How do you separate e and z isomers?
You separate them on the basis of their physical properties.
If they are solids, two common techniques are
Their solubilities may be different enough in a given solvent that one isomer may crystallize as a hot solution cools while the other isomer stays in solution.
Their affinities for the stationary phase may be different enough that they can be separated by liquid chromatography.
If they are liquids, three common techniques are
Liquids can also be separated by liquid chromatography.
The boiling points of the isomers might be different enough that you can separate them by fractional distillation.
The affinities for the stationary phase may be different enough that they can be separated by gas chromatography.
If all else fails, you might try
If the isomers contain another functional group, you may be able to prepare a derivative of the isomers and separate the derivatives.