Laboratory Products

Speed up your Karl Fischer titration with HYDRANAL-Methanol Rapid

Nov 01 2017 Comments 0

Karl Fischer (KF) titration is a fast and accurate method for the determination of water content in all types of substances, including pharmaceuticals, chemicals, oils, and food. In 1979, researcher Dr. Eugen Scholz improved Karl Fischer titration by replacing noxious pyridine with imidazole. This innovation became the foundation of Hydranal™, the world’s leading pyridine-free reagents for Karl Fischer titration. The use of imidazole instead of pyridine is greatly improving the speed of the KF reaction.

When using these modern reagents, the speed, time and accuracy of the Karl Fischer reaction is influenced by the medium used in the titration vessel. For volumetric KF titration the most often used reagent combination is a one-component reagent titer 5 with dry methanol. One-component reagents contain all the substrates for KF reaction dissolved in a suitable alcohol. In Hydranal-Composite, one-component reagent, all the reactants including iodine, sulfur dioxide, and the bases imidazole and 2-methylimidazole, are dissolved in diethylene glycol monoethyl ether (DEGEE). Adding 2-methylimidazole in addition to imidazole improves the stability and eliminates the formation of crystals which can interfere with the titrator’s performance. DEGEE used as a solvent additionally stabilizes the reagent. The speed of KF reaction depends on the pH value. The time needed to reach the end-point of the titration will depend on the buffering system used in the reagent. The Hydranal-Composite reagents are already buffered to an optimum pH by using imidazoles. Thus the performance of the titrating agent is optimized to ensure a rapid Karl Fischer reaction, however, there is still room for improvement on the use of the solvent.

Dry methanol is the most commonly used medium in the titration vessel, however it is an unbuffered solvent. Hydranal-Methanol Rapid contains accelerators for the KF reaction and reduces titration times significantly. The volume of Hydranal-Composite dosed into the titration vessel during conditioning depends on the water content of the methanol. Even if a titration vessel is in a good condition, the pre-titration of the methanol usually takes between 1 to 2 minutes. The following titration of an average amount of water in the samples takes 3 to 4 minutes. When using Hydranal Methanol Rapid, you will see a clear improvement in speed and accuracy of the titration. This is due to the accelerators in the medium, which are unique to Hydranal-Methanol Rapid and enable an optimal Karl Fischer titration.

To buy now please click here or to discover more about Hydranal visit us here.

Read comments0

Do you like or dislike what you have read? Why not post a comment to tell others / the manufacturer and our Editor what you think. To leave comments please complete the form below. Providing the content is approved, your comment will be on screen in less than 24 hours. Leaving comments on product information and articles can assist with future editorial and article content. Post questions, thoughts or simply whether you like the content.

Digital Edition

Labmate UK & Ireland October / November 2017

November 2017

In this Issue Articles - How to Achieve Ultimate PCR Optimisation Spotlight Features - Incubators, Freezers & Cooling Equipment - Balances & Strain Gauges - Proteomics, Genomics & Mic...

View all digital editions



Jan 21 2018 Palm Springs, CA, USA


Jan 24 2018 Cardiff, UK

Arab Health

Jan 29 2018 Dubai International Convention & Exhibition Centre

SLAS 2018

Feb 03 2018 San Diego, CA USA


Feb 05 2018 Dubai, UAE

View all events