Thin electrospun films based extraction directly coupled with mass spectrometry

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Electrospun fibres (EFs) have a great potential in microextraction techniques thanks to their advantageous characteristics. They are versatile as a relatively large number of different polymers, with different interaction chemistries, can be used as precursors. In addition, the use of mixtures of polymers as well as the introduction of nanoparticles in the fibrous network have extended the applicability and have improved their performance. Although EFs can be obtained in several formats (e.g as solid phase microextraction coatings), they can be easily fabricated as a mat of ordered or random fibers. These membranes present a high surface to volume ratio which is key for a rapid extraction kinetics. In some cases, EFs membranes can be used as filters where the sample flows through the polymeric network while the analytes are retained. In other cases, the membrane can be immersed into the sample and the analytes are transferred from the bulk solution to the sample thanks to the sample agitation.
Aligned electrospun fibres
In a recent publication, researchers from China and Pakistan have proposed ordered mesoporous silica-carbon composite fibers as sorbent for the isolation, under the thin film microextraction format, of three antidepressants from human plasma (1). The thin film (membrane) is synthesized by a simple electrospinning process followed by carbonization under controlled conditions. The surface of the composite fiber is slightly acid showing a negative charge at pH 8 that allows the interaction with the basic analytes (which present a positive charge at this pH) by a combination of hydrophobic and ionic interactions. This fact and the size exclusion effect of the membrane pores improve the selectivity of the extraction, making the analysis of a complex biofluid possible.

The isolated analytes are determined by mass spectrometry. Each thin film is desorbed and analyzed in a desorption corona beam ionization source combined with MS without any previous chromatographic separation (2). This direct combination provides limit of detection in the low ng/mL range with acceptable precision and good accuracy.

Enjoy the reading of the full article in the journal webpage.

References and related posts:
(1) Electrospun fibrous thin film microextraction coupled with desorption corona beam ionization-mass spectrometry for rapid analysis of antidepressants in human plasma. Link to the article
(2) Magnetic solid phase extraction coupled to ambient ionization mass spectrometry. Link to the post
Note:
Picture of electrsopun fibers has been reproduced from the reference entitled "The effect of the fibre orientation of electrospun scaffolds on the matrix production of rabbit annulus fibrosus-derived stem cells" (Link to the article), which has been published under the open access format.

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