title: Simple modification of karl-Fischer titration method for determination of water content in colored samples.
abstract: The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD = 4.3%), accuracy, and linearity (R(2) = 0.997).
authors.affiliation: Faculty of Pharmacy, University of Ljubljana, Aškerčeva cesta 7, 1000 Ljubljana, Slovenia.
authors.forename: Eva
authors.initials: E
authors.lastname: Tavčar
authors.forename: Erika
authors.initials: E
authors.lastname: Turk
authors.forename: Samo
authors.initials: S
authors.lastname: Kreft