• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2722-2726
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• 2011

Plasticized poly(vinyl chloride), PVCs, with different membrane compositions tested for use in the construction of an ion-selective sensor for the determination dibucaine. A prepared membrane with dioctyl phthalate-PVC and ion-pair of N-(1-naphthyl)ethylenediamine dihydrochloride-tetraphenyl borate had a good potential to acts as a potentiometric sensor for the analysis of dibucaine. A linear relationship was obtained between potential and logC varying between $1.0{\times}10^{-6}$ and $1.0{\times}10^{-2}$ M dibucaine with a good repeatability and reproducibility. The sensor was applied for the determination of the drug in pharmaceuticals and biological fluids such as plasma and urine samples with satisfactory results. The drug electrode has also been used to study the interaction of bovine serum albumin (BSA) with dibucaine. The saturated quantities of dibucaine binding were 13.04, 5.30 and 9.70 mol/mol in 0.01, 0.02 and 0.1% of protein, respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2727-2731
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• 2011

A new method for the determination of josamycin has been developed based on quenching of the fluorescence of 3-mercaptopropionic acid-capped CdTe quantum dots (MPA-CdTe QDs) by josamycin in ethanol. Reaction time, interfering substances on the fluorescence quenching, and mechanism of the interaction of CdTe QDs with josamycin were investigated. Under optimum conditions, the relative fluorescence intensity was linearly proportional to the concentration of josamycin between 12.0 and 120.0 ${\mu}g\;mL^{-1}$ with a correlation coefficient of 0.9956 and a detection limit of 2.5 ${\mu}g\;mL^{-1}$. The proposed method was successfully applied to commercial tablets, and the results were satisfactory, i.e. consistent with those of high-performance liquid chromatography (HPLC).

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.693-698
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• 2002

A method has been described for the determination of Cu(Ⅱ), Pb(Ⅱ), Ni(Ⅱ), Cd(Ⅱ), Mn(Ⅱ) and Fe(Ⅲ) by flame atomic absorption spectrometry (FAAS) after preconcentration on Amberlite XAD-16 resin, using hexamethyleneammonium-hexamethylenedithiocarbamate (HMA-HMDTC) as a chelating agent, and NH3/NH4Cl buffer solution (pH 9). Influences of various analytical parameters such as pH, concentration of nitric acid, amount of analytes, diverse ions and sample volume were investigated. The relative standard deviation (RSD) and the detection limit (LOD) were found in the range of 0.8-2.9% and 0.006-0.277 ㎍/mL,respectively. Recoveries obtained by the column method were quantitative ( >95%) at optimum conditions.The method was applied to the determination of some metal ions in seawater and wastewater samples. A high preconcentration factor (about 150 for seawater and 75 for wastewater samples) and simplicity are the main advantages of this suggested method.

• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1199-1202
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• 2006

A simple, sensitive and rapid spectrofluorimetric method was developed for determination of mefenamic acid in pharmaceutical preparation and human urine. The procedure is based on the oxidation of mefenamic acid with cerium (IV) to produce cerium (III), and its fluorescence was monitored at 354 nm after excitation at 255 nm. The variables affecting oxidation of drug were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 0.03-1.5 mg $L^{-1}$. The limit of detection was 0.009 mg $L^{-1}$ and the relative standard deviation for 5 replicate determinations of mefenamic acid at 1.0 mg $L^{-1}$ concentration level was 1.72%. Good recoveries in the range of 102-107 and 102-109% were obtained for pharmaceutical preparation and human urine, respectively. The proposed method was applied to the determination of MF in one pharmaceutical preparation and human urine. The amounts of mefenamic acid found are very similar to those obtained by a standard method.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2488-2492
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• 2010

A method is described for the determination of the Po nuclides in a water sample. After the Po nuclides were purified from interfering elements in a water sample using a manganese dioxide precipitation followed by a solvent extraction method, the Po nuclides were deposited onto the silver plate. A large volume of the water sample was effectively pretreated with manganese dioxide precipitation method. To determine the optimum conditions for plating Po, the effects of the pH, volume, temperature and time on the Po deposition were investigated in hydrochloric acid solution. The investigated determination method of Po nuclides with solvent extraction was applied to a tap water sample.

• Journal of the Korean Chemical Society
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• v.9 no.3
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• pp.113-115
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• 1965

In previous paper, the determination procedure of fission products mainly consists of many steps which are usually derived from classical analysis schemes. In the present paper a simple and more rapid method of the determination of fission products by means of a smaller amount of reagent than that correspond to the stoichiometric ratio of element to be determined is investigated. The yield of Ba-140 in fission products is determined by this method.

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.943-947
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• 2002

The two reactions between iron ion (Fe3+ ) and o-chlorophenylfluorone (o-CPF) and copper ion (Cu2+ ) and o-CPF are sensitive at pH 6 in the presence of Triton X-100. We have determined the formation constants of the complexes by the spectral correction technique. Because of the poor selectivity of o-CPF to metals, the competition coordination of only the iron ion from the Cu-o-CPF complex was found and applied to the selective detection of iron traces by the Selective Competition Coordination Determination (SCCD) approach.The analysis of several samples shows that the relative standard deviations are less than 5.0% and the recovery of iron ions between 94.5% and 106%.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.985-987
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• 2008

Parathion is an organophosphate pesticide being legally applied for the purpose of agriculture and is being manufactured in Korea. A gas chromatography/mass spectrometric method was developed for the determination of parathion urinary metabolite, p-nitrophenol. p-Nitrophenol was extracted from weak acidic urine, and then measured by gas chromatography-mass spectrometry (selected ion monitoring). The recovery of pnitrophenol in the overall procedure was 88.2%. The detection limit of the assay was 1.0 $\mu$ g/L based upon assayed urine of 2.0 mL. The method was applied to the determination of p-nitrophenol in urine of workers of a parathion industry. Spot urines of workers of a parathion industry were sampled at the end of shift and pnitrophenol was analyzed using above developed method. p-Nitrophenol could be detected in all of the urine samples at concentrations varying from 3.0 to 681 $\mu$ g/L.

• Journal of the Korean Chemical Society
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• v.10 no.1
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• pp.4-10
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• 1966

A new method of cobalt determination has been developed by employing ethylenediamine tetrabutyl acetate(EDTA-butyl ester) synthesized from EDTA and Butyl alcohol. The synthesized EDTA ester dissolved in butyl alcohol extracts various metal ions from aqueous solutions. Cobaltous ion extracted into organic phase containing EDTA ester to form Co (II)-EDTA butyl ester complex is back extracted into alkaline aqueous phase forming a stable pink colored complex of Co (III). The optimum condition for spectrophotometric determination of cobalt via the new complex has been established. The absorption peak occurs at 540$m{\mu}$ and Beer's law was obeyed over the concentration range of 0∼50 ${\mu}g/ml$ of cobalt.

• Journal of the Korean Chemical Society
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• v.17 no.6
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• pp.439-443
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• 1973

2-Mercaptothiazoline is very sensitive reagent for silver, which have been used for highly selective amperometric determination of silver. A method is described for the determination of micro-quantity of silver by amperometric titration with 2-mercaptothiazoline in ammonical solution. Direct titration of milligram amount of silver (0.05∼1.00mg) is possible in the presence of a number of foreign ions in ammonical solution containing ethylenediaminetetraacetic acid as masking agent under atmosphere. The interfering elements are gold and platinum. The milligram amounts of silver can be determined by the proposed method within an error ${\pm}$5%.