Fundamentals and applications of stir bar sorptive dispersive microextraction: A tutorial review

Current trends in sample preparation focus on the miniaturization of the process so that lower sample and solvent volumes are used, resulting in what is known as microextraction techniques. Among the variety of microextraction techniques that have been developed over the years, stir bar sorptive dispersive microextraction (SBSDME) is one of the most recent techniques. It was presented only a few years ago as a hybrid microextraction technique that combines the principles of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE). This novel microextraction technique introduces, into the sample solution, a bar-shaped magnet coated with a magnetic (nano)material, which is maintained on the surface by magnetism. Once stirring starts, the competitive action between magnetism and rotational force is exploited. So, at low rotational speed the (nano)material is retained on the magnet reminding SBSE, whereas a high sufficiently rotational speed the rotational force surpasses magnetism so that the magnetic (nano)material is dispersed into the sample solution as in DSPE. Upon halting rotation, the magnetic field prevails again and attracts the magnetic (nano)material containing the analytes back on the surface of the stirring bar. Finally, the extracted analytes are chemically or thermally desorbed before their measurement with the appropriate analytical instrument. When compared separately to SBSE and DSPE procedures, SBSDME affords, in a single approach, advantages such as lower extraction times than SBSE and easier extraction and post-extraction treatment than DSPE. The main purpose of this tutorial review is to describe the fundamentals and the experimental variables involved in this technique, as well as to compile and critically discuss the published papers concerning analytical methods based on the use of the SBSDME approach, analyzing its evolution and future prospects. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

SBSDME is a novel microextraction technique that combines the principles of SBSE and DSPE, dispersing magnetic (nano)material into the sample solution through horizontal stirring, leading to improved extraction efficiency. It offers advantages of shorter extraction times and simplified processing in a single approach.