The question of how much ethanol is really in 10% blend came up on another thread.
A couple of sites give a simple method to get an idea how much ethanol is present. The basis for the test is that ethanol in gasoline can be extracted into a separate water phase (aqueous) and the change in volume of the gasoline phase (organic) can be used to calculate the amount of ethanol originally present in the gasoline. The only equipment needed is a graduated cylinder from a chemistry set:
1) http://www.aviationfuel.org/faqs/alcohol_testing.asp
2) http://www.ehow.com/how_2143193_test-fuels-alcohol-content.html
One site claims the accuracy is +/- 1% V:V. It is unclear wether they compared this method with more accurate means of quantification to support this claim.
A couple of sites give a simple method to get an idea how much ethanol is present. The basis for the test is that ethanol in gasoline can be extracted into a separate water phase (aqueous) and the change in volume of the gasoline phase (organic) can be used to calculate the amount of ethanol originally present in the gasoline. The only equipment needed is a graduated cylinder from a chemistry set:
1) http://www.aviationfuel.org/faqs/alcohol_testing.asp
2) http://www.ehow.com/how_2143193_test-fuels-alcohol-content.html
One site claims the accuracy is +/- 1% V:V. It is unclear wether they compared this method with more accurate means of quantification to support this claim.