Why is Karl Fischer used?

Why is Karl Fischer used?

Karl Fischer titration is a widely used analytical method for quantifying water content in a variety of products. Karl Fischer discovered that this reaction could be modified to be used for the determination of water in a non-aqueous system containing an excess of sulfur dioxide.

What does Karl Fischer test for?

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 the use of KF factor?

It is fitted for determining water in gases, liquids and solids. The coulometric titrator helps in detecting free water, dissolved water, and emulsified water. It is a swift process which demands a minimal amount of sample preparation.

How do you use Karl Fischer?

The titration can be performed volumetrically or coulometrically. In the volumetric method a Karl Fischer solution containing iodine is added until the first trace of excess iodine is present. The amount of iodine converted is determined from the burette volume of the iodine-containing Karl Fischer solution.

What is titration cell?

The titration cell also consists of a smaller compartment with a cathode immersed in the anode solution of the main compartment. The two compartments are separated by an ion-permeable membrane. The Pt anode generates I2 from the KI when current is provided through the electric circuit.

What is loss of drying?

Loss on Drying (LOD) Loss on drying is a widely used test method to determine the moisture content of a sample, although occasionally it may refer to the loss of any volatile matter from the sample. Loss in drying does not usually refer to molecularly bound water or water of crystallisation.

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.]

What is principle of Karl Fischer instrument?

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 Karl Fischer instrument?

A Coulometric Karl Fischer instrument is often referred to as a coulometer. The advantage of the Coulometric Karl Fischer method is the capability to accurately measure small amounts of moisture. Sensitivity of these instruments is as low as 0.1 microgram (µg) of water.

Which electrode is used in Karl Fischer?

Principles of Karl Fischer titration The titration reaches its endpoint when the titrating agent has achieved a volume sufficient to react the total amount of water in the sample. Water and iodine are used up in an equimolar ratio.

What are the applications of the Karl Fischer method?

Karl Fischer Titration Procedure. The Karl Fischer titration experiment can be performed in two different methods. They are: Volumetric determination – This technique is suitable to determine water content down to 1% of water. The sample is dissolved in KF methanol and the iodine is added to KF Reagent.

Why are Karl Fischer reagents used in drug analysis?

Karl Fischer method uses the Karl Fischer Reagents to determine the moisture content of a sample and it is a widely popular method because it allows you to determine the water content of drug in a very fast, accurate and specific way in addition to needing a very small amount of sample for the analysis.

What was the purpose of Karl Fischer’s titration?

Ans. Karl Fischer titration is merely described as a means of measuring the sample water content. A few of the modern instruments, like the Aquamax KF, apply the coulometric principle, whereby the water that exists in the sample is titrated coulometrically to a predefined endpoint, where free iodine exceeds a minute. Q2.

What makes up a combititrant for Karl Fischer?

a) In one-componentvolumetric KF, the titrating reagent (also known as a CombiTitrant, or a Composite) contains all of the chemicals needed for the Karl Fischer Reaction, namely iodine, sulfur dioxide, and the base, dissolved in a suitable alcohol.

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