Anwendung mikroanalytischer Methoden zur Lösung kunst- und kulturgeschichtlicher Probleme

Zusammenfassung Mit bekannten mikroanalytischen Arbeitsmethoden — Oberflächenreaktionen, Abstrichuntersuchungen mit dem Korundstäbchen, Schutzschichtreaktionen sowie dem Abdruckverfahren — lassen sich archaeometrische Probleme einer Lösung näherbringen. Die Art der Korrosion kupferhaltiger Oberflächen wurde diskutiert.

---

Application of microanalytical methods to the solution of artistic- and cultural historical problems

Summary Archeometrical problems are brought closer to a solution by means of known microanalytical procedures-surface reactions, surface scraping studies with the corundum rod, protective layer reactions as well as the imprint method. A discussion of the corrosion of copper-bearing surfaces is included.

---

---

Vortrag anläßlich der Tagung Chemische Analysen — Kunst- und Kulturwissenschaften im Reiß-Museum in Mannheim, 19.–21. September 1974.     

The surface activity of the lower homologues of n-alkylammonium chlorides in aqueous solutions. Effect of hydrophobic hydration

Summary The surface tensions of aqueous solutions ofn-alkylammonium chlorides (methyl to hexyl) have been measured at 25 °C. With methylammonium chloride the surface tension increased with concentration, whereas with ethylammonium chloride and higher homologues, the surface tension decreased with concentration. The results suggest that this transition is attributed to the effect of hydrophobic hydration. For propylammonium chloride and higher homologues, the relation between the surface tension lowering da and the concentrationC in the range of 0–10 dyne/cm, can be expressed by the equation; = AC + BC, whereA andB are constants. The surface tension coefficientB has been found to increase approximately twofold for each additional CH₂ group of alkyl chain.

---

Zusammenfassung Es wurden die Oberflächenspannungen wäßriger Lösungen vonn-Alkylammoniumchloriden (Methyl- bis Hexylammoniumchloride) bei 25 °C gemessen. Für Methylammoniumchlorid nimmt die Oberflächenspannung mit der Konzentration zu, aber bei allen höheren Homologen mit der Konzentration ab. Die Ergebnisse deuten darauf hin, daß dieser Übergang durch die hydrophobe Hydration bedingt wird. Für Propylammonium-chlorid und die höheren Homologen wird die Beziehung zwischen der Erniedrigung der Oberflächenspannung und der KonzentrationC in dem Bereich von 1 bis 10 dyn/cm durch die folgende Gleichung ausgedrückt: = AC + BC (A undB sind Konstanten). Es wurde gefunden, daß B für jede zusätzliche CH₂-Gruppe etwa um den Faktor 2 größer wird.

     

The influence of “two-phase” synthesis conditions on blown film extrusion of LDPE

LDPE synthesized under two-phase conditions is known to have a good balance of blown film properties. Good optical properties and high impact strength are characteristic for two-phase LDPE grades. In order to obtain systematic information, LDPE was synthesized at several different pressures with two different melt index levels. Blown film was extruded at different output rates and melt temperatures. The influence on haze and dart drop impact was studied. Two-phase conditions were found to improve haze and dart drop impact and the improvement was impressive, especially for the low melt index grades. By increasing the output rate, the dart drop values were further improved. The influence of melt temperature on dart drop impact goes through an optimum and overall haze decreases with increasing melt temperature. For films made from two-phase grades, dart drop impact decreases as internal haze increases. For corresponding internal haze values, the films made from single-phase grades have lower dart drop values and they are somewhat scattered.     

Kinetic study of copper(II) complexation with 9-ethyl-3-carbazolecarboxaldehyde-thiosemicarbazone and kinetic-spectrophotometric determination of copper(II)

The kinetics of complexation reaction of Cu(II) with 9-ethyl-3-carbazolecarboxaldehyde-thiosemicarbazone (ECCAT) has been examined spectrophotometrically. The ligand was synthesized for the first time. The complexation reaction was carried out in a DMF-water medium at 35°C. The complex has maximum absorbance at 393 nm. Kinetic and activation parameters of the complexation reaction were calculated by the Arrhenius and Eyring equations using the data obtained from investigating the effect of temperature on reaction rates under the specified conditions. We also proposed reaction rate equations. Based on the studied complexation reaction, a simple kinetic method for the spectrophotometric determination of copper(II) has been developed. The calibration graphs are linear in the concentration range 0.2–1.9 μg/mL. The species that caused interference were investigated. The text was submitted by the authors in English.     

Zur Ermittlung und rechnerischen Überprüfung thermodynamischer Daten aus experimentell gefundenen Werten, 10. Mitt.: Zur Frage der Parameterzahl und Fehlerverteilung bei einigen Rechenansätzen für binäre thermodynamische Systeme

Zusammenfassung Es wird eine vergleichende Untersuchung über die Anwendungsmöglichkeit zweier dreiparametriger und zweier zweiparametriger Ansätze angestellt. Die Bestimmung der Konstanten erfolgt nach der Methode der kleinsten Quadrate, die entstehenden Fehlerquadratsummen werden als Funktion der Iterationszahl dargestellt und verglichen. Ebenso wird mit den Verbesserungen _i und den mittleren Fehlern der einzelnen Parameter verfahren. Es ergibt sich, daß der Ansatz vonWilson für stark assoziierende Systeme mit nahezu horizontaler Grenztangente die kleinste Fehlerverteilung aufweist. Die beiden dreiparametrigen Ansätze vonRedlich-Kister und vonMusil-Breitenhuber zeigen sich für das Systemn-Hexan-Methylamin besser geeignet als für die Systeme Benzol-Methanol und CCl₄-Methanol. Die Problematik der Parameterzahl wird an Hand der Fehlerverteilung bei den Ansätzen vonMB undRK aufgezeigt und diskutiert.Das Programm wurde in der Programmiersprache FORTRAN erstellt und mit der UNIVAC-490-Computer-Anlage des Grazer Rechenzentrums gerechnet.

---

Four thermodynamical statements are tested with regard to their applicability to binary systems, two statements having three and two only two parameters. The least square method ofGauss shows that theWilson statement has the smallest dispersion of errors for systems with nearby horizontal boundary tangent. [vv], _i and are shown as functions of the number of iterations. The problem of the parameters' number is shown and discussed by means of the dispersion of errors for theMusil-Breitenhuber (MB) andRedlich-Kister (RK)-statements.The programme is written in FORTRAN and has been used the UNIVAC-490-Computer of the Graz Computer Centre.

---

---

Mit 5 Abbildungen

---

Herrn Professor Dr.Robert Fischer zum 65. Geburtstag in Dankbarkeit und Verehrung gewidmet.

---

bis 6. Mitt.:F. Gölles, Mh. Chem.92, 981 (1961);93, 191, 201 (1962);94, 1108 (1963);95, 1656 (1964);96, 1366 (1965);7. bis 9. Mitt.:F. Gölles undA. Höpfner, Mh. Chem.97, 368, 911 (1966);99, 230 (1968).     

Darstellung und Reaktionen des 3-Ethinyl-2,4-diformyl-pentandials

Preparation and physical and chemical properties of 3-ethinyl-2,4-diformyl-pentandial (3 a) and its salts are described.3 a contains 2 malonaldehyde groups. Starting from3 a, 4H-pyranes, 4H-dihydropyridines, dipyrazoles, diisoxazoles, bisdiazepines and vinamidine derivates are obtained.

---

---

Mit 1 Abbildung     

Zur Umsetzung des 3,4,5,6-Tetrahydro-6-hydroxy-4,4,6-trimethyl-1,3-thiazin-2-thions mit sekundären Aminen

Tetrahydro-6-hydroxy-trimethyl-1,3-thiazine-2-thione (1) reacts with secondary amines via the dialkylammonium-3-oxoalkyldithiocarbamate3, either via isothiocyanates6 to 4-dialkylaminodihydro-2(1H)-pyridinethiones7 or to dialkylammonium dithiocarbamates (13), depending on the amine used and the reaction conditions. Subsequently, 6-dialkylaminotetrahydro-1,3-thiazine-2-thiones11 or tetrahydro-6-mercapto-1,3-thiazine-2-thione10 are formed. On being heated to reflux,11 reacts to pyridinethione7 and 4-dialkylaminodihydrothiopyranthione19. With secondary amines only13 is formed from tetrahydro-6-hydroxytetramethyl-1,3-thiazine-2-thione20. The reaction of dihydrotrimethyl-1,3-thiazine-2-thione21 with secondary amines leads to N,N-dialkylthioureas16 or dialkylammonium thiocyanates17 and with dialkylformamides 4-dialkylaminodihydropyridinethiones7 are formed. Dihydrotetramethyl-1,3-thiazine-2-thione24 reacts neither with secondary amines nor with dialkylformamides.     

Koordinationschemie von Dinitroresorcin mit Kupfer-, Kobalt-, Nickel-, Eisen- und Zinksalzen

The reactions of the bidentate dinitrosoresorcinol (DNR) with copper, cobalt, nickel, iron and zinc salts were investigated. This ligand was found to react with these metal salts in aqueous media where hydrogen ion was confirmed to be liberated except in case of iron. The solid complexes were prepared in alcoholic media. Chemical analyses, magnetic and spectral data were compatible to determine the structure of these complexes and their mode of chelation.

---

---

Mit 2 Abbildungen     

Beiträge zur Chemie der Pyrrolpigmente, 19. Mitt.: Die elektrochemische Oxidation von Pyrromethenonen und Pyrromethenen (Gallenpigment-Partialstrukturen)

The electrochemical oxidation of arylmethylene-pyrrolinones, pyrromethenones and pyrromethenes as representative bile pigment partial structure models was investigated by means of a rotating disc platinum electrode using acetonitrile as the solvent. Two different oxidation reactions were found. The first reaction being a reversible one-electron oxidation with compounds of the arylmethylene-pyrrolinone series and pyrromethenones which are unsubstituted in position 5 of the pyrrole ring. A two step reaction (the first one reversible, the second irreversible) on the other hand was found to be typical for pyrromethenones bearing a methyl group in this position.Through protonation the first step is at a higher potential, whereas the second one is lowered and becomes reversible. The resulting oxidation pattern can be interpreted analogous to the oxidation of hydroquinones in aprotic solvents.The geometrical isomers of a pyrromethenone were oxidized at appr. the same potential, but there is a strong dependence of the potential of the first oxidation step on the substitution: a higher degree of alkylation favours oxidation by lowering the oxidation potential.

---

---

Mit 1 Abbildung     

Selective pressurized liquid extraction of polychlorinated biphenyls from fat-containing food and feed samples influence of cell dimensions, solvent type, temperature and flush volume

Sulphuric acid impregnated silica was used for the lipid free extraction of polychlorinated biphenyls from fat containing food and feed matrices using pressurized liquid extraction on a Dionex ASE300, with 34 mL cells. Data were compared to a previous publication where extractions had been performed on a Dionex ASE200, with 33 mL cells. Four different fat/fat retainer ratios (FFRs) were tested (0.100, 0.075, 0.050 and 0.025) at 50 and 100 degrees C using n-pentane, n-hexane or n-heptane as extraction solvent. The best results were obtained with a FFR of 0.025 when applying a temperature of 100 degrees C. Both n-pentane and n-heptane were capable of replacing n-hexane as extraction solvent. A flush volume of 60% was sufficient as suggested in US Environmental Protection Agency Method 3545. The applicability of the method was demonstrated for naturally contaminated fish meal as well as various spiked and certified materials.