Bilayer dual-phase SPE cartridge featuring CHROMABOND® WAX for extraction and concentration of analytes in combination with GCB (graphitized carbon black) for sample cleanup, allows to substitute a single WAX based SPE cartridge and a dispersive Solid Phase extraction (dSPE) with GCB in a powder format. State-of-the-art spherical polymer for highest demands in solid phase extraction. PS/DVB copolymer with secondary and tertiary ammonium modification for mixed-mode SPE with weak anion exchange and reversed-phase properties (WAX). Exchange capacity ≥ 0.8 meq/g, pKa 6 + 9. High-purity material with ideal flow properties and highest reproducibility. Allows highest reproducibility with extremely low blind values due to an optimized production process. Suitable for analysis of per- and polyfluoroalkyl substances (PFAS) e.g. in aqueous, solid, biosolids, and tissue samples as well as highly pigmented matrices e.g. food, feed or environmental matrices. Especially suitable for PFAS analysis e.g., according to EPA method 1633 and DOD QSM 5.1/5.3.