Simplified miniaturized analytical set-up based on molecularly imprinted polymer directly coupled to UV detection for the determination of benzoylecgonine in urine

High-performance molecularly imprinted polymers grafted magnetic photonic crystal microspheres for selective enrichment of Ochratoxin A

Development of selective enrichment materials for the accurate analysis of ochratoxin a (OTA) in environmental and food samples is an effective way to protect human health. Here, a molecularly imprinted polymer (MIP) known as plastic antibody was synthesized onto the magnetic inverse opal photonic crystal microsphere (MIPCM) using a low-cost dummy template imprinting strategy targeting OTA. The MIP@MIPCM exhibited ultrahigh selectivity with an imprinting factor of 130, high specificity with cross-reactivity factors of 3.3-10.5, and large adsorption capacity of 60.5 μg/mg. Such MIP@MIPCM was used for selective capture of OTA in real samples which was quantified in combination with high-performance liquid chromatography, giving a wide linear detection range of 5-20,000 ng/mL, a detection limit of 0.675 ng/mL, and good recovery rates of 84-116%. Moreover, the MIP@MIPCM can be produced simply and rapidly and is very stable under different environmental conditions and easy to store and transport, so it is an ideal substitute of biological antibody modified materials for the selective enrichment of OTA in real samples.

Molecularly imprinted polymer-specific solid-phase extraction for the determination of 4-hydroxy-2(3H)benzoxazolone isolated from Acanthus ilicifolius Linnaeus using high-performance liquid chromatography-tandem mass spectrometry

The minor constituent found in Acanthus ilicifolius Linnaeus, 4-hydroxy-2 (3H) benzoxazolone alkaloid (HBOA), has a range of versatile applications. Herein, a quick and straightforward method for extracting HBOA from A. ilicifolius Linnaeus was proposed. HBOA was used as a template, whereas methacrylic acid, ethylene glycol dimethacrylate, and acetonitrile were used as functional monomers, cross-linkers, and porogens, respectively. Molecularly imprinted polymers (MIPs) were synthesized by precipitation polymerization, and their adsorption isotherms, dynamics, and selective binding ability were characterized and analyzed. The results showed that the adsorption amount of the template was 90.18 mg/g. The MIPs were used as solid-phase extraction fillers and actual sample extraction columns, with a linear range of 0–100 μg/L, average recovery of 78.50–101.12%, and a relative standard deviation of 1.20–3.26%. The HBOA concentrations in the roots, stems, and leaves were 1,226, 557, and 205 μg/g, respectively. In addition, MIP–SPE was successfully used in isolating and purifying HBOA from different parts of A. ilicifolius Linnaeus, indicating its effectiveness in extracting and determining HBOA in other herbs.

Current trends in the development of polymer-based monolithic stationary phases

This review focuses on the development and applications of organic polymer monoliths, with special attention to the literature published in 2021. The latest protocols in the preparation of polymer monoliths are discussed. In particular, tailored surface modification using nanomaterials, the development of chiral stationary phases and development of stationary phases for capillary electrochromatography are reviewed. Furthermore, the optimization of pore forming solvents composition is also discussed. Finally, the use of monolithic stationary phases in sample treatment using solid-phase extraction and enrichment methods, molecularly imprinted polymers and enzymatic reactors is mentioned.

Green molecularly imprinted polymers for sustainable sample preparation

The use of molecularly imprinted polymers in sample preparation as selective sorbent materials has received great attention during the last years leading to analytical methods with unprecedented selectivity. However, with the progressive implementation of Green Analytical Chemistry principles, it is necessary to critically review the greenness of synthesis and further use of molecularly imprinted polymers in sample preparation. Accordingly, in the present review, the different steps and strategies for the preparation of molecularly imprinted polymers, the used reagents, as well as their incorporation to microextraction techniques are reviewed from a green perspective and recent alternatives to make the use of molecularly imprinted polymers more sustainable are provided.