• YAKHAK HOEJI
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• v.23 no.3_4
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• pp.181-186
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• 1979

A high performance liquid chromatograpic procedure is described for determining ginseng saponins such as ginsenoside-Rb1, -Rb2, -Rc, -Rd, -Re, -Rf, -Rg1, and-Rg2. Ginseng saponins extracted with 90% methanol and water-saturated butanol were compared with pure standard ginsenosides. The resolution of the saponins was satisfactory and detection limit for each saponin was about 5.mu.g. Separation of the saponins was accomplished using a .mu. Bondapak carbohydrate analysis column, mobile phase of acetonitrile-water-butanol (80:20:15) and differential refractive index (RI) detector. The reproducibility and the recovery were also studied. This method was applied for determining the saponin contents of several parts of leaf, fresh ginseng, white ginseng, and red ginseng.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.378-380
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• 1994

The hydrolysis of metampicillin to ampicillin was investigated using high perofrmance liquid chromatography. We developed the simultaneous determination of metampicillin and ampicilin using a Zorbox CN column and 5% acetonitrile and 8% methanol in 0.02 M phosphate buffer (pH 7.0) as mobile phase. Matampicillin was hdyrolyzed to ampicillin with half life of 41.5 min at physiological pH and temperature. In acdic pH, metampicillin was rapidly hydrolyzed to ampicillin within a chromatogrphic separation.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.608-613
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• 1999

Optimum conditions of chiral derivatization reaction of $\beta$-blockers (acebutolol, arotinolol, betaxolol, bisoprolol, celiprolol, metoprolol and pindolol) with (-)-menthyl chloroformate were investigated for the resolution by HPLC. With more than 30 times molar excess of (-)-methyl chloroformate chiral derivatization reactions were completed within one hour at room temperature except arotinolol and celiprolol. Diastereomeric derivatives of $\beta$-blockers were well resolved on the ODS column using acetonitrile-methanol-water as a mobile phase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.581-585
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• 1993

Five flavonoids isolated from the ethyl acetate fraction of Cedrela sinensis A. Juss. were identified by high performance liquid chromatography. Separation was achieved by reversed phase chromatography on ${\mu}-bondapak$ C18 column with isocratic elution method. The content of the major flavonoid, quercitrin was about 9.48%(w/w) and 37.06%(w/w) for the methanol extract and ethyl acetate fraction, respectively.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.35-39
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• 2004

The method for the chiral analysis of (-)-yatein was developed and the distribution of this component in the plants of three genera like Juniperus, Thuja and Chamaecyparis belonging to Cupressaceae family was examined. The chiral analysis of (-)-yatein from the plants was carried out by high performance liquid chromatography on (R,R)-Whelk-O1 column using 81 v/v% methanol as mobile phase. The yatein content in the leaves of Juniperus was the highest in compare with that of the other two genera, providing the possibility of the chemical discrimination of the plants in Juniperus from the other plants in the Cupressaceae family. In general, the yatein content in the leaves was much higher than that in the twigs. This method could be applied for the quality control of (-)-yatein in the plants belonging to Cupressaceae family.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.394.2-394.2
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• 2002

A sensitive and selective reversed-phase LC-ESI-MS method to quantitate pseudoephedrine in human plasma was developed and validated. Phenacetin was used as an internal standard. Samples were prepared simply by acetonitrile precipitation without an evaporation step. Chromatographic separation was achieved on a XTerra MS C18 column ($150{times}2.1$ mm I.D.. 3.5 $\mu\textrm{m}$ particles). using gradient elution with 0.5% (v/v) trifluoroacetic acid (TFA) in water and 0.5% (v/v) TFA in methanol at a flow-rate of 0.1 ml/min. (omitted)

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.283.1-283.1
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• 2003

This study was designed to develop and validate an isocratic reversed phase high performance liquid chromatographic(HPLC) method for the quantitation of sobrerol in drug preparations, and obtain the data pool that can be used in the revision of pharmacopoeia. The separation of sobrerol and the other compounds (S-carboxymethylcysteine, acetaminophen, methyl paraben, propyl paraben, and sobrerol degradants) was achieved in a C18 column with an acetonitrile-methanol-water(24.5:10.5:65.0) mobile phase. (omitted)

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1470-1475
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• 2009

The seed coat of the black soybean contains 3 main anthocyanins such as delphinidin-3-O-$\beta$-glucoside, cyanidin-3-O-$\beta$-glucoside, and petunidin-3-O-$\beta$-glucoside. As a part of our effort on discovering and breeding new black soybean cultivars which possesses specific anthocyanin component rich, we determined the anthocyanin profiles of the 2 cultivars recently developed soybean cv. Gaechuck #1 and cv. Gyeongsang #1, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and compared their content and identity with those of previously known 10 cultivar controls. The Cosmosil-$5C_{18}$-AR-II column were selected for the analysis because of the best peak separation. The column temperature was set up at $35^{\circ}C$. The mobile phase consisting of water containing 0.5%(v/v) formic acid and methanol gave good separation between the 3 anthocyanin analytes and internal standard (quercetin 3-O-$\beta$-rutinoside) and peaks with suppressed tail. The MS/MS spectra of each individual anthocyanin standard were detected in positive electron spray ionization (ESI) modes. It was disclosed that the anthocyanin contents of the soybean cv. Gaechuck#1 and cv. Gyeongsang#1 are roughly higher than those of the 10 controls.

• Analytical Science and Technology
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• v.26 no.4
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• pp.221-227
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• 2013

A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the investigation of the ginsenoside Rg1 in human plasma. After addition of internal standard (digoxin), plasma was diluted with acetone and methanol (80:20), the supernatant was concentrated and analyzed by LC-MS/MS. The optimal chromatographic separation was achieved on an Agilent Eclipse XDB-C18 column ($4.6{\times}150mm$, $5{\mu}m$) with a mobile phase of 0.1% formic acid in water and 0.1% formic acid in methanol at a flow rate of 0.9 mL/min gradient mode. The standard calibration curve for ginsenoside Rg1 was linear ($r^2=0.9995$) over the concentration range 1~500 ng/mL in human plasma. The intra- and inter-day precision over the concentration range of ginsenoside Rg1 was lower than 7.53% (correlation of variance, CV), and accuracy exceeded 98.28%. This LC-MS/MS assay of ginsenoside Rg1 in human plasma is applicable for quantifying in the pharmacokinetic study.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1215-1220
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• 2004

Reactive distillation (RD) is a combination process where both separation and reaction are considered simultaneously in a single vessel. This kind of combination to enhance the overall performance is not a new attempt in the chemical engineering areas. The recovery of ammonia in the classic Solvay process for soda ash of the 1860s may be cited as probably the first commercial application of RD. The RD system has been used for a long time as a useful process and recently the importance of the RD is enlarged more and more. In addition to that, the application fields of RD are diversely diverged. To make the most of the characteristic of RD system, we must decide the best operating condition under which the process shows the most effective productivity and should decide the best control algorithm which satisfies an optimal operating condition. Phosgene which is a highly reactive chemical is used for the production of isocyanates and polycarbonates. Because it has high reactivity and toxicity, its utilization is increasingly burdened by growing safety measures to be adopted during its production. Dimethyl Carbonate (DMC) was proposed as a substitute of phosgene because it is non-toxic and environmentally benign chemical. In this study, RD is used for DMC production process and the transesterification is performed inside of column to produce DMC. In transesterification, the methanol and ethylene carbonate (EC) are used as the reactants. This process use homogeneous catalyst and the azeotrope exists between the reactant and product. Owing to azeotrope, we should use two distillation columns. For this DMC production process, we can suggest two configurations. One is EC excess process and the other is methanol excess process. From the comparison of steady state simulation results where the Naphtali-Sandholm algorithm is used, it showed the better performance to use the methanol excess process configuration than EC excess process. Then, the dynamic simulation was performed to be based on the steady state simulation results and the optimal control system was designed. In addition to that, the optimal operating condition was suggested from previous results.