What does Karl Fischer measure?
As shown in Formula (1) below, the Karl Fischer method uses Karl Fischer reagent, which reacts quantitatively and selectively with water, to measure moisture content. Karl Fischer reagent consists of iodine, sulfur dioxide, a base and a solvent, such as alcohol.
Why is Karl Fischer used?
Karl Fischer titration is widely used for direct analysis of water content in various industries, as a reliable and robust method. It is used for determination of water in silk, wool, wood, paper, and even in building materials such as zeolite and cement.
What is drift in KF?
Simply put, drift is background moisture that the Karl Fisher titrator is detecting. But before the titrator can go into a “ready” mode it most likely will go through a “pre-titration” mode. During the “pre-titration” mode excess drift (moisture) is detected and removed by the reagent inside the vessel.
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 use of coulometer?
The silver coulometer is a standard instrument used to determine the mass of silver deposited at a platinum cathode by the passage of an electric current through an aqueous silver nitrate solution.
Why is DST used in KF calibration?
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 primarily used for titer determination in volumetry.
Why pyridine is used in Karl Fischer titration?
EMD Chemicals Inc. What is Karl Fischer Titration? 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. He used a primary alcohol (methanol) as the solvent, and a base (pyridine) as the buffering agent.
Why use methanol in Karl Fischer?
Methanol is typically used as the working medium in the titration cell. Two- component reagents have better long-term stability and faster titration times than one- component reagents, but are usually more costly, and have lower solvent capacity.
What is the Karl Fischer method?
What is the Karl Fischer Method? – Principle, Method, Applications, Advantages & Disadvantages What Is Karl Fischer Titration? Karl Fischer titration is a titration method that uses volumetric or coulometric titration to determine the quantity of water present in a given analyte.
What is Karl Fischer titration?
What Is Karl Fischer Titration? Karl Fischer titration is a titration method that uses volumetric or coulometric titration to determine the quantity of water present in a given analyte. This method for quantitative chemical analysis was developed by the German chemist Karl Fischer in the year 1935, Today, specialized titrators
What is the sensitivity of the Karl Fischer instruments?
Sensitivity of these instruments is as low as 0.1 microgram (µg) of water. This method is normally used for moisture content below 1% or for samples where the moisture is less than 200 micrograms. Click on the Coulometric button for more information about Coulometric Karl Fischer Instruments.
What is a coulometric 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.