SDB-RPS is a poly(styrenedivinylbenzene) copolymer that has been modified with sulfonic acid groups to make it hydrophilic. SDB-RPS is not bonded to silica but is a 100% copolymeric particle that is spherical, porous and cross-linked. The sulfonation imparts unique selectivity for organic analytes that are polar in nature, such as drugs, drug metabolites, water-soluble pesticides and pesticide metabolites. SDB-RPS is also useful for comprehensive drug screening, in which a wide range of analytes are simultaneously extracted. SDB-RPS can be used as a reversed phase sorbent and substituted into existing methods. Organic analytes with polar character have been shown to extract better on SDB-RPS than on traditional C18 bonded silica.