Chemical analysis and distribution investigation of trace elements in indium matrix by spark source mass spectrometry

Summary High-purity indium was analysed by spark source mass spectrometry, using electrical and photoplate detection. For the calibration of the differences in elemental sensitivity, a standard sample was prepared in which 10 impurities were determined by graphite furnace atomic absorption spectrometry. In this way accuracies of less than 40% were obtained for relatively homogeneous elements at ppm and sub-ppm level. About 40 elements could be determined with detection limits of 10 to 30 ppb. Two pattern recognition methods, principal component analysis and clustering analysis, were applied to obtain information on trace element distribution, which indicated that a number of elements were strongly spatially correlated in the analysed sample.

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Chemische Analyse und Verteilungsbestimmung von Spurenelementen in Indium-Matrix durch Funkenquellen-Massenspektrometrie

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On leave from: Department of Chemistry, Nanjing Normal University, Nanjing, People's Republic of China     

Classification of the distribution of trace impurities by spark source mass spectrometry analysis

Spark source mass spectrometry in combination with principal component analysis and clustering analysis was used to investigate the trace element distributions in metallic samples. The analysis of Zn and Cu samples and a comparison with direct imaging secondary ion microscopy demonstrated the consistency of the approach.On leave from Department of Chemistry, Nanjing Normal University, Nanjing, People's Republic of China.     

Comprehensive quantitative analysis by spark source mass spectrometry: A technique on the brink

Spark Source Mass Spectrometry has been shown to be a particularly sensitive method for the detection of small concentrations of a wide range of elements in solid samples. However, unless improved commercial instrumentation becomes available it is a method which, in spite of its great potential, will fall into progressive decline.     

Determination of trace impurities in cobalt by spark source mass spectrometry

An analytical method, SSMS, for the determination of trace impurities in cobalt is described. This element is used as raw material for the production of⁶⁰Co in Embalse Nuclear Power Station. Tin, aluminum, lead, silicon, molybdenum, calcium, vanadium, boron, chromium, zirconium, tungsten, nickel, magnesium, iron, zinc and copper were determined. Manganese, analyzed by AAS, was used as an internal standard. The measurements were semiquantitative. The accuracy of the results was compared with that of emission spectrography and atomic absorption spectrometry, the agreement was found to be satisfactory.     

Improvement in precision and accuracy of spark source mass spectrometric analysis by sample dissolution and isotope dilution

Summary In order to avoid the influence of sample heterogeneity, matrix effects and the non-availability of well analyzed standard samples on the precision and the accuracy of spark source mass spectrometric analysis, metal and silicate samples are dissolved chemically. For quantitative analysis, isotope dilution and calibration with standard solutions are used, whereby a precision of better than ±3% and ±8%, respectively, is obtained. This development has improved the precision by about a factor of 3 and increased the reliability of the analysis.

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Verbesserung der Genauigkeit und der Richtigkeit der funken-massenspektrometrischen Analyse durch chemisches Auflösen der Probe und Anwendung der Isotopenverdünnungsmethode

Zusammenfassung Um den Einfluß der Probenheterogenität, von Matrixeffekten und des Fehlens von gut analysierten Standardproben auf die Genauigkeit und Richtigkeit der funken-massenspektrometrischen Analyse zu vermeiden, sind metallische und silicatische Proben chemisch gelöst worden. Zur quantitativen Analyse wird die Isotopenverdünnungsmethode und eine Eichung mit Standardlösungen verwendet, wobei eine Genauigkeit von besser als ±3% bzw. ±8% erreicht wird. Diese Entwicklung hat die Genauigkeit gegenüber der direkten Methode um einen Faktor von ungefähr 3 verbessert und die Zuverlässigkeit der Analyse erhöht.

     

Use of spark source mass spectrometry for the analysis of copper cathodes

Summary More than 50% of the copper production is used as electrorefined material of high electrical conductivity in the field of electrical engineering. A lot of the normal copper impurities has a decreasing influence on the electrical conductivity so that an electrorefining process is necessary. The use of Periodic Current Reversal (PCR) leads to higher practical current densities producing cathodes of good quality. Some laboratory tests were made by the switching cycles. The contents of the impurities of the cathodes produced were analyzed by SSMS. Using a standard sample 4 photoplates were exposed and a sensitivity factor was determined for each element. Then the cathodes produced by the PCR-electrorefining process were analyzed. The analytical data were corrected by the sensitivity factors.

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Einsatz der Funkenmassenspektrometrie bei der Analyse von Kupferkathoden

Zusammenfassung Mehr als 50% der Weltkupferproduktion wird als elektroraffiniertes Cu in der Elektroindustrie eingesetzt. In beträchtlicher Weise beeinflussen Anzahl und Gehalt der Verunreinigungselemente die elektrische Leitfähigkeit. Ihre Entfernung erfolgt durch Raffinationselektrolyse; eine Elektrolyse mit periodischer Stromumkehr erlaubt höhere Stromdichten bei gleich guter physikalischer Qualität. Einige Untersuchungen wurden unter Anwendung der reversiblen Stromumkehr mit unterschiedlichen Stromdichten und Umschaltzeiten an Cu-Kathoden vorgenommen und deren Verunreinigungsgehalte mittels Funkenmassenspektrometrie bestimmt. Unter Verwendung eines Standards wurden 4 Photoplatten exponiert, und für jedes Element wurde ein Empfindlichkeitsfaktor ermittelt. Danach wurden die mittels Stromumkehrraffinationselektrolyse hergestellten Cu-Proben untersucht. Die Konzentrationswerte wurden mit Hilfe der Empfindlichkeitsfaktoren korrigiert.

     

Investigation of the analytical performance of gliding spark source mass spectrometry (GSSMS) for the trace analysis of nonconducting materials

A radiofrequency (rf) spark discharge in vacuum developing across the surface of dielectrics – a so-called gliding spark – has been applied to the direct mass spectrometric trace analysis of nonconducting materials. The special configuration of the electrodes strengthened the electric field over the surface of a nonconducting sample and created optimum conditions for the sputtering and ionization of the sample material. Mass spectrometric investigations of the charge composition of atomic ion and molecular ion formation in radiofrequency gliding spark plasma showed a significant difference to that of the original rf spark discharge between two conducting electrodes. The analytical figures of merit (reproducibility, relative sensitivity factors and detection limits of chemical elements) of gliding spark source mass spectrometry have been studied by using the glass standard reference materials NIST SRM 610 and 611 for the determination of trace elements in glass matrix. Received: 31 March 1999 / Revised: 10 May 1999 / Accepted: 13 May 1999     

Investigation of the analytical performance of gliding spark source mass spectrometry (GSSMS) for the trace analysis of nonconducting materials

A radiofrequency (rf) spark discharge in vacuum developing across the surface of dielectrics – a so-called gliding spark – has been applied to the direct mass spectrometric trace analysis of nonconducting materials. The special configuration of the electrodes strengthened the electric field over the surface of a nonconducting sample and created optimum conditions for the sputtering and ionization of the sample material. Mass spectrometric investigations of the charge composition of atomic ion and molecular ion formation in radiofrequency gliding spark plasma showed a significant difference to that of the original rf spark discharge between two conducting electrodes. The analytical figures of merit (reproducibility, relative sensitivity factors and detection limits of chemical elements) of gliding spark source mass spectrometry have been studied by using the glass standard reference materials NIST SRM 610 and 611 for the determination of trace elements in glass matrix.     

New methods for the determination of elements in trace amounts

Summary Recent methods for the determination of elements on trace amounts are discussed, which have been mainly developed in the author's laboratories. The review comprises the following sections: reagents and reactions, charge transfer reactions, candoluminescence, molecular emission spectroscopy in flames, enzymatic methods, gas-liquid chromatography of metal chelates, mass spectrometry of metal chelates.

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Neue Methoden zur Bestimmung von Elementen in Spurenmengen

Zusammenfassung Verfahren werden besprochen, die in den letzten Jahren hauptsächlich in den Laboratorien des Autors entwickelt wurden. Der Überblick umfaßt folgende Kapitel: Reagentien und Reaktionen, Charge-Transfer Reaktionen, Candoluminescenz, Molekular-Emissions-spektroskopie in Flammen, enzymatische Methoden, Gas-Flüssigkeits-Chromatographie von Metallchelaten und Massenspektrometrie von Metallchelaten.

Lecture presented at Euroanalysis I Conference, 28. 8.–1. 9. 1972 in Heidelberg, Germany.     

Candoluminescence-a new flame technique for trace analysis-II Determination of nanogram amounts of manganese

The yellow candoluminescence of manganese stimulated in a 8:1 w w calcium oxide-calcium sulphate matrix at the edge of a hydrogen-nitrogen-air flame is used to determine 0.1-3.0 ng of manganese in 1-mul samples. Large amounts of chloride ions enhance the emission, and many transition metals suppress it.     

Influence of spark generator parameters in the analysis of graphite electrodes by spark source mass spectrometry

Spark source mass spectrometric analyses of doped carbon samples were performed at different pulse lengths, pulse frequencies and breakdown voltages. The pulse length and pulse frequencies had no influence on the analysis. The relation between breakdown voltage, spark gap and sample matrix was determined. With increasing breakdown voltage, the abundance of the multiply charged ions was found to decrease, whereas the abundance of the cluster ions increased. The breakdown voltage was also found to affect the absolute and relative intensities of different elements in different manners. Interpretation of these results led to some new considerations on the phenomena in a spark discharge.     

Determination of trace constituents in high purity germanium tetrachloride by spark source mass spectrometry

Summary A procedure was developed for the determination of trace constituents at sub-ppm levels in high purity germanium tetrachloride (GeCl₄) by spark source mass spectrometry using the photoplate detection system. Experiments were conducted to study the loss of various elements present in the chloride form in GeCl₄ by using energy dispersive X-ray fluorescence. Relative sensitivity factors for various elements were determined using synthetically prepared samples. Blanks were determined for graphite powder and for quartz bi-distilled water. Intensities of the doubly charged ions for a number of elements were also determined and used for confirming the semi-quantitative results. The paper presents typical results obtained in the analysis of high purity GeCl₄ obtained from a commercial source. For a number of elements results were compared with those obtained with graphite furnace atomic absorption spectrometry.

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Bestimmung von Spurenbestandteilen in hochreinem Germaniumtetrachlorid mit Hilfe der Funkenionen-Massenspektrometrie

Zusammenfassung Ein Verfahren zur Bestimmung von Spurenbestandteilen in hochreinem GeCl₄ im sub-ppm-Bereich mit Hilfe der Funkenionen-MS mit Photoplattendetektion wurde ausgearbeitet. Untersuchungen über den Verlust verschiedener Elemente als Chloride wurden mit energiedispersiver Röntgenfluorescenz durchgeführt. Relative Empfindlichkeitsfaktoren wurden anhand synthetischer Proben bestimmt. Für Graphitpulver und bidestilliertes Wasser wurden Blindwerte bestimmt. IntensitÄten für zweifach geladene Ionen verschiedener Elemente wurden gemessen und zur BestÄtigung halbquantitativer Ergebnisse herangezogen. Typische Resultate für eine handelsübliche Probe werden angegeben. In einigen FÄllen wurden Vergleiche mit den Ergebnissen aus der Graphitofen-AAS angestellt.

     

A new crosslinker for mass spectrometric analysis of the quaternary structure of protein complexes

Mass spectrometric structural analysis of crosslinked peptides is a powerful method to elucidate the spatial arrangement of polypeptides in protein complexes. Our aim is to develop bifunctional crosslinkers that, after crosslinking protein complexes followed by proteolytic digestion, give rise to crosslinked peptides that can be readily tracked down by mass spectrometry. To this end we synthesized the crosslinker N-benzyliminodiacetoyloxysuccinimid (BID), which yields stable benzyl cation marker ions upon low-energy collision-induced dissociation (CID) tandem mass spectrometry. Sensitive detection of the marker ion upon low-energy CID is demonstrated with different BID-crosslinked peptide preparations. With BID it becomes possible to retrieve crosslinked and crosslinker-adducted peptides, without the necessity of purifying crosslinked peptides prior to identification. The basic design of this crosslinker can be varied upon, in order to meet specific crosslinking needs.     

Determination of trace impurities in zircaloy-2 and tellurium by spark source mass spectrometry

Determination of trace impurities in zircaloy-2 and tellurium by Spark Source Mass Spectrometry (SSMS) is reported. The advantage of SSMS lies in the fact that along with metallic trace constituents even the nonmetallic impurities and gases including hydrogen can also be determined.     

A laser ion source for trace analysis

Summary A laser ion source has been set up which is based on resonant stepwise excitation and ionization of atomic vapor confined in an ionization chamber. Using a pulsed copper vapor/dye laser system with a high repetition rate (6.5 kHz) one expects high efficiency and high selectivity for this new type of ion source. First test experiments with lead are reported.

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Eine Laserionenquelle zur Spurenanalyse

     

A new mass spectrometric classification of alkylbenzenes

A classification of alkylbenzenes is proposed based on the relative intensities of pairs of ions, of which one is formed from the other by loss of a hydrogen molecule.     

A new catalytic polarographic system for determination of trace amounts of tungsten

A new catalytic polarographic system for the determination of trace amounts of tungsten is described. It is found that the tungsten-2-mercaptobenzothiazole (MBT) complex yields a sensitive catalytic hydrogen wave at -1.10 V (vs. SCE) in strongly acidic medium. The peak height is a linear function of tungsten concentration over the range 0.004-1.4 mug/ml in 0.9M H(2)SO(4)-20 mg/ml NaCl-0.01 mug/ml MBT medium. The method can be applied for determination of trace amounts of tungsten in geochemical materials.     

Application of mass spectrometric techniques for the trace analysis of short-lived iodine-containing volatiles emitted by seaweed

Knowledge of the composition and emission rates of iodine-containing volatiles from major widespread seaweed species is important for modeling the impact of halogens on gas-phase atmospheric chemistry, new particle formation, and climate. In this work, we present the application of mass spectrometric techniques for the quantification of short-lived iodine-containing volatiles emitted by eight different seaweeds from the intertidal zone of Helgoland, Germany. A previously developed online time-of-flight aerosol mass spectrometric method was used to determine I₂ emission rates and investigate temporally resolved emission profiles. Simultaneously, iodocarbons were preconcentrated on solid adsorbent tubes and quantified offline using thermodesorption–gas chromatography-mass spectrometry. The total iodine content of the seaweeds was determined using microwave-assisted tetramethylammonium hydroxide extraction followed by inductively coupled-plasma mass spectrometry analysis. The highest total iodine content was found in the Laminariales, followed by the brown algae Ascophyllum nodosum, Fucus vesiculosus, Fucus serratus, and both red algae Chondrus crispus and Delesseria sanguinea. Laminariales were found to be the strongest I₂ emitters. Time series of the iodine release of Laminaria digitata and Laminaria hyperborea showed a strong initial I₂ emission when first exposed to air followed by an exponential decline of the release rate. For both species, I₂ emission bursts were observed. For Laminaria saccharina und F. serratus, a more continuous I₂ release profile was detected, however, F. serratus released much less I₂. A. nodosum and F. vesiculosus showed a completely different emission behavior. The I₂ emission rates of these species were slowly increasing with time during the first 1 to 2 h until a more or less stable I₂ emission rate was reached. The lowest I₂ emission rates were detected for the red algae C. crispus and D. sanguinea. Total iodocarbon emission rates showed almost the same general trend, however, the total iodocarbon emission rates were about one to two orders of magnitude lower than those of molecular iodine, demonstrating that I₂ is the major iodine containing volatile released by the investigated seaweed species. In addition, a clear dependency of iodocarbon emission from the ozone level (0–150 ppb O₃) was found for L. digitata.