of antimony, arsenic, bismuth, selenium, tellurium and tin by low pressure atomic absorption spectrometry with a quartz tube furnace atomizer and hydride generation with air addition

A new method has been developed for the determination of antimony, arsenic, bismuth, selenium, tellurium and tin by hydride generation-atomic absorption spectrometry in an electrically heated quartz tube furnace under sub-atmospheric pressure. The hydride generator, operating at a pressure lower than atmospheric, is used to generate and collect the hydrides of these elements. A certain volume (at atmospheric pressure) of air is then added to the generator after the formation of the volatile hydride. The gaseous mixture of the hydride and air is drawn into an evacuated, heated quartz tube by a vacuum pump. The proposed method gives improved sensitivities and detection limits.     

Determination of antimony,arsenic, bismuth,selenium, tellurium,and tin in metallurgical samples using the hydride AA technique—I: Analysis of low-alloy steels

Interferences in the gas phase are very unlikely and have not yet been observed with the hydride AA technique. Gas/liquid interferences between the volatile hydride forming elements and the major and minor components of low-alloy steels can be eliminated by working in the presence of higher acid concentrations and/or in acid mixtures containing nitric acid. Conditions could be found that allow the interference-free determination of the hydride forming elements in low-alloy steels directly against acid standards with detection limits around or below 0.0002%. The influence of the valence state on the determination of antimony and arsenic was investigated.     

Simultaneous determination of trace arsenic, antimony, bismuth and selenium in biological samples by hydride generation-four-channel atomic fluorescence spectrometry

A new and sample technique for the simultaneous determination of trace arsenic, antimony, bismuth and selenium in biologic samples by hydride generation-four-channel nondispersive atomic fluorescence spectrometry was development. The conditions of instrumentation and hydride generation of arsenic, antimony, bismuth and selenium were optimized. For reducing hexavalent Se to the tetravalent state was to heat the sample with 6 mol l⁻¹ HCl, and then pre-reducing pentavalent As and Sb to the trivalent state was achieved by the addition of 0.05 mol l⁻¹ thiourea. The interferences of coexisting ions were evaluated. Under optimal conditions, the detection limits for As, Sb, Bi and Se were determined to be 0.03, 0.04, 0.04 and 0.03 ng ml⁻¹, respectively. The precision for seven replicate determinations at the 5 ng ml⁻¹ of As, Sb, Bi and Se were 0.9, 1.2, 1.3 and 1.5% (R.S.D.), respectively. The proposed method was successfully applied to the simultaneous determination of As, Sb, Bi and Se in a series of Chinese certified biological reference materials using simple aqueous standard calibration technique, the results obtained are in good agreement with the certified values.     

Determination of mercury, selenium, bismuth, arsenic and antimony in human hair by microwave digestion atomic fluorescence spectrometry

A novel method for determination of Hg, Se, Bi, As and Sb based on microwave digestion followed by continuous flow vapour generation atomic fluorescence spectrometry was developed. The digestion for Hg was based on a two stage digestion involving HNO(3) and H(2)O(2), whilst for the hydride forming elements a common digestion using HCl and H(2)O(2) was found to be the most effective. The instrumentation and chemistry were optimised in order to provide the best accuracy and precision. The method detection limit for hair samples was found to be 0.2 ng g(-1) for Hg and between 2 and 10 ng g(-1) for the hydride forming elements. The atomic fluorescence detector showed excellent linearity over the concentration ranges studied with linear correlation co-efficients between 0.99984 and 0.99997. To validate the accuracy of the method a human hair certified reference material (GBW 0706) was analysed and excellent agreement with the certified value was obtained for all elements.     

Thermal studies on arsenic,antimony and bismuth alkylxanthate complexes

Six xanthate derivatives of arsenic(III), antimony(III), and bismuth(III) {(ROCS₂)₃M; R=methyl, ethyl, isopropyl, n-butyl, cyclohexyl and benzyl} have been prepared and the thermal behaviour investigated by thermogravimetry. A thermal decomposition mechanism for the complexes is proposed on the basis of the thermogravimetric data and mass spectral measurements.     

Sequential determination of tin, arsenic, bismuth and antimony in marine sediment material by inductively coupled plasma atomic emission spectrometry using a small concentric hydride generator and L-cysteine as prereductant

A hydride generation system using a small concentric hydride generator combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) was established to determine tin, arsenic, bismuth and antimony in a marine sediment material with L-cysteine as a pre-reductant. Influences of concentrations of three kinds of acids (HCl, HNO₃ and HClO₄), L-cysteine, and sodium tetrahydroborate(III) as well as sodium hydroxide were investigated. The interferences from transition ions were found to be insignificant for determination of the four elements in presence of L-cysteine. Under optimized conditions the detection limits were 0.6 ng/mL for arsenic(III), 0.8 ng/mL for antimony(III), 1.7 ng/mL for tin(IV), and 1.2 ng/mL for bismuth(III). The method was applied to determine the four elements in standard marine sediment materials and the results were in agreement with certified values. Received: 4 September 1997 / Revised: 14 October 1997 / Accepted: 7 November 1997     

Sequential determination of tin, arsenic, bismuth and antimony in marine sediment material by inductively coupled plasma atomic emission spectrometry using a small concentric hydride generator and L-cysteine as prereductant

A hydride generation system using a small concentric hydride generator combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) was established to determine tin, arsenic, bismuth and antimony in a marine sediment material with L-cysteine as a pre-reductant. Influences of concentrations of three kinds of acids (HCl, HNO₃ and HClO₄), L-cysteine, and sodium tetrahydroborate(III) as well as sodium hydroxide were investigated. The interferences from transition ions were found to be insignificant for determination of the four elements in presence of L-cysteine. Under optimized conditions the detection limits were 0.6 ng/mL for arsenic(III), 0.8 ng/mL for antimony(III), 1.7 ng/mL for tin(IV), and 1.2 ng/mL for bismuth(III). The method was applied to determine the four elements in standard marine sediment materials and the results were in agreement with certified values.     

Trapping interference effects of arsenic,antimony and bismuth hydrides in collection of selenium hydride within iridium-modified transversally-heated graphite tube atomizer

Interference effects of co-generated hydrides of arsenic, antimony and bismuth on trapping behavior of selenium hydride (analyte) within an iridium-modified, transversely heated graphite tube atomizer (THGA) were investigated. A twin-channel hydride generation system was used for independent separate generation and introduction of analyte and interferent hydrides, i.e. in a simultaneous and/or sequential analyte–interferent and interferent–analyte mode of operation. The influence of the analyte and modifier mass, interferent amount, trapping temperature and composition of the gaseous phase was studied. A simple approach for the elimination of mutual interference effects by modification of the gaseous phase with oxygen in a substoichiometric ratio to chemically generated hydrogen is proposed and the suppression of these interference effects is demonstrated. A hypothesis on the mechanism of trapping and mutual interference effects is drawn.     

Chemistry of arsenic,antimony and bismuth compounds derived from xanthate,dithiocarbamate and phosphorus based ligands

The chemistry of both tri- and penta-valent compounds of arsenic, antimony and bismuth derived from xanthate, dithiocarbamate and phosphorus based ligands have been reviewed. Synthesis, properties, structural aspects and applications of their compounds have been described.     

New pentafluorothiophenoxo derivatives of tin,lead, antimony,bismuth, gold and platinum

Summary Salts of the anions [SnX₅]^–, [SnX₄Cl, [SnX₃Cl₂]^–, [SnX₃]^–, [PbX₃]^–, [SbX₄]^–, [SbX₃Cl]^–, [SbX₂Cl₂]^–, [BiX₄]^–, [AuCl₂]^–, [AuX₂]^–, [AuXCl]^–, [AuX₄]^–, [Au₂X₆]^2– and [PtX₄]^2–, where X^– = C₆F₅S^–, have been isolated and characterised. The neutral SbX₃ and BiX₃ species, have also been isolated and shown to be pyramidal monomers (¹⁹F.n.m.r., i.r., and Raman spectral evidence). Various physical properties of the complexes prepared, as well as their stereochemistries (where these could be ascertained), are similar to those of the known corresponding halogeno compounds of these elements. These results further demonstrate the pseudo-halide nature of the pentafluorothiophenoxide ion.Author to whom all correspondence should be directed at: Laboratoire de Chimie de Coordination, Uniyersité Louis Pasteur, 67008 Strasbourg, France.     

Study of processes in the hydride generation atomic absorption spectrometry of antimony,arsenic and selenium

Studies of the decomposition rate of the reducing agent sodium tetrahydroborate in alkaline and acidic media and of the reaction rate of the formation of the hydrides under the usual analytical conditions are described. The stripping of the hydrides with different lengths of the stripping coil, with different amounts of hydrogen in the carrier gas and with sodium hydroxide added during and after the stripping process are discussed. Some evidence for the existence of an intermediate during the decomposition reaction of the sodium tetrahydroborate is given. The role of temperature, hydrogen and oxygen during the atomization of the hydrides in an electrically heated quartz cuvette is discussed. Under certain conditions, antimony atoms form dimers or elemental antimony precipitates in the heated cuvette.     

Synthesis and spectroscopic characterization of arsenic(III), antimony(III), bismuth(III), tin(II) and lead(II) dithiocarbamate adducts

The complexes of arsenic(III), antimony(III), bismuth(III), tin(II) and lead(II) with monomethylsubstituted piperidinodithiocarbamates of general formula M(Rdtc)₃ and M(Rdtc)₂ have been prepared and characterized by spectroscopic methods. The results of the spectroscopic studies indicate that the dithiocarbamate ligands are always bidentate, in both the 1:3 and the 1:2 complexes. All the complexes are nonconducting in DMF solution. The thermal behaviour of the complexes has been investigated by TG and DTG techniques. The molecular weight determinations indicate that the trisdithiocarbamates of arsenic and antimony are monomeric, while the bismuth trisderivatives tend to dimerize: polymeric structures can be suggested for the tin(II) and lead(II) compounds.     

氢化物发生-原子荧光光谱法测定高纯锌中砷、锑、铋

提出了以硫脲-抗坏血酸-盐酸羟胺作为混合还原掩蔽剂,氢化物发生-原子荧光光谱法（HG-AFS）测定高纯锌中砷、锑、铋的方法。考察了测定的最佳条件、共存元素对测定的影响及方法的准确度和精密度。方法适用于高纯锌中0.00002％～0．01％砷、锑、铋的测定。     

An oblique section hydride generator for the simultaneous determination of arsenic, antimony and bismuth in geological samples by inductively coupled plasma-atomic emission spectrometry

Summary An oblique section hydride generator is developed for use in combination with inductively coupled plasmaatomic emission spectrometry. The generator offers less interferences from concomitant ions and transition metal ions when compared with the conventional hydride generators reported in literature. The emission signals and the detection limits of the analytes are also improved. The recommended hydride generator has been applied to the determination of arsenic at g/g level and antimony and bismuth at subg/g level in geological standard reference materials. A good agreement is achieved between the data obtained by the present study and the certified values.

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Abgeschrägter Hydridgenerator für die Simultanbestimmung von As, Sb und Bi in geologischen Proben durch ICP-AES

     

The atomic absorption determination of antimony,arsenic, bismuth, cadmium, lead, and tin in iron, copper,and zinc alloys with the graphite furnace

Antimony, arsenic, bismuth, cadmium, lead, and tin can be determined in metallurgical samples by flame atomic absorption spectrometry at levels of 0.005 wt%, but lower concentrations frequently necessitate preconcentration. The graphite furnace allows determination of these elements at concentrations 1–2 orders of magnitude lower than is possible with flame techniques. All six elements have detection limits at or below 1μg g⁻¹ in a variety of alloys. Calibration for antimony and load was done with standards containing the principal component of the alloy as a synthetic matrix. Bismuth, cadmium, and tin could be determined accurately only by the standard addition method. Arsenic could be determined in iron alloys with synthetic standards, but standard additions were required for copper alloys.     

电感耦合等离子体发射光谱法测定粗二氧化碲中 铜、铅、锑、铋、砷和硒

粗二氧化碲作为碲精炼或碲化工产品生产的重要原料,其中共存元素铜、铅、砷、锑、铋、硒含量的准确测定对于生产过程质量控制和贸易结算具有重要意义,但目前没有粗二氧化碲中铜、铅、砷、锑、铋、硒含量检测的标准分析方法。采用王水和饱和氟化氢铵分解试样,在王水和酒石酸介质中,选用Cu 327.393 nm、Pb 220.353 nm、Sb 217.582 nm、Bi 223.061 nm、As 193.696 nm、Se 196.026 nm为分析谱线,采用电感耦合等离子体发射光谱(ICP-AES)法测定粗二氧化碲中铜、铅、锑、铋、砷和硒含量。各元素校准曲线的相关系数均大于0.999;铜、铅、锑、铋、砷和硒的检出限分别为0.0004%、0.0005%、0.0006%、0.0007%、0.0004%和0.0007%,定量检出限分别为0.0012%、0.0016%、0.0020%、0.0025%、0.0013%和0.0025%。按照实验方法测定5个粗二氧化碲样品中铜、铅、锑、铋、砷和硒,测定结果的相对标准偏差(RSD,n=7)为0.79%~4.8%,加标回收率为96.0%~103%。方法简单,精密度和准确度较高,可用于测定粗二氧化碲中铜、铅、砷、锑、铋、硒含量。     

Grey cast iron reference material certified for antimony, arsenic, bismuth, and lead

Summary Almost 200 kg of grey cast iron, to which amounts of antimony, arsenic bismuth and lead were added, was prepared in the form of eighty bars. From these bars a number of disks (32 mm diameter, 10 mm thick) were cut. Homogeneity tests within disks and between disks cut from the same and from different bars showed that the inhomogeneity is less than 1.0 and 1.5% for antimony and lead, respectively. By means of electrothermal atomic absorption spectrometry, instrumental neutron activation analysis or radiochemical proton activation analysis the following 95% confidence intervals were certified: 263.5 ± 4.4 ppm for antimony, 347.1 ± 5.8 ppm for arsenic, 33.6 ± 0.8 ppm for bismuth and 296 ± 16 ppm for lead. The reference material is available for potential users.

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Referenzmaterial für graues Gußeisen, zertifiziert für Antimon, Arsen, Bismut und Blei

Zusammenfassung 200 kg graues Gußeisen mit Zusätzen von Sb, As, Bi und Pb wurden in Form von 80 Stangen hergestellt, die in Scheiben zerschnitten wurden (Durchmesser 32 mm, Dicke 10 mm). Homogenitätstests innerhalb und zwischen den Scheiben von derselben und von verschiedenen Stangen zeigten, daß die Inhomogenität für Sb bzw. Pb weniger als 1,0 bzw. 1.5% betrug. Durch elektrothermische AAS sowie durch Neutronenaktivierungsanalyse oder radiochemische Protonenaktivierungsanalyse wurden die folgenden Werte zertifiziert (95% Vertrauensintervall): 263,5 ± 4,4 ppm Sb, 347,1 ± 5,8 ppm As, 33,6 ± 0,8 ppm Bi und 296 ± 16 ppm Pb. Die Referenzmaterialien stehen Interessenten zur Verfügung.

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Senior Research Assoociate of the National Fund for Scientific Research (Belgium)