Why Water and Sodium Titrate is only use for the Calibration of Karl Fischer Titrator ?
- Sodium tartrate dihydrate is the volumetric standard for Karl Fischer titration. Under normal conditions, it is stable and non-hygroscopic.
- Sodium tartrate dihydrate has a stoichiometric water content of 15.66% and is mainly used for titer determination in volumetric.
Karl Fisher Titration
- Karl Fisher Titration is a method for the determination of moisture content. The technique was established by a chemist named Karl Fischer. It is based on a mixture which reacts with water and converts the water into a non-conductive chemical. Karl Fisher provides for the specific detection of water. There are two methods used to perform the Karl Fischer titration test.
- Volumetric Karl Fischer
- Coulometric Karl Fischer
Volumetric Karl Fischer
- In this method, the moisture determination is based on the amount, or volume, of reagent used to convert the water.
- Samples are dissolved in a solvent before the titration begins.
- A reagent is added until the water is removed.
Coulometric Karl Fischer
- In this method, the reagent and solvent are combined in the titration cell.
- When a sample is introduced into the titration cell and dissolved, reagent is released by the induction of an electrical current.
- The amount of current required to convert the water is the determinant of the amount of moisture.
- A Coulometric Karl Fischer instrument is often referred to as a coulometer.