Hydrophilic molecularly imprinted thermal-responsive polymers based sorbent for ambient ionization mass spectrometric analysis of sulfonamide antibiotics from food samples

The thermal-responsive magnetic molecularly imprinted polymer (TrMMIP) sorbent was synthesized by surface imprinting method, and then used for magnetic solid-phase extraction (MSPE) and subsequent integrated into the ion source for elution and ionization. The shrinking-strength states change of the thermal-responsive polymer chain on TrMMIP alters the wettability of the sorbent when the working temperature crosses the lower critical solution temperature (LCST) of the polymer, and thus affects its behavior of in the extraction and clean-up process. The targeted analytes could be effectively extracted due to the high selectivity of MIPs and well dispersibility of polymer chain under the open state. Additionally, a hydrophilic polymer chain wrapped on the sorbent surface further protected target substances from co-elution during cleanup. Analytical methods for sulfonamide antibiotics (SAs) detection in complex food samples (milk, honey, fish) were developed, demonstrating potential for rapid and sensitive SAs analysis in diverse food and biological samples.

Preparation of surface molecularly imprinted polymer and its application for the selective extraction of teicoplanin from water

In this study, a new surface molecularly imprinted polymer (SMIP) of teicoplanin (TEC) was prepared in an aqueous solution using amino-modified silica gel as a carrier. The molar ratio of the template molecule, functional monomer and cross-linker in the optimized synthesis system was 1 : 15 : 40. The structure and morphology of SMIP were characterized by Fourier-transform infrared spectra and scanning electron microscopy, respectively. It was shown that the silica gel modified with different active groups; the type and structure of functional monomers have a great influence on the specificity of SMIP. The SMIPs synthesized from a series of methacrylic acid and its hydroxylalkyl esters as functional monomers have good specificity for TEC. The results of static adsorption experiments showed that the adsorption capacity of SMIP was 6.5 times that of non-molecularly imprinted polymer, which were 152.6 mg g⁻¹ and 23.6 mg g⁻¹, respectively, indicating that SMIP had a larger affinity for TEC. Finally, the SMIP was successfully used as a dispersive solid-phase extraction adsorption material to selectively extract and enrich TEC from the water sample. The limit of detection of the proposed liquid chromatographic method for TEC was 5 μg L⁻¹.

A novel surface molecularly imprinted polymer for specific absorbing teicoplanin in environmental water.

Recent Advances in Functionalized Mesoporous Silica Frameworks for Efficient Desulfurization of Fuels

Considerable health and climate benefits arising from the use of low-sulfur fuels has propelled the research on desulfurization of fossil fuels. Ideal fuels are urgently needed and are expected to be ultra-low in sulfur (10-15 ppm), with no greater than 50 ppm sulfur content. Although several sulfur removal techniques are available in refineries and petrochemical units, their high operational costs, complex operational needs, low efficiencies, and higher environmental risks render them unviable and challenging to implement. In recent years, mesoporous silica-based materials have emerged as promising desulfurizing agents, owing to their high porosity, high surface area, and easier functionalization compared to conventional materials. In this review, we report on recent progress in the synthesis and chemistry of new functionalized mesoporous silica materials aiming to lower the sulfur content of fuels. Additionally, we discuss the role of special active sites in these sorbent materials and investigate the formulations capable of encapsulating and trapping the sulfur-based molecules, which are challenging to remove due to their complexity, for example the species present in JP-8 jet fuels.

Trends in sensitive detection and rapid removal of sulfonamides: A review

Sulfonamides in environmental water, food, and feed are a major concern for both aquatic ecosystems and public health, because they may lead to the health risk of drug resistance. Thus, numerous sensitive detection and rapid removal methodologies have been established. This review summarizes the sample preparation techniques and instrumental methods used for sensitive detection of sulfonamides. Additionally, adsorption and photocatalysis for the rapid removal of sulfonamides are also discussed. This review provides a comprehensive perspective on future sulfonamide analyses that have good performance, and on the basic methods for the rapid removal of sulfonamides.

Novel Thermosensitive Core⁻Shell Surface Molecularly Imprinted Polymers Based on SiO₂ for the Selective Adsorption of Sulfamethazine

In this research, a novel, sulfamethazine, thermosensitive, molecularly-imprinted polymer (MIP) with an obvious core–shell structure for the enrichment of sulfamethazine (SMZ), which involved temperature sensitive monomer N-Isopropylacrylamide, functional monomer methacrylic acid and cross-linking agents ethyleneglycol dimethacrylate (EGDMA) and N,N′-methylenebisacrylamide, was successfully compounded using the surface polymerization method. To ensure the best experimental group, we designed and compared three groups of controlled experiments of MIPs with different crosslinking agents. When the adsorption temperature was almost the lower critical solution temperature (LCST) of Poly(N-Isopropylacrylamide), the preparative MIPs showed outstanding adsorption capacity and specific identification to sulfamethazine. Moreover, this allowed the MIPs to better facilitate by combining the template molecules, as well as optimizing the imprinting factor. In addition, after 80 min, the adsorption of the MIPs leveled off and remained constant, and the adsorption quantity reached (a maximum of) at 8.1 mg·g⁻¹.

Thermo-responsive molecularly imprinted polymer containing magnetic nanoparticles: Synthesis, characterization and adsorption properties for curcumin

A novel intelligent thermoresponsive-magnetic molecularly imprinted polymer (TMMIP) nanocomposite based on N-isopropylacrylamide (NIPAM) & Fe₃O₄ was designed for the controlled & sustained release of Curcumin (CUR) with the ability to response external stimulus. The TMMIP nanocomposite was prepared using acryl functionalized β-cyclodextrin (β-CD) and NIPAM as functional monomers and CUR as target molecule. The recognition cavities which caused by host-guest interactions had direct influence to enhanced drug loading and sustained release of CUR. According to in-vitro release experiment in two different temperatures (below & above LCST of NIPAM) the prolonged & controlled release of CUR were observed. The release rate could be controlled by changing the temperature because of the phase transition behavior of NIPAM monomer. Also, the proposed biosensor displayed effective role in separation science, reasonable adsorption capacity (77mgg^-1), fast recognition (10min equilibration), selective extraction toward CUR in the presence of structural analogues and easily separation using external magnetic field. Moreover, the synthesized TMMIP was confirmed by various characterization.

Synthesis of core–shell imprinting polymers with uniform thin imprinting layer via iniferter-induced radical polymerization for the selective recognition of thymopentin in aqueous solution

Core–shell imprinting microspheres for the selective and rapid recognition of thymopentin with the aid of a novel polymeric ionic liquid.