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 (), accuracy, and linearity ().
Tavar, E., Turk, E., & Kreft, S. (2012). Simple modification of karl-fischer titration method for determination of water content in colored samples. Journal of Analytical Methods in Chemistry, 1(1). https://doi.org/10.1155/2012/379724