• YAKHAK HOEJI
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• v.28 no.2
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• pp.61-67
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• 1984

A method is described for the spectrophotometric determination of platinum (IV) with 2-oximino-1-indanone based on solvent extraction of Pt:2-oximino-1-indanone complex. The 2-oximino-1-indanone reacted with Pt(IV) to form a dark-orange complex which shows a characterisic maximum absorption at 342nm. The optimum PH for the platinum extraction lies between 5.4~8.0. Beer's law obeys up to 0.98-16.3ppm of platinum (IV) and the molar absorption coefficient is $1.06{\times}10^{-4}L.mol^{-1}.cm^{-1}$. The relative standard deviation of the method was $\times2.1%$. The composition of the complex is estimated to be Pt : In= 1 : 1, by the mole ratio method and ion exchange resin experiment. The optimum condition for the determination of platinum has been studied in detail. The 2-oximin-1-indanone is found to be a selectivereagent for the determination of platinum, since the synthesixed 2-oximino-1-indanone did not react with other metals such as cobalt, cadmium, copper, manganese nickel, iron, lead and zinc, to form the complex. In this studies, we have also clarified Sindhwani and Singh's spectrophotometric determination data of various metals with acenaphthenequinone monooxime (Talanta 20,248, 1973), whose results were not correct.

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1137-1142
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• 2004

A spectrophotometric and first derivative spectrophotometric method was developed in aquatic Tween 80 micellar solutions for selective determination of nickel without using any pre-separation step. 1-(2-Pyridylazo)-2-naphthol (PAN), as a sensitive chromogenic complexing agent formed a red-colored Ni(II)-PAN complex in Tween 80 media with satisfactory solubility and stability. Conditions such as pH, PAN concentration, type and concentration of micellizing agent were optimized. Molar absorptivity of Ni-PAN complex was found $4.62\;{\times}\;10^4L\;cm^{?1}\;mol^{?1}$ at 569 nm, under the optimum condition. Calibration graphs were derived by zero, first and second derivative spectrophotometry at maximum wavelengths of 569, 578 and 571 nm with linear ranges of 30-1800, 20-2500 and 30-2000 ng $mL^{?1}$ , respectively. Precision as standard deviation as well as accuracy as recovery percent were in the range of 1-20 ng $mL^{?1}$, and 93.3-103.3%, respectively, for the entire of the linear ranges. Spectrophotometric detection limit was 3 ng $mL^{?1}$ and effects of diverse ions on the first derivative determination of nickel were studied to investigate selectivity of the method. Interferences of cobalt and copper on the nickel determination were prevented using o-phenanthroline as masking agent. The recommended procedures were applied to the various synthetic and stainless steel alloys, tea leaves and human hair, with satisfactory results.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.68-72
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• 2007

A new PVC membrane potentiometric sensor that is highly selective to Hg2+ ions was prepared, using bis(2-hydroxybenzophenone) butane-2,3-dihydrazone (HBBD) as an excellent hexadendates neutral carrier. The sensor works satisfactorily in the concentration range of 1.0 × 10-6 to 1.0 × 10-1 mol L-1 (detection limit 4 × 10-7 mol L-1) with a Nernstian slope of 29.7 mV per decade. This electrode showed a fast response time (~8 s) and was used for at least 12 weeks without any divergence. The sensor exhibits good Hg2+ selectivity for a broad range of common alkali, alkaline earth, transition and heavy metal ions (lithium, sodium, potassium, magnesium, calcium, copper, nickel, cobalt, zinc, cadmium, lead and lanthanum). The electrode response is pH independent in the range of 1.5-4.0. Furthermore, the developed sensor was successfully used as an indicator electrode in the potentiometric titration of mercury ions with potassium iodide and the direct determination of mercury in some binary and ternary mixtures.

• Bulletin of the Korean Chemical Society
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• v.19 no.10
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• pp.1036-1042
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• 1998

The preconcentration and determination of trace elements in water samples were studied by a solvent sublation utilizing dithizonate complexation. After metal dithizonates were formed, trace amounts of cadmium, cobalt, copper and lead were floated and extracted into small volume of a water-immiscible organic solvent on the surface of sample solution and determined in the solvent directly by GF-AAS. Several experimental conditions as formation condition of metal-dithizonate complexes, pH of solution, amount of dithizone, stirring time, the type and amount of surfactants, N2 bubbling rate and so on were optimized for the complete formation and effective flotation of the complexes. And also four kinds of light solvents were compared each other to extract the floated complexes, effectively. After the pH was adjusted to 4.0 with 5 M HNO3, 8.0 mL of 0.05% acetone solution of dithizone was added to 1.00 L water sample. The dithizonate complexes were flotated and extracted into the upper methyl isobutylketone (MIBK) layer by the addition of 2.0 mL 0.2% ethanolic sodium lauryl sulfate solution and with the aid of small nitrogen gas bubbles. And this solvent sublation method was applied to the analysis of real water samples and good results of more than 85% recoveries were obtained in spiked samples.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.269-278
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• 2014

This study aimed to provide the fundamental data on the field of cosmetics by comparing heavy metal concentration in terms of domestic/foreign products, types and colors. The study determined the concentrations of lead, cadmium, arsenic, chromium, antimony, nickel, copper and cobalt in cosmetics such as lipstick, lip gloss, lip balm, foundation and eye liner. From the period of January to August, 2013, 121 samples were collected from cosmetic stores distributing to the general market. The average metal concentrations were as follows; $0.663{\mu}g/g$ for lead, $0.010{\mu}g/g$ for cadmium, $0.056{\mu}g/g$ for arsenic, $1.144{\mu}g/g$ for chromium, $0.008{\mu}g/g$ for antimony, $0.405{\mu}g/g$ for nickel, $0.319{\mu}g/g$ for copper and $0.108{\mu}g/g$ for cobalt. Except for chromium, the heavy metal concentrations were significantly higher in foreign products than in domestic products (p < 0.05). Also, The mean concentrations of heavy metal were significantly different (p < 0.05) when classified by cosmetic type. The highest mean concentrations shown in lipstick were $1.430{\mu}g/g$ of chromium, $0.616{\mu}g/g$ of lead and $0.385{\mu}g/g$ of nickel, in foundation $1.155{\mu}g/g$ of lead and $1.023{\mu}g/g$ of chromium. In eye liner, the highest mean concentrations were $1.424{\mu}g/g$ of chromium and $0.830{\mu}g/g$ of nickel. Additionally, The concentrations of heavy metal were significantly different by color (p < 0.05). Brown colored cosmetics were found to have the highest mean concentrations of chromium, nickel and copper, ivory colored cosmetics the highest mean concentrations of chromium and lead, and pink colored cosmetics the highest concentrations of lead and chromium.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.305-313
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• 2010

Mineralogical characteristics of Cu-Co ores from the Central African Copperbelt in the Democratic Repblic of Congo are studied using powder X-ray diffractometer, general area detector X-ray diffractometer, and electron proble microanalyzer. Black ores are mainly composed of heterogenite (cobalt oxide/hydroxide mineral) and malachite (copper carbonate mineral), whereas green ores are only composed of malachite. Heterogenite shows very bright white color under the reflected microscope, and belongs to 3R polytype, because it has d-spacings at $4.39{\AA}$ and $2.316{\AA}$. Since NiO and $Fe_20_3$ content of heterogenite are lower than those of 3R polytype from other localities, it cannot completely exclude the presence of 2H polytype in heterogenite from this study. Malachite is light grey color under the reflected microscope with approximate chemical formula of $Cu_{1.97}Co_{0.02}Fe^{2+}{_{0.01}}CO_3(OH)_2$. Heterogenite and malachite were probably formed at the supergene emichment stage, the last mineralization stage in the Central African Copperbelt. Cobalt seems to be much more emiched in the black supergene (oxy)hydroxide ore than those in the primary sulfide ore.

• Resources Recycling
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• v.17 no.1
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• pp.51-58
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• 2008

Artificial mattes were prepared with adding pyrite or chalcopyrite as sulfur sources with Cu-Ni-Co-Fe alloy. The major phases identified by X-ray diffraction pattern were $(FeSi)_9S_8$, $CuFeS_2$, FeS, $Co_4S_3$, $Ni_3S_2$ and $Cu_2S$ for both mattes, and the matte prepared by adding chalcopyrite showed the higher peak of $Cu_2S$ due to high content of copper. Under optimum conditions, more than 95% copper, 90% nickel and 90% cobalt were extracted into leaching solution and sulfur concentration in the mattes did not much affect the leaching efficiency of the metals. The increase of the amount of pyrite or chalcopyrite added decreased pH in leaching solution and increased the concentration of iron ion dissolved in the leaching solution and the amount of residue.

• Resources Recycling
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• v.23 no.1
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• pp.64-69
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• 2014

For the recovery of Co and Cu, bioleaching behavior of Co, Cu, Fe, Mg, Al by Aspergillus niger culture from the molasses growth medium was investigated. Series of leaching tests have been conducted by varying Aspergillus niger's type, molasses concentration in the growth medium, pulp density and reaction time. The results showed that increase of the molasses concentration in the growth medium from 1% to 4% increased the leaching percentage of Co and Cu and the optimal molesses concentration was found to be 4% in the growth medium. Maxinum 90% of Co and 70% of Cu were dissolved from the leaching test at the 10 g/L pulp density, 4 % of molasses concentration in the growth medium after 21 days by Aspergillus niger KCTC 6985. But in case of using Aspergillus niger KCTC 6144, the maxium leaching percentage of Co and Cu was reached 90% respectively at a pulp density 5 g/L and 4% of molasses concentration.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.189-197
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• 2003

Soluble glass bolus with selenium (Se), copper (Cu) and cobalt (Co) was administered intraruminally to Philippine grazing does fed under backyard farming conditions to determine its effect on blood mineral status. Forty-five does were dosed with SGB intraruminally every 6 months, whereas 15 were without SGB during this experimental period of 10 months. Blood of does in both treatment groups were collected every other month and blood Se, plasma Cu, Ca, P and Mg were determined in this study. All does did not show clinical Se, Cu, Ca, P or Mg deficiency during this experimental period. Selenium concentration of treated does increased (p<0.01) after beginning of this experiment, whereas the level of control does decreased slowly (p<0.01). Two months after SGB administration, all treated does had higher blood Se than the lower limit of $20{\mu}g/l$ suggested by NRC (1981), whereas some control does had lower blood Se concentration than the lower limit of $20{\mu}g/l$. On the other hand, plasma Cu concentration of treated does started to increase more remarkably than control does 4 months after this experiment had started although the difference was insignificant. There were no significant differences between plasma Ca, P or Mg concentration of does in both treatment groups. Soluble glass bolus had no harmful effects on plasma macro mineral concentrations of grazing does. This study showed that SGB was available as mineral supplement to improve imbalances of selected mineral of grazing goats in the traditional backyard conditions in Luzon Island, Philippines.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2981-2987
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• 2011

A comparative study of the photodynamic and antioxidant activities of methyl pheophorbide-a (MPa, 1) and its transition metal(II) complexes (2-5) is described. Four transition metal complexes (palladium(II): 2, zinc(II): 3, cobalt(II): 4 and copper(II): 5) of MPa were prepared by reaction between the corresponding transition metal and 1, respectively, and were characterized by $^1H$-NMR and UV-vis spectroscopic and mass spectrometric analyses. In vitro results show a photodynamic therapy (PDT) efficacy with A549 cells might be attributed to a heavy atom effect of the transition metal complexes of MPa. Among them, 4 and 5 showed higher photodynamic activity than that of 1 at the concentration of 5 ${\mu}M$ at 24 h incubation after photoirradiation. The images of morphological change for 2-5 show evidence for the PDT effect with A549 cells. And the all transition metal complexes of MPa showed higher antioxidant activity than that of MPa, in which 4 showed the highest antioxidant activity.