Reprospher RP18 columns having a pore size of 100Å, 200Å or 300Å are present in various modifications and may be loaded with octadecyl derivatives to varying degrees. Endcapping can be either simple (C18), or double (C18-DE) or not (C18-NE). C18 aqua columns are also endcapped and additionally have diol groups. C18 TN columns are not endcapped. All columns are available with different particle sizes. The Reprospher 100 C18 Linie is an equivalent to Phenomenex Phenosphere NEXT C18 as well as Shimadzu Shimpack GIST c18.