• Mass Spectrometry Letters
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• v.13 no.4
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• pp.158-165
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• 2022

Many therapeutic class drugs such as beta-blocker, corticosteroids, NSAIDs, etc are prohibited substances in the horse racing industry. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology makes it possible to isolate drugs from interference, enables various drug analyses in complex biological samples due to its sensitive sensitivity, and has been successfully applied to doping control. In this paper, we describe a rapid and sensitive method based on solid-phase extraction (SPE) using solid phase cartridge and LC-MS/MS to screen for different class's 35 drug targets in equine plasma. Plasma samples were pretreated by SPE with the NEXUS cartridge consisted non-polar carbon resin and minimum buffer solvent. Chromatographic separation of the analytes was performed on ACQUITY HSS C18 column (2.1 × 150 mm, 1.8 ㎛). The elution gradient was conducted with 5 mM ammonium formate (pH 3.0) in distilled water and 0.1% formic acid in acetonitrile at a flow rate of 0.25 mL/min. The selected reaction monitoring (SRM) mode was used for drug screening with multiple transitions in the positive ionization mode. The specificity, limit of detection, recovery, and stability was evaluated for validation. The method was found to be sensitive and reproducible for drug screening. The method was applied to plasma sample analysis for the proficiency test from the Association of Racing Chemist.

• FOCUS: LIFE SCIENCE
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• no.1
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• pp.4.1-4.15
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• 2024

The Avantor® ACE® UltraCore series encompasses High Performance Liquid Chromatography (HPLC) and Ultra High Performance Liquid Chromatography (UHPLC) columns designed to deliver high throughput and high-efficiency ultra-fast separations. Utilizing ultra-inert solid-core silica particles with monodisperse particle distribution, these columns combine the high efficiency of UHPLC with the operability of HPLC instrumentation, yielding lower backpressure and high-resolution separations suitable for a broad spectrum of analytes. The Avantor® ACE® UltraCore range includes three primary product types: • UltraCore BIO: Designed for large biomolecules (≥5 kDa), these columns offer exceptional performance in separating biologically derived compounds. • UltraCore: Ideal for standard small organic molecules, providing rapid separations for both synthetic and natural mixtures. • UltraCore Super: Equipped with encapsulated bonding technology for small organic molecules in extreme pH conditions, optimal for high pH buffer requirements. The Avantor® ACE® UltraCore columns present a versatile and high-efficiency solution for chromatographic separation needs, accommodating a wide range of molecular sizes and providing enhanced resolution and reduced analysis time. Their adaptability to both HPLC and UHPLC systems, combined with the advantages of solid-core technology, makes them an invaluable tool in analytical and preparative chromatography.

• Clean Technology
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• v.7 no.1
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• pp.27-34
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• 2001

The waste slurry generated from CMP process contains particulate and heavy metals. It is hard to treat the waste slurry by conventional treatment method because the particulates in the waste are too fine to be easily separated the solid from the waste for the purpose of water recycling. The investigation was focused on finding the optimum condition of coagulation with two different coagulants. When the solid content in the waste slurry solution was 0.1wt%, the optimal ranges of pH and PACl concentration were 4~6 and 20~50 mg/L, respectively. When the solid content was increased to 0.5wt%, the optimal condition was 4~5 for pH and 50~100 mg/L for PACl concentration.

• YAKHAK HOEJI
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• v.46 no.6
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• pp.392-397
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• 2002

A simple and sensitive high performance liquid chromatographic method to quantitate ursodeoxycholic acid in crude drug pharmaceuticals was investigated. Ursodeoxycholic acid react with 2-bromoacetyl-6-methoxynaphthalene (Br-AMN) in the presence of triethylamine to form highly fluorescent derivative. The derivatization procedure was performed at 7$0^{\circ}C$ and completed within 30 min. The optimal wavelength of the fluorescence detector are λ$_{ex}$=300 nm and λ$_{em}$ = 460 nm. The LOD of the ursodeoxycholic acid was 25 ng/mι based on the S/N =3, and the LOQ was 80 ng/mι based on S/N = 10. Crude drug pharmaceuticals pretreated by solid phase extraction (Sep-pak $C_{18}$ cartridge) which were shown very good separation and recovery values for the compound.d.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1633-1635
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• 1996

This phenomena of streaming-electrification is generated between solid and liquid boundary called electric double-layer which is generated by potential difference. A charge separation at interfaces between a moving fluid and a solid boundary can give rise to the generation of substantial electric field and at last these can give rise ta insulating failure. Therefore injection of the adverse-charge in streaming-electrified insulating oil to eliminate the accumulation charge and its related phenomena was investigated.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1845-1852
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• 2001

This paper deals with the experiment to obtain quantitative information about conditions of the interface between a water drop and surrounding oil. Velocity distributions in very close region of the interface are measured by introducing a new illumination technique and a telecentric lens. It enables precise measurements of velocity distributions in the close region to the interface. Although the measured velocity distributions exhibit strong influence from the solid wall of an experimental tube, the coincidence of inner and outside velocities on the interface is clearly confirmed for the clean interface. The shearing stresses on the interface, which are proportional to the velocity gradient normal to the interface, clearly show conditions of contaminated interface, which can be divided into two parts. From front stagnation point to somewhere near a separation point, the distribution of shearing stresses is well coincide with that of the Hadamard's analytical solution, while the distribution on the latter part of the interface sows quite different feature, which is supposed to be strongly influenced by contamination of the surface.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.04a
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• pp.1-11
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• 1993

Cartridge filters are widely used in liquid-solid separation processes. To select a proper filter system for the requirements of a given application, a knowledge of filter efficiency and dirt capacity is required. The filter manufacturer needs to provide data which are based on test procedures simulating real parameters on a laboratory scale. There does not exist at present a standard for liquid filter testing (with the exception of the Multipass Test to ISO4752 for hydraulic filters). Users have to work with data based on different test procedures. This paper will discuss principles of filter testing, efficiency andd dirt capacity results as a function of test parameters, and data interpretion to provide a guideline for the end user.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.1
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• pp.61-70
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• 2005

In order to reduce salt(as NaCl) contents in food waste and to improve the quality of discharged wastewater produced during the recycling process of food waste for the purpose of compost and feed stuff, a salt reduction process by added water into food waste was developed. The pilot plant with a rotary type salt reduction equipment to manage continuously 0.5 ton food waste per hour was constructed and the efficiency was tested. The amount of added water was calculated by the water content and the efficiency of dewatering process of food waste. Approximately 0.8 liter water per a kilogram of food waste was injected into the reactor in which food waste was pouring simultaneously, then diluted/mixed in a rotary reactor. About 1.1 liter of leachate including added water was generated, but the leachate contained a very high content of organic particles, so most particles were recovered by two step solid-liquid separation process. The first step was a gravitational filtering process using screens with a pore diameter of 1mm, and the second separation process was centrifugal process. Organic quality of food waste which had been desalted was maintained by inputting the entirely recovered organic particles. The efficiency of salt reduction of food waste was estimated by measuring a chloride anion by titration and salinity by a probe. The results by the two different measuring methods were always over 50%, and the quality of final wastewater was improved up to $200mg/{\ell}$ as TS(total solid) by an additional settling process after the two step solid-liquid separation process.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2724-2730
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• 2012

A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [$PYC_4SO_3H$][$HSO_4$], and characterized using FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.

• Journal of Animal Environmental Science
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• v.19 no.2
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• pp.169-176
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• 2013

This survey was conducted to investigate the present conditions of operational management in the 45 animal manure public resource center (APRC) in Korea. The regional distribution, processing capacity per year, capacity of liquid fertilizer storage tank, solid-liquid separation, utilization of facilities, odor reduction facility, on-site odor strength, complained in the community, liquid fertilizer sprayed area, use the Agrix, land application recipe, composting degree, quality management and general grading were surveyed and evaluated. General grading was divided with 5 stages (very good, good, fair, lack and bad). The number of evaluated "very good" animal manure public resource center was 7, and "good" was 5 and more than "fair" was 27. However, the number of evaluated negatively including "lack" and "bad" was occupied as 40% of the 45 animal manure public resource center.