Development of Karl Fischer Reagents

I-1. Questions & Answers about Karl Fischer Reagents
c) Store Karl Fischer reagents at or below room temperature and in a
location that is not exposed to the light. Seal bottles to prevent the
absorption of moisture.
(2) Volumetric Reagents
a) Refer to the relevant sections for information about points that require
particular care during volumetric titration, such as changes over time in
the titer of Karl Fischer Reagent SS-Z (or SS), the titer of standard watermethanol
and the evaluation procedures.
b) Avoid the following combination when using volumetric reagents;
� Karl Fischer Reagent SS and Dehydrating Solvent KTX
� Karl Fischer Reagent SS-Z and Dehydrating Solvent CP
(3) Coulometric Titration
a) The analytical capability of Aquamicron AX and AS anolytes is
approximately 800-1,000mgH2O per 100ml of anolyte. However, if a
sample is added in stages so that the total amount exceeds 150ml, the
sample will have an effect that causes a gradual decline in current
efficiency. This may lead to inaccurate results. In such cases, discard all
the reagent and begin again with fresh reagent.
b) The analytical capability of Aquamicron CXU catholyte is approximately
130-150mgH2O per 5ml of catholyte. With prolonged use, however, the
reagent will gradually turn light brown and then dark brown. If the color
begins to change, the reagent should be completely removed, with a
pipette, etc., and replaced with fresh reagent. Do not add fresh reagent to
discolored reagent.
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