Are there any chemists in the crowd?

A few years ago Sportys sold an Alcohol test kit that consisted of a reagent
that was added to a small sample vial of fuel.
If the sample contained alcohol, the sample turned purple. Light purple
indicated 1%, dark 5%.

Sporty no longer carries the test kit. I am down to my last kit and would
sure like to know what the chemical they used that turns purple in the
presence of alcohol in the fuel.

It is the most convenient way I have found to positively test the fuel.

Thanks

Paul
N1431A