Determination of some pharmaceuticals using simple potentiometric sensors of coated-wire type

Summary The preparation of simple potentiometric sensors of the coated-wire type is described and working instructions for their use are given. The sensors prepared from an ordinary aluminium conductor, being simple and cheap, can well serve to monitore the titrations based on ion-pair formation. The application possibilities are discussed and shown as practical examples on analyses of nasal and eye drops containing cationic surfactants or salts of alkaloids.

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Bestimmung einiger Arzneimittel mit Hilfe einfacher potentiometrischer Sensoren

Zusammenfassung Die Herstellung einfacher potentiometrischer Sensoren mit isoliertem Draht und deren Verwendung wurde beschrieben. Aus einfachem Aluminiumdraht sind sie billig und können für Titrationen auf der Grundlage von Ionenpaar-Bildung dienen. Die Möglichkeiten ihrer Anwendung wurden erörtert und praktiziert für die Untersuchung von Nasen- und Augentropfen mit kationischen Schaumbildnern oder von Alkaloidsalzen.

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According to the Poster XII-23 presented at Euroanalysis V, Cracow, August 1984; the comments inserted into the text are a consequence of the discussion.     

Electrolysis at the interface of two immiscible electrolyte solutions: Determination of ionophores

The principles of electrolysis and facilitated ion transfer at the interface of two immiscible electrolyte solutions are outlined. The method of determination of ionophores is exemplified by assay of monensin in cultures ofStreptomyces cinnamonensis.Dedicated to Professor W. Simon on the occasion of his 60th birthday     

Some properties of ionization waves of varietyR in a neon glow discharge

The parameters of ther-ionization waves in a neon discharge were measured at two neutral gas temperatures (298°K and 77°K). The experimental results of the measurements of the artificially excitedr-ionization waves over the region of the homogeneous positive column in discharge tubes with different radius (from 0·5 cm to 1·2 cm) are reported. The results are arranged as simple functions of pressure, electric field and discharge tube radius. The product of the wave-length and the electric field and the ratio of the group and phase velocities are independent of the temperature. The temperature changes of the dependences of the frequency and phase and group velocities are connected with the temperature changes of the atomic ion life-time in neon discharge. The validity of the dependences for wave parameters is confined to the artificially excited waves in a homogeneous positive column.Authors express their gratitude to M. Novák, L. Láska, K. Rohlena and V. Krejí for helpful discussions and valuable remarks on this work.     

1,2,1′,2′-双蒽醌-3,12-二羧酸的还原反应

1,2,1＇,2＇-双蒽醌-3,12-二羧酸(1)是一个π-共轭体系芳环化合物,内环酮基由于受空间效应和共振效应的影响,不能被还原成相应的醇或相应的碳氢基团,却成了不常见的内“双氧桥”化合物(4)。化合物2,3,4的结构已经确定,并对1的还原机理进行了初步讨论。