Preconcentration of some metals using metalfix chelamine resin prior to ICP-AES analysis

Preconcentration and separation of Ni, Pb and Cd have been investigated using the metalfix chelamine resin prior to inductively coupled plasma – atomic emission spectrometry (ICP-AES) under various experimental conditions. The recoveries of the analytes obtained with 95% confidence level were 92 ± 1% for Ni, 100 ± 4% for Pb and 93 ± 3% for Cd.     

Preconcentration and matrix separation of precious metals in geological and related materials using metalfix-chelamine resin prior to inductively coupled plasma mass spectrometry

A method for determining Au, Pt, Pd, Ir and Rh in ores and silicates and Fe-formation rocks is described. Sample decomposition was carried out with aqua regia and HF, followed by fusion of any insoluble residue with Na₂2O₂ in a glassycarbon crucible. The precious metals were separated, in 1.2 mol dm⁻³ HCl media, from the matrix elements by ion-exchange, using a mini-column with tetraethylenepentamine (metalfix-chelamine) resin. The resin was destroyed with HNO₃ and H₂O₂ in a high-pressure vessel assisted by microwave heating, and the precious elements were determined by flow-injection inductively coupled plasma mass spectrometry. The sample treatment, optimization of analytical variables and measurable concentration levels are discussed. The limits of quantification (10 sd_{n − 1}) calculated from a procedural blank sample solution were 4.0, 2.0, 1.5, 0.8 and 0.5 ng g⁻¹ for Au, Pt, Pd, Ir and Rh, respectively. The accuracy of the proposed method was tested by determining these elements in SARM 7 platinum-ore reference material. For all the analytes, the relative standard deviation of the combined dissolution, separation and determination methods was below 3.5% (n = 6).     

Neutron activation analysis of some noble metals with preconcentration procedure using a new type of cation chelating resin

The characteristic properties of the chelating resin-3926(II) and the advantage of using it in the preconcentration procedure was described. The chemical recoveries determined by the trace technique were presented. The preconcentration procedure put forward in this paper may be used satisfactorily in neutron activation analysis.     

Preconcentration of silver from rocks by extraction with bismuth dibenzyldithiocarbamate prior to neutron activation analysis

The method developed for determining trace levels of silver in geological materials involves the extraction of silver with a toluene solution of bismuth dibenzyldithiocarbamate followed by neutron activation of the extract. At pH 2 and in the presence of 0.1M EDTA, silver is quantitatively extracted. Under these conditions only small amounts of copper are coextracted. The detection limits of silver for three different modes of neutron activation analysis: /three cycles with Ge/Li/ detector, one cycle with Ge/Li/ detector and one cycle with NaI/Tl/ detector/ were 12, 20 and 11 ng g^–1, respectively.     

Preconcentration of benzalkonium chloride using sodium dodecyl sulfate attached to a strong anion exchange resin

A surfactant-mediated solid phase extraction procedure is applied for the preconcentration of benzalkonium (BA) chloride from a river water sample. Dodecyl sulfate is attached to a strong anion exchange resin and aqueous samples are passed through a column containing this surfactant-resin material. Benzalkonium chloride, a cationic compound very useful in cosmetics and an important fungicide, is adsorbed from the aqueous solution onto the sorbent via hydrophobic and electrostatic interactions. When using traditional silica-based nonpolar sorbents, strong electrostatic interactions between the cationic analyte and the silica surface make elution difficult. Using the presented sorbent, electrostatic attractions occur between the benzalkonium cations and removable dodecyl sulfate anions. Removing this ion pair from the sorbent results in efficient elutions. The results of this solid-phase extraction (SPE) method are presented in terms of various rinse solutions parameters, breakthrough studies and a real river water sample.     

Preconcentration of trace metals from salt solutions using thiuram disulphide as collector

Traces of Fe, Co, Ni, Cu, Zn, Cd and Pb in salt solutions (e.g. KCl, Ca(NO₃)₂, A1₂(SO₄)₃, Cr₂(SO₄)₃, (NH₄)₂SO₄) are determined by flame AAS after preconcentration with thiuram disulphide (TDS) as collector precipitate. The preconcentration recovery is mainly influenced by pH, TDS amount and its aging in the sample solution. Conditions of an optimal preconcentration procedure were elaborated. Detection limits vary from 0.5 ng/ml (for Cd) to 8.3 ng/ml (for Pb) and the relative standard deviation is 2 to 6 %. The accuracy of the results was checked by differential pulse anodic stripping voltammetry and by electrothermal AAS.     

Application of a macroporous resin containing imidazoline groups to preconcentration and separation of gold, platinum and palladium prior to ICP-AES determination

A new functional resin with a long functional side chain was synthesized by modification of aminated macroporous poly(vinyl chloride) resin with cyanoethylene and ethylenediamine. Traces of Au(III), Pt(IV) and Pd(II) in aqueous solution were quantitatively adsorbed in the acidity range of pH 4 and C(H(+)) 3 M. The rate of equilibration is high; Cu(2+), Fe(3+), Ni(2+), etc. exhibit little interference on the adsorption of the sought noble metals. The saturated adsorption capacities for Au(III), Pt(IV), Pd(II) and Ir(IV) in 2 M HCl were 4.0, 1.57, 2.26, 1.85 mmol g(-1). Adsorbed ions can be quantitatively desorbed by 4% thiourea +0.25 M H(2)SO(4). The resin has good reusability, and can be used for preconcentration and separation of Au(III), Pt(IV) and Pd(II) prior to their determination by ICP-AES with satisfactory results.     

Preconcentration of rare earth elements on silica gel loaded with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one prior to their determination by ICP-AES.

A new chelating resin, silica gel loaded with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (PMBP), was prepared and used for the preconcentration of trace amounts of rare earth elements (REEs) in water samples prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). REEs (La, Eu, Yb and Y) were quantitatively retained on the column packed with modified silica gel in the pH range 5 - 8 and separated from the matrix, and then recovered by eluting with 2.0 mol L(-1) HNO3. The adsorption capacity of modified silica gel for La, Eu, Yb and Y was 0.208, 0.249, 0.239 and 0.224 mmol g(-1), respectively. The method has been successfully applied for the determination of La, Eu, Yb and Y in geological and environmental samples with satisfactory results.     

High-capacity chitosan-based chelating resin for on-line collection of transition and rare-earth metals prior to inductively coupled plasma-atomic emission spectrometry measurement

High-capacity chitosan-based chelating resin, N-(2-hydroxyethyl)glycine-type chitosan, was synthesized using chloromethyloxirane (CMO) as a cross-linker and a coupling arms and hydroxylethylamine and bromoacetic acid as a synthesizer for the N-(2-hydroxyethyl)glycine chelating moiety. The CMO could bind with both of hydroxyl and amino group of the chitosan resin, and then couple with the chelating moiety. Increasing the amounts of chelating moiety could increase the capacity of the resin toward metal ions. Most transition and rare-earth metals could adsorb quantitatively on the resin at wide pH ranges and could be separated from alkaline and alkaline-earth metals. The resin was packed in a mini-column (40 mm length × 2 mm i.d.) which was installed in a Multi-Auto-Pret system. The Multi-Auto-Pret system coupled with ICP-AES was successfully applied to the determination of transition and rare-earth metals in river water samples.     

8－羟基喹啉纤维微柱分离富集ICP－AES测定多种痕量元素

制备了８－羟基喹啉纤维滤纸片，作为微柱填充物，同时富集了九种痕量元素，并分离了样品中的高盐组分。富集后的痕量组分采用电感耦合等离子体原子发射光谱法（ＩＣＰ－ＡＥＳ）测定，回收率为９０％～１０２％。     

Approaches to multi-element analysis of metals using optical atomic spectroscopy

Summary Optical atomic emission techniques available to the spectrochemist for control and research in metallurgy include the spark source, the d.c. are source, the glow discharge lamp, hollow cathode discharges, lasers and ICP and DC coupled plasmas. Of these techniques mainly developments using the spark and d.c. are techniques are reviewed.The specifications of spectrometers being built today for the metal industry do not differ significantly from those of the previous decade. The main changes are the use of holographic instead of ruled gratings and using gratings with a higher number of grooves. Advantages of the Michelson interferometer are listed and should dispel any doubts about the use of interferometry in atomic spectroscopy. The possibilities of the new detectors called image detectors are detailed and compared with the photographic plate and the photomultiplier. The significant advances in data acquisation and processing are summarised. The continuous-casting techniques for steel present a special analytical problem: the need to monitor and control the aluminium added. Three optical emission methods are shortly described and the results presented. The role of argon when injected into the conventional spectrochemical excitation sources is described and evaluated. Attention is also given to highspeed analysis of diverse ferrous alloys, while the features of the electrically vapourised conductive plasma are shortly given. As regards phenomenon studies information is summarised concerning the electron concentrations in the high voltage spark and the dependence of the excitation processes on the lateral movement of the sample vapour as it moves up from the cathode through the spark gap. Reliable analysis of trace elements present in metals is important for modern technology. The d.c. arc using solid samples and background near the analysis line for referencing is presently again allowing satisfactory analyses to be made. Some results are presented.

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Verfahren zur Multielement-Analyse von Metallen mit Hilfe der optischen Atomspektroskopie

Zusammenfassung Dem Spektrochemiker stehen für Kontrolle und Forschung in der Metallurgie die folgenden optischen Atomemissionsverfahren zur Verfügung: der Funke, der Gleichstrombogen, die Glimmentladungslampe, Hohlkathodenentladungen, Laser sowie ICP und DC-Plasmen.Der Überblick beschränkt sich im wesentlichen auf die Entwicklungen der Funken- und Gleichstrombogenverfahren. Die technischen Daten der heute in der Metallindustrie eingesetzten Spektrometer unterscheiden sich kaum von denen des vorangegangenen Jahrzehnts. Änderungen bestehen hauptsächlich darin, daß anstelle mechanisch geteilter Gitter holografische Gitter sowie Gitter mit höherer Strichzahl verwendet werden.Die aufgezeigten Vorteile des Michelson-Interferometers sollten jeden Zweifel am Nutzen der Interferometrie in der Atomspektroskopie zerstreuen. Die neuen als image detector bezeichneten Empfänger werden ausführlich beschrieben und ihre Leistungsfähigkeit mit der photographischen Platte sowie mit dem Photovervielfacher verglichen. Die bei der Erfassung und Verarbeitung von Daten erzielten bedeutenden Fortschritte werden aufgezählt. Ein besonderes analytisches Problem stellen die kontinuierlichen Stahlgußverfahren dar; hierbei ist es notwendig, die Zugabe von Aluminium zu steuern und zu überwachen. Drei entsprechende Methoden der optischen Emission werden kurz erläutert und ihre Ergebnisse vorgestellt. Weiterhin wird die Bedeutung des Argons beim Einleiten in die üblichen spektrometrischen Anregungsquellen beschrieben. Besondere Aufmerksamkeit wird darüber hinaus der Schnellanalyse verschiedener Eisenlegierungen gewidmet, wohingegen die Eigenschaften des sog. elektrisch verdampften leitenden Plasmas nur kurz wiedergegeben werden.Die bezüglich phänomenologischer Untersuchungen gewonnenen Ergebnisse werden zusammengefaßt, so etwa Angaben zur Elektronenkonzentration im Hochspannungsfunken und zur Abhängigkeit der Anregungsprozesse von der Querbewegung des Probendampfes, die dieser beim Durchlaufen der Funkenstrecke aufweist. Die zuverlässige Analyse von Spurenelementen in Metallen ist für die moderne Technologie von Bedeutung. Hier erlaubt der Gleichstrombogen gegenwärtig die zufriedenstellende Analyse fester Proben, wenn als Bezug der Untergrund in der Nähe der Analysenlinie herangezogen wird. Einige entsprechende Ergebnisse werden vorgestellt.

     

Preconcentration and preseparation by electro-deposition of traces of metals

Several theoretical ideas on metal electro-deposition on inert solid electrodes, from solutions oftrace metal ion concentrations, are formulated. The results may be of importance in the application of electro-depositions as analytical preconcentration and preseparation methods.     

Preconcentration and determination of trace metals by flow injection micelle-mediated extraction using flame atomic absorption spectrometry

Micelle-mediated extraction/preconcentration is incorporated on-line into a flow injection system used to determine low levels of Cd(II), Co(II), Cu(II), Mn(II), Ni(II), Pb(II) and Zn(II) present in various samples. The analyte is complexed with HBDAP (N,N′-bis(2-hydroxy-5-bromo-benzyl)1,2-diaminopropane). Under optimal conditions, a solution of 30% (m/v) NaCl and a sample solution containing 2.5 mL of 1% (m/v) sodium dodecyl sulfate (SDS), 0.5 mL of 1.8 × 10⁻³ M HBDAP and 2.5 mL of pH 8.5 borate buffer solution in 25 mL were pumped through the cotton filled mini-column; onto which the surfactant-rich phase containing the complex is collected. A solution of 0.5 M HNO₃ in 50% acetone is used as the eluent. The limits of detection are (ng mL⁻¹) Cd = 0.39, Cu = 3.2, Co = 7.5, Mn = 3.0, Ni = 3.4, Pb = 17.9 and Zn = 0.89 if the sample is allowed to flow for 30 s, but improved for extended preconcentration periods. Analysis of liquid and solid reference materials showed good agreement with the certified values. Complex formation constants between HBDAP and these metal ions were also determined potentiometrically.     

Preconcentration of strontium using aphrons

Aphrons containing di-(2-ethylhexyl)phosphoric acid (DEHPA) as an active substance were used for preconcentration of strontium from acetate buffers. Conditions for preparation of reasonably stable aphrons using non-ionic and anionic detergents in n-alkane and water mixture were found. After distribution of strontium, aphrons were separated from water solution by filtration with micro-filters. The separation efficiency was compared to the results obtained in liquid-liquid extraction of strontium with DEHPA in n-alkane. The results show that the preconcentration efficiency for strontium for aphrons is as good as for liquid-liquid extraction systems.     

Preconcentration procedures for trace cadmium determination in natural aqueous systems prior to zeeman etaas

Nanotrace Cd determination in natural waters using two new flotation collectors, lead(II) heptyldithiocarbamate, Pb(HpDTC)₂, and cobalt(III) heptyldithiocarbamate, Co(HpDTC)₃, are presented. The optimization of the most important experimental parameters for flotation is given. Zeeman electrothermal atomic absorption spectrometry (ZETAAS) is used as an instrumental technique for Cd measurement. The results are compared with those obtained by other preconcentration procedures as independent methods. The limit of detection of ZETAAS using Pb(HpDTC)₂ as collector is 4.8?ng/L, while using Co(HpDTC)₃ it is 3.0?ng/L.     

Determination of some precious metals by neutron activation analysis

A neutron activation procedure for the determination of Ru, Pd, Os, Ir, Pt and Au in a single irradiation in silicate rocks, meteorites and sulfide ores has been developed. An alkali fusion was used to dissolve and mix 100 to 200 mg powder samples with appropriate carriers. The individual metals were separated and brought to a state of high radiochemical purity by distillation, ion exchange and solvent extraction techniques. Precious metal activities were counted by both γ and β-methods. The procedure was evaluated by replicate analyses of the granite and diabase rock standards, G-1 and W-1 and a Cu−Ni sulfide matte which had previously been analysed by emission spectrographic and spectrophotometric methods. The results were compared with previously published data. A major discrepancy was found only for Ir in W-1.     

高性能球型氢氧化亚镍的ICP-OES分析方法

建立了镍氢电池正极材料氢氧化亚镍中主成分锌、钴及杂质钙、镁、锰、镉的ICP AES测定方法。选择了仪器最佳工作条件 ,研究了镍基体对被测元素的干扰。方法的回收率为 95 .9%～ 1 0 3% ,RSD为 0 .93%～ 1 8%。     

Qualitative and semi-quantitative analysis in ICP-AES using multivariate calibration

This paper describes a two step algorithm for qualitative and semiquantitative analysis in inductively coupled plasma—atomic emission spectroscopy (ICP-AES) including the preceding data acquisition. Sample and calibration spectra were recorded in 0.05 nm spectral windows centered about the most prominent lines of the 49 covered elements. In the first step of the analysis of an unknown sample spectrum it is decided which of these elements can be excluded from further operations because of the absence of their most prominent lines applying a multivariate criterion for peak detection. For the remaining elements quantitative analysis is performed via multivariate calibration taking into consideration the most prominent line of each element and possibly interfering lines of those elements which were not found absent during the first step. After the estimation of the element concentrations multivariate detection limits are used as criterion for the presence of an element. Results for six synthetic samples of increasing complexity prepared from standard solutions and three standard reference materials are given.     

Preconcentration of trace chalcophile elements by a zincon--loaded resin and its application to neutron activation analysis (author's transl)]

A chelating agent-loaded resin consisting of an anion exchange resin and zincon which has widely been employed as a specific reagent for zinc(II) and copper(II) in spectrophotometry was prepared. The adsorption behavior of some chalcophile elements was studied in detail, with respect to pH, flow rate and exchange capacity. From the results, it was confirmed that the zincon-loaded resin reacts selectively with copper(II), zinc(II), mercury(II) and lead(II) at lower pH region, and the above reaction is stoichiometric as in the case of the reaction of zincon with metal ions in aqueous solution. Furthermore, the zincon-loaded resin was applied to the selective concentration of trace amounts of chalcophile elements in natural water samples prior to neutron activation analysis. Water samples taken from the Watarase River were filtered and the pH of each filtrate was adjusted to ca. 5.5. After preconcentration was made by the column method (zincon-loaded resin: 2 x 10-4 mol/g resin, 1.0 g, 7 mm phi x 35 mm), the resin in the column was washed and dried in a desiccator. The standard material was also prepared according to the above mentioned scheme. The sample and the standard materials packed in polyethylene vials were irradiated for 40 min by a neutron flux of 5 x 10(13 n.cm-2.sec-1 in the JRR-4 of the Japan Atomic Energy Research Institute. After cooling the materials, activity measurements were made. The results were 53 ppb for copper, 0.25 ppb for mercury.     

Preconcentration and separation of trace amounts of palladium using dithiooxamide functionalized chelating resin followed by its determination using radiotracer technique

The work describes a procedure of preconcentration and separation of trace amounts of Pd(II) by solid phase extraction of the metal ion by dithiooxamide groups incorporated into a matrix of polystyrene-divinylbenzene whereas the determination of palladium has been carried out by radiotracer technique using ¹⁰⁹Pd (T _1/2 = 13.43 hr, E _γ = 311, 647 keV). The experiments were carried out using both batch method and column operation. Parameters such as the amount of resin, effect of pH, equilibration rate, sorption and desorption of metal ions have been studied. The maximum sorption capacity for palladium was found to be 0.10 mmol·g⁻¹ at pH 6.0. The method is rapid, has a good accuracy and can be used routinely.