Karl Fisher moisture titration

Moisture has been determined by Karl Fisher moisture titration at 300°C (model Metrohm 756 KF Coulometer with 707 KF oven, available from Brinkmann Instruments, Inc. of Westbury, NY, USA). 

Small amounts of moisture (up to about 0.5%) in crystalline sugars can be determined chemically by titration with Kad Fisher reagent. A volumetric Karl Fisher titration procedure for moisture in molasses is accepted by AO AC. Automatic Karl Fisher titrators are available, and as acceptance of pyridine-free reagents increases, their use may increase. 

The effects of moisture content in drug substances iancthed dosage form have been widely studied. Static moisture content can be determined by many methods like Karl Fisher titration, loss on drying (LOD), and TGA. Dynamic hygroscopicity of a drug substance has beerLcWaato four... 

The analytical method for moisture determination must be validated before use during process validation studies. There are numerous techniques for moisture analysis that range from physical methods, such as loss on drying, to chemical methods, such as Karl Fisher titration. A comparative review of the conventional techniques are presented in an overview [32], The measurement of residual moisture is lyophilized pharmaceuticals by near-infrared (NIR) spectroscopy has recently been expanded [33]. 

In its simplest form, the Karl Fisher titration is a one-point determination of moisture content. The principal advantage is specificity for water. It is also a non-thermal method, which is very sensitive and can be easily automated. The main disadvantage is that the solid must dissolve in the titration medium to be sure that the total amount of moisture is released. If the analysis is carefully designed in such a way that moisture is extracted from the solid to the same degree each time, accurate and reproducible results can be obtained for solids that do not dissolve. 

Fig. 15 Normalized Karl Fisher titration for dicalcium phosphate (A) milled sample (B) anhydrous sample with adsorbed moisture.

The influence of sorbed moisture on chemical stability and the flow and compaction of powders and granulations is well established. The moisture content and hygroscopicity of excipients is particularly important as total product processing as well as finished product stability can be affected. Hygroscopicity, moisture-sorption isotherms, and equilibrium moisture content can be determined by thermogravimetric analysis and Karl Fisher titration methods. 

The characterization of the total mass thus obtained, performed on representative samples taken during the vial filling procedure, gave additional information on the properties of the material. The average moisture content, measured by Karl-Fisher titration, was lower than 3%. The particle size distribution of the whole mass, measured using the Sympatec analyzer with Helos measuring device, was to peak at 80-90 pm with an upper limit of 435 pm. 

Analysis. Free fatty acids were ethylated in ethanol dehydrated with molecular sieves using gaseous HCl as the catalyst. Ethyl esters of fatty acids were analyzed on a DB-23 capillary column (0.25 mm x 30 m J W Scientific, Folsom, CA) connected to a Hewlett-Packard 5890 gas chromatograph (Avondale, PA) as described previously (19). The water content in the oil layer was determined by Karl Fisher titration (moisture meter CA-07 Mitsubishi Chemical, Tokyo, Japan). The contents (by weight) of free fatty acids and fatty acid ethyl esters were analyzed by a thin-layer chromatography/flame ionization detector... 

Resin Moisture content Karl Fisher Titration ARpf 1610... 

Pig. 10.6 AS 1160 resin moisture content by Karl Fisher titration. All aged samples show an... 

Karl Fisher titration is a complex but accurate method for moisture determination. The test involves heating a small sample in a pyrolysis oven, transfer of the resulting... 

Moisture Panametrics moisture instrument adaption of Karl Fisher titration... 

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