• 대한본초학회지
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• 제23권4호
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• pp.45-49
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• 2008

Objectives: To investigate the quantitative determination of marker constituents of Dioscoreae Rhizoma by the packaging methods Methods: HPLC for the determinations of allatoin in the Dioscoreae Rhizoma. the separation method was performed on an Luna $NH_2$ column($250mm{\times}4.6mm,\;5{\mu}m$, Phenomenes) using solvent water-acetonitrile(2:8, v/v%) with photo diode array detector(210nm). The flow rate was 2.0 mL/min. Results: Retention time of allatoin in HPLC chromatogram was about 4.8 min and calibration curve showed good linearity($R^2$=0.9994) at concentrations from 50.0 to 1000.0 ${\mu}g/mL$ of allantoin. Average content of allantoin by packaging methods was $0.16{\sim}0.40%$. In addition. weight loss rate(%) of Dioscoreae Rhizoma according to the packaging methods was $-0.60{\sim}1.80%$. Conclusions: The variation on content of the marker constituent of Dioscoreae Rhizoma by the packaging methods didn't show difference.

• BMB Reports
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• 제43권11호
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• pp.761-765
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• 2010

Salivary testosterone levels in Korean adults were quantitatively measured for the first time by liquid chromatography-electrospray-tandem mass spectrometry (LC ESI MS/MS). Salivary testosterone was separated on a multiple reaction monitoring (MRM) chromatogram within 7 min. The LC ESI MS/MS assay was validated over the linearity range of 0.01-2.00 ng/ml (r=0.99987) using testosterone-$d_3$ as an internal standard. The lower limit of quantification (LOQ) was 0.01 ng/ml. The intra- and inter-assay precisions were 1.54% to 4.09% and 0.96% to 4.29%, respectively. The mean recovery was 93.32% (range 88.43-98.05%). The validated assay was then applied to measure the salivary testosterone levels of Korean adults. In men, the salivary testosterone level collected between 9：00-11：00 am was approximately 2.8 times higher than that in women (P < 0.0001). Salivary testosterone levels in both sexes negatively correlated with age. The present assay would also be useful in measuring salivary testosterone levels in clinical laboratories.

• 대한기계학회논문집B
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• 제26권3호
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• pp.498-506
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• 2002

Improvements of fuel properties have become essential for exhaust emission reduction as well as for optimization of directly-related design factors and exhaust gas aftertreatment. In this study, the potential possibility of oxygenated fuel such as ethylene glycol mono-n-butyl ether(EGBE) was investigated for the sake of smoke reduction from diesel engine. Because EGBE include oxygen content approximately 27%, it is a kind of effective oxygenated fuel that the smoke emission of EGBE is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficient at high load and speed in diesel engine. And, it was tried to analyze the quantities of the low and high boiling point hydrocarbon among the exhaust emissions in diesel engine. It have been investigated by the quantitative analysis of the hydrocarbon $C_1$~ $C_{6}$ using the gas chromatography. This study was carried out by comparing the chromatogram with diesel fuel and diesel fuel blended EGBE 20vo1-%. The results of this study show that the hydrocarbon $C_1$~C$_{6}$ among the exhaust emission of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed. In particular, high boiling point hydrocarbons such as $C_{5}$ and $C_{6}$ were reduced remarkably at high speed and load.d.

• KSBB Journal
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• 제11권5호
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• pp.529-535
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• 1996

효소적으로 합성된 메틸프룩토시드(methyl fruc­t to side )와 당의 혼합물로부터 Amberlite IRA -900 을 고정상 담체로 하여 당과 배당체를 액체 크로마 토그래피법으로 정밀 분리함으로써 메틸프룩토시드 를 출발물질로 하는 새로운 sugar ester의 합성 공 정이 연구개발되도록 하고, 액체 크로마토그래피법 에 의한 알킬배당체의 정밀 분리기술이 실용화될 수 있도록 최적조업조건과 해상도 빛 생산성을 검토하였다. Amberlite IRA-900을 고정상 담체로 한 메틸프 룩토시드의 정밀분리공정은 이론단수의 개념에 근거 한 선형 크로마토그래피 모델로 모사할 수 있었으며 에틸프룩토시드와 자당의 용출 크로마토그램을 잘 예측할 수 있었다. 급액농도가 각각 3g/L와 5g/L 인 메틸프룩토시드와 자당의 수용액으로부터 메틸프 룩토시드를 정밀분리하기 위해서는 급액을 $60^{\circ}C$에서 충전체적의 75%까지 주입하고공탑유속 1.13cm/mm의 중류수로 용출시킬 때 해상도 1.1에서 95% 이상의 회수율과 7mg MF/g-resin/h의 생산성을 얻었다.

• 한국식품영양과학회지
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• 제35권3호
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• pp.353-358
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• 2006

유자씨앗 중의 플라보노이드 및 리모노이드 화합물을 methanol 및 ethanol로 추출 HPLC로 정량한 결과 ethanol추출의 경우가 거의 모든 화합물에서 높게 나타났고 화합물의 종류도 더 많이 검출되었다. Limonin이 methanol 추출의 경우 140.34 mg/100g, ethanol 추출의 경우 170.98 mg/100g으로 개별화합물 중 가장 높은 함량을 나타내었고 그다음이 caffeic acid, naringin, lutin, nomilin 등의 순으로 높았다. HPLC/MS에 의하여 약42가지 화합물의 분자량 측정이 가능하였으며 mass spectrum과 extracted current ion chromatogram으로 분자량 측정이 가능하였다.

• 한국미생물·생명공학회지
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• 제1권1호
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• pp.13-18
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• 1973

Bacillus subtilis의 생균 및 포자액을 자외선 조사와 diethylsulfate 처리로서 adenine 요구변이주 총 62주를 분리하였다. 이들 변이주는 발효배지에 자외선흡수 물질을 축적하고 있음을 확인하였으며 이 축적물은 thin-layer chromatogram 자외선흡수 곡선등으로 hypozanthine, uracil 임을 동정하였다. 이 중에서 hypoxanthine만을 축적하는 변이주 BS-137의 배지성분을 검토한 결과 탄소원소로서는 glucose가 좋았으며 질소원으로서는 yeastext와 NaNO$_3$ 가 적당하였다. 아울러 배양액으로부터 hypoxanthine을 분리 정제하는 방법을 확립하였다.

• Tribology and Lubricants
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• 제33권2호
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• pp.45-51
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• 2017

Engine oil is a substance used for the lubrication of internal combustion systems. However, in some case, defects in engine systems may contaminate engine oil with fuel. Contaminated engine oil can cause problems in the normal functioning of a vehicle. In this study, we investigate the functional properties of engine oil contaminated with diesel fuel. The test results indicate that the engine oil contaminated with diesel fuel has low flash point, pour point, density, kinematic viscosity and cold cranking simulator value. The contaminated engine oil which has low plash point can cause fire and explosion accident. Furthermore, a four ball test indicates that the contaminated engine oil increases wear scar to poor lubricity. Moreover, we investigate the GC pattern using SIMDIST (simulated distillation) for determination of diesel in engine oil. The SIMDIST analytic result, diesel was detected at earlier retention time than engine oil in chromatogram. Thus the SIMDIST method can define whether engine oil is contaminated by diesel fuel or not. We can use the SIMDIST method for the diagnosis of oil condition instead of analyzing other physical properties that require many analytic instruments, large volume of oil sample and long analysis time.

• 한국물환경학회지
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• 제23권6호
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• pp.843-849
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• 2007

Monitoring of NOM characteristics is important for improving removal efficiency of natural organic matter (NOM) in water treatment processes. In this study, several NOM characteristics, which include specific UV absorbance (SUVA), total carbonate content, molecular weight distribution, and fluorescence properties, were measured using samples collected from a pilot-scale water treatment plant consisting of coagulation/flocculation (C/F), filtration, ozonation and granular activated carbon (GAC) processes. The highest removal of NOM was observed in C/F and filtration processes as demonstrated by the reduction of dissolved organic carbon (DOC) by 25% and 21%, respectively. Despite nearly no change in DOC, however, the lowest SUVA value and the highest total carbohydrate content were observed in the sample from ozonation process. This indicates that non-degradable aromatic compounds become depleted and biodegradable organic compounds are enriched during the process. Comparison of synchronous fluorescence spectra of the samples showed that ozoation process increased protein-like fluorescence while it decreased fulvic-like and terrestrial humic-like fluorescence. Consistently, a slight peak of protein-like fluorescence was observed in the sample from ozonation process. The greatest change in molecular weight distributions of the samples was observed in C/F process. Comparison of size exclusion chromatogram of the samples revealed that NOM fractions with the molecular weight greater than 2000 Da were reduced by over 90% after C/F process. SUVA values and total carbohydrate content of the samples were well correlated with a ratio of protein-like fluorescence and terrestrial humic-like fluorescence intensities with the correlation coefficients of 0.99 and 0.91, respectively. This suggests that synchronous fluorescence properties of NOM could be used as useful tolls for monitoring changes of some NOM characteristics during water treatment processes.

• 한국식품과학회지
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• 제6권3호
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• pp.185-187
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• 1974

시판(市販) 주요(主要) 건어제품(乾魚製品)의 총(總) MA함량(含量) 및 동(同) MA의 유리(遊離) 및 결합상태(結合狀態)를 분획(分劃)해 본 결과 다음과 같았다. 1. 총(總) MA의 함량(含量)을 TBA number로 표시(表示)해본 바, 건(乾) 멸치류가 비교적(比較的) 높았고 다음이 뱅어포이었으며, 오징어 및 명태류는 대체로 낮았다. 특히 멸치류는 종류에 따라 MA함량이 크게 달랐으며, 대살멸치(42.3)가 가장 높았고, 소살멸치(13.7)가 가장 낮았다. 그리고 명태도 건조공정이 상이(相異)한 제품 즉, 황태(黃太)(1.62) 및 흑태(黑太)(0.66) 등 종류에 따라 총(總) MA함량이 서로 차이가 있었다. 2. 총(總) MA함량이 가장 높은 대살멸치의 수용성획분(水溶性劃分)에 있어서의 결합(結合) 및 유리(遊離) MA를 Sephadex G-10 column으로 분획(分劃)해 본 결과, 2개(個)의 결합(結合) MA 및 1개(個)의 유리(遊離) MA가 chromatogram 상(上)에 나타났고, 결합(結合) 및 유리(遊離) MA의 비율(比率)은 94.5 : 5.5로서 대부분(大部分)이 결합상태(結合狀態)로 존재(存在)하고 있었다.

• 미생물학회지
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• 제37권1호
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• pp.66-71
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• 2001

1.5 L 교반 탱크반응조에서 이미 그 특성 이 밝혀진 TNT 분해세균인 Stenorophomonas maltophilia의 배양을 이용하여 dinitrotoluenes (DNTs) [2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT)]를 호기적 조건하에서 미생물학적으로 제거하는 시험을 하였다. 2,4-DNT와 2,6-DNT는 각각 10일과 14일의 배양기간 중에 완전히 분해되었다. 이차 탄소는 DNT리 분해에 필수적이었으며 이차 탄소가 없는 상태에서는 거의 분해되지 않았다. DNTs의 분해에 이차 탄소가 미치는 효과에 대하여 조사하였다. 이차 질소원이 없는 상태에서 DNTs는 완전히 분해되었으나 이차 탄소원이 첨가된 배지에서는 부분적으로 분해되었다. HPLC와 GC-MS가 잔존 DNTs와 중간대사산물을 확인하기 위하여 사용되었다. 그 결과, HPLC와 GC-MS chromatograms은 대상 화합물인 2,4-DNT와 2,6-DNT, 그리고 각각의 중간대사산물인 2-amino-4-nitrotoluene과 2-amino-6-nitrotoluene을 성공적으로 확인할 수 있었다.