[nealk7370]

I am currently having difficulty developing or finding a method for moisture analysis of isopropanol with a range of 0%-20% for moisture content. Is there something like this out there? I have found a few methods but none that are in my desired detection range.

[Babcock_Hall]

Which methods have you looked into, and what were their detection ranges?

[nealk7370]

Three methods I have found that I was able to mess around with, Salting out, Karl Fisher titration and adding IPA drop wise to Xylene.

The first method doesn't purify the IPA past the Azeotrope so it's essentially the same as distilation.
The Karl fisher and the Xylene method doesn't display accurate results under 2% moisture.

[wildfyr]

High field NMR done very carefully?

[Babcock_Hall]

(edited)
I have read about a version of the Karl Fischer method that uses a coulometer, but I know almost nothing about it, other than that it works at lower levels of water.  The NMR method seems reasonable, but one would have to correct for differences in T₁ relaxation, which might be one of the thing to which wildfyr alluded.

[Enthalpy]

Wouldn't the density suffice?
https://en.wikipedia.org/wiki/Hydrometer
For booze it works, and isopropanol's density differs much from water.

If deducing a mix ratio from the density, beware the mixture may contract like water and ethanol do, so the volume fractions don't simply add.

[nealk7370]

Unfortunately I do not have access to an NMR machine. In the meantime I have been using density to determine the % but was hoping for a more analytical approach with an instrument or something along those lines. I appreciate all the help so far!

[OrganicDan96]

just an idea but could IR be used? make a series of stock solutions of known concentration of water and make a calibration curve based on the absorbance of the O-H stretch of water. then measure an IR of the unknown and determine concentration using calibration curve.

[Babcock_Hall]

Exactly how are you determining density?

[rolnor]

People making moonshine or brewing wine use a hydrometer
https://en.m.wikipedia.org/wiki/Hydrometer
Maybe thats what you have used?
I should be possible to use a strong base like BuLi and an apropriate indicator to se the breakingpoint where all water is converted to OH- and the pH goes up as EtO- is formed?

[DrCMS]

We use potentiometic Karl Fisher titration and get good results down to ~100ppm water.