Publications by authors named "Kyung-Ho Row"

Deep eutectic solvents (DES), regarded as promising green solvents, have gained attention due to their distinctive properties, particularly in analytical chemistry. While the use of DES in solvent extraction and separation has been extensively studied, its application in the synthesis of adsorbents has just begun. Phenolic resin, with its polyhydroxy structure and stable spherical morphology, could serve as an effective as adsorbents for enrichment of active ingredients in herbal medicine.

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Article Synopsis
  • Essential oils are complex mixtures vital for various industries, with deterpenation being necessary to enhance product quality.
  • This study introduces a new in situ isolation method using deep eutectic solvents (DESs) to effectively remove terpenes from essential oils.
  • The research identified tetrabutylammonium chloride (TBAC) as the optimal solvent, achieving a successful extraction recovery rate of 81.8-84.4% by evaluating different conditions and molar ratios.
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A novel chiral porous column was fabricated by lipase immobilized MIL-100(Fe) biocomposites as chiral stationary phase through covalent coupling and applied to capillary electrochromatographic enantioseparation. MOF-based lipase biocomposites not only enhance stereoselective activities but also improve the stability and applicability of the enzyme. The functionalized porous columns were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and powder X-ray diffraction.

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In this work, magnetic nitrogen-doped porous carbon (FeO@N-PC) was prepared via incomplete combustion coupled with solvothermal synthesis for extraction of four benzoylureas (BUs) insecticides. Among them, nitrogen-doped porous carbon was produced through incomplete combustion of filter paper loaded with mixture formed by Zn(NO)·6HO and polyethyleneimine solution, and magnetic nanoparticles were further introduced by solvothermal method. Compared with magnetic porous carbon (FeO@PC), the surface hydrophilicity of FeO@N-PC was improved by virtue of the doping of nitrogen atoms, and the dispersion of FeO was more uniform, which greatly exposed the adsorption site.

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Biogenic amines are present in large quantities in fermented foods and are a key marker for assessing food safety. This paper proposes a novel method for high-performance liquid chromatography analysis of biogenic amines using deep eutectic solvent as a mobile phase additive. After screening eight synthetic deep eutectic solvents and comparing them with several common additives, deep eutectic solvents based on choline chloride and ethylene glycol showed significant effects in improving the separation of biogenic amines.

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In this work, a magnetic molecularly imprinted chitosan membrane (MMICM) was synthesized for the extraction of chlorobenzene compounds in environmental water using the membrane separation method. The optimal extraction amount for chlorobenzene (9.64 mg·L) was found to be a 1:2 solid to liquid ratio, with a 20 min extraction time and 35 °C extraction temperature.

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  • Biphasic chiral recognition was used to separate acidic drugs in capillary electrochromatography, utilizing β-cyclodextrin as a mobile phase additive and a monolithic chiral stationary phase made from proteins.
  • A specialized pretreated capillary was coated with a ligand and the chiral stationary phase was created using bovine serum albumin and pepsin through a single-step polymerization process.
  • The system achieved excellent separation efficiency for various acidic drugs, with consistent results across multiple tests, demonstrating its potential for effectively separating chiral compounds.
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Nanozymes with multiple activities have drawn immense interest owing to their great prospect in biochemical analysis. Fabricating nanomaterials-based artificial enzymes for multiple-enzyme mimetic activity is a significant challenge. This paper reports a sensitive biosensing platform to mimic the peroxidase, oxidase, and catalase-like activity by bimetallic CuPd embedded holey carbon nitride (CuPd@H-CN).

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Growing concerns related to antibiotic residues in environmental water have encouraged the development of rapid, sensitive, and accurate analytical methods. Single-drop microextraction has been recognized as an efficient approach for the isolation and preconcentration of several analytes from a complex sample matrix. Thus, single-drop microextraction techniques are cost-effective and less harmful to the environment, subscribing to green analytical chemistry principles.

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β-Sitosterol is a major bioactive constituent in plants with potent anticancer effects against many human cancer cells, but its bioavailability and therapeutic efficacy are limited by its poor solubility in water. In this study, C -imidazole chitosan, C -1-methylimidazole chitosan, C -1-ethylimidazole chitosan, C -1-vinylimidazole chitosan, C -1-allylimidazole chitosan, and C -1-butylimidazole chitosan were prepared to extract β-sitosterol from edible oil samples via ultrasonic-assisted solid liquid extraction. The structures and properties of the newly synthesized products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and elemental analysis.

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  • - A highly efficient open tubular capillary electrochromatography (OT-CEC) column was developed for separating peptides by creating a two-layer copolymer on a silica-fused capillary.
  • - The optimal conditions for this separation process, such as buffer pH and organic modifiers, were systematically tested, leading to impressive separation results with 2.4 million theoretical plates achieved.
  • - The OT-CEC column demonstrated excellent stability and repeatability, effectively separating over 18 peptides from cytochrome C tryptic digests, indicating its strong potential for protein separation in future applications.
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A reliable and efficient method for the simultaneous extraction and determination of antibiotics of ciprofloxacin and levofloxacin from milk was developed with solid phase extraction based on tailored adsorbent materials of deep eutectic solvents modified phenolic resin (DES-R-SPE). Six types of polyhydric alcohol-based hydrophilic DESs were prepared to modify the phenolic resin with the compositions of 3-aminophenol as a functional monomer, glyoxylic acid as a crosslinker, and polyethylene glycol 6000 as a porogen. And the prepared DES-Rs showed better extraction capacities for the target analytes than the unmodified phenolic resin because of more hydrogen bonding and electrostatic interactions supplied by DESs.

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A visual, rapid, and sensitive micro-solid phase extraction method was developed for the detection of p-hydroxybenzoic acid using molecularly imprinted chitosan microspheres based on deep eutectic solvents, both as a functional monomer and template. The parameters were optimized by using the response surface methodology strategy. The extraction capacity of p-hydroxybenzoic acid from pear rind under the optimized conditions using response surface methodology was 46.

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A deep eutectic solvent (DES) was prepared from choline chloride (ChCl) and methacrylic acid (MAA) and used as an eco-friendly surfactant and functional monomer. The process of producing DES and its free energy of formation (ΔG = -37.225 kcal mol-1) were evaluated theoretically by density-functional theory.

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A type of molecular-imprinted polymer with magnetic molybdenum disulfide as a base and deep eutectic solvent as a functional monomer (FeO@MoS@DES-MIP) was prepared with surface molecular imprinting method. It was applied as the adsorbent for the selective recognition and separation of (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate, and (-)-epigallocatechin gallate in green tea in the process of magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography (HPLC). The structure of FeO@MoS@DES-MIP was characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy.

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Novel molecularly imprinted chitosan microspheres were prepared on the surface of magnetic graphene oxide, with deep eutectic solvents both as a functional monomer and template. The prepared molecularly imprinted chitosan microspheres-magnetic graphene oxide was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area, thermogravimetric analysis were subsequently combined with solid-phase micro-extraction for simultaneous separation and enrichment of the extraction of chlorophenols from environmental water. Factors affecting the extraction efficiency of chlorophenols were optimized using response surface methodology.

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Water pollution, especially by inorganic and organic substances, is considered as a critical problem worldwide. Several governmental agencies are listing an increasing number of compounds as serious problems in water because of their toxicity, bioaccumulation, and persistence. In recent decades, there has been considerable research on developing analytical methods of heavy metal ions and organic pollutants from water.

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Hexagonal boron nitride (h-BN) is introduced as a 2D scaffold during the preparation of molecularly imprinted polymers (MIPs). The MIPs were prepared from deep eutectic solvents (DES) or from DES containing h-BN, crosslinking agent (ethylene glycoldimethacrylate), initiator (AIBN), porogen (methanol), and template (quercetin). The recognition site of the monomer is protected by the hydrogen bond of the DES before the MIP is polymerized.

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The utilization of microalgae as bioenergy source was limited by the excessive cost and energy consumption during the process of lipid extraction and separation. CO-induced switchable ionic liquids (S-ILs) with reversible hydrophobic-hydrophilic conversion were synthesized and applied for lipid extraction and separation. The reversible transition mechanism of switchable IL is due to the formation of carbamate.

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Hydrophilic and hydrophobic deep eutectic solvents (DESs) as "green" solvents were applied in this study for the microextraction of environmental samples. A series of DESs (five hydrophilic and three hydrophobic) were synthesized and characterized by Fourier transform infrared spectroscopy. Physicochemical property parameters of eight DESs including water solubility, density, conductivity, and freezing point were assessed.

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A protein-based molecularly imprinted monolithic column was synthesized based on ionic liquids (ILs) and deep eutectic solvents (DESs) in a stainless steel column (50 mm × 4.6 mm id). An IL (1-allyl-3-butylimidazolium Br) and acrylamide were used as dual monomers.

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Hydrophilic molecularly imprinted chitosan (HMICS) were synthesized based on hydrophilic deep eutectic solvents (DESs) and the DESs was used as both a template and functional monomer for the enrichment of gallic acid (GA) from red ginseng tea using a solid phase microextraction (SPME) method. Using the response surface methodology (RSM) strategy, the optimal extraction amount (8.57 mg·g) was found to be an extraction time of 30 min, a solid to liquid ratio of 20 mg·mL, and five adsorption/desorption cycles.

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Introduction: Ephedrine is a typical compound found in lots of plant species that is used in several medicines for the treatment of asthma and bronchitis. However, excess amounts are harmful to humans, so it needs to be removed.

Objective: This study developed a multi-phase extraction (MPE) method with a molecular imprinted polymer (MIP) coated ionic liquid (IL)-based silica (SiO @IL@MIP) to simultaneously extract and separate ephedrine from Pinellia ternata, 10 medicines, and urine samples.

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Aristolochic acid I is a toxic compound found in the genus of Aristolochia plants, which are commonly used as herbal cough treatment medicines. To remove the aristolochic acid I in extract efficiently and selectively, a molecularly imprinted polymer composed of ethylimidazole ionic liquid-based zeolitic imidazolate framework-67 was synthesized and used as the adsorbent. Under the conditions optimized by the software design expert, the sorbent showed highest adsorption amount of 34.

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Quercetin is a phytochemical with disease prevention and health promotion activities that has attracted significant research attention. In this study, choline chloride and betaine-based natural deep eutectic solvents were prepared using a heating method. Their physical and chemical properties were also tested.

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