Monolithic materials have gained in popularity over the last 5-10 years mainly as a result of the difficulty in producing stable silica based packed capillaries for use in CEC.This was almost entirely a result of difficulties in fabricating reproducible and robust retaining frits.Monoliths however, require no retaining fits and because of their relative ease of manufacture, can be manufactured in situ and are readily anchored to the capillary wall.Although monolithic materials have been produced from both silica monomers and organic monomers, the latter type have been particularly researched because of the large numbers of monomers that are available resulting in a wealth of stationary phases with a wide range of chemistries.