Ontwsep™ Diol is a diol-based extraction cartridge made of highly purified spherical silica gel. It removes polar samples from non-polar solutions via polar effects; it is equivalent to an unbonded silica gel matrix in terms of hydrogen bonding with samples, and it can distinguish structural isomers from other structurally identical compounds such as silica gel columns. Furthermore, the carbon chain carried by the bonded phase can provide sufficient non-polar interactions, making it suitable for extracting non-polar molecules.