Many LC/MS methods require comprehensive analysis, which is contrary to conventional sample preparation. Instead of separating compounds based on chemical differences, it is possible to remove interferences such as phospholipids, surfactants, and proteins by size exclusion chromatography (SEC). In this application, we demonstrate the utility of 300 µL SEC Tips to isolate drugs from oral fluid buffer solutions. The SEC Tips are dry initially, and are readily swollen into a gel by simple capillary action – a patent-pending method known as INTip™ Swelling. The pores of the SEC resin are too small for the larger compounds such as surfactants and phospholipids, so these interferences pass through the resin quickly and are readily separated from common drugs and metabolites. We present limits of detection that show the usefulness of this method for meeting the suggested guidelines for oral fluid drug testing.

SEC tips incorporate a unique pipette tip design for automated group separation of complex sample mixtures and patent-pending INTip Swelling method.

Learn more about SEC tips used in this method.