Molecularly Imprinted Polymeric Fibers for Solid-Phase Microextraction

Abstract

Solid-phase microextraction (SPME) is widely used in analytical laboratories for the analysis of organic compounds, thanks to its simplicity and versatility. However, the current commercially available fibers are based on nonselective sorbents, making difficult in some cases the final determination of target compounds by chromatographic techniques. Molecularly imprinted polymers (MIPs) are stable polymers with selective molecular recognition abilities, provided by the template used during their synthesis. In the present work, a simple polymerization strategy allowing the obtainment of molecularly imprinted polymeric fibers to be used in SPME is proposed. Such a strategy is based on the direct synthesis of molecularly imprinted polymeric fibers (monoliths) using silica capillaries as molds, with silica being etched away after polymerization. The system propazine:methacrylic acid was used as a model for the preparation of molecularly imprinted fibers, and its ability to selectively rebind triazines was evaluated. Variables affecting polymer morphology (i.e., polymerization time, fiber thickness) and binding-elution of target analytes (i.e., solvents, time, temperature) were studied in detail. The imprinted fiber showing the best performance in terms of selectivity and affinity for triazines was successfully applied to the extraction of target analytes from environmental and food samples.

Quercetin molecularly imprinted polymers: Preparation, recognition characteristics and properties as sorbent for solid-phase extraction

“…So, molecularly imprinted polymers (MIPs) display excellent application prospects. In particular, MIPs used as adsorbents of solid-phase extraction (SPE) are being widely involved in the concentration and determination of drug molecules, and the extraction of active components from natural products [2,[14][15][16].…”

Recent Developments and Applications of Microextraction Techniques for the Analysis of Pesticide Residues in Fruits and Vegetables

“…Due to their relative low recommended operating temperature (200 -300 O C) of the commercially available fiber, the recent trend is focused on the development of new fibers using sol-gel technology, with high thermal stability (>320 O C) [27][28][29][30][31][32][33][34][35][36][37] and molecular imprinted polymers (MIPs) [38][39][40][41][42]. Ionic liquids and sol-gel prepared ionic liquid coated fibers have also been recently developed and have been used extensively for the SPME extraction of pesticide residues in water samples [43][44][45][46], but their use for the extraction of analytes from food samples is a potential research area to be explored in the future.…”

Molecular imprinted polymers as synthetic receptors for the analysis of myco- and phyco-toxins

“…The sample is repeatedly drawn and ejected through the capillary for analytes extraction, being directly desorbed by the mobile phase 18 . In a further development of the in-tube SPME technique, the capillary tube is no more filled with preformed imprinted beads, but an imprinted porous monolith is synthesised in situ and used as it is 19 or after dissolution of the silica support 20 , avoiding in this manner the need for capillary frits and the cumbersome and difficult step of capillary packing.…”