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Book title: Handbook of Solid Phase Microextraction
Editors: Pawliszyn J
Publisher: Elsevier
City: Oxford
ISBN: 978-0-12-416017-0

Abstract: The solid-phase microextraction (SPME) concept originates from the use of optical fibres, which could be purchased coated with several types of polymeric films that act as an extraction phase. The development of the technique accelerated rapidly with the implementation of the coated fibres incorporated into a microsyringe, resulting in the easy-to-operate and -automate tool. The extraction coating has also been used on other elements of the analytical system, resulting in a range of SPME implementations. In addition to widely used fibre and in-tube geometries, SPME devices can take different configurations, such as the coated interior of vessels, the coated exterior of stirring mechanisms as magnetic bars or even pieces of polydimethylsiloxane tubes and thin membranes. Each of these implementations has unique features and associated advantages. Efficient agitation is critical for the optimum operation of SPME devices. For field sampling, the device needs to incorporate controlled agitation mechanism as a part of the construction (e.g. a fan in air sampling or drills in aqueous sampling). Extraction temperature is another important parameter to consider during SPME, specifically headspace SPME of complex samples. To prevent loss of sensitivity, the coating can be cooled simultaneously with sample heating, which practically has been developed as cold-fibre SPME, an approach that was miniaturised and automated on a commercial autosampler in a similar way as a standard syringe SPME device. The other way to increase the mass uptake rates, and therefore the sensitivities, is to use large surface area sorbent resulting in a thin-film microextraction. Several types of field sampling devices have been designed to preserve extracted analytes in the coating. These devices are similar in operation to a syringe. In parallel, a needle trap (NT) device was designed, in which the whole diameter of the needle is packed with the sorbent. Simultaneous use of SPME and NT devices in on-site application facilitates measurement of free and total concentration of the target analyte. A convenient-to-handle in vivo SPME device was designed. In each implementation, coating design determines selectivity, sensitivity, performance and robustness of the SPME method. Because of its solvent-free nature and the small size of the fibre or capillary, SPME can be interfaced conveniently to analytical instruments of various types. A simple modification or direct use of syringe inlet systems facilitate convenient coupling of SPME devices to many analytical instruments. Keywords Agitation, cold fibre, thin-film microextraction, needle trap, in vivo samplers, coatings, preparation, affinity, matrix compatible, interfaces, gas chromatography, liquid chromatography, mass spectrometry, capillary electrophoresis
Template and target information: Review - solid-phase microextraction (SPME)