Wasserbestimmung in Phenolen durch Karl-Fischer-Titration

Scholz, Eugen

doi:10.1007/bf00467691

Cited by 6 publications

(4 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One-component KF reagents oxidize phenols such as pyrogallol and aminophenols, while two-component KF reagents oxidize dihydroxybenzenes and naphthols. [41] Alkoxides and sugars are hygroscopic, [42,43] and if stored incorrectly, the water content may surpass 1% by weight. Hence, volumetric titration is preferred.…”

Section: Alcohols and Ethersmentioning

confidence: 99%

Experimental methods in chemical engineering: Karl Fischer titration

Rivera‐Quintero,

Patience,

Patience

et al. 2024

Can J Chem Eng

View full text Add to dashboard Cite

Karl Fischer titration (KF) measures the water content in organic and inorganic compounds. Water reacts with a titrant solution containing iodine and a sulphurous monoalkyl ester to produce a monoalkyl sulphate ester and HI. In volumetric titrators, a burette injects the titrant directly into a cell while coulometric titrators generate titrant in situ. Regardless of the volume of the sample, volumetric titration is limited to 100 mg, while coulometric titration is best suited for . KF is fast (), considered accurate (), and precise (). However, factors such as humidity, non‐standard analytes (hexane, isopropanol, ethylene glycol), tritrant composition, and temperature compromise its repeatability: the % sample standard deviation, (), varied from 2% to 60% (). This high variability is, in part, due to the experimental design that included samples and conditions ill‐suited for the technique. However, even for the tests for which KF is suitable, . Certain compounds react with the titrant, which increases the variability. The main sources of error affecting the analysis are ambient moisture, pH, solvent, sample handling, and titration speed. As of 2023, the Web of Science has indexed 1332 articles with Karl Fischer as a key word (Topic), but more than 3600 mentioning the technique (All fields). A bibliometric analysis classifies these contributions into five clusters: spectroscopy, stability, temperature, solubility, and mixtures.

show abstract

Section: Alcohols and Ethersmentioning

confidence: 99%

Experimental methods in chemical engineering: Karl Fischer titration

Rivera‐Quintero,

Patience,

Patience

et al. 2024

Can J Chem Eng

View full text Add to dashboard Cite

show abstract

“…Such results may indicate that there is a side reaction that increases in magnitude with each increase in analyte concentration. In at least one case (18), after analysis of several samples, the recovery of water from a sample was found to be greater than 100%, indicating a lack of efficiency in the iodine generation step of the coulometric system. Solution of this problem can be verified by a calibration check after several samples are run.…”

Section: Em Sciencementioning

confidence: 99%

Moisture determination using Karl Fischer titrations

Macleod¹

1991

Anal. Chem.

View full text Add to dashboard Cite

An accurate and precise moisture determination is often essential in resolving issues where water is involved.Water has been identified as a contaminant limiting the reactivity of products (e.g., monomers, various resins and coating materials, prepregs), a reactant limiting the lifetime of a material (e.g., halocarbons, acetylsalicylic acid), a medium for reaction between components in a mixture (e.g., pharmaceutical formulations), and as a factor limiting the accuracy of other measurements (e.g., mass balance).Although a number of chromatographic, spectroscopic, electronic, thermal, and wet chemical methods have been used to determine moisture, the Karl Fischer titration, originally described in 1935 (1), is the approach most widely used.This REPORT includes discussions of the reaction chemistry, side reactions, reagent composition, and experimental mechanics as well as the issues involved in assay development for the Karl Fischer titration.

show abstract

“…Reduction of iodine by oxidizable species (e.g., ammonia, thiols, Tl+, Sn2+, In+, thiosulfite, ascorbic acid, and hydroxylamines) results in the consumption of iodine, which may be erroneously interpreted as high moisture content in the sample. Phenolic derivatives, including hydroxy and aminophenols and naphthols, are also oxidized (18) with corresponding reduction of iodine. may be possible after oxidation of the offending functionalities (3,16).…”

Section: Reportmentioning

confidence: 99%

“…may be possible after oxidation of the offending functionalities (3,16). In the case of the phenols, a solvent system with a reduced apparent pH may decrease the magnitude of the problem (18).…”

Section: Reportmentioning

confidence: 99%

Moisture Determination Using Karl Fischer Τitrations

MacLeod¹

1991

Anal. Chem.

View full text Add to dashboard Cite

An accurate and precise moisture de-termination is often essential in resolving issues where water is involved.Water has been identified as a contaminant limiting the reactivity of products (e.g., monomers, various resins and coating materials, prepregs), a reactant limiting the lifetime of a material (e.g., halocarbons, acetylsalicylic acid), a medium for reaction between components in a mixture (e.g., pharmaceutical formulations), and as a factor limiting the accuracy of other measurements (e.g., mass balance).Although a number of chromatographic, spectroscopic, electronic, thermal, and wet chemical methods have been used to determine moisture, the Karl Fischer titration, originally described in 1935 (J), is the approach most widely used.This REPORT includes discussions of the reaction chemistry, side reactions, reagent composition, and experimental mechanics as well as the issues involved in assay development for the Karl Fischer titration.

show abstract

Wasserbestimmung in Phenolen durch Karl-Fischer-Titration

Cited by 6 publications

References 6 publications

Experimental methods in chemical engineering: Karl Fischer titration

Experimental methods in chemical engineering: Karl Fischer titration

Moisture determination using Karl Fischer titrations

Moisture Determination Using Karl Fischer Τitrations

Contact Info

Product

Resources

About