title: Chemically modified polymeric sorbents for sample preconcentration.
abstract: Solid-phase extraction is an attractive alternative in sample preparation because it overcomes many drawbacks of liquid-liquid extraction and makes on-line determination possible by hyphenation with chromatographic techniques. Driven by the need for more effective and more selective sorbents, advances in solid-phase extraction include the development of new materials. This paper describes different types of chemically modified sorbents for the solid-phase extraction of compounds from aqueous samples. Chemical introduction of different functional groups into a polymeric resin improves the efficiency of solid-phase extraction by providing better surface contact with the aqueous samples; also, these sorbents have a greater capacity than the typical solid-phase materials for polar compounds have. The most important new sorbents are the chemically modified resins based on styrene-divinylbenzene copolymers. Preparation of these new sorbents is described, and advantages and drawbacks of off-line procedures and on-line procedures are also discussed. Applications for off-line and on-line chromatographic determinations of polar compounds are presented.
authors.affiliation: Departamento de Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Spain. leongon@eucmax.sim.ucm.es
authors.forename: M E
authors.initials: ME
authors.lastname: León-González
authors.forename: L V
authors.initials: LV
authors.lastname: Pérez-Arribas
mesh_terms: D000327:Adsorption; D002845:Chromatography; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D012116:Resins, Plant / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry
chemical_list: D011108:Polymers; D011137:Polystyrenes; D012116:Resins, Plant; D014753:Vinyl Compounds; C004985:divinyl benzene