• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2637-2642
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• 2011

A new ultrasonic-assisted micellar extraction and cloud-point pre-concentration method was developed for the determination of major saikosaponins, namely saikosaponins -A, -C and -D, in Radix Bupleuri by high performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD). The non-ionic surfactant Genapol X-080 (oligoethylene glycol monoalkyl ether) was chosen as the extraction additive and parameters affecting the extraction efficiency were optimized. The highest yield was obtained with 10% (w/v) Genapol X-080, a liquid/solid ratio of 200:1 (mL/g) and ultrasonic-assisted extraction for 40 min. In addition, the optimum cloud-point pre-concentration was reached with 10% sodium sulfate and equilibration at $60^{\circ}C$ for 30 min. Separation was achieved on an Ascentis Express C18 column (100 ${\times}$ 4.6 mm i.d., 2.7 ${\mu}M$) using a binary mobile phase composed of 0.1% acetic acid and acetonitrile. Saikosaponins were detected by ELSD, which was operated at a $50^{\circ}C$ drift tube temperature and 3.0 bar nebulizer gas ($N_2$) pressure. The water-based solvent modified with Genapol X-080 showed better extraction efficiency compared to that of the conventional solvent methanol. Recovery of saikosaponins ranged from 93.1 to 101.9%. An environmentally-friendly extraction method was successfully applied to extract and enrich major saikosaponins in Radix Bupleuri.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.491-501
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• 2002

A cross-examination between KT&G Central Research Institute and Guangzhou Institute for Drug Control was carried out in order to select optimum conditions for extraction, separation and determination of ginsenosides in red ginseng and to propose a better method for the quantitative analysis of ginsenosides. The optimum extraction conditions of ginsenosides from red ginseng were as follows: the extraction solvent, $70\%$ methanol; the extraction temperature, $100^{\circ}C;$ the extraction time, 1 hour for once; and the repetition of extraction, twice. The optimum separation conditions of ginsenosides on the SepPak $C_{18}$ cartridge were as follows: the loaded amount, 0.4 g of methanol extract; the washing solvents, distilled water of 25 ml at first and then $30\%$ methanol of 25 ml; the elution solvent, $90\%$ methanol of 5 ml. The optimum HPLC conditions for the determination of ginsenosides were as follows: column, Lichrosorb $NH_2(25{\times}0.4cm,$ 5${\mu}m$, Merck Co.); mobile phase, a mixture of acetonitrile/water/isopropanol (80/5/15) and acetonitrile/water/isopropanol (80/20/15) with gradient system; and the detector, ELSD. On the basis of the optimum conditions a method for the quantitative analysis of ginsenosides were proposed and another cross-examination was carried out for the validation of the selected analytical method conditions. The coefficient of variances (CVs) on the contents of ginsenoside-$Rg_{1}$, -Re and $-Rb_1$ were lower than $3\%$ and the recovery rates of ginsenosides were $89.4\~95.7\%,$ which suggests that the above extraction and separation conditions may be reproducible and reasonable. For the selected HPLC/ELSD conditions, the CVs on the detector responses of ginsenoside-Rg, -Re and $-Rb_1$) were also lower than $3\%$, the regression coefficients for the calibration curves of ginsenosides were higher than 0.99 and two adjacent ginsenoside peaks were well separated, which suggests that the above HPLC/ELSD conditions may be good enough for the determination of ginsenosides.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권1호
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• pp.47-51
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• 2004

Ceramide III was prepared by the cultivation of Saccharomyces cerevisiae. Ceramide III was partitioned from the cell extracts by solvent extraction and analyzed by Normal Phase High Performance Liquid Chromatography (NP-HPLC) using Evaporative Light Scattering Detector (ELSD). We experimentally determined the mobile phase composition to separate ceramide III with NP-HPLC. Three binary mobile phases of n-hexane/ethanol, n-hexane/lsoprophyl Alcohol(IPA) and n-hexane/n-butanol and one ternary mobile phase of n-hexane/IPA/methanol were demonstrated. For the binary mobile phase of n-hexane/ethanol, the first mobile phase composition, 95/5(v/v), was step-increased to 72/23(v/v) at 3 min. In the binary mobile phase, the retention time of ceramide III was 7.87min, while it was 4.11 min respectively in the ternary system, where the mobile phase composition of n-hexane/IPA/methanol, 85/7/8(v/v/v), was step-increased to 75/10/15(v/v/v) at 3 min. However, in the ternary mobile phase, the more peak area of ceramide III was observed.

• 한국자동차공학회논문집
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• 제19권4호
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• pp.38-46
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• 2011

This paper presents roll angle estimator which used Kalman filter. Recently, the uses of the ELSD (Electronic Limited Slip Differential) and TVD(Torque Vectoring Differential) for vehicle yaw control are studied in many researches. However the roll angle can be negative effect of ELSD and TVD control. Therefore the information of roll angle can be used for vehicle yaw control. Moreover it can be used for rollover prevent control. Recently, most of the vehicles use lateral acceleration and yaw rate sensor. In this paper, design of Kalman filter which used lateral acceleration and yaw rate information is developed. In this paper, in order to verify the estimator ability, the CarSim and Matlab/Simulink are used.

• 한국응용과학기술학회지
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• 제30권4호
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• pp.664-671
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• 2013

역상 HPLC 에 의한 화장품에 사용하는 수용성 고분자인 Xanthan gum의 간편하고 정확한 정량분석 방법을 개발하였다. 분석조건은 $C_{18}$분리관과 ELSD 검출기를 사용하였으며, 25mM ammonium acetate/acetonitrile의 기울기 용리에 의해 분리 되었다. 이때 검량선의 상관계수(correlation coefficient) $r^2=0.9993$, 정량범위 $50.3{\sim}604.1{\mu}g/ml$, 검출한계 $12.0{\mu}g/ml$ 및 정확성이 우수하였다. 이 방법은 화장품 중 Xanthan gum를 정확하고 간편하게 정량분석 가능함을 보여 주었다.

• 한국응용과학기술학회지
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• 제29권4호
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• pp.585-593
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• 2012

역상 HPLC에 의한 polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80의 ethylene oxide(EO)분리 및 간편하고 빠른 정량분석 방법을 개발하였다. 분석조건으로 분리관은 YMC Pack Ph ($250mm{\times}4.6mm$ i.d., $5{\mu}m$) 과 Phenomenex C4 ($250mm{\times}4.6mm$ i.d., $5{\mu}m$)을 사용하였고, 검출기는 ELSD를 사용하였으며, 이동상은 water/acetonitrile의 기울기 용리에 의해 분석되었다. 이때 검량선의 상관계수($r^2$)는 $180.2{\sim}980.5{\mu}g/mL$ 농도 범위에서 0.997이상 이었고, 검출한계, 정밀성이 우수하였다. 이 방법은 olysorbates의 산화에틸렌 분리분석 및 간편하고 빠르게 정량분석 가능함을 보여 주었다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.553-558
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• 2012

A simple new method was developed for the determination of betaine in Fructus Lycii using hydrophilic interaction liquid chromatography with evaporative light scattering detection (HILIC-ELSD). Good chromatographic separation and reasonable betaine retention was achieved on a Kinetex HILIC column ($2.1{\times}100mm$, $2.6{\mu}m$) packed with fused-core particle. The mobile phase consisted of (A) acetonitrile and (B) 10 mM ammonium formate (pH 3.0)/acetonitrile (90/10, v/v). It was used with gradient elution at a flow rate of 0.7 mL/min. The column temperature was set at $27.5^{\circ}C$ and the injection volume was $10{\mu}L$. The ELSD drift tube temperature was $50^{\circ}C$ and the nebulizing gas (nitrogen) pressure was 3.0 bar. Stachydrine, a zwitterionic compound, was used as an internal standard. Calibration curve over $10-250{\mu}g/mL$ showed good linearity ($R^2$ > 0.9992) and betaine in the 70% methanol extract of Fructus Lycii was well separated from other peaks. Intraand inter-day precision ranged from 1.1 to 3.0% and from 2.4 to 5.3%, respectively, while intra- and inter-day accuracy ranged from 100.0 to 107.0% and from 94.3 to 103.9%, respectively. The limit of quantification (LOQ) was $10{\mu}g/mL$ and the recoveries were in the range of 98.2-102.7%. The developed HILIC-ELSD method was successfully applied to quantitatively determine the amount of betaine in fourteen Fructus Lycii samples from different locations, demonstrating that this method is simple, rapid, and suitable for the quality control of Fructus Lycii.

• 한국약용작물학회지
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• 제7권1호
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• pp.45-50
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• 1999

지모의 고품질 품종 육성 및 재배법 개선과 유통중인 생약으로서의 안전성을 위한 품질 평가 기준을 설정하기 위해 지모의 지표성분의 HPLC 분석법을 확립하고자 하였다. 먼저 지모의 유효성분을 분리하고 지표성분화 한 후 HPLC 분석 정량법을 검토하므로써 지모의 품질 분석법을 구명한 결과는 다음과 같다. 지모를 MeOH로 대량 추출하여 계통 추출법으로 용매분배 후 조사포닌 분획인 n-BuOH ext.를 얻었으며 이 n-BuOH ext. 을 silica gel 컬럼 크로마토그래피를 수행하여 화합물 1를 순수 분리 정제하였다. 화합물 1의 $^1H$, $^{13}C$ NMR spectra 등을 검토한 결과 화합물 1은 지모의 주요 약효성분인 timosaponin A III로 확인되었다. Timosaponin A III은 지모의 주요 성분이자 혈당 강하작용과 항암활성 등의 주요 약효를 보이는 성분으로 지모의 품질 평가 기준으로서 지모의 지표성분으로 하기에 적합하였다. Timosaponin A III의 HPLC 분석법 확립을 위해 ELSD 검출기 가 사용되었으며 ODS계 컬럼을 사용하고 60% acetonitrile를 이동상으로 하여 0.9ml/min의 유속으로 분석을 한 것이 가장 적절한 timosaponin AIII의 HPLC 분석 조건이었다. Timosaponin AIII의 HPLC 분석을 위한 지모 시료의 추출조건 검토에서는 1g 분말시료를 80% MeOH를 추출용매로 할 때 $80^{\circ}C$에서 총 2회 환류 추출하는 것이 성분의 총 회수율을 가장 높이는 추출조건이었다.

• Journal of Ginseng Research
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• 제35권1호
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• pp.31-38
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• 2011

In order to distinguish the cultivation area of Panax ginseng, principal component analysis (PCA) using quantitative and qualitative data acquired from HPLC was carried out. A new HPLC method coupled with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous quantification of ten major ginsenosides, namely $Rh_1$, $Rg_2$, $Rg_3$, $Rg_1$, Rf, Re, Rd, $Rb_2$, Rc, and $Rb_1$ in the root of P. ginseng C. A. Meyer. Simultaneous separations of these ten ginsenosides were achieved on a carbohydrate analytical column. The mobile phase consisted of acetonitrile-water-isopropanol, and acetonitrile-water-isopropanol using a gradient elution. Distinct differences in qualitative and quantitative characteristics for ginsenosides were found between the ginseng roots produced in two different Korean cultivation areas, Ganghwa and Punggi. The ginsenoside profiles obtained via HPLC analysis were subjected to PCA. PCA score plots using two principal components (PCs) showed good separation for the ginseng roots cultivated in Ganghwa and Punggi. PC1 influenced the separation, capturing 43.6% of the variance, while PC2 affected differentiation, explaining 18.0% of the variance. The highest contribution components were ginsenoside $Rg_3$ for PC1 and ginsenoside Rf for PC2. Particularly, the PCA score plot for the small ginseng roots of six-year old, each of which was light than 147 g fresh weight, showed more distinct discrimination. PC1 influenced the separation between different sample sets, capturing 51.8% of the variance, while PC2 affected differentiation, also explaining 28.0% of the variance. The highest contribution component was ginsenoside Rf for PC1 and ginsenoside $Rg_2$ for PC2. In conclusion, the HPLC-ELSD method using a carbohydrate column allowed for the simultaneous quantification of ten major ginsenosides, and PCA analysis of the ginsenoside peaks shown on the HPLC chromatogram would be a very acceptable strategy for discrimination of the cultivation area of ginseng roots.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2210-2212
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• 2014