What is the Karl Fischer test?

What is the Karl Fischer test?

What is the Karl Fischer test?

Karl Fischer (KF) Titration is a technique for the determination of moisture content. It is a process based on the reaction of iodine with water. The KF method is one of the few techniques that will measure water content and not be affected by other volatiles.

What type of titration is used in Karl Fischer?

Karl Fischer titration is a classic titration method in chemical analysis that uses coulometric or volumetric titration to determine trace amounts of water in a sample. It was invented in 1935 by the German chemist Karl Fischer. Today, the titration is done with an automated Karl Fischer titrator.

What is the principle of Karl Fischer titration?

The principle of Karl Fischer titration is completely based on the oxidation reaction between sulphur dioxide and iodine. Water reacts with sulphur dioxide and iodine to form hydrogen iodide and sulphur trioxide. When all the water is consumed, it reaches an endpoint.

What is a Karl Fischer titration used to quantify?

Karl Fischer titration is a widely used analytical method for quantifying water content in a variety of products. The fundamental principle behind it is based on the Bunsen Reaction between iodine and sulfur dioxide in an aqueous medium.

What is included in Karl Fischer reagent?

Karl Fischer reagent consists of iodine, sulfur dioxide, a base and a solvent, such as alcohol. As described below, this method can be used in both volumetric and coulometric titration systems.

What is the formula for KF standardization?

How do you calculate Karl Fischer factor? The water equivalence factor F is determined according to the formula 0.1566 x w / v in mgs of H2O per ml of reagent, where W is the sodium tartrate weight in mgs, and V is the reagent volume in ml.

Why imidazole is used in KF titration?

The use of imidazole instead of pyridine is greatly improving the speed of the KF reaction. When using these modern reagents, the speed, time and accuracy of the Karl Fischer reaction is influenced by the medium used in the titration vessel.

Does Karl Fischer measure bound water?

Karl Fischer titrations are effective at quantifying even the tightly “bound”, and are often considered a better moisture analysis method than loss on drying. In fact, this extra water that is measured using Karl Fischer is often referred to as the “bound” water.

How do you calculate Karl Fischer factor?

The water equivalence factor F, in mgs of H2O per ml of reagent, is calculated according to the formula 0.1566 x w/v, where W is the weight in mgs of sodium tartrate and V is the volume in ml of the reagent.

What is pyridine free KF reagent?

An essentially pyridine-free Karl Fischer reagent useful in the determination of water, comprises a dissolving agent containing sulfur dioxide and a pyridine substitute in a Karl Fischer solvent, and a titrating agent containing iodine in a Karl Fischer solvent, wherein the pyridine substitute is an alkali or alkaline …