• Archives of Pharmacal Research
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• 제19권5호
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• pp.396-399
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• 1996

High-performance liquid chromatographic method with UV detecction was developed for the determination of theophylline and its metabolites in human urine using ${beta}$-hydroxyethyl theophylline$({beta} -HET)$ as an internal standard. For extraction of urine sample, quality control sample and xanthine-free blank urine were mixed with decylamine (ion-paring reagent) and ${beta}$-HET. After saturation with ammonium sulfate, the mixture was then extracted with organic solvent at pH values of 4.0-4.5. All separations were performed with ion-pair chromatography using decylamine as an ion-pairing reagent and 3mM sodium acetate buffered mobile phase (pH 4.0) containing 1% (v/v) acetonitrile and 0.75 mM decylamine. The detection limits of theophylline, 1, 3-DMU, 1-MU, 3-MX and 1-MX in human urine were 0.17, 0.17, 0.39, 0.19 and 0.19 ${\mu}g$/ml, based on a signal-to-noise ratios of 3.0. The mean intraday coefficients of variation (C.V.s) of each compound on nine replicates were lower than 2.0%, while mean interday C.V.s on three days were lower than 1.6%. All separations were finished within 40miutes.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.1043-1047
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• 2008

Simultaneous determination of amitraz, bromopropylate, coumaphos, cymiazole and 2,4-dimethylaniline in 200 honey samples purchased in Korea was performed by reversed-phase high-performance liquid chromatography with multiple UV detection. 2% Acetone in hexane was used for a liquid-liquid extraction and 20-40% water in acetonitrile solutions were used as mobile phases. The LOD for the analytes varied between 0.4 and 1.5 $\mu$g/L and the recoveries were yielded between 64 and 94%. Relative standard deviation of the repeatability of the method is less than 15%. Amitraz was not present in amount above 10 $\mu$ g/L and one for coumaphos and cymiazole and two for bromopropylate, and three for 2,4-dimethylanilne were detected in amount above 10 $\mu$ g/ L. Levels of the acaricide residues found were less than 50 $\mu$ g/L.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2666-2670
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• 2011

High-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) were used to identify five active components in the modified herbal decoction Bo-Yang-Hwan-O-Tang (mBHT), i.e., amygdalin, decursin, paeoniflorin, salvianolic acid B, and calycosin-7-O-${\beta}$-D-glycoside. These components were identified by comparing their retention times and mass spectra with those of reference compounds. The conditions of both analytical methods were optimized and validated. Sufficient separation of target analytes was achieved using a buffer consisting of 40 mM sodium borate and 60 mM sodium dodecylsulfate (SDS) containing 10% methanol (pH 9.5) at 250 nm for CE analysis and gradient elution with a water-methanol mobile phase and ultraviolet (UV) photodiode array detector (DAD) at 250 nm for HPLC analysis. The mBHT components were determined within 65 min by HPLC and 16 min by CE. All calibration curves showed high linearity (R > 0.999) within the ranges tested. Intra-day and inter-day precision were less than 1.6% and 1.8% for HPLC and 2.5% and 4.8% for CE, respectively. The accuracy of the methods ranged from 98.8% to 102.3% for HPLC and from 95.9% to 108.2% for CE.

• 한국식품조리과학회지
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• 제23권1호통권97호
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• pp.99-106
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• 2007

This study investigated the effect of UV-B irradiation on the quality of Pleurotus ostreatus. The changes of vitamin $D_2$ contents, color value and flavor pattern in mushrooms were analyzed by high-performance liquid chromatography (HPLC), chromameter and gas chromatography - surface acoustic wave (GC-SAW) electronic nose. By exposure to UV-B irradiation (0 kj/m$^2$, 10 kj/m$^2$, 20 kj/m$^2$), vitamin $D_2$ content increased from 0 (control) to 48.50 g/g (DM: dry matter, 10 kj/m$^2$) and 61.58 g/g (DM, 20 kj/m$^2$). Although there was no significant difference in L, a, b values among the three groups, flavor changes were detected by GC-SAW electronic nose. The number of peaks increased from 10 in the control group (0 kj/m$^2$), to 14 and 15 for the 10 kj/m$^2$ and 20 kj/m$^2$ groups, respectively. Nevertheless, the changes of flavor pattern were not detrimental to the mushroom quality. These results suggested that UV-B irradiation is an effective method to increase the vitamin $D_2$ content without degrading the quality.

• 한국응용과학기술학회지
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• 제15권3호
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• pp.27-31
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• 1998

Antioxodative substances in Mulberry leaves were examined. Antioxidative substances in Mulberry leaves were extracted by 80% methanol agueous solution. Antioxidative activity of extract was determined by examining hydrogen donating ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the inhibitory effect on the formation of the peroxide from Linoleic acid in the test tube at $50^{\circ}C$. Antioxidative substance were, then, separated and indentified by thin layer chromatography(TLC), UV-Vis spectrum and High performance liquid chromatography(HPLC) methods. Hydrogen donating ability on DPPH and antioxidative ability on linoleic acid of the extracted antioxidative substance were higher than those of 100ppm butylated hydroxy toluene(BHT). The extracted antioxidative substances were separated by TLC using ethylacetate : chloroform : formic acid : water(8 : 1 : 1 : 1 v/v) as a solvent, and a spot at Rf=0.35 was detected. The spot was scraped from the plate, and extrated by methanol. The extract was analyzed by UV-Vis spetra and HPLC, and chlorogenic acid was identified as a antioxidative substance.

• Journal of Applied Biological Chemistry
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• 제59권2호
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• pp.107-112
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• 2016

Pectolinarin was isolated from the ethyl acetate fraction of Cirsium setidens using open column chromatography and was analyzed using spectrometry. Pectolinarin content in Cirsium spp. was determined using HPLC/UV. Pectolinarin content in the aerial part of Cirsium spp. was higher than that in the root and pappus. Pectolinarin content was highest in the aerial part of C. chlorolepis (110.65mg/g extract). Consequently, the aerial part of C. chlorolepis has potential for use in new natural medicinal products, health supplements, and beverages.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.525-532
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• 2000

A new spectroscopic method for pesticide residues detection on agricultural products was developed. The general determination methods are high performance liquid chromatography (HPLC), gas chromatography (GC) or GC-mass spectrometry. They have provided relatively good detection limit and accuracy with complicated and time-consuming (5hrs above) procedures. In addition freshness is very important for evaluating qualities of agricultural products. This requires a simple and fast method for detection of pesticides. Reflectance, transmittance and fluorescence spectrometry of pesticides were tested using UV range because most of pesticides contain conjugation band in the molecular structures. Fluorescence spectrometry showed better sensitive to detect pesticide residues than did reflectance and transmittance spectrometry. Intensity and shape of fluorescence spectra showed different patterns with different structures of pesticides. Detection limit for fluorescence spectrometry was 0.1 ppm to 10 ppm depending on the structures of pesticides. Application of fluorescence spectrometry appears to be an easy method for detection of pesticide residues on agricultural products.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권1호
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• pp.57-68
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• 1998

Polycyclic aromatic hydrocarbons (PAMs) are ubiquitous contaminants in marine environments. PAMs 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 are 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 PAM 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), acenaphthylene (ACNPN), fluorene (FLURN), phenanthrene (PHEN), anthracene (ANTHR), fluoranthene (FLRTH), pyrene (PYR), benzo(a)anthracene (BaA), chrysene (CHRY), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), dibenz(a,h)anthracene(DahA), benzo(g,h,i)peryne (BghiP) and indeno(1,2,3,-cd)pyrene (I123cdP). The PAM contents in oysters from the intertidal and subtidal zones of Chinhae Bay ranged from < 0.1 to 992.0 ug/kg (mean $69.8\pm9.8$ ug/kg).

• 분석과학
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• 제6권4호
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• pp.411-415
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• 1993

지방산을 UV 검출기를 사용하여 HPLC로 분석하기 위하여 2-bromoacetyltriphenylene을 유도체화제로 응용하였다. 18-crown-6-ether를 촉매로 한 유도체화반응은 매우 신속, 간편하고 정량적으로 진행되었으며, HPLC상에서 지방산의 검출한계가 1ng 수준으로 그 감도가 양호하였다. 또한 $C_{12}$부터 $C_{22}$까지 9종류의 포화지방산이 역상컬럼상에서 acetonitrile-물 gradient 조건으로 동시에 분리가 가능하였다. 이를 응용하면 각종 생체 시료로부터 미량의 지방산들에 대한 동시분석이 가능하리라 기대된다.

• KSBB Journal
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• 제30권4호
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• pp.197-201
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• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acids and their methyl and ethyl esters as fluorenylmethoxycarbonyl (FMOC) derivatives was performed using a recently developed chiral column (Chiralpak IE) based on polysaccharide derivative under simultaneous UV detection and fluorescence detection. The degree of enantiomer separation of ${\alpha}$-amino acid esters as FMOC derivatives is generally higher than that of the corresponding ${\alpha}$-amino acids. Especially, ${\alpha}$-amino acid methyl esters showed the greatest enantioseparation. As this method developed in this study can be applied to determine the chemical and optical purity of ${\alpha}$-amino acids and esters, it is expected to be quite useful for their chiral separation using Chiralpak IE.