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IDRANAL® - Reagents for complexometric titrations
Sigma-Aldrich offers a few of the aminopolycarboxylic acids marked by the registered trade mark
IDRANAL®. For use in complexometric titration.
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IDRANAL® I |
IDRANAL® II |
IDRANAL® III |
IDRANAL® IV |
IDRANAL® V |
IDRANAL® VI |
IDRANAL® VII |
| Abr. |
NTA |
EDTA |
EDTA-Na2 |
DCTA |
DTPA |
EGTA |
HEDTA-Na3 |
| Art. |
34539 |
31064 |
34549 |
34588 |
34589 |
34596 |
34461 |
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View complete product list for complexometric titration
Indicator buffer tablet
Visual indicators are used in complexometric titrations. Eriochrome Black T is the indicator
most widely used but whose aqueous solution is not stable. Therefore IDRANAL Indicator buffer
tablets are used. These tablets contain Eriochrome Black T as the metal indicator and a buffer substance.
They are suitable to titrating Ca, Mg, Zn, Pb and for the determination of water hardness.
Application
A 100 ml water sample is boiled after adding 2 drops of concentrated hydrochloride acid -
e.g. Art. 30721- cooled to 40 °C, and mixed with an IDRANAL Indicator buffer tablet and 1 ml of 25% ammonia solution- e.g. Art. 30501. Titration is carried out with IDRANAL solution.
A high carbonate content in the water can slow down the colour change. It can be overcome by boiling
the weakly acidified water.To avoid this slow down colour change totally the water containing little or no magnesium should be titrated with IDRANAL II-Zinc, or with IDRANAL A, B or C which already contains IDRANAL II-Zinc.
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