• Analytical Science and Technology
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• v.6 no.3
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• pp.329-334
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• 1993

The formation of Mo(VI)-alizarin red S chelate ion its extraction into an organic solvent by ion-pairing for the separarive determination of trace Mo(VI) in natural water was applied in seawater samples. Removed Fe(III) and Zn(II), and Cu(II) by precipitating with anthranilic acid at pH 4.0 and 2.0, seawater 100mL was sampled in 250mL separatory funnel. After Mo(VI)-ARS chelate ion was formed by adding 0.01M alizarin red S solution 1.0mL to the water sample of pH 4.6, 0.6% aliquat-336 chloroform solution 10mL was added and the solution was vigorously shaked for about 30 seconds to form the ion-pair between Mo(VI)-ARS and aliquat-336 perfectly. The solution was stood for about 30 minutes. And the organic phase was taken for the absorbance measurement of the ion-pair at 520nm. The content of Mo(VI) was obtained from the standard calibration curve. Several extraction conditions such as pH, adding amounts of alizarin red S and aliquat-336, and shaking and standing times were optimized and the interferences and release of concomitant ions was also studied. This procedure was applied to the analysis of Eastern and Yellow seawaters. It could be confirmed from the recoveries of over 85% in samples spiked with a given amount of Mo(VI) that this method was also quantitative in the determination of trace Mo(VI) in a seawater.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.5
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• pp.384-390
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• 2006

To improve the extractability of carnosine and the levels of pro-oxidants such as iron in eel (Anguilla japonica) extracts, we examined the effects of extraction time, temperature, ion exchange chromatography and ultrafiltration (UF). The respective protein and total iron were reduced approximately 55 and 60% at 60$^{\circ}C$, 63 and 70% at 80$^{\circ}C$, 68 and 76% at 100$^{\circ}C$ and 82 and 48% with ion exchange chromatography, respectively, compared to the untreated extract. However, there was no significant difference in the carnosine levels in the eel extracts. Ultrafiltration reduced the protein content of the extract by 52% compared with the untreated extract. UF reduced the protein contents of the samples from 60, 80, and 100% heat treatment and ion exchange chromatography treatment by 27, 50, 46 and 47%, respectively. UF reduced the total iron contents of the identical four treatments by 14, 22, 23, and 43%, respectively, while UF increased the carnosine by 23, 17, 20, and 6%, respectively.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.313-323
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• 2022

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

• Journal of the Korean Chemical Society
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• v.27 no.4
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• pp.262-267
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• 1983

A study has been carried out for a scheme of the selective extraction and determination of cesium, sodium and nuclides by the ion association with dicyclohexyl-24-crown-8 and sodium tetraphenylborate from primary coolant of a pressurized water reactor. For that purpose, the effects of hydrogen, cesium and borate ions on the extraction have been investigated. Interferences of iodine and xenon nuclides were found but could be removed by reducing with sodium thiosulfate and back extraction with 1 N hydrochloric acid solution, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.7 s.250
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• pp.638-645
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• 2006

Recently, we reported that significant ion loss occurred prior to its detection in the conventional single particles mass spectrometry and more seriously the loss is ion-kinetic-energy-dependent. These lead to significant error in the measured chemical composition of nanoparticles. Here we attempted to design a novel ion optics that is capable of 100% detection of ions generated from single nanoparticle. Using a commercial software SIMION, we simulated the trajectories of ions launched at different speeds inside the previous single particle mass spectrometer We tested how affect changes in shape of repelling plate, adding Einzel lens, substitution of tube electrode between extraction and acceleration grids. As a results, we could find a best design by assembling the trials in the present condition.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.15-24
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• 1989

The transport of Chromium(Vl) ion from waste water throughl the liquid surfactant membrane containing tri-n-octylamine as a carrier, was analyzed by a slab model and was investigated through experiments. For the experiment of membrane stability, concentrations of surfactant and liquid parafnn oil were analyzed. Extraction euperiments were carried out to observe the effect of system variables, such as stirring speed, concentration of carrier, and NaOH in internal aqueous phase, and concentrations of H$_2$SO$_4$and initial chromium(VI) ion in external aqueous phase at $25^{\circ}C$. It is concluded that the most stable formation of liquid membrane emulsion was obtained when surfactant concentration is above 3 wt. ％ and liquid parafnn oil concentration is 50 vol. ％. The transport of chromium(VI) ion in bacth extractor increased with increasing carrier concentration, the volume ratio of emulsion to external aqueous phases, and initial concentration of chromium(VI) ion under the optimum stirring speed of chromium(VI) ion below 2 ppm. The theoretical equation on the transport of chromium(Vl) ion agreed well with the experimental results.

• Korean Journal of Pharmacognosy
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• v.9 no.4
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• pp.169-171
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• 1978

Methanolic extracts of fresh ginseng, white ginseng and red ginseng were found to have a biological antioxidant activity against ethanol induced lipid peroxidation in the mouse liver. This antioxidant activities were repressed by the addition of ferric ion to the Korean ginseng in the process of its extraction.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.240-240
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• 2011

The first neutral beam injector (NBI-1) has been developed for the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. A first long pulse ion source (LPIS-1) has been installed on the NBI-1 for an auxiliary heating and current drive of KSTAR core plasmas. Performance of ion and neutral beam extractions in the LPIS-1 was investigated initially on the KSTAR NBI-1 system, prior to the neutral beam injection into the main plasmas. The ion source consists of a JAEA magnetic bucket plasma generator with multi-pole cusp fields and a set of KAERI prototype-III tetrode accelerators with circular apertures. The inner volume of plasma generator and accelerator column in the LPIS-1 is approximately 123 liters. Final design requirements for the ion source were a 120 kV/ 65 A deuterium beam and a 300 s pulse length. The extraction of ion beams was initiated by the formation of arc plasmas in the LPIS-1, called as an arc-beam extraction method. A stable ion beam extraction of LPIS-1 has been achieved up to an 100 kV/42 A for a 4 s pulse length and an 80 kV/25 A for a 14 s pulse length. Optimum beam perveance of 1.21 microperv has been found at an accelerating voltage of 80 kV. Neutralization efficiency has been measured by using a water flow calorimetry (WFC) method of calorimeter and an operation of bending magnet. The full-energy species of ion beams have been detected by using the diagnostic method of optical multichannel analyzer (OMA). An arc efficiency of the LPIS was 0.6~1.1 A/kW depending on the operating conditions of arc discharge.

• Journal of Life Science
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• v.13 no.2
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• pp.168-174
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• 2003

The chemical compositions and antioxidant activity of green tea extracts in medilite-extraction water were compared to that of distilled water(DW). Antioxidant activity was fetermined by the formation of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates and microsomes and the scavenging activity of free radicals by DPPH ($\alpha$, $\alpha$'-diphenyl-$\beta$-picrylhydrazyl). The order of total polyphenolic compounds and extracted yield by extracts was medilite 325 mesh-extraction water, medilite 600 mesh-extraction water and distilled water(DW). The ranges of scavenging activity of green tea extracts in DPPH method were 60.95% - 64.51%. The inhibition ratios of TBARS formation in the rat liver homogenates and microsomal fractions were significantly lower with green tea extracts by DW-extraction than with both medilite 325 mesh and 600 mesh-extraction water. The concentration of iron ion of water containing medilite 325 mesh and green tea extracts and of water containing medilite 600 mesh and green tea extracts were significantly higher compared to DW. Therefore, this result suggested that enhanced concentration of iron ion in green tea extracts by medilite-extraction water containing high iron ion content was associated with enhanced peroxidation of the rat liver microsomal fractions. These results showed that total polyphenolic compounds, the % of yield and mineral compounds of green tea extracts were increased using medilite 325 mesh and 600 mesh-extraction water.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.02a
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• pp.67-67
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• 1999