Relatively nonpolar phase for RP and ion pairing chromatography. Polarity similar to C8, but with different selectivity for polycyclic aromatic hydrocarbons, polar aromatics, fatty acids etc. Separation mechanism based on π–π interactions and hydrophobic (van der Waals) interactions, some residual silanol interactions. 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.