It can be converted to an ion-exchange capacity of ∼0.5 milli-equivalents per gram of sorbent (meq/g), which is comparable to those of some of the leading commercial mixed-mode cartridges, such as 0.3 meq/g of Oasis MAX, 0.6 meq/g of SampliQ Si SAX, and 0.6 meq/g of ISOLUTE SAX.