• 공업화학
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• 제7권3호
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• pp.453-463
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• 1996

$NH_4Cl$을 염소화제로 사용하여 시약 PbS와 Pb함유 자연광물인 방연광의 염소화 반응에 대해 조사하였다. 방연광의 적정 염소화 반응조건은 반응온도 $425^{\circ}C$, 방연광에 대한 $NH_4Cl$의 무게비 4.0, 반응시간 2시간이었다. 이 조건하에서 방연광중의 PbS는 $NH_4Cl$에 의해 효과적으로 $PbCl_2$로 염소화되었으며 그 전화율은 90%였다. 방연광의 염소화 반응에서 염소화제로 사용한 $NH_4Cl$은 $NH_3$와 HCl로 효과적으로 분리되었으며 양론적으로 90%의 $NH_3$를 회수할 수 있었다.

• 한국대기환경학회지
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• 제20권4호
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• pp.483-491
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• 2004

The purpose of this study is to develop an ozone passive sampler and to evaluate its performance p-Acetamidophenol using as the reagent for ozone reacts specifically with the ambient ozone to produce a fluorescence material (p-acetamidopheonl dimer). The volume of absorbent solution and the extraction time determined at suitable conditions for measuring ozone were 100$\mu$L and 60 min, respectively. The changes of fluorescence were observed with incresing the storage period of passive samplers in ambient air. but the cool storage in a refrigerator did not remarkably influence the increase of fluorescence. The measurement for the precision oi the passive sampling was carried out with duplicate measurement of passive samplers. The intra-class correlation coefficients of passive samplers using dry and wet filters were 0.992 and 0.962, respectively The results from field validation tests indicated practical agreement (dry filter: r=0.963, wet filter: r=0.995) between the passive sampler and an UV photometric $O_3$ analyzer. The limit of quantification of ozone passive samplers with sampling time of 8 hr (wet filter) and 24 hr (dry filter) were 8.0 ppb and 2.7 ppb, respectively.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 추계학술발표대회
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• pp.119-127
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• 2000

The development and performance of a competitive indirect immunoassay for the quantitative measurement of polychlorinated biphenyl compounds in insulating oils is presented. Reagent preparation and the assay characterisation, optimisation and validation steps are described. The dynamic range of the assay for Aroclors 1254 and 1260 in methanol was $50-800 {\mu}g\;ml^{-1}$ with $50\%$ signal inhibition values of 217 and $ 212 {\mu}g\;ml^{-1}$ respectively. Impending legislation in the UK is likely to decree that oils containing $ >50 {\mu}g\;ml^{-1}$ PCB be considered contaminated. Assay sensitivity increased with the degree of PCB chlorination. The assay of structurally related compounds of environmental concern yielded cross-reactivity values of under $0.6\%$. The immunoassay proved reliable for the analysis of transformer oils containing $>70{\mu}g\;ml^{-1}$ PCB, but over-estimated PCB levels in oils containing $<20{\mu}g\;ml^{-1}$ of the analyte with the oils requiring pre-treatment using either solid-phase extraction techniques or washing with KOH-ethanol/sulphuric acid to remove matrix interferents. The analytical performance of the assay was compared against a commercially available semi-quantitative immunoassay kit for PCBs in soil and water.

• Bulletin of the Korean Chemical Society
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• 제14권2호
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• pp.234-238
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• 1993

The method of study describes the determination of the nanogram amounts of mono-, di-, and tri-butyltin compounds in sea water. The procedure is based on 1) the conversion of tin compounds to non-ionic species by sodium tetraethyl borate as an alkylation reagent, 2) one-step ethylation and 3) extraction. No further purification or concentration of the extract was required before GC-FPD (Flame Photometric Detector). The detection limits for mono-, di- and tri-butyltin were 12.50, 6.02, and 4.19 ng/L. The linear range (0-120 ng/L) was solely dependent on the detector response height. Sea water samples (n=24) were obtained from Masan Bay, Busan, Ullsan, Gunsan, Sockcho, Yeasu, Donghae, Inchun, Kanghwa, and Ahsan in Korea. The samples were collected between June, 1992 to July, 1992 and the distribution of monobutyltintrichloride (MBTC), dibutyltindichloride (DBTC), and tributyltinchloride (TBTC) in sea water was recorded. The concentrations of butyltin compounds in seawater were found to be in the range of N.D. (not detected)-61.93 ng/L for MBTC, N.D.-32.16 ng/L for DBTC, and N.D.-55.76 ng/L for TBTC.

• 분석과학
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• 제26권1호
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• pp.19-26
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• 2013

자외선 흡광도가 거의 없는 농작물의 생장 조절용 농약으로 사용되고 있는 지베렐린(GAs) 중 하나인 지베렐린 산($GA_3$)은 발색단이 미약해서 자외선 검출기를 이용하여 분석하기가 어려운 물질이다. 액체-액체 추출법을 이용하여 과일류로부터 지베렐린 산을 효과적으로 추출하기 위하여 시료의 pH와 추출용매에 대한 최적의 추출조건을 확립하고자 하였다. 페나실 브로마이드를 유도체화 시약으로 사용함으로써 자외선 검출기에 선택적이며 감도가 좋은 $GA_3$-유도체 화합물을 만들었으며, 최적의 유도체화 조건을 확립하기 위해서 반응온도 및 시간, 유도체화 시약의 양, 염기의 양 등을 변화시켜주는 실험이 수행되었다. 유도체화 된 $GA_3$는 C18 컬럼을 사용하여 방해물질이 없이 HPLC/UV-vis로 효과적으로 분석되었으며, HPLC/ESI-MS를 사용하여 유도체화된 화합물의 구조를 확인하였다. 사과의 경우, 검출한계(LOD)와 정량한계(LOQ)는 각각 0.008 mg/kg, 0.027 mg/kg로, 배의 경우, 검출한계(LOD)와 정량한계(LOQ)는 각각 0.003 mg/kg, 0.012 mg/kg로 낮은 검출한계와 정량한계를 보였다. 확립된 유도체화 방법은 과일류 중에 존재하는 $GA_3$의 효과적이고 편리한 분석에 응용될 수 있을 것이다.

• 자원리싸이클링
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• 제28권3호
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• pp.35-44
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• 2019

본 연구에서는 제지슬러지소각재(PSA)와 세 가지 킬레이트제(fumarate, IDA, EDTA)를 가지고 간접탄산화에 의해 이산화탄소를 저장하고 탄산칼슘을 생성하는 실험을 진행하였다. Fumarate와 IDA를 용제로 사용하면 간접탄산화반응이 촉진되어 물을 사용했을 때보다 더 많은 양의 이산화탄소를 저장하였다. 0.1 M 농도의 fumarate와 IDA를 사용했을 때, 이산화탄소 저장량은 각각 63, $89kg-CO_2/ton-PSA$이었고, 탄산칼슘 생성량은 각각 144, $202kg-CaCO_3/ton-PSA$이었다. 그러나 EDTA를 용제로 사용한 경우에는 탄산화반응이 거의 진행되지 않았다. PSA로부터 칼슘용출효율은 킬레이트제의 농도가 높고 Ca-ligand 안정화상수가 클수록 증가하였다. 또한 탄산화효율도 Ca-ligand 안정화상수의 영향을 받았다. Ca-ligand 안정화상수가 클수록 P SA로부터 더 많은 칼슘이 용출되었지만, 이 값이 탄산칼슘의 안정화상수($10^{8.35}$)보다 크면 탄산화반응이 진행되기 어려웠다.

• 핵의학기술
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• 제22권2호
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• pp.74-78
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• 2018

본 연구는 그리냐르 시약과 $[^{11}C]$$CO_2$ 가스의 반응온도를 최적화하여 $[^{11}C]$아세트산의 방사화학적 수율을 향상시킬 수 있는 방법을 개발하고자 하였다. 본 연구에서는 $TRACERlab^{TM}$ $FX_{C-Pro}$ 자동합성장치에 기체포집 반응법과 고체상 추출 카트리지 분리정제법을 적용하여 $[^{11}C]$아세트산을 합성하였다. 그리냐르 시약으로 3.0 M $CH_3MgCl$를 사용하였으며, 표지반응 시 무수 tetrahydrofuran을 사용하여 0.5 M $CH_3MgCl$로 희석하여 사용하였다. 사이클로트론에서 생산된 $[^{11}C]$$CO_2$ 가스를 포집 후 반응용기에 담겨있는 그리냐르 시약에 불어넣을 때 반응용기를 액체질소로 냉각하여 $0^{\circ}C$, $-10^{\circ}C$, $-55^{\circ}C$가 각각 되게 한 후 표지반응을 진행하였다. 표지 반응 후 1 mM 아세트산 용액을 넣어 반응액을 희석한 후 고체상 추출 카트리지 IC-H와 IC-Ag를 차례로 통과시켜 불순물을 제거하고, 최종산물인 $[^{11}C]$아세트산은 SAX 카트리지에 통과시켜 흡착시킨 후 주사용수를 통과시켜 유기용매 및 불순물을 제거한 후 생리식염수로 용출하였다. 용출된 $[^{11}C]$ 아세트산은 $0.22-{\mu}m$ 멸균필터를 사용하여 멸균 후 HPLC로 방사화학적 순도를 측정하였다. 사이클로트론의 빔 전류를 $50{\mu}A$로 고정하고 빔 조사를 20분간 하여 생산된 $[^{11}C]$$CO_2$ 가스를 그리냐르 시약과 반응시킬 때 온도가 $0^{\circ}C$일 때 $15.2{\pm}1.6GBq$ (n=5)의 $[^{11}C]$아세트산이 합성되었고, 표지반응온도가 $-10^{\circ}C$일 때는 $18.7{\pm}2.1GBq$ (n=19)가 합성되었으며, $-55^{\circ}C$일 때는 $7.7{\pm}1.7GBq$ (n=19)가 합성되었다. 방사화학적 수율이 가장 높았던 $-10^{\circ}C$에서 빔 조사시간에 따른 $[^{11}C]$ 아세트산의 합성수율을 비교하였을 때 10분간 빔을 조사할 때보다 20분간 조사할 경우 약 1.9배 생산량이 증가하는 것을 확인할 수 있었다. 본 연구를 통해 $[^{11}C]$$CO_2$ 가스와 그리냐르 시약을 $-10^{\circ}C$에서 반응 할 경우 방사화학적 수율을 크게 개선할 수 있어 향후 임상에서 통상적으로 생산 시 유용한 표지조건으로 활용될 수 있을 것이라 기대된다.

• Reproductive and Developmental Biology
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• 제34권3호
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• pp.217-221
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• 2010

When fully grown oocytes are removed from their follicles, they can resume meiosis and mature spontaneously under in vitro conditions. However, nuclear maturation under in vitro condition is not accompanied by complete cytoplasmic maturation, which is essential for successful fertilization and the initiation of zygotic development. This study analyzed change of proteins in follicular fluids during the porcine follicular development. Follicular fluids were collected from follicles of diameter 1~2 mm, 2~6 mm and 6~10 mm in ovary of slaughtered pigs. Total proteins were extracted from follicular fluids by M-PER Mammalian Protein Extraction Reagent. We confirmed totally 27 same spots, 1 spot from follicle fluid of 2~6 mm follicle and 5 spots from follicle fluid of 6~10 mm in diameter were analyzed by MALDI mass spectrometry and searched on NCBInr. In results, spot No. 28 from 2~6 mm follicle was Ig lambda chain C region, and spot No.32 and 33 from 6~10 mm was Apolipoprotein A-(APOA4). Spot No.29 and 31 were failed to analyze. These results indicate that the porcine oocyte during in vitro maturation depend on specific different expressed proteins may play an important roles in the sequence of molecular events in porcine oocyte maturation and follicular development.

• 한국대기환경학회지
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• 제22권1호
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• pp.117-126
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• 2006

The purpose of this study is to develop a badge-type passive sampler for the measurement of short-term nitrogen dioxide and to evaluate its performance. The principle of the method is a colorimetric reaction of nitrogen dioxide with sulfanilic acid, N-1-naphthylethylendiamine, and phosphoric acid. First, it has been shown that the filter paper should be rinsed with ultrapure water and ultrasound, and then dried in a vacuumed desiccator. The concentration and volume of absorption reagent (triethanolamine) were $20\%$ and 100 ${\mu}L$, respectively. The extraction time was determined as 60 min. Second, duplicate measurements (n= 116) were carried out for evaluating the precision of the passive sampler. The relative error and the correlation coefficient between duplicates are $3.4\pm 3.0\%$ and 0.994, respectively. In addition, the $95\%$ confidence interval of intraclass correlation coefficient and the estimated value are 0.992$\sim$0.996 and 0.994, respectively. Third, a paired t-test was carried out for evaluating the accuracy of the passive sampler (n=40). In the result of the test, the $95\%$ confidence interval of the difference was -1.710 ppb <$\gamma$< 0.788 ppb. Finally, the average concentration of blanks, measurement detection limit, limit of detection, and limit of quantification are $2.4\pm 0.4$ ppb, 104 ppb, 3.8 ppb, and 7.0 ppb, respectively.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1018-1023
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• 2001

Oleamide (cis-9-octadecenamide) is endogenous primary amide of fatty acid that is produced in small amounts in animal brains. It is known to induce sleep and to lower temperature by destroying the lipid plasma membrane structure of cells, thereby disclosing gap junction channels. To develop a new biological production method for oleamide, a screening program was conducted to isolate a microorganism producing oleamide. Among 1,500 soil microorganisms tested, KK90378 exhibited a potent positive reaction with Dragendoff`s reagent, used to detect the primary amide of oleamide. KK90378 was identified as a Streptomyces species based on cultural and morpohological characteristics, the presence of diaminopimelic acid in the cell wall, and the sugar patterns for the whole-cell extrat. Streptomyces sp. KK90378 produced oleamide 3 days after culture at $28^{\circ}C$, pH 7.2 A series of purification steps, including hexane extraction, silica gel column, and preparative thin layer chromatographies, were performed for the purification of oleamide. A spectrophotometric analysis using $^1H$, $^13C$-NMR, and GC-MS confirmed that the chemical structure of the purified oleamide was identical to that of authentic oleamide.