This module introduces the terminology associated with solid phase extraction (SPE). It explains the chemistry and physical properties associated with SPE sorbents and substrates. The different steps in a solid phase extraction protocol are fully discussed, and sorbent selection, eluent solvent strength optimization, and the use of pH and ionic additives to control selectivity in SPE is investigated. Principles associated with choosing sorbent mass in SPE to optimize analyte recovery are outlined and specific issues related to pharmaceutical sample preparation highlighted.
Upon completion of this unit you will be able to select SPE sorbents for particular analyte extractions. Choosing appropriate sample prep strategies for analyte and sample matrices will be simpler. You will condition and equilibrate sorbents to maximize analyte retention and minimize interference retention. Establishing the best selectivity from an SPE protocol based on sample loading, washing, and elution conditions will never have been clearer.