We all are familiar with stir bar sorptive extraction (SBSE) and dispersive methodologies in this context. The advantages of both techniques are also well known and a deep research is being carried out to characterize new sorbent phases which improve the efficiency and open up the application field of these microextraction techniques.
Research teams from the University of Valencia at Spain and Ioannina at Greece have joined their deep knowledge in dispersive techniques to bring us a very elegant combination of stir bar sorptive dispersive microextraction mediated by magnetic nanoparticles (SBSEDµE) (1). The main advantage of the proposed methodology is clear as it permits the use of a wider variety of sorbent phases while maintaining the advantages of agitation and simplicity of sorbent recovery provided by the magnetic element.
The sorbent is either coated on the stir bar or dispersed in the sample matrix depending on the stirring speed. The general procedure is shown in Figure 1. In a first step, the bar containing the attached magnetic nanoparticles (MNPs) is introduced into the sample. Then, the bar is stirred at high velocities inducing the detachment of the MNPs from the bar into the sample, the extraction of the analytes taking place. The continuous reduction of the stirring velocity induces again the attachment of the MNPs on the bar simplifying the final elution step.
The analytical problem selected for the evaluation of this novel approach is the determination of organic UV filters in seawaters. For this aim, oleic acid-coated cobalt ferrite MNPs was selected as sorbent material. They have carried out a rigorous study to properly characterize and evaluate the potential of SBSEDµE.
From this blog, we congratulate our colleagues for being the first in envisage the potential of the direct combination of these two microextraction concepts. As usual, the simplicity of the approach is its key strength.
Enjoy the reading!!
(1) Development of stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles and its analytical application to the determination of hydrophobic organic compounds in aqueous media. Link to the article