Abstract-Addition of a macrocyclic ligand, such as a crown ether or cryptate, to the solution of an organic compound containing alkali metal ions prior to field desorption mass spectral analysis, has been shown to result in a reproducible, smooth field desorption process at low anode temperature. Crystalline dibenzo-18-crown-6 ether complexes of NaI and KI give field desorption spectra in which free and complexed ligands are ofcomparable intensity. Cryptate complexes retain the metal ion even more strongly. as illustrated by the fact that the complex of LiCl with C2. 1 .I]-cryptate yields almost exclusively the complexed lithium peak on field desorption. Alkali metal salts with organic anions also desorb more smoothly after complexation, although in the case of simple carboxylates the anion is found only in a cluster peak

of the brómate or the peroxide introduces complications into the extraction procedure. The brómate slowly decomposes producing bromine gas and the silver peroxide produces a precipitate during the extraction process.Tests indicate that a fuming time of 80 min and an oxidation time of 10 min were optimal for the sample sizes used in this study. Samples of equilibrium 103Ru-103mRh were evaporated to dryness, reconstituted with hot sulfuric acid or with hot hydrochloric acid, and then carried through the extraction procedure. Fuming a sample to dryness was very detrimental to the subsequent extraction of 103Ru, but it had no effect on 103mRh yields. Approximately 40% of reconstituted 103Ru was not extracted by the organic phase. It should be mentioned that, even with repeated evaporation to dryness, there were no isotopic losses by volatilization, nor was secular equilibrium disturbed.The extraction is fast and simple. Rhodium-103m yields are good and the 103Ru can be completely recovered and used again. The fact that the 103mRh sulfato complex is highly stable gives reason to believe that 103mRh can be successfully isolated in a pure form suitable for biological usage. It is believed that the procedure is sound, and that, with some additional work, the extraction of 103mRh from 103Ru can be made quantitative. Furthermore, the extraction system used in this study might be applicable to the large scale recovery of rhodium. LITERATURE CITED(1) T. Lengyel, "Preparation and Control of Rhodium-103m Radiopharmaceuticals", IAEA, STI/PUB/294, 137, 1971.

No abstract

Die Umsetzung von Propylen (I) und Essigsäure (II) in Gegenwart von Luftsauerstoff an einem Palladiumkatalysator zu Allylacetat (III) wird in einer Technikumsanlage untersucht.

Die gemeinsame Oxidation von p‐Xylol (I) und o‐Toluylsäuremethylester (II) zu Phthalsäureanhydiid (III) und Toluylsäure (IV) sowie die anschließende Veresterung der Toluylsäure (IV) zum Methylester (II) werden untersucht.Durch eine mathematische Auswertung der Versuchsergebnisse werden die optimalen Bedingungen für den Ablauf der beiden Reaktionsschritte bestimmt, unter denen sich Phthalsäureanhydrid in 90%iger Ausbeute und mit 99,8%iger Reinheit herstellen läßt. Zur Abtrennung des Phthalsäureanhydrids in der ersten Stufe wird das Reaktionsgemisch mit Wasser hydrolysiert und die dabei gebildete Phthalsäure aus dem Reaktionsgemisch abgetrennt.