• Applied Biological Chemistry
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• 제46권3호
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• pp.207-213
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• 2003

시판의 amylase와 protease효소제로 원료를 처리하여 담금한 효소제 사용 고추장 숙성과정 중 휘발성 향기성분을 purge and trap 장치로 포집하여 GC-MSD로 분석, 동정한 결과 alcohol 16종, ester 16종, acid 7종, aldehyde 4종, alkane 2종, benzene 1종, ketone 3종, alkene 1종, amino 2종, phenol 1종, 기타 1종 등 54종의 휘발성 향기성분이 동정되었다. 동정된 향기성분 수는 담금직후에 alcohol 7종, ester 6종, aldehyde 3종 등 총 23종이 검출되었으나, 30일에는 alcohol 4종, ester 1종을 비롯한 8종이 추가 검출되어 31종으로 증가되었다. 120일에는 49종으로 향기성분 수가 최대에 달하였다. 숙성 전 과정을 통하여 검출된 향기성분은 2-methyl-1-propanol, ethanol, 3-methyl-1-butanol 등 alcohol류 6종, ethyl acetate, isoamyl acetate, ethyl butyrate 등 ester류 5종, butanal, acetaldehyde 등 aldehyde 3종, 기타 6종 등 총 20종이었다. 향기성분의 면적비율(peak area%)은 숙성기간에 따라 다소 차이가 있으나 ethanol, ethyl acetate, ethyl butyrate, ethenone, 2-methyl-1-propanol, 3-methyl-1-butanol 등이 높아 이들 성분이 효소제사용 고추장의 향기 주성분으로 나타났다. 숙성시기별로는 담금직후에 ethyl acetate가, 90일에는 3-methyl-1-butane이, 이외의 기간에는 ethanol이 가장 높았다.

• 한국환경보건학회지
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• 제2권1호
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• pp.5-9
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• 1975

For analysis of Xanthene dyes according to the developing solvent and adsorbent was applied to Thin-layer chromatography with silicagel and cellulose plate. Silicagel chromato-plate used were prepared under different condition of activation. Using eight developing solvent, the influence of the condition for activation upon the separation of Xanthene dyes was investigated. The results are shown in Table 3. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) mixture and n-butanol+Ammonia water (4:1) mixture gave clear separation for Xanthene dyes, including Fluorescein, Erythrosine Rhodamin B, Eosine, Rose bengale, phloxine and Acid red those Rf values decrease in the described ordor. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) was applied to two adsorbents which were purchased from different manufactures. The results of Chromatograms are obtained Figure 6.

• Nuclear Engineering and Technology
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• 제4권4호
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• pp.327-330
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• 1972

낮은 방사능의 $^{99m}$ Mo으로부터 methyl ethyl ketone으로 추출하여 제조된 Na $^{99m}$ TcO$_4$를 가지고 폐검진에 사용되고 있는 $^{99m}$ Tc Ferric Hydroxide Macroaggregates를 제조하였으며 여러 pH 범위에서 입자의 크기와 수가 변하는 모양을 검토하였고 pH 6-7에서 평균입자의 크기가 scanning에 가장 적당한 20~60$\mu$이었다. 토끼와 인체에 주사하여 좋은 곁과를 얻었다.

• 대한화학회지
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• 제38권1호
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• pp.80-86
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• 1994

Bruceantin유사체 전합성의 중요한 중간체인 ethyl $({\pm})$-8-oxo-10-oxa-l'H-spiro[1, 3]dioxolane-4,4'-tricyclo [9.2.1.0 1,6]dodec-6-ene-9-carboxylate (7)의 합성경로를 개발하였다. 시작물질로서 ethyl 2-cyclohexanonecarboxylate and methyl vinyl ketone을 사용하여, Robinson annulation, allylic oxidation등을 응용하였으며, regiospecific acylation and the formation of epoxy methano bridge 형성 반응 등이 연구되었다. Actalone (3)의 ketalization 반응에서 새로운 decarboethoxylation 반응을 발견하였으며, 이 반응을 이용하여 3차 알코올과 엔온을 가지고 있는 4,4a,5,6,7,8-Hexahydro-4a-hydroxy-2(3H)naphthalenone (14)를 합성하였다.

• 한국식품위생안전성학회지
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• 제14권1호
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• pp.76-83
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• 1999

Solid phase microextraction (SPME) was used for the determination of 6 standard solvents (methanol, isopropanol, methyl ethyl ketone, ethyl acetate, cyclohexane, toluene) in food packaging materials. SPME method is a solvent-free sample preparation technique in which a fused silica fiber coated with polymeric organic liquid is introduced into the headspace above the sample. SPME method using fiber coated polydimethylisiloxane (PDMS) was compared with static headspace (SHS) method used as a reference. It was found that the optimal adsorption condition using PDMS-SPME method was 2$0^{\circ}C$ for 15 minutes for the standard solvents. Detection limits, linearity, reproducibility and recovery of both SHS and PDMS-SPME methods have been determined using 6 standard solvents. Both methods were characterized by high reproducibility and good linearity. Using SHS methods, the mean recovery of the 6 standard solvents was ranged from 75.5% to 105.8% with a mean relative standard deviation (RSD) of 0.3% to 4.8%. With PDMS-SPME method, the mean recovery of the 6 standard solvents was ranged from 86.7% to 108.3% with a mean RSD of 0.4% to 2.5%. The detection limits of both methods were the same for toluene, cyclohexane and methyl ethyl ketone; those of PDMS-SPME method were higher than those of SHS method for methanol, isopropanol and ethyl acetate. PDMS-SPME fiber shoed excellent adsorption for non-polar solvents such as toluene, while it showed relatively low adsorption for polar solvents such as methanol.

• Archives of Pharmacal Research
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• 제17권4호
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• pp.281-283
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• 1994

5-sec-butylthiomethyl-5-alkyl (methyl or phenyl) hydantoins (3-x) were prepared by the reaction of sec-buylthiomethyl alkyl (methyl or phenyl) ketone (1-2), potassium cyanide and ammonium carbonate. 3-(2-Bromoethyl) hydantoins (5-6) were the reaction products of 5-sec-buythiomethyl-5-alkyl (methyl or phenyl) hydantoin and 1, 2-dibromothane in the presence of potassium hydroxide. Alkylation of 5 and 6 with an excess of alkyl (methyl or ethyl iodide in THF with sodium hydride as base gave three 1-alkyl (methyl or ethyl)-3-(2-bromoethyl) hydantoins (7-9). Treatment of the 2-bromothyl group with potassium thioacelate and triethylamine gave three 1-alkyl (methyl or ethyl)-3-92-acetylthioethyl) hydantoins (10-12). Hydrolysis of the 2-acetylthiuoethyl group with sodium hydroxide in methanol afforded the three 1-alkyl (methyl or ethyl)-3-(2-mercaptorthyl) hydantoins.

• Korean Chemical Engineering Research
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• 제43권5호
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• pp.637-640
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• 2005

극성과 비극성의 물질인 methyl tert-butyl ether(MTBE)와 2,2,4-trimethylpentane 혼합물과 methyl ethyl ketone(MEK)와 2,2,4-trimethylpentane 2성분의 액체혼합물 그리고 극성의 물질인 MTBE과 MEK 2성분 액체혼합물의 밀도를 densitometer를 사용하여 278.15 K, 288.15 K, 298.15 K에서 각각 측정하였다. 측정한 밀도로부터 얻은 2성분계 과잉몰부피의 측정값과 Huron-Vidal의 혼합법칙을 사용한 Peng-Robinson-Stryjek-Vera(PRSV)의 3차 상태방정식으로부터 계산한 계산값이 잘 일치하였으며 극성물질을 포함한 혼합물의 몰부피 계산에 3차의 PRSV 상태방정식이 이용될 수 있음을 확인하였다.

• Archives of Pharmacal Research
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• 제12권1호
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• pp.17-21
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• 1989

We have reported earlier on the reactivity of 7-dithiocarboxy-3-phenyl-5,6-dihydro imidazo[2,1-b]thiazolium-betaine with several para-substituted phenacyl bromides. In this work reactions of 7-dithiocarboxy-3-phenyl(or methyl)-5,6-dihydro imidazo[2,1-b]thiazolium-betaine with a series of aliphatic alkylating agents of ${\alpha}$ -halo ketone,${\gamma}$-halo koto ester and ${\alpha}$ -halo ester were examined for the similar purpose. In case of ${\alpha}$-halo ketone or ${\gamma}$-halo koto ester such as ${\alpha}$ -chloro acetone or ethyl 4-chloro acetoacetate new biheterocyclic compound was obtained via ring transformation reaction. However, reaction of the betaine with methyl(or ethyl) bromoacetate used as a ${\alpha}$-halo ester, gave, in-stead, S-alkylated quarternary ammonium salt.

• 한국환경보건학회지
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• 제45권5호
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• pp.474-486
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• 2019

Objectives: This study was performed to investigate the emission characteristics of aldehydes emitted by the printing industry and to evaluate their impact on adjacent residential areas. Methods: Aldehydes and THC were measured from the front of the control device in the printing and coating process. Aldehydes and ketones were measured by workplace area, residential area, and background area to evaluate their impact. Results: The concentrations of formaldehyde (<0.047 ppm) and acetaldehyde (<0.068 ppm) in the printing and coating process were relatively low, and the methyl ethyl ketone used as the primary solvent was the main carbonyl compound in the printing process. The daily mean concentrations of formaldehyde and acetaldehyde were not significantly different by workplace area, residential area, or background area. However, the concentration of methyl ethyl ketone was high in the order of workplace area, residential area, and background area. Conclusions: The concentrations of formaldehyde and acetaldehyde in the adjacent residential areas are considered to be more influenced by secondary sources of photochemical reactions than by primary sources. Methyl ethyl ketone is considered to be highly influenced by the primary source, which is printing facilities.

• 한국환경과학회지
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• 제33권9호
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• pp.645-665
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• 2024

For volatile organic compounds (VOCs) emanating from workplaces within the Noksan national industrial complex, the emission characteristics of pollutants were identified through zone-based measurements using vehicles equipped with selective ion flow tube mass spectrometry(SIFT-MS). The average concentration of total VOCs was higher in zones 2, 4, and 5 than in zones 1, 3, and 6, and was 2.1 to 4.2 times higher than background concentrations. The average concentrations of pollutants investigated were (from highest to lowest) methyl ethyl ketone, formaldehyde, methanol, and n-hexane. However, the pollutants that should be prioritized for reduction to decrease ozone generation were (from highest to lowest) methyl ethyl ketone, n-hexane, for maldehyde, and ethylbenzene+xylene. Benzene, a substance governed by atmospheric environmental standards, exhibited a frequency distribution exceeding the stipulated limits, and concentrations exceeding 100 ppb were identified for methyl ethyl ketone, methanol, toluene, and n-hexane. In certain class 4 and 5 workplace facilities, VOC emissions and emission prevention installations were inadequately managed, necessitating the formulation of management measures for small enterprises. Also, workplaces that emit large amounts of VOCs need to upgrade to VOC-prevention installations with higher processing efficiencies. To efficiently monitor VOCs in a wide range of areas, such as the Noksan national industrial complex, it is considered appropriate to monitor workplaces that emit high concentrations of VOCs using mobile SIFT-MS in real time rather than relying on fixed monitoring methods. A specialized method targeting approximately 10 VOCs is necessary to quickly track emission sources.Furthermore, it is essential to phase in a system for the intensive management of suspected workplaces based on accumulated data from SIFT-MS in areas where high VOC concentrations are measured and to establish a cooperative system for sharing data between relevant institutions.