| 摘要 |
A method for the colorimetric determination of water content of an unknown sample, using the Karl Fischer reaction. The Karl Fischer reagent in a container has added to it a dye whose optical absorption preferably does not overlap with the optical absorption of the Karl Fischer reagent. Measurement of the optical absorption of the reagent/dye mixture is then made at two wavelengths, one wavelength being strongly absorbed by iodine in the reagent while the other wavelength is strongly absorbed by the dye. After the unknown sample is added, optical absorption measurements are again made at the two wavelengths. The measurements made at the wavelength where the dye strongly absorbs are used to correct the optical absorption measurements made at the wavelength where iodine strongly absorbs. This corrects for all factors affecting optical density other than the amount of water in the unknown sample.
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