• Proceedings of the PSK Conference
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• 2003.04a
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• pp.305.1-305.1
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• 2003

A simple, specific and sensitive method for the determination of levofloaxcin (LFX) in human serum was developed by a high performance liquid chromatography/diode array detector and applied to pharmacokinetic study of LFX in human volunteers. This method involves several steps such as precipitation with acetonitrile, extraction with methylene chloride, evaporation, and concentration, using 0.5ml of the serum. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.214.1-214.1
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• 2003

Metabonomic analysis using Liquid Chromatography-Mass Spectrometry (LC-MS) was employed to test the feasibility to predict chemical-induced toxicity. Time-dependent metabolic variations were evaluated in rats treated with the model hepatotoxin, ${\alpha}$- naphthylisothiocyanate (ANIT). Urine samples of ANIT treated group and control group were collected up to 7 days postdose. Urine samples were analyzed by gradient HPLC combined with electrospray mass spectrometry. The chromatographic results were data-reduced and analyzed using principal component analysis to show the time dependent biochemical variations induced by ANIT toxicity. (omitted)

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.88-92
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• 2010

DNA structure studies attract many interests in pharmaceutical, biochemical and medical disciplines. Among them, base pairs play a vital role in biological information transfer. Therefore, they need to be analyzed in various ways and the pair of guaninine and cytosine is the present analytical object. Separation of guanine and cytosine was researched by Aspen chromatography simulator and HPLC(High Performance Liquid Chromatography) experiments. Aspen chromatography simulation resulted in various chromatograms with changes of sample concentration, eluent flow rate and number of plate. The resolutions and yields of guanine and cytosine were calculated to obtain a best separation condition. $C_{18}$ HPLC column and water/methanol/acetic acid mixture(90/10/0.2) were used for separation of guanine and cytosine. HPLC parameters(resolution and number of theoretical plate) were calculated under different flow rates and sample concentrations. Aspen chromatography simulation and HPLC experimental results were compared with fair agreement.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.566-569
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• 2005

A novel purification method was developed for producing homoharringtonine from Cephalotaxus koreana, to guarantee high purity and yield. Our simple, efficient procedure for isolating and purifying homoharringtonine from C. koreanabiomass consisted of solvent extraction, synthetic adsorbent treatment, low-pressure chromatography, followed by high performance liquid chromatography (HPLC). The use of active clay treatment and silica gel low-pressure chromatography in the pre-purification process allowed for the rapid, efficient separation of homoharringtonine from interfering compounds and dramatically increased the yield and purity of crude homoharringtonine for high-performance liquid chromatography (HPLC) purification steps compared with alternative processes. Homoharringtonine could be obtained simply with high yield and purity from biomass using this purification method, while minimizing solvent use and the scale and complexity of HPLC operations for homoharringtonine purification. Purified homoharringtonine was identified and characterized.

• Environmental Engineering Research
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• v.23 no.4
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• pp.390-396
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• 2018

This study investigated the transformation of dissolved organic matter (DOM) in a free-water surface flow constructed wetland. Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) coupled with preparative high-performance liquid chromatography (prep-HPLC) was used to analyze the compositions of biopolymers (polysaccharides, amino sugars, proteins, polyhydroxy aromatics, lipids and lignin) in DOM according to the molecular size at three sampling points of the water flow: inflow, midflow, and outflow. The prep-HPLC results verified the decomposition of DOM through the decrease in the number of peaks from three to one in the chromatograms of the sampling points. The Py-GC/MS results for the degradable peaks indicated that biopolymers relating to polysaccharides and proteins gradually biodegraded with the water flow. On the other hand, the recalcitrant organic fraction (the remaining peak) in the outflow showed a relatively high concentration of aromatic compounds. Therefore, the ecological processes in the constructed wetland caused DOM to become more aromatic and homogeneous. This indicated that the constructed wetland can be an effective buffer area for releasing biochemically stable DOM, which has less influence on biological water quality indicators, e.g., biochemical oxygen demand, into an aquatic ecosystem.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.109-113
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• 2017

Single analytical procedure including extraction, liquid chromatography, and mass spectrometric analysis was evaluated for the simultaneous measurement of lysophospholipids (LPLs). LPLs, particularly, lysophosphatidic acids (LPA) and sphingosine 1-phosphate (S1P) are lipid messengers ubiquitously found in various biological matrix. The molecular species mediate important physiological roles in association with many diseases (e.g. cancer, inflammation, and neurodegenerative disease), which emphasize the significance of the simple and reliable analytical method for biomarker discovery and molecular mechanistic understanding. Thus, we developed analytical method mainly focusing on, but not limited by those lipid species S1P and LPA using reverse phase liquid chromatography-tandem mass spectrometry (RPLC-ESI-MS-MS). Extraction method was modified based on Folch method with optimally minimal level of ionization additive (ammonium formate 10 mM and formic acid). Reverse-phase liquid-chromatography was applied for chromatographical separation in combination with negative ionization mode electrospray-coupled Orbitrap mass spectrometry. The method validation was performed on human blood plasma in a non-targeted lipid profiling manner with full-scan MS mode and data-dependent MS/MS. The proposed method presented good inter-assay precision for primary targets, S1P and LPA. Subsequent analysis of other types of LPLs identified a broad range of lysophosphatidylcholines (LPCs) and lysophosphatidyl-ethanolamines (LPEs).

• Journal of the Korean Chemical Society
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• v.38 no.3
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• pp.221-223
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• 1994

We tried to apply the linear solvation energy comparison method to solute retention in normal phase liquid chromatography. Correlation coefficients of regression of lnk' collected in a fixed eluent against solute polarity indices have proven to be lower than those obtained from reversed phase liquid chromatography data. This event can be attributed to complexity of solute retention process in normal phase liquid chromatography. We concluded from the regression results that each specific polarity of the stationary phase is greater than that of the mobile phase and that the difference in each polarity between the stationary phase and the mobile phase decreases as the volume fraction(${\phi}$) of the more polar solvent in the mobile phase increases. Correlations of lnk' of a single solute against solvent polarity indices have proven to be meaningless owing to covariance among the solvent polarity indices. Instead, a good linear relationship between lnk' and solvent ${\pi}^*$ was observed, and its linearity is better than that between lnk' and ${\phi}$.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.412-416
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• 1997

Seven brands of commercial apple juice in Korea obtained from local stores were analyzed for patulin. Sep-Pak silica cartridge purification of the extract by ethyl acetate offered a good separation of patulin from other components. Patulin was determined by reverse phase liquid chromatography using a J'sphere $4\;{\mu}m$ ODS-H80 column with an ultraviolet detector set at 274 nm. Patulin concentrations in four samples ranged from 4 to $20\;{\mu}g/L$ and the other three samples from 30 to $45\;{\mu}g/L$. The limit of detection was $3\;{\mu}g/L$, and the recovery was $80{\sim}90%$ at the contamination level of $3.78{\sim}125.9\;{\mu}g/L$.

• Journal of Environmental Science International
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• v.2 no.1
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• pp.57-68
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• 1993

Polycyclic aromatic hydrocarbons (PAMs) are ubiquitous contaminants in marine environments. PAHs enter estuarine and nearshore marine environment via several routes such as combustion of fossil fuels, domestic and industrial effluents and oil spills PAHs have been the focus of numerous studies in the world because they owe potentially carcinogenic, mutagenic, and teratogenic to aquatic organisms and humans from consuming contaminated food. However, one can hardly find any available data on PAM content in marine organisms in Korea. The present study was carried out in order to determine PAH content in oysters from the intertidal and subtidal zones of Chinhae Bay, which is located in near urban communities and an industrial complex, and the bay is considered to be a major repositories of PAHs. 16 PAHs were analyzed by High Performance Liquid Chromatography (HPLC) with uv/vis and fluorescence detectors in oysters: they are naphthalene (NPTHL), acenaphthylene (ANCPL), acenaphthene (ACNPN), fluorene (FLURN), phenanthrene (PKEN), anthracene (ANTHR), fluoranthene (FLRTH), pyrene (PYRf), benzo(a)anthracene (BaA), chrysene (CHRY), benzo(b)- fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), dibenz(a, h)anthracene (DhA), benzo(g, h, i)peryne (Bghip) and indeno(1, 2, 3, -cd)pyrene (I123cdP). The PAH contents in oysters from the intertidal and subtidal zones of Chinhae Bay ranged from < 0.1 to 992.0 $\mu\textrm{g}$/kg (mean 69.8 $\pm$ 9.8 $\mu\textrm{g}$/kg). Key words . polycyclic aromatic hydrocarbon, high performance liquid chromatography, oyster, Chinhae Bay.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.129-135
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• 2019

Salvia miltiorrhiza Radix is cultivated in Korea and China and is traditionally used to treat cardiovascular diseases. In this study, we developed and validated a quantitative analysis method for S. miltiorrhiza Radix using high-performance liquid chromatography (HPLC). Identification was performed using ultra performance liquid chromatography-tandem mass spectrometry. For quantitative analysis, we used seven marker compounds. Separation conditions for HPLC were optimized using an ODS column with gradient conditions of 1% formic acid in distilled water and 1% formic acid in acetonitrile, with a flow rate of 0.8 mL/min and a detection wavelength of 280 nm. This method showed good linearity ($R^2=0.9998$), precision (relative standard deviation ${\leq}3.3%$), accuracy (recovery of 94.16-102.89%), limit of detection ($7.53{\mu}g/mL$), and limit of quantification ($23.71{\mu}g/mL$). This approach successfully quantified marker compounds in S. miltiorrhiza Radix. The individual marker compounds were identified by comparing the molecular masses and retention times with does standard compounds. Marker compound contents of S. miltiorrhiza Radix were investigated with different cultivation regions. Seven marker compounds were detected and quantified in all samples. Among them, salvianolic acid B showed the highest contents and it ranged from 4.13 to 7.15%. The salvianolic acid B content (7.15%) of marker compound was the highest in Bonghwa, and the tanshinone IIA content (1.90%) was the highest in Pohang. The results of marker compounds and developed method were intended to provide a favorable reference for the study of S. miltiorrhiza Radix from different regions of Korea.