Authors: M. Costas-Rodriguez; Francisco Pena-Pereira
Book: Miniaturization in sample preparation, Ed. De Gruyter Open, pp. 276-307, 2014
Currently, microextraction techniques are established as reliable and environmen-tally-friendly sample preparation procedures. The success of these techniques comes from their simple operation, rapid sampling, low cost, (virtually) solventless nature, good recoveries and large enrichment factors (EFs). However, they are not free of limitations. Depending on the microextraction mode, difficulties related to fiber breakage, stripping of coatings, instability and losses of organic solvents and porous membranes are still present. The development of more selective, efficient and versatile procedures to overcome these limitations is an expanding field of study. To date, over 20000 papers have been devoted to microextraction techniques, includ-ing 750 reviews. During 2013 and early 2014 alone, 70 reviews were published in the literature. A high number of them were focused on important and groundbreaking topics such as i) green aspects, developments and perspectives of microextraction approaches (Spietelun et al., 2014), ii) new sorbent materials as extractant phases (Majors, 2013; Pereira et al., 2013) and iii) application of these approaches in new areas such as bioanalysis (Ahmad, 2013). Innovations and trends are focusing not only on the extraction process itself, and also on automation and the integration of the sample preparation step with analytical instrumentation. Thus, errors associ-ated with manual handling can be minimized, sample and reagent consumption can be reduced, and sensitivity and precision can be improved. Furthermore, the use of ultrasonic (Bendicho et al., 2012) and microwave irradiation (Li et al., 2013), elec-trochemical supports and autosamplers (commercially available) are being used to improve the capabilities of microextraction approaches (Spietelun et al., 2014).