Sample preparation has been commonly considered a critical step of the analytical process. In this sense, remarkable efforts have been made to develop efficient sample preparation techniques which could overcome the limitations of conventional approaches. Since its inception in the early 1990’s, solid-phase microextraction (SPME) has become a widespread miniaturized sample preparation technique for extraction and preconcentration of target analytes from a large variety of matrices. Interestingly, sampling, extraction, enrichment and sample introduction can be integrated into a single step in SPME. This book chapter focuses on the basic principles and current state of the art of SPME. Specifically, both thermodynamic and kinetic aspects of the SPME technique are discussed in detail. In addition, those experimental variables that show a paramount role in the extraction process, and should therefore be optimized and controlled for optimal performance, are considered. Valuable contributions that enabled the development of this solventless technique and current challenges are identified. Other related SPME devices, such as internally cooled SPME, in-tube SPME and membrane SPME, are also described.
Keywords: Automation, Direct immersion, Divinylbenzene, Fiber coatings, Gas chromatography, Headspace, High-performance liquid chromatography, In-tube SPME, Internally cooled SPME, Kinetics, Membrane-SPME, Molecularly imprinted polymers, Poly(dimethylsiloxane), Polymeric ionic liquids, Preconcentration, Sample preparation, Sample preparation, Sol-gel sorbents, Solid-phase microextraction, Thermodynamics.