• Archives of Pharmacal Research
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• v.11 no.2
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• pp.99-113
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• 1988

Quantitation of ethenzamide, isopropylantipyrine and caffeine takes about 41 hrs by conventional GC method. Quantitation of allylisoprorylacetylurea takes about 40 hrs by conventional UV method. But quantitation of them takes about 6 hrs by DRIFT developing method. Each standard and sample sieved, powdered and acquired DRIFT spectrum. Out of them peak of each component was selected and ratio of each peak to standard peak was acquired, and then linear stepwise multiple regression was performed with these data and concentration. Reflectance value, Kubelka-Munk equation and Inverse-Kubelka-Munk equation were modified by us. Inverse-Kubelka-Munk equation completed the deficit of Kubelka-Munk equation. Correlation coefficients acquired by conventioanl GC and UV against DRIFT were more than 0.95.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.13-17
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• 2021

Qantitative analysis of six compounds: (+)-catechin, benzoic acid, gallic acid methyl ester, paeonol, paeoniflorin, and albiflorin from Paeonia lactiflora extracts was performed using high-performance liquid chromatography and an ultraviolet (UV) detector, following different extraction methods. A reverse-phase column was used in a gradient elution system, and UV detection was performed at 280 nm. The results showed that the quantity of paeoniflorin was the highest in ethanol and water extracts (73.89 and 57.87 mg/g, respectively) among the six compounds. This study contributes a good analysis method for the contents of P. lactiflora and would be propitious for developing medicines and functional foods.

• YAKHAK HOEJI
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• v.57 no.3
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• pp.161-166
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• 2013

Sinomenium acutum has been used for the treatment of rheumatoid arthritis, arrhythmia, and pain. We evaluated the quality of S. acutum extract by quantitatively analyzing its components such as sinomenine, magnoflorine and syringaresinol with the simultaneous determination method using HPLC-DAD. A total of 53 samples collected from different localities were evaluated with this quality evaluation method. Sinomenine, magnoflorine and syringaresinol from tested samples ranged from 0.0649~9.1050%, 0.7460~10.7590% and 0.0010~0.2441%, respectively. In the current study, we were able to exhibit the diverse quality of S. acutum samples collected from various locations using the simultaneous determination method.

• YAKHAK HOEJI
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• v.51 no.3
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• pp.174-178
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• 2007

A reverse-phase high performance liquid chromatography method with electrospray ionization and detection by mass spectrometry is described for the simultaneous determination of doxifluridine and its active metabolite 5-flu-orouracil (5-FU) in monkey serum. The method has greater sensitivity and simpler process than previous published methods with good accuracy and precision. A proper liquid/liquid extraction was used to extract simultaneously doxifluridine and 5-FU which has considerable difference in the polarity. Extracts were analyzed using LC/MS/MS providing a short analysis time within 5 min. The lower limit of quantification was validated at 10.0 ng/ml of serum for both doxifluridine and 5-FU. Accuracy and precision of quality control (QC) samples for both analytes met FDA Guidance criteria of ±15% for average QC accuracy with coefficients of variation less than 15%. The method will be applicable for preclinical studies and bioequivalence studies.

• Natural Product Sciences
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• v.22 no.2
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• pp.77-81
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• 2016

A reversed-phase high-performance liquid chromatographic method is described for the simultaneous determination of three antibacterial flavonoids, artocarpanone, artocarpin, and cycloartocarpin in ethyl acetate extracts from Artocarpus heterophyllus heartwoods. Separation was achieved using a TSK-gel ODS-80Tm column ($5{\mu}m$, $4.6{\times}150mm$) at $25^{\circ}C$ with a gradient elution system of methanol and water as follows: 0-8 min, 60:40; 8-27 min, 80:20; 27-35 min, 60:40, v/v, at a flow rate of 1 mL/min, and a quantitative UV detection at 285 nm. The method was validated by measuring the key parameters, including specificity, linearity, sensitivity, accuracy, repeatability and reproducibility. A high degree of specificity and sensitivity was achieved. The calibration curves for all three flavonoids showed good linearity with a coefficient of determinations ($R^2$) of ${\geq}0.9995$. The recoveries of the method were from 98-104%, with good reproducibility and repeatability (RSD values of less than 2%) were also achieved. Ethyl acetate was the best solvent for extraction of these three flavonoids using the heat reflux conditions for 1 h. This optimized sample preparation and HPLC method can be practically used for a routine standardization process of the extracts from the A. heterophyllus heartwoods.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.46-54
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• 1989

The extraction method and quantitative analysis for the fat-soluble vitamins present in food stuffs and vitamin products have been investigated. The simultaneous separation and analysis of the vitamins by reverse phase high performance liquid chromatographic method was conducted using an isocratic elution with methanol : water (95 : 5) eluent on a Novapak $C_{18}$ column. The detection of vitamins was achieved by a variable wavelength UV detector. To improve the detection sensitivity detection wavelengths were set at the highest absorption bands such as 330, 265, 285, and 290nm for the respective vitamins. The analysis for the fat-soluble vitamins was finished within 40 minutes. Alkaline hydrolysis and enzymatic hydrolysis were investigated for the sample preparation; and liquid-liquid extraction and liquid-solid extraction were attempted for the extraction of vitamins. Both hydrolysis methods were turned out to be appropriate for the analysis for vitamins A, D, and E, while for the analysis of vitamin K the enzymatic hydrolysis method demonstrated better results. Diethyl ether, pentane, and n-hexane were found to give higher recovery for the liquid-liquid extraction and silica cartridge for the liquid-solid extraction.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.867-873
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• 2023

In this study, for the purpose of standardized quality control of a cold medicine, we simultaneous analyzed four main chemical components of a cold medicine: acetaminophen, caffeine, methyl paraben, and propyl paraben. The sample was subjected to quantitative analysis using high performance liquid chromatography (HPLC), after pretreatment of four components. The experiment was carried out by using Isocratic elution at wavelength of 270nm. Acetonitrile and water (H₂O) were used as a mobile phase at a flow rate of 1.0mL/min in a commercial C18 reversed-phase column. A volume of 10uL cold medicine were injected into the column with column oven temperature at 35℃. As a result of the experiment, the values of Resolution were 4.983, 1.596, 5.519, and 1.678 respectively-well over Rs >1.5, which indicates that the separation of four components were efficient. In addition, value of symmetry factor of the components was 1.056, 1.069, 1.032, and 1.133 respectively, to show its symmetrical stability. The calibration curve of all four components exhibits good linearity with R² >0.9995 to 0.9999. Furthermore, the limit of detection(LOD) were between 0.0118 to 1.5973 mg/mL, while the limit of quantification (LOQ) were between 0.0353 to 4.7919 ㎍/mL with the recovery rate of 79.6% ~ 120.5%. The results of this study showed an efficient quality evaluation of a simultaneous analysis method for cold medicine components.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.57-61
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• 2021

Saikosaponin derivatives such as saikosaponins A, B1, B2, B3, B4, C, and D present in Bupleurum falcatum were analyzed by a high performance liquid chromatograph equipped with an evaporative light scattering detector, using different extraction solvents (water and 70% ethanol). The samples were injected into a YMC Pack Pro C18 column and separated using a gradient elution system with a mobile phase composed of acetonitrile and water at a flow rate of 1.1 mL/min. The content of saikosaponin derivatives was higher in 70% ethanol extract than in water extract. This study provides an efficient analytical method for determining the optimal conditions for extraction of saikosaponin derivatives, which can be used as a basis for development of functional foods and pharmaceutical products from B. falcatum.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.4
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• pp.169-190
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• 2020

The purpose of this paper is to analyze academic papers published by North Korean scientists, to uncover major areas of research in North Korean science and technology, and to uncover the intellectual structures that underlie these science and technology. Through quantitative analysis, it is to find out who the main research actors are, what research areas are being dealt with, which research areas last a long time, which areas have been discontinued, and which research areas are receiving new attention. In order to detect major research areas and intellectual bases in North Korean science and technology, North Korean scientists' articles were collected from WoS (SCIE). CiteSpace, a scientific quantitative analysis tool, was used to identify major research areas based on author simultaneous citation analysis. The main research areas in North Korea are found to be material properties, vibration analysis, incline matrice, sodium cointercalation, and external magnetic field.

• Analytical Science and Technology
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• v.23 no.2
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• pp.119-127
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• 2010

An effective method for the simultaneous analysis of ${\beta}$-lactams from surface water was established. After solid-phase extraction with HLB (Hydrophilic Lipohilic Balance) cartridge at pH 2, seven ${\beta}$-lactams (amoxicillin, ampicillin, penicillin G, cefaclor, cefadroxil, cefatrizine and cephradine) were determined using LC/ESI-MS/MS. In this newly established method, correlation coefficients ($r^2$) of calibration curves for seven ${\beta}$-lactams in blank surface water appeared to be 0.9911~0.9995 in the concentration range of 0.01~1.0 ng/mL. The limits of detection (LODs) and the limits of quantificaiton (LOQs) in spiked surface water were shown to be 0.0003~0.0234 ng/mL and 0.0046~0.0778 ng/mL, respectively. The developed method is believed to serve as a rapid and reliable method for the qualitative and quantitative analysis of residual ${\beta}$-lactam antibiotics from aquatic environment.