Not really a recipe in the sense of what I normally post here, but it seemed like the best place to file it all the same.
With COVID-19 raging worldwide, vulnerable people in our family, and limited availability (due to others hoarding/panic buying), I wanted to make my own hand sanitiser. Unfortunately, I only had Isopropyl 70% on the shelf, which isn't sufficiently strong once watered down with the other sanitiser ingredients.
This is a technique to seperate the Isopropyl and water from a 99.9 Isopropyl solution, in order to extract more concentrated alcohol - it's not technically purification as we're not doing anything to the alcohol itself.
Water and alcohols like Isopropyl are miscible - they can be mixed together in all proportions, so there isn't a way to "filter" the alcohol out.
This process is known as "salting out" or dehydrating Isopropyl. Essentially what it's doing is taking a mix of Isopropyl and water (such as you might have in Isopropyl 50% or 70%), and dissolving salt into the water to make brine - the heavier brine will sink to the bottom forming a seperate layer.
Care must be taken with this, Isopropyl is extremely flammable. It can also be absorbed through the skin and poison you.
Cooking Time
| Prep | Cooking | Total |
|---|---|---|
| 30 mins | mins | 30 mins |
Ingredients
- Wide bottomed Jar and Lid
- Table Salt
- Isopropyl Alcohol 70% (or even 50%, you'll just get less)
- Syringe or turkey baster
Method
- Pour a lot of table salt into the bottom of the jar - the aim is to saturate the solution, so you want too much
- Pour in the Isopropyl
- Put the lid on the jar
- Shake vigourously until the salt and the isopropyl are well mixed (not all of the salt will dissolve)
- Place on a flat surface and leave to stand for 15-30 mins
- The mixture should now have seperated into a layer of brine (at the bottom) and a layer of alcohol at the top (the clear layer)
- Carefully unscrew the lid (you don't want to knock and cause remixing)
- Use the baster/syringe to extract the alcohol
- Carefully put into a new container and seal
- Handle very *carefully*, it can be inhaled as well as absorbed through the skin, and is extremely flammable