Laboratory intercomparison study on the analysis of short-chain chlorinated paraffins in an extract of industrial soil

Short-chain chlorinated paraffins (SCCPs) comprise a class of organic pollutants used in many industrial applications and released into the environment. The analytical determination of SCCPs is very challenging. Although there is at present no fully validated measurement procedure that might be applied in routine monitoring, the European Union Water Framework Directive (WFD) has required regular monitoring of this class of compounds at river-basin scale since 2007.To assess the status quo of the analysis of SCCPs in relation to the requirements of the WFD, we organized an interlaboratory comparison on the quantification of SCCPs in an extract of an industrial soil. Six laboratories participated in the exercise using three different techniques [i.e. gas chromatography (GC) coupled to mass spectrometry (MS) in electron-capture negative ionization mode, GC with atomic emission detection, and carbon-skeleton GC-MS]. The results reported were in the range 8.5–3200 mg/L. This confirms that reliable quantification of SCCPs is still very difficult to achieve and that the comparability of SCCP data reported to the European Commission is at least questionable.     

3D-shaping of biodegradable photopolymers for hard tissue replacement

Continuously increasing life expectancy results in a rising number of bone diseases and fractures. Replacements from natural sources are not only limited in their availability, they also have some serious disadvantages such as possible immunological reactions or transmission of diseases. New synthetic biodegradable materials based on photopolymers could be an alternative solution. In these investigations an acrylate-based monomer formulation has been developed, consisting of a biodegradable basis monomer which is derived from gelatin, different reactive diluents, an appropriate photoinitiator and filler materials. For the three-dimensional shaping process stereolithography is the method of choice because of its capability to produce cellular structures with high resolutions.     

Untersuchungen über das unterschiedliche Verhalten von N- und S-Methyliden gegenüber elektrophilen Reaktionspartnern

A straight forward synthesis of trimethylammonium trifluoroacetyl methylide (2) starting from trimethylammonium-di-trifluoracetyl methylide (1) using aniline is described. Moreover, the nucleophilic reactivity of N- and S-Ylides with identical anionic component towards acetylating agents were studied with respect to the contribution of the cationic component.

Herrn Prof. Dr.G. Zigeuner, Universität Graz, mit besten Wünschen zur Vollendung des 65. Lebensjahres gewidmet.     

RPA description of the electric polarizability of the nucleon

Excited states of the nucleon are described as RPA configurations on a mean-field ground state taken from the MIT bag model. A residual interaction of a structure as in the Nambu-Jona-Lasinio model is used. The particlehole states are coupled to good total angular momentum and isospin. Valence excitations of particle-hole type and quark-antiquark (q $\bar q$ ) states from the Dirac-sea are included. The dependence of the baryon spectrum and multipole response functions on the coupling constantG is studied. At critical values ofG the 3q-ground state becomes degenerate with strongly collectiveq99-2 modes. The model is used to calculate the averaged electric polarizability of the neutron and the protonα. Without residual interactionα=7·10^?4 fm ³ is found. With residual interaction the value increases toα=(?11)·10^?4 fm ³. The measured value ofα is reproduced within experimental error bars.     

Zur Chemie der vicinalen Triketone, 4. Mitt.

o-Halogenated (o,o-dihalogenated) anilines react with phenalenetrione (PT) in boiling xylene or acetic acid to give 7H,8H-naphtho[1.8–bc]phenoxazin-7-one derivatives. The analogous reaction with 2.6-dimethyl-or 2.6-diethyl-aniline in xylene gives oxazepines, while in acetic acid preferential addition of the aniline with the para position to the NH₂-group to the central C=O-group ofPT occurs. It can be shown, that the first step in the ring closure reaction is the formation of semiaminales.Es wird gezeigt, daß Aniline, die in 2-bzw. 2,6-Stellung halogensubstituiert sind, mit Phenalentrion (PT) in Xylol oder Eisessig zu den entsprechenden 7H,8H-Naphtho[1,8–bc]-phenoxazin-7-on-derivaten reagieren. Die analoge Umsetzung mit 2,6-Dimethyl-bzw. 2,6-Diäthyl-anilin in Xylol führt zu Oxazepinen, während in Eisessig bevorzugt Addition des zur NH₂-Gruppe in p-Stellung befindlichen H-Atoms an die mittelständige C=O-Gruppe desPT stattfindet. Es wird experimentell bewiesen, daß diese Ringschlußreaktion über primär gebildete Halbaminale abläuft.

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Herrn Prof. Dr.O. Kratky, Graz, mit besten Wünschen zum 70. Geburtstag gewidmet.     

MODE OF COACTION OF PHYTOCHROME AND BLUE LIGHT PHOTORECEPTOR IN CONTROL OF HYPOCOTYL ELONGATION

Abstract The rate of hypocotyl longitudinal growth in seedlings of Sesamum indicum L. is strongly inhibited by continuous blue light (cBL)† and slightly by continuous far-red light while continuous red light (cRL) or red light pulses are hardly effective from 60 h after sowing onwards. Between 36 and 60 h after sowing the growth rate responds to red light pulses the effect of which is fully reversible by long wavelength far-red light. When seedlings are kept in cBL for 3 days and then treated with red light hypocotyl growth rate responds strongly. However, RL effectiveness decreases with time after transfer from BL to RL. BL → darkness transfer experiments with different levels of P_fr established at the beginning of darkness show that after a BL pretreatment phytochrome (P_fr) alone is capable of fully controlling growth rate. When white light (WL) is given no BL effect is detectable in weak WL. Only high light fluxes maintain a typical BL growth rate. At medium WL fluxes elongation rate returns gradually to the dark rate. The simplest explanation of the data is that light absorbed by a separate BL photoreceptor is necessary to maintain responsivity to P_fr. With increasing age of the seedlings the requirement for BL increases strongly. On the other hand, brief light pulses—given to demonstrate photoreversibility of phytochrome—remain equally effective provided that responsivity to P_fr exists.     

Determination of chloramphenicol in bovine milk by liquid chromatography/tandem mass spectrometry

A rapid confirmatory liquid chromatographic/tandem mass spectrometic method was developed for determination of chloramphenicol in bovine milk. Chloramphenicol was extracted directly from milk by solid-phase extraction on a C18 cartridge. The extract was further cleaned up on neutral aluminium oxide. Three transition products were monitored in negative ion mode after atmospheric pressure chemical ionization. The detection capability related to the transition product of lowest abundance was 0.03 microg/kg. The mean recovery was 90% at levels of 0.1-0.2 microg/kg. The relative repeatability standard deviations were 4.3, 3.8, and 2.8% at levels of 0.1, 0.2, and 1.0 microg/kg, respectively.     

Die stabilisierung von tris(amino)phosphin durch komplexbildung

Ammonolysis of (CO)₅M · PCl₃ (M = Cr, Mo, W) results in the formation of the complexes (CO)₅M · P(NH₂)₃, stable at ambient temperature. IR data indicate that P(NH₂)₃, which is unstable in the free state under the same conditions, transfers about the same electron density to the metal atom as P(NMe₂)₃. Other spectral data (NMR, mass spectra) are discussed.