• Analytical Science and Technology
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• v.17 no.6
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• pp.476-480
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• 2004

A simple, rapid, reproducible and selective UV-Visible spectrophotometric method has been developed for determination of germanium in a week acid medium (pH = 3.0) in the presence of mandelic acid (MA) and malachite green (MG). A single extraction in chlorobenzene was used for the analysis. The germanium-MA ion association complex exhibits an absorption maximum at ${\lambda}_{max}=618nm$ with MG as counter ion and has an apparent molar absorptivtity of $1.313{\times}10^5L\;mol^{-1}\;cm^{-1}$. The values obtained by this UV-Visible spectrophotometric method are in good agreement with the values from inductively coupled plasma-mass spectrometer analysis.

• Journal of the Korean Chemical Society
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• v.52 no.6
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• pp.622-629
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• 2008

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1851-1853
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• 1996

In this paper the criteria for insulating oil condition of pole transformer were suggested by applying the UV-Visible spectrophotometric method. Ageing of insulating oil caused the change in absorbances of oil os well os the deterioration of electrical properties of oil. By comparing the electrical properties such as $tan{\delta}$ and breakdown voltage with the UV-Visible absorbances of oil, criteria for absorbance values determining oil condition were established. This UV-Visible spectrophotometric method might be applied in ageing analysis of oil and be expected to replace the current method.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.421-425
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• 2001

Among the many parameters describing water quality, total nitrogen content(TN) is regarded as important one in relation to water quality management of the waterbodies for its role in eutrophication process. This study evaluated for accuracy, convenience and promptness of nitrogen analysis methods : (1)UV spectrophotometric method, (2)summation method, (3)cadmium reduction method. And, the detection limit of each method was calculated using EPA method. The UV spectrophotometric method after oxidation appears to be more convenient and accurate in determination of the TN contents than the summation method and cadmium reduction method. The summation method is necessary to separate determinations of the organic nitrogen, ammonia, nitrite, and nitrate. And, because summation method has many other methods for each contents, it can be detected for wide range of concentration.

• YAKHAK HOEJI
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• v.53 no.5
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• pp.235-240
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• 2009

The interaction of cadmium (II) ion with quercetin was investigated in aqueous solution at different pH. The quercetin/cadmium stochiometries for cadmium (II) binding have been determined by UV-vis spectrophotometric method. The complexation of Cd(II) ion with 54.72 ${\mu}M$ quercetin (A=1.00793) was formed in 0.2 M $NH_3-0.2$ M $NH_4Cl$ (pH 8.0) buffer solution. 1:1 Cd(II)-complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH when interacted with quercetin in buffer solution. These results suggest that Cd(II)-quercetin complex has the optimal condition of chelation in basic buffer solution.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.5
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• pp.94-100
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• 1996

Criteria for insulating oil condition of pole transformer were suggested by applying the UV-Visible spectrophotometric method. Aging of insulating oil caused the change in absorbances of oil as well as the deterioration of electrical properties of oil. By comparing the electrical properties such as tan$\delta$ and dielectric breakdown voltage with the UV-Visible absorbances of oil, following criteria for absorbance values determining oil condition were established, fair condition is below 0.580, need attention is 0.580-0.900 and poor condition is above 0.900. This W-Visible spectrophotometric method may be applied in aging analysis of oil and expected to replace the current visual method. It is necessary to develop cheap, light and portable UV-Visible spectrophotometer in near future for field application.

• Archives of Pharmacal Research
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• v.14 no.4
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• pp.285-289
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• 1991

A convenient spectrophotometric method was examined for the determination of amantadine sulfate (AMTS) which has no UV-VIS chromopohores. AMTS was ion-paired quantitatively with methyl orange (MO) at $70^{\circ}C$ for 30 min. The ion-paired complex was extracted with dichloromethane and the absorbance was measured at 421.5 nm. A linear relationship was observed in the range of $2.5{\times}10^{-7}\;M$ to $3.75{\times}10^{-6}\;M$ and the correlation coefficient was 0.999 (n=3). This assay method was applied to the quantification of AMTS in commercial tablet form with good recovery and high precision.

• YAKHAK HOEJI
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• v.31 no.5
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• pp.330-337
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• 1987

The weak UV absorbing ephedrine alkaloids such as ephedrine, pseudoephedrine, methylephedrine and norephedrine could be analyzed by charge-transfer spectrophotometric method. The results obtained are summarized as follows: (1) It was possible to determine a weak UV absorbing ephedrine alkaloids using the intense charge-transfer UV bands in chloroform. (2) This method was suitable for the spectrophotometric determination of ephedrine alkaloids in mixed pharmaceutical preparation. (3) Linear relationship was found between absorbance and concentration in the range of 1.0$\times$$10^{-5}M$~5$\times$$10^{-5}M$ of ephedrine ($\varepsilon$= 2.72$\times$$10^{4}LM^{-1}cm^{-1}$ and pseudoephedrine ($\varepsilon$=2.84$\times$$10^{4]LM^{-1}cm^{-1}$), 1.0$\times$$10^{-5}M$~5$\times$$10^{-5}$M of methylephdrine ($\varepsilon$=1.68$\times$$10^{4}LM^{-1}cm^{-1}$) and 1/3$\times$$10^{-4}M$~4/3$\times$$10^{-4}M$ of norephedrine ($\varepsilon$=0.74$\times$$10^{4}LM^{-1}cm^{-1}$. (4) CT- complex of ephedrine, pseudoephedrine and methylephedrine has absorption maxima at 293nm and norephedrine have absorption maximum at 253nm. (5) CT-complexes were formed in a 1:1 ratio between ephedrine alkaloids and iodine in chloroform. (6) By UV, IR, and $^1H$-NMR spectra, it could be inferred that CT-complexes were formed by interaction between the basic nitrogen of ephedrine alkaloids as electron (n) donor and iodine as electron ($\sigma$) acceptor.

• YAKHAK HOEJI
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• v.33 no.3
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• pp.141-148
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• 1989

The weak UV absorbing antihistaminics such as chlorpheniramine, triprolidine, tripelennamine and diphenhydramine were analyzed by charge-transfer spectrophotometric method. The results obtained are summarized as folows. It was possible to determine a weak UV absorbing antihistaminics using the intense charge-transfer UV bands in chloroform. Charge transfer complexes were formed in a 1:1 ratio between antihistaminics and iodine in chloroform. Linear relationship was found between absorbance and concentration in the range of $1.0\;{\times}\;10^{-5}M-5.0\;{\times}\;10^{-5}M$ for chlorpheniramine( ${\varepsilon}\;=\;2.082\;{\times}\;10^4$) and tripelennamine ( ${\varepsilon}\;=\;1.578\;{\times}\;10^4$), $1.0\;{\times}\;10^{-5}M-8.0\;{\times}\;10^{-5}M$ for triprolidine ( ${\varepsilon}\;=\;1.120\;{\times}\;10^4$) and $1.0\;{\times}\;10^{-5}M-1.0\;{\times}\;10^{-4}M$ for diphenhydramine ( ${\varepsilon}\;=\;9.900\;{\times}\;10^3$). Charge transfer complexes of chlorpheniramine, triprolidine and tripelennamine have absorption maxima at 293 nm and complex form of diphenhydramine has absorption maximum at 270 nm. By UV, IR spectra, it could be inferred that CT-complexes were formed by interaction between the basic nitrogen of antihistaminics as electron donor (non bonding electron) and iodine as electron acceptor (${\sigma}$ bonding electron).

• YAKHAK HOEJI
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• v.52 no.6
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• pp.426-433
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• 2008

The interaction of cadmium (II) ion with protocatechuic acid ($H_3PA$) and ethylenediaminetetraacetic acid (EDTA) were investigated in aqueous solution at different pH. The protocatechuic acid and EDTA/cadmium stochiometries for cadmium (II) binding have been determined by UV-vis spectrophotometric method. The complexation of Cd (II) ion with protocatechuic acid was formed in solution. Among the two potential sites of chelation present in the protocatechuic acid structure, the carboxylic function presents higher complexation power toward Cd (II). 1 : 1 Cd (II)-complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH when interacted with protocatechuic acid in 0.2 M $NH_3$ - 0.2 M ${NH_4}Cl$ (pH 8.0) buffer. These results suggest that Cd $({H_2}PA)^+$ complex has the optimal condition of chelation in buffer solution at 64.22 ${\mu}M$ protocatechuic acid (A=1.01455).