Macherey-Nagel SPE Cartridge, CHROMABond SiOH BIGpack 3 ml, 500 mg, PP, 5x50/PAK

Unmodified, weakly acidic silica, very polar. Adsorbs humidity from air, for this reason it should be kept well closed and if necessary dried before use. Due to its high affinity for polar compounds it should not be conditioned with polar (e.g., methanol) or water-containing solvents.