How could the purity of the ethanol collected be checked in fractional disstilation method?

The purity of ethanol collected in fractional distillation can be checked using a hydrometer to measure the specific gravity, a refractometer to measure refractive index, or by conducting a simple chemical test like bromine water test or iodine test to detect the presence of impurities. Additionally, a gas chromatography analysis can provide a detailed breakdown of the components present in the collected ethanol sample.