• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.316-321
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• 2001

The Acanthopanax genus belonging to the Araliaceae family is widely used as a traditional medicine having tonic and sedative effects. For the quality control of Acanthopanacis Cortex, lignan compound, acanthoside D, was isolated from the MeOH extract of Acanthopanax sessiliforum Seeman. (Araliaceae) and identified by the spectroscopic analysis. A quantitative analysis of acanthoside D using HPLC method showed that the average contents were $0.081{\pm}0.058%$ in 39 samples collected throughout the regions of Korea.

• Clean Technology
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• v.17 no.3
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• pp.215-224
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• 2011

It is an important issue to develop quality assessing system for biofuel for the purpose of accelerating the mass production of biofuel. It is particularly challenging to conduct testing method in the mass production of bioethanol while meeting quality specifications such as ASTM (American Society for Testing & Materials) D4806-10. In order to address this challenge, this paper proposes on-line spectroscopic quality assesment system based on Near Infrared spectrum and Partial Least Squares method in Chemometrics. As a result of testing a number of preprocessing methods and Partial Least Squares, it was found out that Savitzky-Golay method showed the best performance in terms of spectrum correction, noise reduction, and model maintenance. The proposed system allows us to assess multiple quality components continuously using spectroscopic facilities with the cheap cost. Since the value of R2 is more than 0.99, it is possible to replace the laboratory analysis.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2002.11a
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• pp.97-117
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• 2002

A chemoinfometrical method for quantitative determination of crystal content of indomethacin (IMC) polymorphs based on fourie-transformed near-infrared (FT-NIR) spectroscopy was established. A direct comparison of the data with the ones collected from using the conventional powder X-ray diffraction method was performed. Pure $\alpha$ and ${\gamma}$ forms of IMC were prepared using published methods. Powder X-ray diffraction profiles and NIR spectra were recorded for six kinds of standard materials with various content of ${\gamma}$ form IMC. The principal component regression (PCR) analyses were performed based on normalized NIR spectra sets of standard samples of known content of IMC ${\gamma}$ form. A calibration equation was determined to minimize the root mean square error of the prediction. The predicted ${\gamma}$ form content values were reproducible and had a relatively small standard deviation. The values of ${\gamma}$ form content predicted by two methods were in close agreement. The results were indicated that NIR spectroscopy provides for an accurate quantitative analysis of crystallinity in polymorphs compared with the results obtained by conventional powder X-ray diffractometry.

• Tribology and Lubricants
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• v.35 no.3
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• pp.151-157
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• 2019

Insulated oil degradation produces charged by-products, such as acids and hydro-peroxides, which tend to reduce the insulating properties of the oil. In this study, UV-vis spectroscopy measurement technology is developed and experimentally compared with other measurement methods, such as the titration method and IR spectroscopy, to validate its ability to monitor the degradation of electrical insulating paper. The degradation characteristics of the insulating paper are appropriately represented through various types of measurement methods, such as the Tan (delta) method, $CO_2$ gas production measurement, the titration method, and IR spectroscopy. The results are demonstrated to be well comparable to a change in the fluorescence emission ratio (FER), which is defined as the shift in fluorescence intensity in the measured wavelength range, and also to the chromatic ratio, which is defined as a color shift to longer wavelength ranges. The results also show that, by using UV-vis spectroscopy, it is possible to detect the degradation of the insulating paper. This study suggests that UV-vis spectroscopy can be applied as an alternative to high-performance liquid chromatography, which is the internationally recognized measurement technology for cellulose paper degradation. The FER detector is also verified to be useful as an effective condition-monitoring device for power transformers.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.49-54
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• 2021

Plasma-polymerized methyl methacrylate (MMA) thin films were synthesized by remote plasma, and effects of plasma power, reaction pressure and direct-indirect plasma on the growth rate and chemical bonding were investigated with alpha-step, FT-IR, XPS and Langmüir probe method. As the plasma power and pressure increased, the tendency of growth rate showed maximum value at a certain range. FT-IR and XPS analyses revealed that composition ratio of C/O and hydrocarbon (C-C) % in the deposited films increased with plasma power, but ester (COO) C % decreased with it. Direct plasma method was effective for fast growth rate, but indirect plasma method was favorable for maintaining the chemical structure of MMA.

• Natural Product Sciences
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• v.27 no.4
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• pp.284-292
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• 2021

Recently, a phytoestrogenic functional food has been developed using the fruits of Sophora japonica. Phytochemical investigation of fruits of S. japonica led to the isolation of eight flavonoid glycosides using various chromatographic techniques. The isolated compounds were identified as genistin (1), sophoricoside (2), genistein 7,4'-di-O-β-D-glucopyransoide (3), sophorabioside (4), genistein-7-O-β-D-glucopyranoside-4'-O-[(α-L-rhamnopyranosyl)-(1→2)-β-D-glucopyranoside] (5), sophoraflavonoloside (6), nicotiflorin (7) and kaempferol-3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-(1→3)-β-D-glucopyranoside (8), respectively, by comparison of their spectroscopic data with those reported in the literature. In addition, a new HPLC-DAD method for simultaneous determination of the isolated compounds was developed to quantitate the contents of flavonoids in S. japonica and S. flavescens. The method was validated in terms of limit of detection, limit of quantitation, specificity, linearity, precision and accuracy. The validated method was successfully applied to determine eight flavonoids in two Sophora species. The contents of eight flavonoids varied according to the parts and species. Particularly, it was found that only the fruits of S. japonica contained sophoricoside, a phytoestrogenic isoflavone.

• Journal of Pharmaceutical Investigation
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• v.27 no.2
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• pp.119-123
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• 1997

The physicochemical and structural properties of new capsaicin derivative, DA-5018, were examined. The reference standard of this compound was obtained by the recrystallization. A method for the determination of the dissociation constant of the compound is described. pH-solubility and distribution coefficient were determined by chromatographic method. Fundamental properties on thermal behaviors were investigated by TG, DTA and DSC. Structural analysis based on spectroscopic method coincided with the chemical structure of DA-5018. Approximate dissociation constant of the compound determined by UV spectral method was 9.35. Solubilities and partition coefficients in various pH buffer solution appeared pH-dependency. No crystal transition or further transition was found in the thermal analysis. This compound showed good stability, but pH 13 buffer and acetone made some degradative products.

• Macromolecular Research
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• v.12 no.6
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• pp.604-607
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• 2004

We report an important and useful method for preparing ${\omega}-sulfonated$ polystyrene-stabilized cadmium sulfide (CdS) nanoclusters. The ${\omega}-sulfonated$ polystyrene $(M_n\;=\;5000\;g/mol)$ was prepared successfully through chain-end sulfonation of poly(styryl)lithium using 1,3-propanesultone; the resulting polymer was used successfully as a polymeric stabilizing agent for the preparation of semiconductor CdS nanoclusters by reduction of cadmium acetate in a mixture of toluene and methanol (9:1, v/v). The nanoclusters that formed were characterized by a combination of transmission electron microscopy, X-ray diffraction, and UVN is spectroscopic analysis. The ${\omega}-sulfonated$ polystyrene-stabilized CdS nanoclusters synthesized in this study exhibited the cubic phase (zinc-blende phase) structure in the range of 2-8 nm.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1233-1236
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• 2010

2,3-Dichloro-1,4-naphtoquinone 1 compound was reacted with octadecanethiol 2 in two different mole ratio. Compound 3 was obtained from the reaction of 1 and 2 in 1:2 mole/mole ratio. Compounds 7 and 8 were obtained from reaction of 1 and 2 in 1:1 mole/mole ratio and known compound 9 was synthesized as by-product in this reaction. Novel compounds 5a-e were obtained from reaction of 1 and related thiols 4a-e. Known compounds 6c and 6e were synthesized as by-product in this reaction. The structures of the compounds were characterized by elemental analysis, UV-vis, FTIR, $^1H$-NMR, $^{13}C$-NMR and Mass spectroscopies.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.177-177
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• 2009

We examine the process to enhance the productivity of the thin-film transistor-addressed liquid-crystal display (TFT LCD) panels with the objective of optimizing the relation between the Type of color PR dispense nozzle and the amount of dispensing of color PR consumption, directly affecting a spectroscopic analysis. Most manufacturers of the panels have been utilizing a spin-type coater. We show that we successfully optimize the spectral values by controlling the color PR dispense type(Static dispense or Dynamic dispense) and the amount of color PR. From this study, we accomplished to decrease 43% in color PR consumption and to decrease 30% in color PR Stained, to decrease 30% rework rate.