Understanding Solid-Phase Microextraction: Key Factors Influencing the Extraction Process and Trends in Improving the Technique

In view of the demands made of contemporary analytical techniques and the need to implement green technologies in analytical practice, solvent-free techniques of preparing samples for analysis, such as SPME, are taking on a greater significance. With this technique, analytes can be sampled from media with a complex composition, from contaminated media, and from media with polar matrix constituents. The cited literature presents information on modifications of existing approaches in regard to the SPME apparatus (miniaturization, automation, combination with monitoring and measurement instrumentation) and on completely new devices such as CCF-SPME, intube SPME, and M-SPME, which guarantee high recoveries of a broad spectrum of analytes. Studies of the effects on the extraction process of parameters such as the extraction time and temperature, the type of extraction coating and its thickness, and fiber derivatization have provided the opportunity to control both its efficiency and, to some extent, its selectivity. SPME has achieved enormous significance in analytical practice as far as the preparation of samples for analysis is concerned. Thanks to the merits of this technique and the possibilities of improving it through novel design approaches and the implementation of new, highly selective extraction fiber coatings, one can expect further developments in this field. For the readers' benefit, Table 2 was prepared as a kind of quick reference tool to the problems raised in this paper.