Benzothiazole-2-diazonium tetrafluoroborate and its 6-bromo, 6-methyl, and 6-methoxy derivatives are relatively stable and have high electrophilicities. They are rapidly converted in weakly alkaline media to the corresponding anti-diazotates, from which primary nitrosoamines can be obtained by acidification.

Conclusions

A statistical analysis of the crystalline splittings of the³⁵Cl NQR spectra in the series R₁R₂P(O)Cl (R₁, R₂=Alk, Ar, Hal) revealed that the error in correlating the frequencies with theσ-constants of the substituents is due mainly to the crystal effect.

The possibility of using the sol-gel method for preparation of inorganic ion-exchangers with a silica gel matrix has been demonstrated on the ammonium molybdophosphate-silica gel (AMP-SG) system. For the preparation of the ion-exchanger a sodium silicate solution, containing AMP and components to cause gelling to silica gel after increase of the temperature of the solution, is poured into a hot stirred silicone oil. The solution forms droplets, which are filtered off after their gelling, washed and dried. Beads containing 65 wt.% of AMP per gram of dry material have been prepared by this method and tested in ion-exchange columns for caesium removal from nitric acid solutions. Caesium may easily be desorbed with ammonium chloride or nitrate solutions. The ion-exchanger is suitable for long-time reversible column operation, having not only good chemical, thermal and radiation stabilities but also good mechanical and hydrodynamic properties and resistance to abrasion. It combines the advantage of the good kinetics of ion-exchange obtained with microparticles of precipitated inorganic ion-exchanger, with the low flow resistance of large particles.

Zusammenfassung

Aus einem HNO₃/HCl/HClO₄/H₂SO₄-Gemisch wurde Ru zusammen mit Os und Ge (teilweise auch Re, Hg, Se und geringen Mengen bis Spuren an As, Cr, Sb, Sn) zuerst abdestilliert und dann aus dem salzsauren Destillat mit CHC1₃ die Hauptmenge von Os und Ge extraktiv abgetrennt [1], während Ru in der wäßrigen Phase verbleibt. Da die Abtrennungen nicht streng quantitativ verlaufen, müssen beide Phasen mehrmals entsprechend nachgewaschen und die jeweiligen Waschlösungen mit den bei der ersten Extraktion erhaltenen Lösungsanteilen vereinigt werden.

Summary

Today, mini computers (e. g., HP-65) are available in a pocket version. They can be programed quickly, simply and very effectively. Thus, mathematical algorithm can be used for retention index calculations from nonadjusted retention time data using an iteration. Although sometimes the true data of retention index, as a function of the adjusted retention time, are non linear, it can be shown that linearization of this function — together with linear regression — is of great practical value. Another improvements are achieved by using nonalcanes as an inner standard in qualitative routine analysis of medium to high polar compounds, as well as by using the retention index as the address for correction factors for quantitative analysis and as the command to start any type of program in gas chromatography, e. g., temperature programs, column switching programs, detector switching programs, and all switching programs in preparative gas chromatography. This is true because retention index data are in minimum by a factor of ten more precise than other measure in qualitative gas chromatography. Algorithms used and programs for the HP-65 pocket computer are given.

Résumé

Par l'analyse par activation, on recherche des traces de métaux et de fluor dans la poussière atmosphérique récoltée au-dessus des différents océans. On a utilisé l'activation neutronique pour l'analyse des métaux, l'activation aux photons pour évaluer la teneur en fluor. On discute de façon détaillée l'importance des résultats obtenus pour Hg et F en fonction du milieu. L'étude du rendement d'extraction du mercure a été faite au laboratoire au moyen d'algues marines, phaeodactylum tricornutum. Au cours d'expériences préliminaires faites en utilisant le radiotraceur (¹⁹⁷Hg), on a évalué différents paramètres expérimentaux. On compare les résultats finaux pour les concentrations de mercure dans les algues avec ceux obtenus par une méthode d'analyse par absorption atomique.