• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.111-114
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• 2003

A new monitoring system has been developed for in-situ and realtime measurement of ozone transport in unsaturated porous media using a fiber optic sensor. The calibration of the fiber optic transflection dip probe (FOTDP) system was successfully carried out at various ozone concentrations using a column with length of 30 cm and diameter of 5 cm packed with glass beads, which don't react with gaseous ozone. The breakthrough curves (BTCs) of ozone was obtained by converting the normalized intensity into ozone concentration. The FOTDP system reflected the ideal transport phenomena of gas phase ozone at various flow rates. The FOTDP system worked well for in-situ monitoring of gas phase ozone at various water saturations and in presence of SOM. However, the FOTDP system did not measure the ozone concentration at more than 70% water saturation.

• 분석과학
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• 제8권4호
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• pp.753-758
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• 1995

Thermal desorption/gas chromatography/mass selective detection method using Tenax cartridges for the determination of gaseous polycyclic aromatic hydrocarbons(PAH) is described. Glass fiber filter can collect only PAH in particulate. Gaseous PAH may penetrate the filter. Glass cartridge packed Tenax-GC was uses fur adsorption of gaseous PAH. The air of inhalation zone was collected fur 2-10 hours. Cartridges were thermally desorbed in the reverse direction to sample flow. The desorption conditions were as follows; desorption temperature; $300^{\circ}C$; desorption time; 20min; column head pressure; 30psi; inlet split vent; closed during desorption.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.45-50
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• 2014

A fully packed capillary electrochromatographic (CEC) microchip with an on-column micro-solid phase extraction (SPE) bed for the preconcentration and separation of organic analytes was prepared. A linear microchannel with monodisperse colloidal silica packing was formed on a cyclic olefinic copolymer microchip with two reservoirs on both ends. Silver-cemented silica packing frit structure was formed at the entrance of the microchannel by electroless plating treatment as a base layer. A gold coating was formed on it by reducing $Au^{3+}$ to gold with hydroxylamine. Finally micro-SPE bed was formed by self-assembly adsorption of 1-dodecanethiol on it. Micro-SPE beds were about 100-150 ${\mu}m$ long. Approximately $10^3$ fold sensitivity enhancements for Sulforhodamine B, and Fluorescein in nM concentration levels were possible with 80 s preconcentration. Basic extraction characteristics were studied.

• Bulletin of the Korean Chemical Society
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• 제23권4호
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• pp.545-549
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• 2002

A simple and rapid technique for the separation and preconcentration of lead in water and biological samples has been devised. Preconcentrationis based on the depositionof analyte onto a column packed with dithizone immobilized on sodium dodecyl sulfate coated alumina at pH $\geq$ 3. The trapped lead is eluted with 5 mL of 4 M nitric acid and determined by flame atomic absorption spectroscopy. A sample of 1 L, results in a preconcentration factor of 200 and the precision at 20${\mu}g$ $L^{-1}$ is 1.3%(n=8). The procedure is applied to tap water, well water, river water, vegetable extract and milk samples, and accuracy is assessed through recovery experiments and by independent analysis by furnace atomic absorption.

• 한국환경과학회지
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• 제12권10호
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• pp.1117-1120
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• 2003

Pesticides were extracted from samples with 70% acetone and methylene chloride in order, and then cleaned up via open-column chromatography apparatus packed with florisil, and finally analyzed simultaneously the organophosphorus pesticides using GC/NPD. Ultra-2 and Ultra-1 fused silica capillary columns were used to separate and identify the products. Recovery of most analytes from soybean sample, taken from pesticide residues well, was greater than(80%) for all except(6) analytes. This method can simultaneously determine multiple pesticides with a high degree of accuracy and precision.

• KSBB Journal
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• 제9권2호
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• pp.147-156
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• 1994

A study was carried out for production of a pigment : bluish purple, using a mutant Streptomyces californicus KS-89-7. The mutant was induced from Streptomyces californicus KS-89 with N-methyl-N-nitro-N-nitrosoquanidin(MNNG). It was immobilized on an inert substance made of colloidal sillica and 3.5% sodium alginate with 1 to 10 ratio. The diameter of inert bead was 2mm, and number of immobilized mutant spore was approximately $1.0{\times}10^7$/ml. It was packed in a column reactor and fermentation was conducted with a substrate made of soluble starch 1%, glycerol 1.0%, sodium glutamate 0.1%, sodium nitrate 0.05%, L-prolin 0.025% and with some trace elements. The aeration for production of the pigment was 2.5m1/min with semi-continuous fermentation. The pigment production reached at peak on 8 days of fermentation, and the mutant produced the pigment 1.8 times more than its parent strain with the maximum pigment production of $1.72g/\ell$. The pigment production continued for 24 hours of fermentation, and at the end of the fermentation the mutant produced the pigment $1.52g/\ell$.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1807-1811
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• 2004

Supercritical fluid chromatography (SFC) was considered for separating racemic ibuprofen. The chromatographic column (3.9 ${\times}$ 150 mm) was packed with Kromasil$^{\circledR}$ CHI-TBB, and the mobile phase was supercritical carbon dioxide with modifier of IPA. The experimental variables were the content of IPA, and temperature and pressure of supercritical mobile phase. To determine the separation condition, the empirical equation of retention factor and resolution was proposed. In the case of retention factor, the empirical equation was in the form, $k\;=\;a{\rho}\;+b/F\;+\;c\;({\rho}/F)\;+\;d$. The empirical equation for resolution was proposed as a linear form, $R\;=\;a{\rho}\;+\;bF\;+\;c$.

• KSBB Journal
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• 제18권1호
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• pp.65-69
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• 2003

Pentoxifylline MIPs에서 시료와 기능성 단위체 사이에는 수소결합이 형성되었다. 수소결합의 능력은 분자구조상 질소원자의 위치에 의해 결정되어졌다. Pentoxifylline과 caffeine theophylline MIPs 모두는 구조상 유사한 시료들과 affinity가 증가하는 결과를 얻어냈다. 특히 caffiene-theophylline MIPs에서 높은 수치의 체류인자와 IF를 얻었다. 이러한 결과로 적합한 복합 주형분자를 사용할 때 우리가 원하는 목적시료만을 선택적으로 분리 할 수 있고 그러므로 solid phase extraction에 사용되기에 적합하다는 결과를 얻어냈다.

• 공업화학
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• 제17권2호
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• pp.201-209
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• 2006

활성탄과 제올라이트 13X를 충진시킨 흡착탑에 흡착질인 벤젠을 포화 흡착시킨 후 여러 가지 탈착 방법에 대한 효율을 살펴보았다. 뜨거운 수증기에 의한 탈착, 세정 기체에 의한 탈착, 진공에 의한 탈착 등을 실험하였고, 그 결과 뜨거운 수증기에 의한 탈착이 가장 좋은 탈착 방법으로 판단되었다. 또한 뜨거운 수증기는 흡착탑 내의 온도를 상승시키면서 탈착을 야기시키고 수증기 탈착 과정 이후에는 건조 공정이 수반되어야만 효율이 높아짐을 알 수 있었다. 건조 공정이 수반되지 않을 경우는 수증기가 추후에 흡착을 방해하는 결과를 초래하였다. 진공에 의한 탈착은 효과가 매우 적은 것으로 나타났는데 이로부터 벤젠의 경우에 압력 변화에 의한 탈착 보다는 온도 변화에 의한 탈착이 더 효과적인 것으로 판단되었다. 세정 기체에 의한 탈착에서는 진공 탈착과 함께 이루어질 때 좋은 탈착 성능이 나타남을 알 수 있었다.

• 대한화학회지
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• 제12권2호
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• pp.47-50
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• 1968

Dowex $1{\times}4$ 陰이온 交煥樹指를 二段階(높이:下段 22cm, 上段 3cm, 直經 1.5cm)로 充塡하여 비스머스 金屬中에 들어있는 不純物인 Pb(II), Ag(I), Cu(II)를 7.5M 鹽酸으로, 그리고 Zn(II), Fe(III)를 0.5M 鹽酸으로 分離하고 上段에 남아있는 Te(IV)은 2M NaOH 용액으로 容出하고 아직도 上段에 남아있는 Au(III)는 樹脂를 태워서 分離하였다. 또 한가지 方法은 같은 樹脂를 10cm 높이로 一段階의 管에 充塡하여 0.5M 鹽酸으로 Pb(II), Ag(I), Cu(II), Fe(III), Zn(II)를 함께 容出하여 비스머스 中에서 分離하였다. 分離된 모든 不純物은 比色法으로 定量하였다.