Nanostructured polyaniline SPME fiber coating for chemical warfare agents analysis

Nanostructured polyaniline (PANI) was electrochemically obtained as a fiber coating of solid-phase microextraction (SPME) and then used in the analysis of selected organoarsenic and organophosphorus compounds in soil samples. Also, comparative studies of the obtained PANI fibers with seven commercially available fibers for varying miscellaneous polarity, and various absorption and/or adsorption natures, were carried out. Quantitative analysis of environmental samples was performed using a gas chromatograph coupled with a tandem mass spectrometer. During the analysis of organophosphorus compounds, the PANI fiber showed at least 20% greater sorption efficiency than any commercially available fiber, whereas, in the case of organoarsenic compounds, the sorption efficiency of the PANI fiber increased with the expansion in the number of phenyl rings in the molecule. The PANI coating material was characterised by N-2 adsorption-desorption, scanning electron microscopy, infrared spectroscopy and thermogravimetric analysis. SEM imaging confirmed a nanostructured form of PANI. The repeatability for one fiber (n = 7), expressed as the relative standard deviation ranges from 3.2% to 4.4% depending on the kind of tested chemical compound. The reproducibility (calculated as relative standard deviation of the 9 prepared fibers) was not greater than 7.2% Under the optimized conditions, the proposed method was linear over approximately 4 orders for organophosphorus compounds (0.02-100 ng g(-1)) and 5 orders for organoarsenic compounds (0.12-5000 ng g(-1)) of magnitude for the tested compounds, with linear determination coefficients (R-2) greater than 0.972, and the limit of detection for the home-made PANI fiber was relatively low (0.006-0.45 ng g(-1)). In comparison with all commercially available SPME fibers, the new PANI fiber was more selective for the tested aromatic and organophosphorus compounds and easily as well as inexpensively prepared. The resulting stationary phase allowed for quantitative analysis of selected organophosphorus and organoarsenic compounds from the group of warfare agents. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Nanostructured polyaniline (PANI) fibers were obtained electrochemically and used as a coating for solid-phase microextraction (SPME) in the analysis of organoarsenic and organophosphorus compounds in soil samples. The PANI fiber showed superior sorption efficiency compared to commercially available fibers, and its sorption efficiency increased with the expansion in the number of phenyl rings in the molecule. The method exhibited a wide linear range and low detection limits for the tested compounds when coupled with gas chromatography-tandem mass spectrometry.