Reactions of benzothiazole-2-thione and benzothiazole-2-one with acetylene

Reaction of benzothiazole-2-thione and benzothiazole-2-one with acetylene in the presence of potassium hydroxide or cadmium acetate gives 2-vinylthiobenzothiazole and 3-vinylbenzothiazol-2-one, respectively. Benzothiazole-2-thione is partially convened to benzothiazol-2-one by the action of Cd(OAc)₂. Under vinylation conditions the latter also forms 2-vinylthioaniline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 270–271, February, 1991.     

Infrared study of co adsorbed species on ru/silicalite catalyst

Carbon monoxide adsorbed species on Ru/silicalite and their reactivity towards oxygen have been studied using in situ diffuse reflectance infrared spectroscopy (DRIFT). Four species were detected: a bridge bonded CO on metallic Ru (1980 cm ^-1), a linearly adsorbed CO on metallic Ru (2040 cm^-1), a linearly adsorbed CO on partially oxidized Ru (2081 cm^-1), and a multicarbonyl on oxidized Ru (2081 and 2133 cm^-1). Among the four CO species the most strongly held species was the bridge bonded CO on metallic Ru while the multicarbonyl was the most weakly held species. These four species have different reactivities towards oxygen. Only the linearly adsorbed CO on metallic Ru can be oxidized at room temperature.     

Radionuclide X-ray fluorescence determination of Cr, Fe, Cu, Zn and Pb in industrial wastewaters after preconcentration of determined elements

Radionuclide X-ray fluorescence analysis was used for the determination of Cr, Fe, Cu, Zn and Pb in industrial wastewaters (from surface treatment of metals and glasses) after precipitation of determined elements by 8-hydroxyquinoline.     

Gradient elution capillary electrochromatography and hyphenation with nuclear magnetic resonance

Coupling of gradient capillary electrochromatography (gradient CEC) and capillary zone electrophoresis (CZE) with nuclear magnetic resonance spectroscopy (NMR) was performed using a recently developed capillary NMR interface. This technique was applied for the analysis of pharmaceuticals and food. An analgesic was investigated using isocratic and gradient continuous-flow CEC-NMR. Comparison of the results demonstrated the superiority of gradient CEC over isocratic CEC. Aspartame and caffeine, both ingredients of soft beverages, were separated and analyzed by continuous flow CZE-NMR. The order of elution could be reversed by altering the pH. This reversal led to an increased sample concentration in the NMR detection cell, thus allowing the acquisition of a totally correlated spectroscopy (TOCSY) two-dimensional (2-D) spectrum of the synthetic peptide aspartame.     

Anionenaustauschtrennungen der mit Tributylphosphat extrahierbaren Elemente. VII

Zusammenfassung Eine Methode zur Abtrennung des Urans wird beschrieben, bei der das Uran aus einer 6-m salzsauren Lösung mit reinem, unverdünntem TBP extrahiert und aus einer Mischung von 30 Vol.% TBP, 60 Vol.% Methylglykol und 10 Vol.% 12-m Salzsäure am stark basischen Anionenaustauscher Dowex 1-X8 (Chloridform) adsorbiert wird. Da der TBP-Extrakt zur Bereitung dieser Mischung verwendet wird, lassen sich Extraktion und Ionenaustausch kombinieren, wodurch nicht nur die Selektivität der Abtrennung des Urans wesentlich erhöht wird, sondern auch eine so weitgehende Anreicherung des Urans auf dem Harz erfolgt, daß auch ppm-Mengen leicht zu bestimmen sind. Das Harz wird zu diesem Zweck zunächst zur Entfernung des TBP mit einer Mischung von 90 Vol.% Methylglykol und 10 Vol.% 12-m Salzsäure, dann zur Entfernung von mitadsorbierten Elementen mit 6-m Salzsäure behandelt; anschließend wird das Uran mit 1-m Salzsäure eluiert und fluorimetrisch bestimmt. Zu Vergleichszwecken wurden 16 geologische Proben nach dieser Methode und auch unter Anwendung einer anderen Anionenaustauschmethode analysiert. Die Ergebnisse zeigen, daß das hier beschriebene Trennverfahren eine quantitative Abtrennung des Urans ermöglicht und zu gut reproduzierbaren Resultaten führt.

---

Anionic exchange separations of the elements that are extractable with tributyl phosphate. VII

Summary A method is described for the separation of uranium in which the latter is extracted from a 6M hydrochloric acid solution by means of pure undiluted TBP and adsorbed from a mixture of 30 volume % TBP, 60 volume % methylglycol and 10 volume % of 12M hydrochloric acid on the strongly basic anionexchanger Dowex 1-X8 (chloride form). Since the TBP-extract is used for the preparation of this mixture, the extraction and the ion-exchange may be combined, whereby not only the selectivity of the separation of the uranium is significantly raised but also there follows such a rar-reaching enrichment of the uranium on the resin that even ppm quantities are readily determined. For this latter purpose, the resin is first treated with a mixture of 90 volume % methylglycol and 10 volume % 12M hydrochloric acid to remove the TBP, and then with 6M hydrochloric acid to remove the co-adsorbed elements; and then the uranium is eluted by means of 1M hydrochloric acid and determined fluorimetrically. For comparison purposes, 16 geologic specimens were analyzed in accord with this procedure and also employing another anion exchange method. The results show that the separation method described here makes possible a quantitative separation of the uranium and leads to good reproducible results.

     

Electron-donor-acceptor complexing reagents in the analysis of pesticides. VI

Summary Pesticides may be detected following thin-layer chromatography by spraying the chromatogram with a reagent which forms a-complex with the pesticide. The effect of various pesticide structures and substituents in choosing a suitable-complexing reagent is discussed, as well as the effect of these factors in influencing the colour of the complex formed. Quantitative analyses may be performedin situ on the thin-layer chromatogram and positive identification of the-complexed compounds may be made by mass spectrometry. The procedure should be applicable for formulation analysis or studies of pesticide decomposition.

---

Zusammenfassung Zum Nachweis von Pestiziden besprüht man deren Dünnschichtchromatogramme (DC) mit einem zur Bildung eines-Komplexes geeigneten Reagens. Die Bedeutung verschiedener Pestizidstrukturen und -Substituenten bei der Wahl eines solchen Reagens wurde erörtert; ebenso der Einfluß der genannten Faktoren auf die Farbe des Komplexes. Quantitative Bestimmungen lassen sich unmittelbar auf dem DC, Nachweise der einzelnen komplexierten Verbindungen mit Hilfe der Massenspektrometrie durchführen. Das Verfahren eignet sich zur Strukturanalyse sowie zur Untersuchung von Pestizidabbauproblemen.

---

---

Issued as NRCC No. 13120.     

The role of elastic scattering analysis in studies of anodic oxidation

Résumé L'analyse par diffusion élastique peut détecter de microquantités à condition qu'elles soient concentrées dans des films minces. En outre, la méthode peut directement fournir des indications sur l'emplacement des éléments. Ces caractéristiques ont été mises à profit pour apporter un instrument utile à l'étude des processus d'oxydation.