Chelatometrische Titrationen in Gegenwart von Gallein als Indicator

Ohne Zusammenfassung     

Chelatometrische Schnellbestimmung von Cu und Zn in Al-Legierungen

Ohne Zusammenfassung

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Chelatometric rapid determination Cu and Zn in Al-alloys

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Wir danken dem österreichischen Fond zur Förderung der wissenschaftlichen Forschung in Wien für die namhafte Unterstützung der Forschungsarbeiten durch die bereitgestellten Geldmittel     

Chelatometrische Bestimmung von Calcium und Magnesium in Salz

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Chelatometrische Bestimmung von Plutonium(IY) unter Anwendung von Xylenolorange als Indicator

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Argentometrische titrationen mit redoxindication Bestimmung von halogeniden, cyaniden, rhodaniden und kalium in gegenwart von variaminblau

Variamine-blue can be used with advantage as a redox indicator in the argentometric determination of halide, thiocyanate, cyanide and potassium. At a suitable pH the first drop of silver nitrate in excess can be detected. The procedure may also be used for the determination of silver by means of potassium iodide. Potassium can be determined titrimetrically by argentometric titration of the tetraphenylboron compound in the presence of the indicator.

Résumé

On peut utiliser avec profit le bleu de variamine comme indicateur d'oxydo-réduction dans le dosage argentométrique des halogénures, du thiocyanate, du cyanure et du potassium. Il est possible de déceler, à un pH convenable, la première goutte de nitrate d'argent en excès. Le procédé permet également de déterminer l'argent au moyen de l'iodure de potassium. On peut effectuer le dosage titrimétrique du potassium par le titrage argentométrique du composé tétraphénylbore en présence de l'indicateur.     

Zur bestimmung von natrium- und lithiumbenzoat

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Oszillopolarographischer nachweis und bestimmung von jodat und perjodat

The oscillopolarographic behaviour of periodate and iodate has been investigated in acid, neutral and alkaline electrolytes. The detection and determination of periodate in iodate may be carried out using iodate as electrolyte and the detection and determination of iodate in periodate may be carried out using 5 M sodium hydroxide as electrolyte.     

Coulometrische permanganatometrische bestimmung von oxalat-, ferro- und arsenitionen

Methods based upon the quantitative electrolytic generation of permanganate in aqueous sulfuric acid solutions of manganous sulfate have been developed for the coulometric permanganatometric determination of oxalate, ferrous, and arsenious ions; the end-point being ascertained by means of colour changes of indicators. In this way coulometric permanganatometry has been established and the possibility of its large practical utilisation has been shown.Thus, by the creation of the coulometric permanganatometry, the coulomb, replacing the mass of the standard, has penetrated into still another part of analytical chemistry for measurement and standardization.     

Spektrofluorometrische bestimmung von hydrazinen und deren anwendung zur quantitativen bestimmung von benzylhydrazin in biologischen proben

A spectrofluorometric determination of strong reducing substances such as hydrazine and alkylhydrazines is described. It is based on the reduction of 1,2-naphthoquinone-4-sulfonic acid to the fluorescent 1,2-dihydroxynaphthalene-4-sulfonic acid. The assay of microgram quantities of hydrazines in blood plasma and of benzylhydrazine in animal organs and urine is reported.     

Potentiometrische und polarographische bestimmung der aktivitätskoeffizienten von cadmium- und zinkionen in konzentrierten wässrigen perchloratlösungen bei 25°C

The activity coefficients of Cd²⁺ and Zn²⁺ were estimated from measurements of cells with transport at high concentrations of LiClO₄, NaClO₄ and Mg(ClO₄)₂. They show an exponential growth with added salt concentration and agree satisfactorily with values calculated from the shifts of the half-wave potentials of Zn and Cd at the dropping mercury electrode in the same solutions.     

Emissionsspektrographische bestimmung von germanium und zinn in galliumarsenid

An emission spectrographic determination of germanium and tin in gallium arsenide is described. For a sample of 5 mg the limit of detection is 3·1 ppm germanium and 7·7 ppm tin. The relative standard deviations are 11% for germanium and 16% for tin. The evaporation of the elements during the excitation is discussed.     

Atomabsorptionsspektralphotometrische bestimmung von zink in galliumarsenid und galliumaluminiumarsenid

The determination by atomic-absorption spectroscopy of zinc in gallium arsenide and gallium aluminium arsenide is described. In 5–20 mg of sample, 0·1–3 μg of zinc can be determined. The coefficient of variation is 4·5%. The influence of the matrix is described and discussed.     

Die jodometrische bestimmung von eisen und kupfer

In cases where many titrations have not to be carried out or where the cost of the reagents may be ignored, it is proposed to employ, for a single determination of 2–3 mval Cu (equivalent to 20–30 ml $\text{N}\text{10}$ thiosulphate), 5 g of solid potassium iodide ; the cuprous iodide remains at first in solution as a complex and finally produces a slight white precipitate. The end-point of the titration is clearer than in the usual method. If a neutral concentrated solution of ferric chloride is added to a small amount of the catalyst, potassium cuprous iodide, prepared as above, it is possible to titrate immediately and accurately the equivalent quantity of iodine which is released.By this procedure a considerable economy of time and increased precision of the titration of copper and iron may be realized.     

Chelatometrische und permanganometrische Methoden zur Bestimmung von pharmazeutisch wichtigen Calciumsalzen

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Zur acidimetrischen bestimmung von Sulfid und hydrosulfid nebeneinunder

Zusammenfassung Es wurde die Methode von Podreschetnikoff verbessert, und gezeigt, daß die abgeünderte Methode zur schnellen und genauen Gehaltsbestimmung von technischem Sulfid und Sulfhydrat sehr geeignet ist.     

Schnelle bestimmung von thymin-dimer und pyrimidine auf ionenaustauscherpapier

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Coulometrische argentometrie : Quantitative bestimmung von chlor-, brom- und jodionen

By electrolytic oxidation of various metal anodes, metal ions can be quantitatively introduced into solution. This process can be used for coulometric determination of anions forming insoluble salts with metal ions.Semimicro and micro determinations of chloride, bromide and iodide ions with electrolytically generated silver ions have been performed at constant current and by a simple apparatus. The end-points have been determined with adsorption indicators, i.e. with dichloro(R)fluorescein for chlorides and eosin for bromides and iodides. The lower concentration limit of applicability of this method depends on the sensitivity of the end-point determination method used.The developed method of coulometric argentometry presents a new possibility for coulometric standardization of volumetric solutions, in conformity with our earlier proposals, as well as a further support for the introduction of the coulomb as a primary standard in all analytical chemistry.     

Direktthermometrische bestimmung von thorium und lanthan in gläsern

A rapid method is described for the determination of thorium and lanthanum in non-silicate glasses. It is suitable for routine use in a works laboratory. The samples are dissolved in nitric acid. The thorium content is calculated from the measured heat of precipitation of thorium iodate, and the lanthanum content by difference from the heat of precipitation of both thorium and lanthanum oxalates together. The apparatus is calibrated by using standard solutions of the two metal ions. The standard deviations for the middle of the range (around 250 mg of the oxides) were 3·1 mg for ThO₂ and 1·7 mg for La₂O₃. An analysis takes about 1·5 hr.