Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

Abstract EN

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 (R2=0.997).