Techniques in chemometrical modeling for micro-pollutants assessment

Summary Chemometrics have been described as effective tools for exploring chemical data, and many software packages are now available on micro-computers. This work evaluate their suitability for environmental analytical chemistry. Guidelines for multivariate method selection are proposed. They are based on the type of variables and the goal of the study. Two examples are proposed to illustrate these methods and their efficiency. Firstly it is shown that a global assessment of Rhine basin mercuric pollution in the Alsace region is possible with Multiple Correspondence Factor Analysis. Several goals are simultaneously reached: a mapping of pollution, a detection of pollution changes during the study period and an evaluation of bio-accumulation as a function of fish species. Secondly the modeling of industrial soil pollution by heavy metals is studied by Multiple Linear Regression. It demonstrates that chemometrics provide us with necessary tools for environmental analytical chemistry but also for toxicological studies or ecosystem modeling.     

The determination of chlorinated biphenyls,chlorinated dibenzodioxins,and chlorinated dibenzofurans by GC-MS

High resolution gas chromatography, with mass selective detection, has been used for the analysis of PCB on methyl 50 % octyl polysiloxane (SB 50 Octyl), methyl octadecyl polysiloxane, and a smectic polysiloxane (SB Smectic); and for the analysis of polychlorodibenzodioxins and polychlorodibenzofurans with 1 to 8 chlorine substituents on 100 % cyanopropyl siloxane (SP 2331), smectic polysiloxane (SB Smectic), a new polar stationary phase (DB-Dioxin). The analysis has also been performed by column coupling.     

Photometrische Sulfitbestimmung mit Trinitrobenzoesäure

SO₃ ^2? can be determined photometrically with trinitrobenzoic acid within 2 min. SO₄ ^2?, S₂O₃ ^2?, S^2? and S_xO₆ ^2? in concentrations up to 1 mMole/100 ml do not interfere. The limit of determination is 0.22 mg SO₃ ^2?/100 ml, the standard deviation for the determination of 7 mg SO₃ ^2? is ± 0.59 Rel.-%.     

A new route to vinyltributyltin compounds by flash pyrolysis of alkyltributyltin acetates

Flash pyrolysis of alkyltributyltin acetates, at high temperatures (600–850° C) under a moderate vacuum provides a convenient route to vinyltin derivatives.     

Ab initio calculation of the C/D ratio of magnetic circular dichroism

A procedure for calculating the magnetic circular dichroism C/D ratio from density functional theory calculations is discussed. The method is simplified considerably through the application of group theory and the irreducible-tensor method and only requires integrals of the magnetic dipole moment operator over a few orbitals and published tables of symmetry factors. The implementation of the method is tested through application to several small and medium-sized molecules.     

Ion solvation in water clusters

We describe here molecular dynamics computer simulations performed to study the solvation of ions (Cl^? and Na⁺) in water clusters. Our simulations show that the calculated structure and dynamics of the clusters is very sensitive to the potential model which is used to describe the interactions. From the comparison with thermodynamic data and data from the photoelectron spectra we conclude that in Cl^?(H₂O)_n (n≤20) clusters the ion is located on the surface of the cluster.     

Synthesen von Heterocyclen, 61. Mitt.: Über Dicumarino- und Dicarbostyrilo-oxathiine

Zusammenfassung Durch Einwirkung von SOCl₂ auf 4-Hydroxycumarin bzw. 4-Hydroxycarbostyril sind Bis-(4-hydroxycumarinyl-[3])-sulfid (I) und Bis-(4-hydroxycarbostyril-[3])-sulfid (II) leicht zugänglich. Diese Sulfide können zu Dicumarino- bzw. Dicarbostyrilo-(1,4)-oxathiinen (III bzw. IV) cyclisiert werden.

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Bis-(4-hydroxycoumarinyl-[3])-sulfide (I) and bis-(4-hydroxycarbostyril-[3])-sulfide (II) have been prepared by the reaction between SOCl₂ and 4-hydroxycoumarin and 4-hydroxycarbostyril. Cyclisation of these sulfides yielded dicoumarino- (III) and dicarbostyrilo-oxathiin-(1.4) (IV).

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Herrn KollegenH. Bretschneider, Innsbruck, mit den besten Wünschen zum 60. Geburtstag.

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Aus der DissertationTh. Kappe, Universität Graz 1961, S. 78–83.     

Synthesen von Heterocyclen, 93. Mitt.

Zusammenfassung Malonsäure und monosubstit. Malonsäuren reagieren in Acetanhydrid mit Cyclanon-anilen in guter Ausbeute zu Spiro-1,3-oxazinen (3–6 bzw.9–13). Diese labilen Verbindungen lassen sich mit POCl₃ leicht in 4-Hydroxy-5,6-polymethylen-pyridone-(2) umwandeln. Analog verhält sich Acetophenonanil.

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Malonic acid and monosubstituted malonic acids react in acetic anhydride with cyclanon-aniles yielding the spiro-1.3-oxazines3–6 and9–13. These compounds are readily converted with POCl₃ to 4-hydroxy-5.6-polymethylene-pyrid-2-ones. Acetophenon-anil reacts in the same manner.

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Herrn Prof. Dr.F. Wessely, Universität Wien, mit den besten Wünschen zum 70. Geburtstag gewidmet.     

Identifizierung von sechs Komponenten des Spurpheromons der Ameisenart Lasius fuliginosus. Vorläufige Mitteilung

Hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, and dodecanoic acid are components of the trail pheromone of the ant species Lasius fuliginosus. The acids were extracted from the contents of the rectal ampullae and identified by the mass spectra and gas chromatographic retention times of the corresponding methyl esters.