The cyanopropyl 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, CN phases show a distinct selectivity for polar organic compounds as well as for molecules containing π-electron systems (e.g., analytes with double bonds). This HPLC phase 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. This HPLC column is packed with CN modification, based on the original NUCLEOSIL silica gel. It is one of the first spherical silicas for HPLC and was originally developed by MACHEREY-NAGEL in 1974. It is exclusively manufactured in Germany and is still one of the most used HPLC silicas in quality control around the globe.