188.8.131.52. Stereochemistry of alkenes (determining the identities of geometric isomers of unsaturated hydrocarbons)
Carbon-carbon double bonds of alkenes can exist in two alternative forms, known as isomers, using the (E)-(Z) notation. To determine the stereochemistry of the alkenes that are present in a sample, they can be co-chromatographed with authentic standards on silver nitrate impregnated thin-layer chromatography plates using hexane as a solvent. This allows separation of the stereoisomers so that the sections of the plate corresponding to the (Z) and (E) alkenes can then be extracted with ether and analysed by GC-MS (Nazzi et al., 2002).