• Analytical Science and Technology
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• v.12 no.1
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• pp.28-33
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• 1999

Glutathione(GSH) in biological samples was determined by high performance liquid chromatographic(HPLC) method with fluorescence detector(FLD) after monobromobimane(MBB) or 4-fluoro-7-sulfobenzofurazan(SBD-F) derivatization. The detection limit of $0.03{\mu}g/mL$ was obtained after MBB derivatization, derivative of MBB was about 200 times more sensitive than that of SBD-F. N-acetylcysteine was used as internal standard and tetrabutylammonium ion as counter ion for better separation. The determination by ion-pairing chromatography after MBB derivatization was characterized by linearity in the range between $0.08{\sim}8.33{\mu}g/mL$ with a good correlation coefficient of 0.998. By precision test appeared relative standard deviation at less than 5% at three different concentrations. This method can be used for the analysis of GSH in plasma and tissue.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.609-612
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• 2009

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.194.2-195
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• 2000

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.195.1-195.1
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• 2000

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.4
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• pp.554-560
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• 2001

Hydrophilic treatment of the packing materials in a cooling tower has been made by the ion assisted reaction (IAR) method to increase the wettability of the packing materials. The effects of hydrophilic treatment of packing materials on the performance of a cooling tower have been investigated in a wide range of operating parameters, such as water flow rate, air flow rate, and the water inlet temperature. A pilot cooling tower has been designed and built to model a counter-flow cooling tower. The results obtained indicate that the packing characteristic value with hydrophilic packing could be substantially increased by 6∼19.3% than that with conventional packing in the operating ranges considered. The correlations of the packing characteristic value as a function of water-to-air ratio are suggested for a counter-flow cooling tower with hydrophilic packing as well as with conventional packing.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.137-144
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• 2015

The present paper deals with the extractive separation and selective recovery of nickel and lithium from the sulfate leachate of cathode scrap generated during the manufacture of LIBs. The conditions for extraction, scrubbing and stripping of nickel from lithium were optimized with an aqueous feed containing $2.54kg{\cdot}m^{-3}$ Ni and $4.82kg{\cdot}m^{-3}$ Li using PC-88A. Over 99.6% nickel was extracted with $0.15kmol{\cdot}m^{-3}$ PC-88A in two counter-current stages at O/A=1 and pH=6.5. Effective scrubbing Li from loaded organic was systematically studied with a dilute $Na_2CO_3$ solution ($0.10kmol{\cdot}m^{-3}$). The McCabe-Thiele diagram suggests two counter-current scrubbing stages are required at O/A=2/3 to yield lithium-scrubbing efficiency of 99.6%. The proposed process showed advantages of simplicity, and high purity (99.9%) nickel sulfate recovery along with lithium to ensure the complete recycling of the waste from LIBs manufacturing process.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.394-394
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• 2010

Ammonium ion (${NH_4}^+$) was suggested as the origin of interstellar $6.85\;{\mu}m$ band. Early study, in which organic molecule and water ice film mixtures were photolyzed so that organic acids could be produced, explained the generation of ${NH_4}^+$ from the reaction of photogenerated organic acid and ammonia ($NH_3$). However, the observed abundance of organic acids or their counter-anions are not so high in interstellar ice and not enough to protonate $NH_3$ into ${NH_4}^+$ in the observed level. Because of the shortage in photogenerated organic acids, the candidate of acid which protonates $NH_3$ should be modified. Here, we prepare $NH_3/H_2O$ binary mixtures and photolyze them with vacuum ultraviolet (VUV, peak at 10.6 and 10.0 eV). We find the ammonium ion (${NH_4}^+$) from photolyzed mixture by using low energy sputtering (LES) and reflection absorption IR spectroscopy (RAIRS). As a hydronium ($H_3O^+$) can be produced by UV irradiation and protonate bases, ${NH_4}^+$ may be formed from the reaction of photogenerated $H_3O^+$ and $NH_3$. We show the generation of ${NH_4}^+$ without any kind of organic molecules or acids, and it may explain the relatively high abundance of ${NH_4}^+$ compared to the counter-anions or organic acids in interstellar ice.

• Bulletin of the Korean Chemical Society
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• v.19 no.4
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• pp.462-466
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• 1998

The homobimetallic anion, $({\eta}^5-MeCp)Mn(CO)_2Mn(CO)_5-M^+\; (M^+=Na^+, PPN^+$) was disrupted by $PR_3\;(R=C_6H_5,\;C_2H_5,\;OCH_3)$ in THF at various temperatures (r.t. ∼65℃) under the pseudo first order reaction conditions where excess of $PR_3$ was employed under a nitrogen atmosphere. For the reaction involving $PPN^+$ analog, Mn-Mn heterolytic cleavage occurred, leading to $PPN^+Mn(CO)_5^-\; and \;({\eta}^5-MeCp)Mn(CO)_2PR_3$ as products; however, in case of $Na^+\; analog,\; Na^+$ seems to play a novel counter ion effect on the disruption reaction by transferring one terminal CO from the $Mn(CO)_5$ moiety on to the $({\eta}^5-MeCp)Mn(CO)_2$ of the corresponding homobimetallic complex, eventually resulting in $Na^+Mn(CO)_4PR_3^-\;and\;({\eta}^5-MeCp)Mn(CO)_3$. This reaction is of overall first order with respect to [homobimetallic complex] with the activation parameters (ΔH≠=23.0±0.7 kcal/mol, ΔS≠= - 8.7±0.8 e.u. for $Na^+$ analog; ΔH≠=28.8±0.4 kcal/mol, ΔS≠=15.7±0.6 e.u. for $PPN^+$ analog reaction).

• Journal of the Korean Society of Safety
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• v.29 no.3
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• pp.34-38
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• 2014

In Display such as LCD, LED, and AMOLED or semiconductor related industries are required to have static ionizer in order to produce reliable goods since the ionizer can create balanced ion that is delivered to producing goods to minimize electrical damages when manufacturing. However, the most general type of ionization is called, "Corona Discharge" that has a slight chances to generate unequal and unstable amount of each +/- ion to the target object. Then, the ionization performance will drastically decrease and end up with quality deterioration problem. In this research, our objective to resolve the current issue via applying "Coupling Condenser" on each counter electrodes of Corona discharging type ionizer. The result is that the ion balance was maintained the satisfied range that is within +/-100V when we changed the duty ratio of the High Voltage of Pulse AC about 40 ~ 70%. In addition, when levelling the High Voltage of Pulse AC, the ion balance holds the range within +20 ~ 0V. Even though we have tested the same experiment for a year, we have seen the range changes roughly ${\pm}50V$.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.349-359
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• 1992

Studies were carried out on the selective removal of inorganic salts such as NaCl and $Na_2SO_4$ from dye solution, using counter diffusion-reverse osmosis and nanofiltration, respectivey. For the dye solution used in the experiments, 1 to 30% of salts were removed by counter diffusion while the loss of dye molecules was less than 0.3%. The separation factors by one pass operation were 10-500 according to ionic species. In five successive operations, removals of anion($Cl^-$) increased but those of cation($Na^+$) decreased due to the Donnan effect. Effects of feed flow rate on removal efficiencies of various ions were also observed at constant flow rate of stripping water. Reverse osmosis of desalted dye solution by counter diffusion was conducted to prepare highly concentrated liquid dyes. The rejection efficiency of dye molecules was greater than 99%. For the rejection efficiency of chloride ion, experimental values were compared with theoretical ones based on solution-diffusion model. Two stage diafiltration was performed in nanofiltration. The rejection efficiency of chloride ion was continuously decreased due to the Donnan dialysis and even negative rejection was observed. The Donnan effect was more pronounced in the second diafiltration.