• 대한화학회지
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• 제49권3호
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• pp.269-277
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• 2005

• 약학회지
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• 제29권3호
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• pp.117-123
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• 1985

A clorimetric determination method of pyruvic acid using hydroxylamine was studied. Hydroxylamine was reacted with pyruvic acid to form complex compound in the presence of Cu(II) ion. Optimal conditions for the quantitative analysis were investigated and the structure of complex was examined spectrometrically. The molar ratio (2:1) and the stability constant ($1.88{\times}10^{4}$) of the complex were measured. It was the characteristic feature of this method that the commonly encountered interfering substances such as fructose, glucose and lactic acid do not infuence the measurement of pyruvic acid.

• 생약학회지
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• 제7권4호
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• pp.241-245
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• 1976

Spectrophotometric determination of aconitine at 231 $m{\mu}$ was carried out. By this means, content of poisonous alkaloids in several tubers of Aconitum spp. on Korean market and natural product of Korea were determined.

• Journal of Pharmaceutical Investigation
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• 제6권2호
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• pp.83-87
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• 1976

Microanalysis of rodenticide by visible absorption method was attempted. The following procedure was found to be very simple and to give accurate results. RH-28787 was added to dimethylformamide (DMF), and extracted after stirring for about 20 minutes in extractor $(30^{\circ}C)$. After extraction, the absorbance of DMF solution, was measured at 346 nm by using spectrophotometer. The result agrees closely with the experimentally determined value by means of the gas chromatograph.

• 약학회지
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• 제24권3_4호
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• pp.159-165
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• 1980

Tetrathiocyanatocobaltate[II] forms complexes with tertiary amine salts or quarternary ammonium salts which were extractable from aqueous solution by organic solvent. In order to study composition of the complex, the colored crystalline complexes produced were evaluated with elemental analysis, infrared and mass spectra. And also a novel spectrophotometric method for the determination of tertiary amine salt or quarternary ammonium salt with tetrathiocyanatocobaltate[II] was established by organic solvent extraction within coefficient of variation of 1.06-1.35%.

• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1623-1626
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• 2005

• 약학회지
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• 제13권2_3호
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• pp.80-83
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• 1969

Acetylsalicylic acid gives a water-insoluble violet complex with $<\alpha>$-Picolin-Cu(II) reagent. The Complex is extractable well with a mixture of $<\alpha>$-Picolin-tetrachloromethane solution. The Complex salt dissolved in the mixed solution shows a maximum absorption at 620 m$<\mu>$. It has a melting point at $171^{\circ}C-$173^{\circ}C and molar ratio of Acetylsalicylic acid: Cu(II): $<\alpha>$-Picolin was estimated as 2:1:2 by continuous variation method and chelate titration method.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1564-1568
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• 2011

A solvent extraction separation, preconcentration and determination of thorium with a new crown, 2-ethyl-N-benzyl-4,7,10,13,16-pentaoxa-1-azacyclooctadecane (MACE), is described in the study. The amount of thorium in the aqueous phase and organic phase was determined by Inductively Coupled Plasma-Optical Emission Spectroscopy and Ultraviolet-Visible, respectively. Thorium loaded organic phase was quantitatively stripped in a stage by using 1.0 M $HNO_3$. Thorium was effectively extracted with MACE in the pH range of 6-7 to produce a 3:2 complex ratio in the chloroform. A highly sensitive and rapid spectrophotometric method was described for determination of trace amounts of thorium with MACE. The effective molar absorption coefficient at 281 nm is $1.98{\times}10^3\;mol^{-1}cm^{-1}$, and the system complies with Beer's law in the range from 0.464 to 2.32 ${\mu}gm\;L^{-1}$ of thorium. Thorium was also determined in standard and environmental samples.

• 한국대기환경학회지
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• 제7권2호
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• pp.137-142
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• 1991

A method is developed for the simultaneous determination of dissolved iron, copper, and zinc in rainwater. The method involves 25-fold evaporative concentration, ion chromatographic separation and subsequent spectrophotometric detection after post-column reaction with 4-(2-pyridylazo) resorcinol. Analytical sensitivities, being defined by the slopes of calibration curves, are 0.93, 0.54, and 0.11 Abs/ $\mu$g/ml for iron, copper, zinc, respectively. Detection limits render around a few tenth of one ng/ml. Precisions evaluated by replicate analysis of real sample are better than 10% RSD. Due to the lack of certified standards for rainwater, the accuracy of the method could not be assessed directly. However, the results of this method agree well with those by inductively coupled plasma mass spectrometry. Analytical results for a suite of Seoul rainwaters are presented herein.

• Journal of Pharmaceutical Investigation
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• 제11권3호
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• pp.1-13
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• 1981

A new application of monoacidic dye is reported for the determination of pipethanate hydrochloride(PTH). The method is based on solvent extraction into chloroform of an ion-pair compound formed between methyl orange(MO) and PTH. PTH is determined by measuring absorbance of the extracts over the range of $2.0{\sim}12.0{\mu}g/ml$ at 420nm. Best accuracy can be obtained for solutions containing $3.0{\sim}8.0{\mu}g/ml$. The color was stable for at least 5 days. The molar absorptivity was $2.88\;{\times}\;10^4\;l,\;mol^{-1},\;cm^{-1}$. Molar ratio and continuous variation plots have a maximum at 0.5 mol fraction of MO, indicating a 1 : 1 MO-PTH ratio.