What is the principle of KF titration?

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 KF in pharma?

Karl Fischer reagent method of water content determination is widely used in pharmaceuticals and other manufacturing industries. This is most reliable and accurate method for moisture determination. The method to use is the Karl Fischer (KF) moisture analysis.

What is KF 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 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 …

What is the limit of KF factor?

The relative Standard deviation between two average KF factors of water and DST determined consecutively should not be more than 3.0 % [Average of two factors (2 with water and 2 with DST) to be considered for calculation.]

Why imidazole is used in KF titration?

The use of imidazole instead of pyridine is greatly improving the speed of the KF reaction. For volumetric KF titration the most often used reagent combination is a one-component reagent titer 5 with dry methanol. One-component reagents contain all the substrates for KF reaction dissolved in a suitable alcohol.

What is kf factor limit?

Standardization is valid, if concentration should be not less than 5 mg and not more than 7mg. The relative Standard deviation between two average KF factors of water and DST determined consecutively should not be more than 3.0 % [Average of two factors (2 with water and 2 with DST) to be considered for calculation.]

Which is a disadvantage of using the KF method?

KF is suitable to measure the liquids, and also with special equipment, gases. The major disadvantage with solids is: water has to be accessible and brought easily into the methanol solution.

Is the KF titration method an accurate method?

KF titration is an accurate method for water determination at levels from a few ppm to near saturation. As technique optimization for different sample types may pose challenges, we present extensive background information and recommendations on:

What are the reactions of the KF reagent?

When you titrate the KF reagents in a titration cell, the following reactions take place: The first reaction is that between iodine and sulphur dioxide in the presence of a neutralizing base to form an alkyl sulphite intermediate. The common base used in Karl Fischer titration is pyridine, primary amines such as imidazole can also be used.

What does the frit do in a coulometric KF?

a) In conventional, or fritted-cell, coulometric KF, a diaphragm – or frit – separates the anode from the cathode that form the electrolytic cell known as the generator electrode. The purpose of the frit is to prevent the iodine generated at the anode from being reduced back to iodide at the cathode instead of reacting with water.