Kupfer

Ohne Zusammenfassung     

Examinations regarding the correctness of quantitative surface analysis using SNMS

Summary For the assessment of the correctness of depth profile analyses with non-ideal technical metal surfaces using secondary neutral particle mass spectrometry (SNMS), the roughness of the sample surface was examined for the transition width of the signal. It is shown that with elements with low sputter rates (Al Mn), similar to that of the substrate element (Fe), there is no significant influence of the roughness. However, clear dependencies are observed for tin and zinc, elements with high sputter rates. Whereas tin gave acceptable results when the roughness was significant, cone formation was observed with zinc which caused abnormal sputter behaviour. The use of high-frequency sputter processes eliminates this cone formation and leads to constant signals, even with thick zinc layers. This method is therefore not only suitable for use with non-conductors, as originally planned, but also offers considerable advantages in the analysis of metal coatings.     

Die anodisch angeregte kationische Polymerisation von Isobutylvinyläther

At low current intensities with tetraethylammonium perchlorate as supporting electrolyte a stationary cationic polymerization of isobutyl vinyl ether in an acetonitrile-diisopropyl ether solvent is obtained at the platinum anode. The electrochemical and kinetic characteristics of the system are determined. An influence of water is found. The molecular weight of the polymer is mainly given by chain transfer to the monomer.

---

---

Mit 1 Abbildung

---

Gegenwärtige Adresse: Semperit AG, A-2514 Traiskirchen.     

Emissionsspektroskopie mit induktiv gekoppelter Plasmaflamme als Detektor zur Elementanalyse nach gas-chromatographischer Trennung

Zusammenfassung Die Kombination eines Gas-Chromatographen mit dem Stickstoff/Argon-Plasma (ICPOES) bei hoher Leistung wird beschrieben und mit Pb- und Si-haltigen organischen Verbindungen getestet. Die direkte Anpassung von GC-Ausgang und Gaseinlaß am ICP-Brennersystem sowie das Aufheizen der Verbindung und des Trägergases ermöglichen die Eingabe kleiner Gasmengen in das Plasma. Die Ergebnisse dieser ersten Studien lassen erkennen, daß sich die ICPOES zur Lösung zahlreicher Probleme im Bereich der Spurenanalyse, der Anreicherung und gas-chromatographischen Trennung organischer Metallkomplexe wird einsetzen lassen, wenn die ICP-Anregung als Detektor in Verbindung mit einem Simultanspektrometer eingesetzt wird. Die Empfindlichkeit des N₂-/Ar-Plasmas bei hoher Leistung wird mit derjenigen des Ar-Plasmas bei niedriger Leistung verglichen. Als analytisches Beispiel wird die Bestimmung geringer Pb-Gehalte in Benzinen beschrieben, wobei auch das Verhältnis Bleitetraethyl/-tetramethyl bekannt wird.

---

ICP optical emission spectrometry as a detector for elemental analysis after gas-chromatographic separation

Summary The combination of a gas-chromatographic device with high-power nitrogen/argon inductively coupled plasma optical emission spectrometry (ICPOES) is described and tested with Pb and Si containing organic compounds. The direct combination of the GC output with the input tube of the ICP burner system and a heating-up device of the carrier gas make it possible to introduce small gas amounts into the ICP torch. The results of these studies suggest that ICP-OES should be applicable to solve many problems of trace elemental analysis, preconcentration and GC separation of organic metal complexes by using the ICP source as a detector system in connection with the simultaneous OES. The sensitivity of high-power nitrogen/ argon ICP is compared with that of low-power argon ICP. For example the determination of low contents of lead in petrol or fuels is given in detail. The ratio of lead tetraethyl/tetramethyl can be determined, too.

     

Multicomponental Fluorimetric Determination of Aluminium, Gallium and Indium

For the fast characteristics of mixtures of Aluminium, Gallium and Indium the fluorimetric evaluation in the form of complexes with 8-Hydroxyquinoline-5-sulphonic acid is described at selected pH. The highly collinear correlated fluorescent spectra and their first derivation were evaluated under various experimental conditions with the Multiple Linear Regression (MLR), Partial Least Squares (PLS) methods and Kalman filtering. When comparing the results, the PLS gives the least relative prediction errors under optimal conditions, 5.6–15.9% for the concentration range of Al 0.025–0.2 μg cm⁻³, Ga 0.1–0.8 μg cm⁻³ and In 0.1–0.8 μg cm⁻³ in the mixture.