Herein we report the development of solid-phase microextraction (SPME) devices designed to perform fast extraction/enrichment of target analytes present in small volumes of complex matrices (i.e. V≤10 μL). Micro-sampling was performed with the use of etched metal tips coated with a thin layer of biocompatible nano-structured polypyrrole (PPy), or by using coated blade spray (CBS) devices. These devices can be coupled either to liquid chromatography (LC), or directly to mass spectrometry (MS) via dedicated interfaces. The reported results demonstrated that the whole analytical procedure can be carried out within a few minutes with high sensitivity and quantitation precision, and can be used to sample from various biological matrices such as blood, urine, or Allium cepa L single-cells.

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Abstract:The current study reports the development of solid phase microextraction (SPME) devices designed to perform fast extraction/enrichment of target analytes present in small volumes of complex matrices (i.e. V ≤ 10 μL). Micro-sampling was performed with the use of etched metal tips coated with a thin layer of biocompatible nano-structured polypyrrole (PPy (tip diameter ≤ 10 µm), or by using coated blade spray (CBS) devices with an extraction phase thickness ≤ 10 µm, facilitating rapid extraction. These devices can be coupled either to liquid chromatography (LC), or directly to mass spectrometry (MS) via dedicated interfaces. The reported results demonstrated that the whole analytical procedure can be carried out within a few minutes (tanalysis ≤ 7 min) with high sensitivity and quantitation precision, and can be used to sample from various biological matrices such as blood, plasma, and urine, towards the analysis of therapeutics, pesticides, and controlled substances as model analytes. As a proof-of-concept, the analysis and quantification of target compounds present in single cells of Allium cepa L was demonstrated.

A micro-solid phase extraction technique was developed using a novel polypyrrole-polyamide nanofiber sheet, fabricated by electrospinning method. The applicability of the new nanofiber sheet was examined as an extracting medium to isolate malathion as a model pesticide from aqueous samples. Solvent desorption was subsequently performed in a microvial, and an aliquot of extractant was injected into gas chromatography-mass spectrometry. Various parameters affecting the electrospinning process including monomer concentration, polyamide content, applied voltage, and electrospinning time were examined. After fabricating the most suitable preparation conditions, influential parameters on the extraction and desorption processes were optimized. The developed method proved to be rather convenient and offers sufficient sensitivity and good reproducibility. The limit of detection (S/N = 3) and limit of quantification (S/N = 10) of the method under optimized conditions were 50 and 100 ng L(-1), respectively. The relative standard deviation at concentration level of 1 ng mL(-1) was 2% (n = 3). The calibration curve of analyte showed linearity in the range of 0.1-1 ng mL(-1) (R (2) = 0.9975). The developed method was successfully applied to tap and Zayanderood river water samples, while the relative recovery percentages of 98% and 96% were obtained, respectively. The whole procedure showed to be conveniently applicable and quite easy to be manipulated.