Development of Karl Fischer Reagents

I-1. Questions & Answers about Karl Fischer Reagents
Chemical are mixtures of dehydrated formamide and dehydrated methanol,
to which a reaction accelerant has been added. Substances that dissolve
well in the main ingredient, formamide, include casein, glucose, starch and
lignin. These solvents are therefore ideal for use in the extraction of moisture
from sugars and foodstuffs.
[Characteristics]
a) Sugars and protein dissolve well in these products.
b) The reaction between water and the Karl Fischer reagent occurs rapidly.
c) The end-point can be readily determined and measured over a short
period of time.
[Applications]
Sugars (sugar, drops, caramel, butter sweets, black sugar sweets, malt
syrup, syrup), gelatin (medical capsules, etc.), nucleic acid food additives,
pharmaceutical products, dried vegetables, cereals, animal feeds, wool, etc.
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Reference: Muroi, K., Tsutsui, C., Koizumi, H., Nihon Shokuhin Kogyo
Gakkaishi 16, 39 (1969).
Dehydrated Solvent ME
The moisture content of gases can be measured indirectly using the
physical or physical-chemical characteristics of water (see Q1), or by means
of the Karl Fischer method, which involves a direct reaction with the water.
The Karl Fischer method is the more reliable, since the water is captured
directly. It is widely used as the standard method and has been included in
the JIS system and other systems.
Dehydrated Solvent was created as a moisture capturing solvent for use with
gases. It is a mixture of dehydrated methanol and dehydrated ethylene
glycol, to which a reaction accelerant has been added. Moisture content can
be measured easily and accurately by passing a certain amount of gas
through about 100ml of Dehydrated Solvent ME, followed by immediate
titration using a Karl Fischer reagent.
Similar measurements can be obtained with a solvent prepared simply by
mixing Dehydrated Solvent GEX or MS with propylene glycol in the ratio of
3:1 (by volume).