• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.98-107
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• 2016

This study examined the effects of environmental conditions and the presence of refractory organic matter on oxidation rates of total organic carbon (TOC) measurements based on high temperature combustion and ultraviolet-sulfate methods. Spectroscopic indices for prediction of oxidation rates were also explored using the UV spectra and fluorescence excitation-emission matrix (EEM) of humic acids. Furthermore, optimum TOC instrument conditions were suggested by comparing oxidation rates of a standard TOC material under various conditions. Environmental conditions included salts, reduced ions, and suspended solids. Salts had the greatest influence on oxidation rates in the UV-sulfate method. However, no effect was detected in the high temperature combustion method. The UV-sulfate method showed lower humic substance oxidation rates, refractory natural organic matter, compared to the other methods. TOC oxidation rates for the UV-sulfate method were negatively correlated with higher specific-UV absorbance, humification index, and humic-like EEM peak intensities, suggesting that these spectroscopic indices could be used to predict TOC oxidation rates. TOC signals from instruments using the UV-sulfate method increased with increasing chamber temperature and increasing UV exposure durations. Signals were more sensitive to the former condition, suggesting that chamber temperature is important for improving the TOC oxidation rates of refractory organic matter.

• Analytical Science and Technology
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• v.15 no.4
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• pp.341-345
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• 2002

The extent of UV-curing photo-polymerization reaction was monitored by near-IR spectroscopic method. Acrylates containing quaternary ammonium salts and Darocur 1173 were used as reactive monomer and a photo initiator, respectively. The extent of photo-polymerization reaction was obtained from the conversion ratio of acrylate double bond calculated from the intensities of measured bands at 1615 nm and at 2105 nm. Near-IR spectroscopic methods can be an useful tool for the monitoring of the progress of photo-polymerization.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.368.1-368.1
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• 2002

Mesaconitine and hypaconitine were isolated from Cho O and identified by the spectroscopic methods. The contents of alkaloid (mesaconitine. aconitine and hypaconitine) in the Cho O and its processed products were determined by high performance liquid chromatography. Processed 1 and 2 methods reduced the contents of alkaloid than those of processed 3 and commercially processed Aconiti Tuber powder. (omitted)

• Korean Journal of Pharmacognosy
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• v.26 no.3
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• pp.273-275
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• 1995

Two phenolic amides were isolated from the stem of Cocculus diversifolius (Menispermaceae) and identified as N-trans-feruloyl tyramine and N-trans-feruloyl 3-methyldopamine by spectroscopic methods.

• Archives of Pharmacal Research
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• v.12 no.4
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• pp.310-312
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• 1989

Three new sesquiterpene alkaloids, tripterregeline, A, B and C were isolated from the stem bark of Tripterygium regelii and their partial structures were determined by various spectroscopic methods.

• Natural Product Sciences
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• v.7 no.1
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• pp.21-22
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• 2001

A cytotoxic compound was purified from the flowers (46 g) of Paulownia tomentosa by normal column chromatography. As a result of the structure analysis by spectroscopic methods, the compound was identified as isoatriplicolide tiglate, which shows in vitro cytotoxicity.

• Korean Journal of Pharmacognosy
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• v.31 no.2
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• pp.249-251
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• 2000

From the whole plants of Amaranthus mangostanus L., rutin was isolated and identified by means of chemical and spectroscopic methods. This is the first isolation of rutin from this plant.

• Natural Product Sciences
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• v.18 no.1
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• pp.13-15
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• 2012

Three lupane type triterpenoids were isolated from the methanol extract of Pyrus pyrifolia fruit peel through repeated silica gel column chromatography. Based on the spectroscopic methods, their structures were determined to be lupeol (1), betulin (2), and betulinic acid (3).

• Archives of Pharmacal Research
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• v.14 no.1
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• pp.52-54
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• 1991

A new acylated monoterpene glucoside, galloylpaeoniflorin, was isolated from Paeony root. The structure was determined by chemical and spectroscopic methods.

• YAKHAK HOEJI
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• v.37 no.4
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• pp.365-369
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• 1993

Five phenolic compounds have been isolated from the stems and leaves of Rosa rugosa Thunb. (Rosaceae) in Korea. They were methyl gallate and catechin from the stems, and quercetin, methyl gallate and hyperin from the leaves respectively. The structures were established by spectroscopic and chemical methods.