Packing material, adsorbents for SPE applications. Benzenesulfonic acid modified silica, strongly acidic cation exchanger (SCX, capacity ~ 0.5 meq/g), adsorbent with hydrophobic and π-π interactions (benzene ring), ion exchange of organic compounds from aqueous matrix, elution of interesting compounds with solvent systems, which compensate the ionic and nonpolar interactions, e.g., methanolic HCl.