Topics: Coulometric Karl Fischer, Moisture Analysis, Moisture Testing, Karl Fischer Oven, Karl Fischer, Karl Fischer Titration, Loss-On-Drying, Moisture, interfacial tension, moisture content, moisture measurement
As usual when we pose a question, like:
Should you use Coulometric or Volumetric Karl Fischer to measure moisture in your product?
We often get a the reaction, “So Who Cares?” We'll try to answer both questions.
Last week, as I was reflecting on a recent moisture content problem, I recalled our series “Loss-on Drying and Other Moisture Mysteries.” In that series I examined moisture chemistry in products. However, I did little to define moisture content.
When we first started measuring moisture with Karl Fischer, I was instructed in the complex chemical reactions involved. I was also was told that the process was skittish.Read More
At one end of the spectrum of the moisture world is the classic Speedy Moisture Tester where you use the reaction of water with calcium carbide to cause a mini explosion resulting in a moisture measurement reading. This method is used frequently for soils, concrete, and other like materials.
Karl Fischer Titration and Loss-on Drying (LOD) are both methods for determining moisture content in a product.
That’s where the similarities end, though. In this article, I will explain the difference between Karl Fischer Titration and Loss-on Drying, and offer some suggestions to help you choose the right method for your application.
A question we get a lot is:
“How do I determine the moisture in my product?"
Of course, the answer is often “it depends”, and the method does depend on the chemical and physical composition of the product. There are several methods used to determine moisture content: Loss-on-Drying (also known as Weight Loss), Karl Fischer, NIR, and Radio Frequency.
As you know the Karl Fischer Method of moisture analysis has a reputation of being water specific. The method works through the use of a special Karl Fischer Reagent.
“Why are my Moisture Test results inconsistent?”
That is an issue for many of you who test for moisture. We discussed the complexities and multiplicity of issues involved with moisture content determination in our “Loss-on Drying Moisture Analysis and other Moisture Mysteries” series.
In addition to intrinsic properties of test samples that may adversely affect moisture testing systems, automatic equipment parameter set-up, operator oversights and sample handling contribute to seemingly intractable moisture test result inaccuracies.
When People are first introduced to the Karl Fischer Moisture Determination Method, eyes glaze over and we can perceive a mental “Why did I ask?”
If you have any history with moisture analysis, you will have found, that for some applications, the Karl Fischer Titration Method is the best and sometimes the only way to get an accurate moisture measurement.