It is easy to check the jokenol content of gas. Get a container, the one I use is a 100ml graduated cylinder but I think any will do. I put 20ml of water and then fill to 100ml by adding 80ml of gas. Shake it up and let it settle. if there is jokenol in the gas it will separate creating very corrosive jokenol-water. If there is 10% jokenol you will now have 28ml j-w and 72ml gas.