Bioanalytical HPLC Applications of In-Tube Solid Phase Microextraction: A Two-Decade Overview

Abstract

In-tube solid phase microextraction is a cutting-edge sample treatment technique offering significant advantages in terms of miniaturization, green character, automation, and preconcentration prior to analysis. During the past years, there has been a considerable increase in the reported publications, as well as in the research groups focusing their activities on this technique. In the present review article, HPLC bioanalytical applications of in-tube SPME are discussed, covering a wide time frame of twenty years of research reports. Instrumental aspects towards the coupling of in-tube SPME and HPLC are also discussed, and detailed information on materials/coatings and applications in biological samples are provided.

Applications of porous frameworks in solid‐phase microextraction

“…In‐tube SPME, also called capillary microextraction, was first assembled in 1997 by Eisert and Pawliszyn as an automated alternative to fiber SPME [25]. The in‐tube SPME technique was presented to overcome drawbacks of SPME fibers, like as fragility, low sorption capacity, the limitation for extraction of weakly volatile or thermally unstable compounds that not suitable to an analysis by GC [26]. In in‐tube SPME, low volume of sample solution migrates toward the solid phase in the tube and the extraction can be carried out until reach to equilibrium.…”

Novel materials as capillary coatings for in‐tube solid‐phase microextraction for bioanalysis

“…The combination of RAMs and in-tube SPME enables biological samples to be directly injected into analytical systems, dismissing the need for prior sample pretreatment. Moreover, after the extraction step, washing with an appropriate solvent is necessary to remove residual proteins from the extraction capillary [21,79,80]. RAM coatings exhibit high extraction efficiency for low-molecular-weight analytes [78].…”

“…Among the above-mentioned nanomaterials, CNTs are becoming popular mainly because they offer high surface-to-volume ratios, thus increasing the extraction efficiencies. They can be divided into single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs), which consist of one or more sealed tubeshaped G layers, respectively [21]. Adsorption occurs in the easily accessible walls and interstitial sites of the CNTs [90].…”

“…In recent years, several review articles highlighting theory, apparatus, advances, future trends, and applications of SPME have been published [6][7][8][9][10][11][12][13][14][15][16][17]. Review articles about in-tube SPME discussing advantages or limitations compared to other techniques, strengths and weaknesses, system configurations, most used extractive phases, current applications in different areas, and different chromatographic couplings have also been published [18][19][20][21][22][23]. In the most recent articles, Ponce-Rodríguez et al [20] revised in-tube SPME coatings with a focus on in-tube SPME coupled to miniaturized HPLC systems.…”

“…Queiroz et al [19] revised the current advances and applications of intube SPME. In a two-decade overview, Manousi et al [21] presented a great discussion regarding instrumental advances. Kataoka [23] focused on current trends in extraction devices, configuration, and characteristics.…”