Development of Karl Fischer Reagents

Chapter III: Applications - 2
(2) Moisture vaporization - Volumetric titration
Reagents used: Karl Fischer Reagent SS-Z (or SS)
Dehydrated Solvent GEX (or MS) + PG (3:1) 50-100ml
Substance
Emulsion inks
Water-based ball-pen inks
14. Adhesives
Key Points
Heating Temperature
( � C)
200
200
Sample Quantity
(g)
0.0626
0.0338
Measurement Value
(mg)
34.78
18.68
Moisture Content
(%)
55.7
55.3
The moisture content of adhesives ranges from minute to high, so both
volumetric and coulometric titration are used. For volumetric titration,
the sample is dissolved or dispersed in a suitable solvent. Moisture
vaporization is used for substances that are totally insoluble.
Coulometric titration can be carried out directly in the case of
substances that dissolve in electrolytes. Moisture vaporization is used
for samples that are even slightly insoluble.
Adhesives are very viscous and instant adhesives solidify quickly when
exposed to air. Because of these and other characteristics, a number of
samples are very difficult to handle and sampling equipment must be
selected with reference to the attributes of each sample. If the viscosity
of the product allows it to be sampled in a syringe, use a thick needle
(2mm diameter). For substances with higher viscosity, use a sampling
spoon or glass rod. Special procedures are needed for instant
adhesives.
Refer to the following document.
Reference: Muroi, K. et al., "Determination of Minute Traces of Water in
Cyanoacrylate Adhesive Compositions by the Coulmetric Karl
Fischer Titration Method Using the Anodic Electrolytic for
Ketones" in Journal of the Japan Adhesive Society 21, 186
(1985).
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