Karl Fischer KF Method

By this method the weighed dry product is dissolved in methanol and titrated with Karl Fischer solution until the color changes from brown to yellow. The visual observation can be replaced by an ammeter, which shows a steep increase in current when the end-point of the titration is reached (dead-stop titration). The samples can be two to four times smaller than for the gravimetric method. To avoid the visual observa- 

The weight loss of the product is measured by an electrical balance at constant temperature or at a given temperature-time profile. For the balance and handling of the 

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Karl Fischer Titration Moisture content of reference standards is commonly and accurately determined by Karl Fischer (KF) titration. KF titration determines total water content, including both the free water and water of hydration trapped in the crystal structure. Coulometric KF-titration is the most sensitive application of the method and is normally used for the small amounts of water found in reference standards. A volumetric technique is available for samples containing large amounts of water. Interference is a relatively common problem in KF titration and thus, due caution must be exercised in the interpretation of KF results. Reagents have been designed to cope with interfering functional groups.48-50... 

Water (content) NFT 60-154 ISO/DIS 6296 ASTM D 1744 Karl Fischer Method (electrometric, alter addition of KF reagent)... 

Considering the related Mettler DL 40 and DL 40 RC MemoTitrators, the DL 40 can be used for ten different volumetric and potentiometric methods titration to a pre-selected absolute (EPA) or relative (EPR) end-point equilibrium titration (EQU)-recording titration (REC)-incremental titration (INC) Karl Fischer water determination (KF)-controlled dispensing (DOSE) pH and pX measurements (pX/E) multi-level titrations and back-titrations with automatic calculation (CALC) and manual titration (MAN)-automatic calibration of electrodes (CAL). 

Golvanometric Titration Method. As exemplified by the Karl Fischer Method, the KF Reagent is added in excess to the test solution, and the excess back titrated with... 

Prior work (3) has indicated that a combination of 3 analytical techniques—loss of weight on ignition (LOI), Karl Fischer titration (KF), and reaction with LiAlH4—results in quantitative data on the amount of acidic OH groups in the zeolite, even in nonheated wet samples. This method discriminates between acidic and non-acidic OH... 

Accdg to Pierson (Ref 11, pl353). the Karl Fischer Method, as described on ppl290—93, should be used for Dynamites that contain aluminum, or those that are high in AN and low in NG It can also be used for rapid detn of small amts of water in miscellaneous materials. The KF reagent consists of sulfur dioxide-iodine in pyridine-methanol solution. It is available in commerce in strength equivalent to 5—6mg water per 1 ml of reagent. It. can also be ptepd... 

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