Preparation and application of a novel magnetic molecularly imprinted polymer for simultaneous and rapid determination of three trace endocrine disrupting chemicals in lake water and milk samples.

Exposure to endocrine disruptor substances will alter the function of the endocrine system and then cause adverse effects on human health. Among these endocrine disrupting chemicals, hexestrol, nonylphenol, and bisphenol A are most commonly used worldwide. In this study, we aim to develop a simple, rapid, and efficient analytical method for the simultaneous determination of trace hexestrol, nonylphenol, and bisphenol A in lake water and milk samples.

Rapid determination of antiviral medication ribavirin in different feedstuffs using a novel magnetic molecularly imprinted polymer coupled with high-performance liquid chromatography.

A novel magnetic molecularly imprinted polymer adsorbing material was successfully synthesized to detect ribavirin in animal feedstuff. Molecularly imprinted polymer was prepared through surface polymerization by using ribavirin as template molecule, methyl methacrylate, and γ-methacryloxypropyl trimethoxy silane functionalized magnetic mesoporous silica as bifunctional monomers, and ethylene diglycidyl ether as crosslinking agent. The prepared magnetic molecularly imprinted polymer was characterized by scanning electron microscopy and infrared spectroscopy.

Simultaneous determination of five organophosphorus pesticide residues in different food samples by solid-phase microextraction fibers coupled with high-performance liquid chromatography.

Background: Excessive or improper use of organophosphorus pesticides (OPPs) may adversely affect human health through the food chain. In the present study, a simple, rapid and effective analytical method was successfully established and used for the determination of OPPs quinalphos and its analogs in different food samples.

Results: Under the optimized experimental conditions, five OPPs (quinalphos, triazophos, parathion, fenthion and chlorpyrifos-methyl) exhibit a good linearity within a range of 0.

Preparation of magnetic ion imprinted polymer with waste beer yeast as functional monomer for Cd(ii) adsorption and detection.

In this work, a magnetic ion imprinted polymer (MIIP) with specific recognition capability toward cadmium was prepared by a sol-gel method using waste beer yeast, which is a macromolecule biomass, as a functional monomer. The obtained Cd(ii)-MIIP was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and adsorption experiments. Then, a MIIP adsorbent based magnetic solid phase extraction (MSPE)-graphite furnace atomic absorption (GFAA) method was established to analyze the cadmium content in food and environmental samples.

Development of molecularly imprinted electrochemical sensor with reduced graphene oxide and titanium dioxide enhanced performance for the detection of toltrazuril in chicken muscle and egg.

A molecularly imprinted electrochemical sensor for toltrazuril (TZR) detection based on molecularly imprinted polymers (MIPs) immobilized on reduced graphene oxide (rGO) and titanium dioxide (TiO) modified platinum (Pt) electrode surface was fabricated for the first time. The synergistic fast electron transfer ability, large electroactive surface area and high catalytic activity from rGO and TiO contribute to amplify the electrochemical signal and consequently improve the sensitivity of the sensor. The cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) tests were used to evaluate the performance of the electrochemical sensor.

Preparation and application of a magnetic plasticizer as a molecularly imprinted polymer adsorbing material for the determination of phthalic acid esters in aqueous samples.

A novel magnetic plasticizer molecularly imprinted polymer adsorbing material (MIP@mSiO -β-CD@Fe O ) was successfully synthesized for the determination of six phthalic acid esters in water, milk, and wine samples. The molecularly imprinted polymers were prepared via precipitation polymerization and a surface molecular imprinting technique, using a cyclodextrin-modified magnetic meso-porous material (mSiO -β-CD@Fe O ) as a magnetic supporter, dibutyl phthalate and butyl benzyl phthalate as the dual template molecules, methacrylic acid as the functional monomer, and ethyleneglycol dimethacrylate as the cross-linking agent. The polymers were characterized by scanning electron microscopy, IR spectroscopy, and X-ray powder diffraction.

Preparation and application of chlorpyrifos molecularly imprinted solid-phase microextraction probes for the residual determination of organophosphorous pesticides in fresh and dry foods.

A solid-phase microextraction probe was prepared on the surface of a stainless-steel wire through molecular sol-gel imprinting technology using chlorpyrifos as a template molecule, tetraethoxysilane as a sol-gel precursor, and acrylamide and β-cyclodextrin as functional monomers. The polymer was characterized by infrared spectrometry and scanning electron microscopy. Moreover, the selectivity and the parameters including the type and volume of the extraction solvents, ionic strength, pH, temperature, extraction time, stirring speed, and desorption time affecting extraction performance were evaluated.

Development of magnetic molecularly imprinted polymers with double templates for the rapid and selective determination of amphenicol antibiotics in water, blood, and egg samples.

A magnetic mesoporous dual-template molecularly imprinted polymer (FeO@mSiO @DMIP) with a specific recognition capability for chloramphenicol (CAP) and florfenicol (FF) was synthesised. CAP and FF were used as dual-template molecules, α-methacrylic acid and FeO@mSiO@-CHCH as dual functional monomers, and ethylene glycol dimethyl methacrylate as a crosslinking agent. For comparison, a magnetic mesoporous non-molecularly imprinted polymer (FeO@mSiO@NIP) was also prepared using the same synthesis procedure, but without the dual templates.

Molecularly imprinted electrochemical sensor based on Au nanoparticles in carboxylated multi-walled carbon nanotubes for sensitive determination of olaquindox in food and feedstuffs.

A novel molecularly imprinted electrochemical sensor (MIECS) was proposed to determine olaquindox (OLA) using gold nanoparticles in molecularly imprinted polymer (AuNPs@MIP) and carboxylated multi-walled carbon nanotubes (cMWCNTs). Glassy carbon electrode (GCE) was modified with cMWCNTs (cMWCNTs/GCE), and AuNPs/cMWCNT/GCE was obtained by electrodeposition on cMWCNTs/GCE using chronoamperometry in HAuCl. Then, the obtained MIP/AuNPs/cMWCNTs/GCE was electropolymerized using OLA as template and o-PD as monomer to determine OLA.

Selective extraction and determination of fluoroquinolones in bovine milk samples with montmorillonite magnetic molecularly imprinted polymers and capillary electrophoresis.

A sensitive and selective method for separating fluoroquinolones (FQs) from bovine milk samples was successfully developed using montmorillonite magnetic molecularly imprinted polymers (MMMIPs) as adsorbents. MMMIPs were prepared using montmorillonite as carrier, fleroxacin (FLE) as template molecule, and Fe3O4 magnetite as magnetic component. MMMIPs possessed high adsorption capacity of 46.

[Preparation and application of di(2-propylheptyl) phthalate molecularly imprinted solid-phase extraction sorbent].

The molecular imprinted polymer (MIP) with high selectivity to di(2-propylheptyl) phthalate (DPHP) was synthesized by precipitation polymerization with dioctyl phthalate (DOP) as dummy template, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EDMA) as cross-linker. The binding ability of the template and functional monomer was investigated by UV spectrometry. Compared with the functional monomer acrylic acid (AA), MAA showed stronger binding capacity to DOP and the best combination mole ratio of 6 : 1.

Characterisation of the essential oil from different aerial parts of Lindera chunii Merr. (Lauraceae).

The essential oils from three organs (i.e. flowers, leaves and stems) of wild Lindera chunii Merr.

Application of response surface methodology to optimise supercritical carbon dioxide extraction of essential oil from Cyperus rotundus Linn.

Supercritical fluid extraction with carbon dioxide (SC-CO2 extraction) was performed to isolate essential oils from the rhizomes of Cyperus rotundus Linn. Effects of temperature, pressure, extraction time, and CO2 flow rate on the yield of essential oils were investigated by response surface methodology (RSM). The oil yield was represented by a second-order polynomial model using central composite rotatable design (CCRD).

Comparative chemical composition of the essential oils obtained by microwave-assisted hydrodistillation and hydrodistillation from Agrimonia pilosa LEDEB. Collected in three different regions of China.

Conventional hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) were performed to obtain the volatile oils of Agrimonia pilosa Ledeb. harvested in three different regions of China, which were subsequently characterized by GC-FID and GC/MS analyses. Compared with HD, MAHD was advantageous in terms of energy savings and extraction time (60 vs.

Comparison of microwave-assisted and conventional hydrodistillation in the extraction of essential oils from mango (Mangifera indica L.) flowers.

Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique, in which a microwave oven is used in the extraction process. MAHD and HD methods have been compared and evaluated for their effectiveness in the isolation of essential oils from fresh mango (Mangifera indica L.) flowers.

Separation of seven fluoroquinolones by microemulsion electrokinetic chromatography and application to ciprofloxacin, lomefloxacin determination in urine.

A simple, reliable microemulsion electrokinetic chromatography (MEEKC) method is developed for the simultaneous separation of seven fluoroquinolones (FQs). The best separation is achieved in a carrier electrolyte containing 1% (v/v) heptane, 100 mmol/L sodium dodecyl sulfate (SDS), 10% (v/v) 1-butanol, and 8 mmol/L phosphate-sodium tetraborate buffer at pH 7.30.

Chiral separation of salbutamol and bupivacaine by capillary electrophoresis using dual neutral cyclodextrins as selectors and its application to pharmaceutical preparations and rat blood samples assay.

An attempt for the simultaneous separation of salbutamol (Sal) and bupivacaine (Bup) enantiomers was performed by capillary elecytrophoresis with a dual mixture of neutral cyclodextrins as chiral selector. The influence on the separation of several parameters such as buffer composition, pH, the concentration ratio of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) to dimethyl-beta-cyclodextrin (DM-beta-CD) was investigated. A better separation was obtained for Sal and Bup with the CD mixtures compared to the use of HP-beta-CD or DM-beta-CD alone.

Separation and determination of norepinephrine, epinephrine and isoprinaline enantiomers by capillary electrophoresis in pharmaceutical formulation and human serum.

A capillary electrophoresis method with ultraviolet (UV) detection was developed and optimized for the enantiomer separation of norepinephrine (NE), epinephrine (EP) and isoprenaline (IP) using dual cyclodextrins (CDs) of 2-hydroxypropyl-beta-CD (HP-beta-CD) and heptakis (2,6-di-o-methyl)-beta-CD (DM-beta-CD) as chiral selectors. Optimal separation was obtained using a running buffer of 50mM phosphate containing 30mM HP-beta-CD and 5mM DM-beta-CD at pH 2.90 and a field strength of 20kV in 45cmx75mum (40cm effective length) uncoated capillary.

[Separation of salicylic acid drugs by aqueous and nonaqueous capillary electrophoresis with conductance detector].

Aim: To develop a method for separating salicylic acid drugs by aqueous and nonaqueous capillary electrophoresis with conductance detector.

Methods: Fused-silica capillary (55 cm x 50 microns ID) was used. The effects of concentration and pH of the running buffer, running voltage and injection time were studied.