• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.165-168
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• 2010

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.546-551
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• 1992

Reaction mechanism on the solvent extraction of nickel(Ⅱ) with N-benzylisonitrosoacetylacetone imine(HIAANB) was studied spectrophotometrically. Absorbance was measured by changing the ligand HIAANB concentration in the chloroform organic phase and the pH values in the agueous solution phase. From the absorbance data, the reaction rate was found to be the first order for HIAANB concentration and the inverse first one for [$H^+$]. The rate determining step of the extraction reaction and the rate equation are as follows; $Ni^{2+}$＋HIAANB ${\to}$ Ni-IAANB$^+$＋$H^+$ -d[Ni$^{2+}$] / dt = K'[Ni$^{2+}$][HIAANB]$_0$ / [H$^+$] Calibration curve for the spectrophotometric determination of nickel(Ⅱ) ion in the aqueous solution was linear below the concentration of 1.17 ppm at the optimum experimental condition. And the ligand-to-metal ratio, the relationship between extractability and pH of the aqueous phase, and the effect of diverse ion on the determination of nickel(Ⅱ) ion were examined.

• Analytical Science and Technology
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• v.17 no.1
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• pp.45-52
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• 2004

Determination of some PAHs in sediments at Ulsan bay has been carried out by extraction of the components into n-hexane followed by synchronous spectrofluorimetric technique. 11 PAHs, such as acenaphthene (Ace), anthracene (Anth), benz(a)anthracene (BaA), benzo(b)fluoranthene (BbFt), benzo(k)fluoranthene (BkFt) benzo(a)pyrene (BaP), chrysene (Chry), phenanthrene (Phen), fluoranthene(Ft), perlyrene (Per), and pyrene (Pyr) in sediment samples were able to determine separately by synchronous spectrofluorimetry. Calibration curves for those components were linear for the concentration range of 0.15~166 ppb PAHs with the correlation factor of 0.9985~0.9999. The total amount of PAHs in sediments varied from 68.8 to 324.4 ng/g. The PAHs concentration was shown a tendency to increase from the outer bay to the inner basin as well the predominant contributors to the aromatic ring groups of the PAHs was 4-ring group.

• Journal of the Korean Chemical Society
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• v.26 no.5
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• pp.326-332
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• 1982

The structure of the complex extracted from an aqueous solution containing methylene blue and tetrafluoroborate with 1,2-dichloroethane has been investigated by comparing IR spectrum of the extract with those of pure components and appeared to be an 1 : 1 contact ion-pair between monovalent ions of opposite charge. The extraction constant obtained from the absorbance data measured at 658nm in 1,2-dichlorethane has a value of 1.1${\times}$at$10^4M{-1}$ 25$^{\circ}$C in the range from 1.43${\times}10^{-2}$ to 2.86${\times}10^{-1}$M HF. In the solvent extraction with nitrobenzene, the identical experiments show that extraction constants are increased with HF concentration possibly due to dissociation of the ion-pair in nitrobenzene.

• Clean Technology
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• v.22 no.2
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• pp.122-131
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• 2016

Caesium radioisotopes, ¹³⁴Cs and ¹³⁷Cs which come from the atmospheric nuclear tests and discharges from nuclear power plants, are very important to study artificial radioactivity. In this work, in order to lower the minimum detection activity (MDA) we investigated environmental radioactivity according to the Environment Measurement Laboratory procedure by ¹³⁷Cs and ¹³⁴Cs which is similar to chemical and environmental behaviors of ¹³⁷Cs. The environmental soils in high mountain areas near nuclear power plant were collected, and an Ammonium Molybdophosphate (AMP) precipitation method, which showed high selectivity toward Cs⁺ ions, was applied to chemically extract and concentrate Caesium radioisotopes. Radioactivity was estimated by a gamma-ray spectrometry. In gamma energy spectrum, with an increasing of ⁴⁰K radioactivity, it increased the MDA of ¹³⁴Cs and ¹³⁷Cs. Therefore, if the natural radionuclides were removed from the soil samples, the MDA of Caesium may be reduced, and the contents of ¹³⁷Cs of in the environmental soils can effectively be estimated. In the standard soil sample of Korea Institute of Nuclear Safety, radioactivity of ⁴⁰K was removed more than 84% on average, and the MDA of ¹³⁴Cs was reduced 2 times. The content of ¹³⁷Cs was recovered over 84%. On the other hand, in environmental soils, AMP precipitation method showed removal ratio of ⁴⁰K up to 180 times, which reduced the MDA about 5 times smaller than those of Direct method. ¹³⁷Cs recovery ratio showed from 54.54% to 70.06%. When considering the MDA and recovery ratio, AMP precipitation method is effective for detection of Caesium radioisotopes in low concentration.