Karl Fischer titration (KFT) is a chemical method used to measure the amount of water in a sample:

 Karl Fischer titration (KFT) is a chemical method used to measure the amount of water in a sample: 

Principle

The reaction of iodine and sulfur dioxide in an aqueous medium, known as the Bunsen Reaction, is modified to determine water in a non-aqueous system. 

Reaction

The reaction converts the reagent into an alkyl sulfite, which is then oxidized by iodine if water is present. This oxidation reaction consumes water. 

Methods

KFT can be performed using either volumetric or coulometric titration. The coulometric method is preferred for low water content and liquid samples, while the volumetric method is used for solid and liquid samples with higher water content. 

Equipment

KFT equipment includes a drying tube, sample injection cap, electrode analysis, drain cook, cathode chamber, detection electrode, rotor, anode chamber, and KF reagent. The KF reagent contains iodine, buffer (imidazole), sulfur dioxide, and solvent (methanol). 

Applications

KFT is used in many industries, including food, beverage, cosmetics, chemicals, and pharmaceuticals. It's the reference method for water determination because of its accuracy, speed, and specificity. 

Titration speed

The titration speed varies for each unit, and the faster the unit titrates, the less accurate it will be.