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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 57 (1985), S. 2965-2971 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 348 (1994), S. 269-271 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Coulometric Karl Fischer reagents normally contain carbon terachloride in the catholyte and chloroform in the anolyte. Both compounds take part in the reaction. They are reduced at the cathode forming chloride ions which increase the water capacity of the reagent. At the same time the reduction of sulphite to compounds of lower valency is suppressed. The accuracy of the coulometric titration is thereby increased.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 312 (1982), S. 462-464 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Unter Verwendung von Imidazol als Base wurden 6 verschiedene Solvent-Formulierungen hergestellt und erprobt. Wir fanden bei allen Formulierungen eine stöchiometrische Reaktion mit Wasser. Sie sind deshalb als KF-Reagentien geeignet. Die Reagentien ermöglichen eine sehr schnelle Titration und geben stabile Endpunkte. Sie scheinen unbeschränkt lagerfähig zu sein.
    Notes: Summary Six different KF-reagents were prepared using imidazole as base component. All reagents give a stoichiometric reaction with water and can be used for the KF-titration. The reagents show a high speed of reaction and lead to stable endpoints. The shelflife seems to be unlimited.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 310 (1982), S. 423-426 
    ISSN: 1618-2650
    Keywords: Best. von Wasser in Ameisensäure, Essigsäure, Carbonsäuren ; Volumetrie ; Karl Fischer-Reagentien ohne Pyridin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung In den meisten Carbonsäuren verläuft die Wasserbestimmung störungsfrei. Ameisensäure neigt stark zur Veresterung, Essigsäure und einige andere Säuren nur bei größeren Einwaagen. Die Veresterung kann durch die Registrierung des Titrationsverlaufs nachgewiesen werden. Durch die graphische Auswertung der Titrationskurven wird der tatsächliche Wassergehalt ermittelt.
    Notes: Summary In most carboxylic acids water can be determined without any interferences. Esterification is strong with formic acid, while acetic acid and other acids tend to get esterified only at higher concentrations. Automatic registration during the titration process allows to determine esterification. The true water content is obtained by graphic evaluation of the titration curves.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 330 (1988), S. 694-697 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Karl Fischer titration can be applied to many phenols without any interference, though some are oxidized during titration. One-component reagents are to be preferred because they are less sensitive to interferences. Only pyrogallol and aminophenols are oxidized in this case. With two-component reagents dihydroxybenzenes and naphthols are oxidized, too. With coulometric titration interferences are more frequent. The oxidation rate depends on the pH and can be suppressed or minimised by adding salicylic acid to the Karl Fischer reagent.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 305 (1981), S. 416-416 
    ISSN: 1618-2650
    Keywords: Best. von Wasser in Cysteinhydrochlorid ; Volumetrie, Karl Fischer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 306 (1981), S. 394-396 
    ISSN: 1618-2650
    Keywords: Best. von Wasser ; Volumetrie ; Karl-Fischer-Reagentien ohne Pyridin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Pyridinfreie Reagentien reagieren schneller und geben genauere Ergebnisse als ein konventionelles Reagens. Die besten Resultate erhält man mit einem Zweikomponenten-Reagens (SO2 + Diethanolamin). Im Bereich zwischen 10 und 100 mg Wasser liegt die Streubreite des Einzelergebnisses unter 0,5%.
    Notes: Summary Non-pyridinic reagents react more quickly and give more accurrate results than a conventional reagent. The most exact values are obtained when using a two-component reagent (SO2 + diethanolamide). Within the range of 10–100 mg of water, repeated tests showed a deviation of less than 0.5%.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 309 (1981), S. 30-32 
    ISSN: 1618-2650
    Keywords: Best. von Wasser ; Volumetrie ; Karl-Fischer-Reagentien ohne Pyridin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Mit Diethanolamin oder Morpholin können KF-Reagentien hergestellt werden, die genau so stabil sind wie die pyridinhaltigen Reagentien. Für die Wasserbestimmungen sind sie besser geeignet, denn die Titrationen verlaufen rascher.
    Notes: Summary Karl Fischer reagents can be prepared by means of diethanolamine or morpholine instead of pyridine. The new reagents are better suited for water determination because the titration proceeds faster. They are as stable as solutions containing pyridine.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 309 (1981), S. 123-125 
    ISSN: 1618-2650
    Keywords: Best. von Wasser ; Volumetrie ; Karl-Fischer-Reagentien, Eichsubstanzen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung iso-Butanol/Xylol und ähnliche Mischungen sind besser als Eichstandards geeignet als das üblicherweise benutzte Methanol.
    Notes: Summary iso-Butanol/xylene and similar mixtures of solvents are more suitable for the standardisation than methanol which is used generally.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 303 (1980), S. 203-207 
    ISSN: 1618-2650
    Keywords: Best. von Wasser ; Volumetrie ; Karl Fischer-Reagens ohne Pyridin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Karl Fischer-Reagentien, die SO2 und Amin im üblichen Molverhältnis 1∶2 enthalten, können nur mit Pyridin hergestellt werden. Stark basische Amine bewirken eine rasche Zersetzung der Reagenslösung und einen instabilen Endpunkt. Erhöht man den SO2-Anteil soweit, daß das Molverhältnis SO2∶Amin mindestens 1∶1 ist, geben auch stark basische Amine hervorragende KF-Reagentien. Sie zeichnen sich durch stabile Endpunkte und hohe Reaktionsgeschwindigkeit aus. Besonders vorteilhaft ist die Anwendung als Zweikomponentenreagens, da beide Komponenten absolut lagerstabil und titerkonstant sind.
    Notes: Summary Karl Fischer-Reagents containing SO2 and amine in the normally applied molar ratio of 1∶2 can be prepared only by using pyridine. Strong basic amines lead to a rapid decomposition of the reagent solution and to an instable endpoint. By raising the SO2-content to a molar ratio SO2∶amine of 1∶1, even strong basic amines can be applied yielding KF-reagents of superior quality. They are characterized by stable endpoints and a high speed of reaction. Application as a two-solution reagent gives an additional advantage, because the single components are absolutely stable for storage and the titre remains constant.
    Type of Medium: Electronic Resource
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