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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Jamun on February 14, 2020, 02:17:13 PM

Title: Measuring water content in a lube oil
Post by: Jamun on February 14, 2020, 02:17:13 PM
Hello everyone,,
I did read in a book that they used Karl fischer method(http://en.wikipedia.org/wiki/Karl_Fischer_titration) to measure the water content in lube oils. We want to know how much of the water remains in the lube oil after a run in the oil purifier. We expect the content to be from 0,1-0.3%. We use RH% sensors on the outlet on the oil purifier that says there is 0%(no decimals). We dont belive that the water content is actually 0%.

Can we use the Karl Fischer method to measure the water content? The wiki site states that "The major disadvantage is that the water has to be accessible and easily brought into methanol solution. Many common substances, especially foods such as chocolate, release water slowly and with difficulty, and require additional efforts to reliably bring the total water content into contact with the Karl Fischer reagents."
Title: Re: Measuring water content in a lube oil
Post by: jeffmoonchop on February 14, 2020, 02:58:46 PM
To ensure water extraction, you could use a KF oven to inject water vapour. Oil vapour may be injected too so I'd check to see whether the ingredients would interact with the KF reagents and cause error. But you may not get good enough extraction by the classic method of injecting oil into the vessel.