Dear Lab Guy,
I would like to purchase your item B61809-4100 to test the content of alcohol in hand sanitizer. I see that it is currently out of stock, can you recommend something to perform a comparative test, having a known specimen?
I'm sorry, but I don’t think this will work for you, and here’s why: Hydrometers do measure density and % alcohol by volume, but if you used this hydrometer to measure a thick, viscous mix like hand sanitizer you would never know if the density/alcohol % you were measuring was that of the aloe/glycerol, the alcohol, or the alcohol + aloe/glycerol mix.
To measure the alcohol content in the hand sanitizer, you could use the H-B DURAC 50/100 Percent Isopropyl Alcohol Hydrometer you mention but to make an accurate measurement of the alcohol % you would have to measure before you mixed the alcohol and aloe/glycerin, or other ingredients together.
If you are making hand sanitizer, measure the alcohol % alone with an alcohol hydrometer. This percentage would have to be greater than the % alcohol you want to end up with because you must consider the dilution of the alcohol with other ingredients. To put this in to perspective, let's say you have 1 cup of 100% alcohol. If you add 1 cup of aloe and glycerol mix you would have 2 cups of 50% alcohol-aloe-mix.
You can also measure alcohol % with a regular Specific Gravity Hydrometer (with ranges hovering around 0.850 – 0.930) and the proper alcohol/specific gravity conversion table. Again, this is also measuring the alcohol before mixing in the other ingredients.
I hope this helped and answered your question. Thanks for writing and answered your question. Thanks for writing in, and please feel free to write back if I can help in any other way.
Yours in science,