The endcapped cyanopropyl phase is based on high purity NUCLEODUR silica gel. This HPLC phase is able to generate a clearly recognizable different retention behavior compared to purely alkyl-functionalized surface modifications. The polarity can be classified as intermediate based on multiple retention mechanisms such as dipole-dipole, π-π, and also hydrophobic interactions. Therefore, this phase shows a distinct selectivity for polar organic compounds as well as for molecules containing π electron systems (e.g., analytes with double bonds). Cyanopropyl HPLC columns can be run in the RP mode using aqueous-organic eluent mixtures as well as in the NP mode, e.g., with hexane as mobile phase.