Im an idiot you need hydrometer or refractometer not a spectrometer
Well spectroscopy would work, so there is that. I am sure a cheap IR spectroscopy machine from China could get it done.
Why no one suggest a burn test? Curious
anything below 70% will burn yellow while higher than that is deep colorless blue?
It’s rough test but from what I know in alcohol stoves it always needed high percentage to burn clean to prevent soot
That also depends on what other ingredients are in it ?
There are a lot of folks selling products that are not to spec of the regulatory agency here where I live. If I were to buy from some dodgy website I wouldn’t trust the lable either. As it seems it is a little more compplicated than I had thought.
Yes there is a way to get rough % in the kitchen. Alcohol generally burns at 40% and up. Take a given amount and light, if burns then over 40. Then with a new sample an add equal amount by volume of water and mix well. If lite and it burns then you’re at over 80. If not then add 50% to a new sample if it burns then your at the 60–79 area. Continued samples of concentration of water with unknown samples will get you pretty close.
Drink it and see
most cleaner stuff are rarely carbon based addictives due to alcohol so it won’t burn yellow. If they are they’re prolly alcohol wipes and the paper will stain the flame.
and since we are only talking rubbing alcohol or hand sanitizer purity, it is always only glycerin for hand moisture and those won’t color flames. Most fragrance related addictives are going to affect how pure alcohol anyway and if the* target* is getting pure content then easy way is to skip any that is not pure blue.
Something like this?
Probably not good for any mixtures like hand sanitizer.
All the Best,
Jeff