Switch to Aquastar® for Karl Fischer Reagents Containing Pyridine

Substitution of Pyridine Containing Karl Fischer Reagents 

Our pyridine containing Karl Fischer Reagents were discontinued in mid 2016 and have been replaced by the adequate imidazole containing reagents.

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Why The Change?

Pyridine containing reagents are no longer “state of the art” for Karl Fischer Titration. For more than 35 years pyridine can be substituted by imidazole. Karl Fischer reagents with imidazole offer several benefits compared to pyridine containing reagents while showing a comparable, or even better performance in terms of accuracy and precision.

The purpose of substances like pyridine and imidazole is to buffer the Karl Fischer solvent in a pH range between pH 5 to 8, which is the optimum condition for the Karl Fischer reaction. Except for the replacement of pyridine by imidazole imidazole-containing reagents do not differ from pyridine-containing reagents, all other components in the reagents stay the same. Since 2005 the Pharmacopoeias changed their requirements and describe the use of non-pyridine containing reagents.

Our Support for The Substitution

We will support your change from our pyridine containing Karl Fischer reagents to our imidazole containing reagents.

For testing and validation purposes we can offer you a free of charge sample kit of the new imidazole-containing reagents. Please ask your local organisation or your account manager or contact us via E-Mail (use the local E-Mail address of your Merck subsidiary or dealer).

If you need any further support for your special application or a comparison of pyridine Karl Fischer Reagents tested against the imidazole Karl Fischer Reagents please send an E-Mail with your name, company name and address to aquastar@merckgroup.com.

Overview Pyridine Reagent Versus Corresponding Imidazole Reagent