What method is used to test for alcohol in gasoline?

The Shaker Test is an effective method used to determine the presence of alcohol in gasoline. This test involves mixing a sample of gasoline with water in a clear container and shaking it. Because alcohol (such as ethanol) is soluble in water, if alcohol is present in the gasoline, it will separate out and form a distinct layer above the water after shaking. This visible separation provides a clear indication of alcohol's presence.

While other methods might seem plausible for assessing fuel quality, they do not specifically indicate the presence of alcohol in the same direct way as the Shaker Test. For instance, the Water Test could indicate the presence of water but does not directly reveal whether alcohol is mixed with the gasoline. The Evaporation Test measures volatility but does not distinguish between gasoline and alcohol. The Density Test assesses the overall density of the fuel mixture, which could be influenced by various components, not solely alcohol.