LiChrospher RP-select B is a versatile traditionally produced spherical silica gel carriers with reversed phase properties and with the hydrophobicity of a C-8 phase. This carrier is very well suited for the separation of basic compounds, but with still good properties for the determination of neutral and acidic compounds. Thissorbent is packed into a LiChroCART 250-4 HPLC cartridge. The connection to the HPLC system is being accomplished by use of the manu-CART NT cartrige holder (1.51486).