• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.693-703
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• 2009

The complex formation of anti-inflamatory drug piroxicam (PX, 4-hydroxy-2-methyl-N-2--pridyl-2H-1,2-benzothiazine-3-carboxadiamide-1,1-dioxide) with transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) in methanol(MeOH)/water binary mixtures were studied by spectrophotometric method at 25$^{\circ}C$, constant pH = 5.0 and I = 0.1 M. The computer program SQUAD was used to extract the desired information from the spectral data. The outputs of the fitting processes were stability constants, standard deviations of the estimated stability constants, concentration distribution diagrams and spectral profiles of all species. The sequence of the stability constants of PX complexes with Co(II), Ni(II), Cu(II) and Zn(II) follow the Cu(II) > Co(II) > Ni(II) ${\approx}$ Zn(II) order. This may be due to different geometry tendencies of these metal ions. The acidity constants of the PX were also determined under above condition from its absorption spectra at different pH values. The computer program DATAN was used for determination of acidity constants of PX. The validity of the obtained acidity constants was checked by a well known computer program SPECFIT/32. The effects of the different parameters like solvent nature, cations characteristics on the stability and acidity constants were thoroughly discussed.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.357-363
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• 1987

The transition temperature of respiratory activity of mitochondria isolated from panicles of rice plant was measured with 41 varieties bred in Korea, which had been agronomically classified into five groups based on their relative cold-tolerance; S (strong cold-tolerance), S-M (moderate to strong cold-tolerance), M (moderate cold-tolerance), M-W (moderate to weak cold-tolerance) and W (weak cold-tolerance). The temperature was found to be $11.5{\sim}13.5^{\circ}C$ for group S, $13.5{\sim}16^{\circ}C$ for group S-M, $16{\sim}17^{\circ}C$ for group M, $17{\sim}18^{\circ}C$ for group M-W, and ${\geq}18^{\circ}C$ for group W respectively with a few exceptions of minor deviation, demonstrating a close correlation between the transition temperature and the chilling susceptivity of a variety. This observation supports the suggestion that the transition temperature of respiratory activity of panicles be adopted as a reliable index for grading a rice variety as to its overall cold tolerance. Also studied is on the methodology for measurement of the transition temperature in the aspect of analytical biochemistry. In addition to the usual polarographic method, a spectrophotometric method which is based on the enzymatic assay of membrane-bound cytochrome C oxidase was examined. This enzyme was found previousely and confirmed again in the present work to be a key factor governing the respiratory trantion at least in plant mitochondria. The optical method was turned out to be very successful, although it was a little more complicate and time-consuming than the electrochemical method.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.243-247
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• 1998

A method for the determination of basic drugs based on their reaction with picric acid to form an ion-association complex extractable into several plasticizers was developed. Ba sic drugs-picric acid complexes in acid medium could be extracted quantitatively into several plasticizers except phosphates. For example, the chlorpromazine-picric acid complex showed maximum absorbance at near 410nm and was applied to extraction spectrophotometric determination of chlorpromazine. The calibration curves are linear (r>0.998) within a range from $10^{-6}to\;5{\times}10^{-4}M$ and the precision of the method was acceptable because RSD was less than 2.6% (n=7). The factors affecting the extraction system was discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.1 no.1
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• pp.25-31
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• 1972

The Undaria pinnatifida collected in the waters of Dongbaek Island were grouped into young and adult ones and calcium and iron contents of each were analyzed by parts, i.e., separately for blade, stripe, and sporophyll by potassium permanganate titration method and spectrophotometric method respectively (O-phenanthrolin used). The results showed that the blades contain higher percentage of calcium than other parts both in young and adult seaweeds and that proportionately twice as much iron is contained in the blades than in the stripes.

• Journal of the Korean Chemical Society
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• v.7 no.1
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• pp.69-73
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• 1963

The basicities of 16 substituted azoxybenzenes have been measured by U.V. spectrophotometric method. The effects of substituents on the basicities are discussed in terms of Hammett's equation. The reaction constants, ${\rho}^X_Y$ and ${\rho}^Y_X$ , in a modified equation, log $K_{XY}/K_{\infty}={\sigma}_X{\rho}^Y_X+{\sigma}_Y{\rho}^X_Y$, are $2.46{\pm}0.12$ and $2.25{\pm}0.26$ respectively. The validity of the equation is analysed by a statistical method, and the structure of the conjugate acid of the substituted azoxybenzenes is proposed.

• Journal of Pharmaceutical Investigation
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• v.4 no.1_2
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• pp.46-54
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• 1974

A new spectrophotemetric method was estalished for the determination of oleic acid. This method is based on the 1,2-dichloroe-thane extraction of the ion-pair formed between methylene blue and oleic acid. But the absorbance of an ion-pair in the 1,2-dichloroe-thane layer was variable with the temperature, the ion-pair was extracted back into a diluted hydrochloric acid solution. The maximum absorbance of the acid extract observed at $660m{\mu}$ and a lineal relationship was observed from the initial amount over the range of $50-800{\gamma}/ml$ of oleic acid in the aqueous phase. The composition ratio of the ion-pair formed between methylene blue and oleic acid was determined to be 2 : 1 by both the mole ratio and continuous variation methods.

• Journal of Pharmaceutical Investigation
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• v.4 no.1_2
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• pp.1-6
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• 1974

S-Benzylthiuronium chloride reacts with ethylene glycol, derived from hydrolysis of the fluorides, to produce a crystalline substances. Using this, the fluorides can be indentified by measuring melting point. And when the zirconium-alizarin solution reacts with ethylenefluoro hydrin or ${\beta}-fluoroethyl$ acetate, the red-violet color disappears to produce a yellow dye, which exhibits absorption maximum at about $530\;m{\mu}$ using the 250-microgram standard. Using these properties, the fluorine compounds can be determined conveniently by this method.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.182-188
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• 1982

A fluorometric method is described which permits the assay of trypsin inhibitor contained in a sample in an extremely small amount, utilizing a novel reagent generally called fluorescamine. The fluorometric assay with an enzyme kinetic approach has been found to be at least 100 times more sensitive than the well-known Kunitz's spectrophotometric method, considerably taster and less complicated, when it was demonstrated with the anti tryptic activities of very dilute extracts from soybean, red-bean and mung bean. Details of experimental procedure as well as theoretical considerations will be discussed.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.99-105
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• 1997

In the paper, aging of insulating oil in pole transformer has been studied by performing accelerated thermal aging test. Dissolved gases were extracted by air bubbling method. Concentration of dissolved gases were modified by extraction ratio of each gases in insulating oil. Aging of insulating materials were proceeded by thermal degradation and oxidation reaction. Both of the reactions followed zeroch order kinetics. Formation rate equations for hydrocarbons, carbon oxides, and hydrogen were derived. It was conformed by gas analysis and UV-Visible spectrophotometric method that iron core and copper coil in pole transformer act as catalyst during the aging process.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.24-33
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• 1997

In this paper, aging of insulating oil in pole transformer has been studied by performing accelerated thermal aging test. Dissolved gases were extracted by air bubbling method. Concentration of dissolved gases were modified by extraction ratio of each gases in insulting oil. Aging of insulting materials were proceeded by thermal degradation and oxidation reaction. Both of the reactions followed zeroth order kinetics. Formation rate equations for hydrocarbons, carbon oxides, and hydrogen were derived. It was conformed by gas analysis and UV-visible spectrophotometric method that iron core and copper coil in pole transformer act as catalyst during the aging process.