Meaning
Analytical chemistry techniques for moisture determination rely on the electrochemical generation of iodine to react with water in a sample. Performing a coulometric karl fisher titration allows for the measurement of extremely low water concentrations, often down to one part per million. The method is used for oils, solvents and plastic resins that require precise dryness for processing.
It calculates moisture content based on the total electrical charge consumed during the reaction.
Iodine Generation
Electrolysis within the titration cell produces the reagent required to neutralize water molecules. In a coulometric karl fisher titration, the amount of iodine generated is proportional to the current passed through the electrodes. This eliminates the need for manual reagent calibration before each test.
Sensitivity Limit
Accuracy at trace levels makes this technique superior to volumetric methods for very dry materials. Because the coulometric karl fisher titration is highly sensitive, it requires a controlled laboratory environment to prevent ambient humidity from contaminating the results. Small sample sizes are sufficient for a defensible measurement.
Sample Recovery
Liquid samples are injected directly into the cell while solids may require a drying oven to release moisture as a gas. The speed of a coulometric karl fisher titration depends on the solubility of the material and the efficiency of the water release. Effective moisture management in production relies on these precise laboratory benchmarks.
