A quick and easy to test for alcohol in fuel is to use a clear water or soda bottle. Put approx one inch of water in an empty bottle and mark the level with a felt tip pen. Fill remainder of bottle with gas to be tested and shake for 5 seconds or so. Allow to set for a minute or two and, if there is alcohol in the fuel, the apparent water level will rise as the water absorbs the alcohol.
I purchased fuel on two occasions from a Shell station that claimed no alcohol and both times it contained alcohol. Very simple test. Larry Flesner