A novel ionic-liquid-supported polythieno[3,2-b]thiophene coating for headspace solid-phase microextraction of phenolic compounds from environmental water via gas chromatography-mass spectrometry

A novel thieno[3,2-b]thiophene (TT) was utilized for the first time to electrochemically fabricate an ionic liquid (IL)-supported polythieno[3,2-b]thiophene (PTT) coating. This innovative coating serves as a new headspace solid-phase microextraction (HS-SPME) material for the extraction of five phenolic compounds, which were subsequently determined via gas chromatography-mass spectrometry (GC-MS). The coating was characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Experimental results confirmed that the ILs were successfully embedded within the polymer matrix, resulting in a well-defined three-dimensional mesoporous architecture. This unique architecture not only exhibited high thermal stability but also maintained a consistent extraction performance when used for the solid-phase microextraction of phenolic compounds. To optimize the extraction and detection performance, various experimental parameters were investigated, including the coating type, pH, salt concentration, extraction time, extraction temperature, stirring rate, desorption time, and temperature. Under the optimal conditions identified, the method exhibited low limits of detection ranging from 0.001 to 0.007 μg mL-1 and wide linearity in the concentration range 0.030 to 10.000 μg mL-1. Noteworthily, the proposed method was successfully applied to the determination of five phenols in actual water samples, achieving satisfactory recoveries between 90.5% and 110.5%‌.

Sustainable synthesis of nanoporous carbons from agricultural waste and their application for solid-phase microextraction of chlorinated organic pollutants

To guarantee the safety of water resources for humans, there is a high demand for the development of highly-efficient probes for solid-phase microextraction and analysis of trace organic pollutants. In this work, we greenly synthesized nanoporous carbons (NPCs) from oilseed rape straw via a facile hydrothermal treatment and potassium bicarbonate activation. Results showed that the NPCs had partly graphitic, amorphous-like structures with a high surface area (up to 1253 m² g⁻¹), large pore volume (up to 0.71 cm³ g⁻¹), high mesopore to total pore volume ratio (up to 29%) and great thermal stability (>400 °C). When the NPCs were utilized as a solid-phase microextraction fiber coating, the extraction efficiencies for chlorinated organic pollutants (COPs) were higher (1–38 times) than with a common commercial polydimethylsiloxane coating because of high surface adsorption energy, strong π–π stacking interactions and large mass transfer capacity. Using the most efficient NPC-8 coating, under optimum extraction conditions (desorption temperature, 290 °C; extraction temperature, 80 °C; extraction time, 25 min), an analysis method for trace COPs in water was developed with good linearity (0.9991–0.9998), high sensitivity (limits of detections, 0.08–0.64 ng L⁻¹), acceptable repeatability (RSDs of single fiber, 2.63–6.73%) and great reproducibility (RSDs of fiber-to-fiber, 2.22–7.12%). Finally, the NPC-8 coating was applied to a real environmental sample with satisfactory recoveries (86.66–103.27%).

Nanoporous carbons were synthesized with green process of oilseed rape straw and applied as efficient adsorbent for microextraction of COPs.