The 3 cc Oasis MAX cartridges contain the Oasis MAX, which is a novel, mixed-mode polymeric sorbent that has been optimized to achieve higher selectivity and sensitivity for extracting acidic compounds with anion-exchange groups. Since the Oasis MAX sorbent is water wettable, it maintains its capability for higher retention and excellent recoveries even if the sorbent runs dry, which means there is no need to take extraordinary steps to keep the sorbent beds from drying out during the critical steps prior to sample loading. These syringe-barrel-type cartridges are designed for use with vacuum manifolds and automated SPE instruments.