A critical review of the state of the art of solid-phase microextraction of complex matrices III. Bioanalytical and clinical applications

Fast Quantitation of Target Analytes in Small Volumes of Complex Samples by Matrix‐Compatible Solid‐Phase Microextraction Devices

“…[5] In recent years,advances in direct sample to mass spectrometry techniques,s uch as paper-spray ionization, probe electrospray ionization, and touch spray [2,[5][6][7] have allowed for the application of these methods towards the quantitative analysis of small volumes of biofluids.However, the sensitivity and precision typically achieved in the laboratory through adequate sample preparation prior to the MS quantification is traded off.T herefore,techniques capable of isolating and enriching target analytes from complex matrices with minimal processing time and adequate sample clean-up are highly desirable for applications that require direct introduction to MS. [1-3, 8, 9] As ac oncept, solid-phase microextraction (SPME) embraces solventless microextraction technologies with different geometrical configurations that efficiently integrate sampling and sample clean-up,while also allowing for enrichment of the molar fraction of ag iven analyte in as ingle step. [10] Given the multiple advantages of this technique, including its feasibility to be coupled to different analytical instruments,S PME has been widely used for analysis of complex matrices such as biofluids,t issues,a nd food samples. [1,[9][10][11][12] Herein our main objective is to introduce two new SPMEbased strategies that allow for the analysis of samples characterized by as mall volume and/or size.O wing to the thin nature of the coatings (Ø 10 mm), fast extraction/ enrichment of target analytes can be achieved with the use of these devices,e ven when sampling from complex matrices.…”

“…[10] Given the multiple advantages of this technique, including its feasibility to be coupled to different analytical instruments,S PME has been widely used for analysis of complex matrices such as biofluids,t issues,a nd food samples. [1,[9][10][11][12] Herein our main objective is to introduce two new SPMEbased strategies that allow for the analysis of samples characterized by as mall volume and/or size.O wing to the thin nature of the coatings (Ø 10 mm), fast extraction/ enrichment of target analytes can be achieved with the use of these devices,e ven when sampling from complex matrices. Theproposed devices can be composed of either amini-fiber (Figure 1), or ac oated blade (Figure 2), allowing for extraction of analytes to be performed either by immersing the mini-fiber into the matrix, or by spotting the sample onto the coated blade.The miniaturized fiber is consisted of apolypyrrole (PPy) coated stainless steel micro-tip that can be conveniently interfaced with MS instrumentation via chromatography,o rd irectly interfaced via nano-electrosprayionization (nano-ESI).…”

“…PPy,ab iocompatible [12] material frequently used in biosensors [14] and biomedical engineering, [15] is awell-established SPME extracting media for in vivo and in vitro bioanalysis. [10] However,t he fabrication of miniature coated sampling devices has not been extensively explored to date due to the multiple challenges associated with the fabrication of such devices (e.g.mechanical stability and thickness of the coating). [10] In this work, acupuncture needles with ad iameter of 120 mmw ere electrochemically etched to at ip with ad iameter size of approximately 5 mm.…”

“…[10] However,t he fabrication of miniature coated sampling devices has not been extensively explored to date due to the multiple challenges associated with the fabrication of such devices (e.g.mechanical stability and thickness of the coating). [10] In this work, acupuncture needles with ad iameter of 120 mmw ere electrochemically etched to at ip with ad iameter size of approximately 5 mm. Then, PPy was electrochemically coated onto the surface, using trifluoroacetic acid (TFA), and cetyltrimethylammonium bromide (CTAB) [16] as counter-ions (a detailed description of the experimental procedure is provided in the Supporting Information).…”

Sample preparation for polar metabolites in bioanalysis

“…New coatings are thus in development for hydrophilic compounds and should be available in the near future. [32][33][34] Electromembrane extraction (EME) is a recent approach for the extraction of ionized compounds. This sample preparation technique is based on the application of an electrical field between two compartments, the sample and the acceptor compartments, separated by a polymeric membrane impregnated by an organic solvent, known as the supported liquid membrane (SLM) (Fig.…”