• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.56-75
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• 2018

Korean Photochemical Assessment Monitoring Stations (PAMS) have been established since the late 2001 to monitor ambient air concentrations of VOC species, which would enhance understanding photo-chemical formation of ozone and subsequently contribute to developing efficient ozone control strategies. The present study aims at identifying major VOC species and examining their trends by analyzing PAMS monitoring data collected from the year 2006 to 2016. All the 18 PAMS sites operated by the Ministry of Environment were included in the study. PAMS monitored the 56 target VOC species, which are classified into four groups, alkenes, lower alkanes ($C{\leq}3$), higher alkanes ($C{\geq}4$), aromatics. The higher alkanes and aromatics dominated over the lower alkanes and alkenes in the type 2 and 3 PAMS sites except Joongheung site. N-butane was a major alkane species, toluene was a major aromatic species and most of VOCs showed decreasing trends in these sites. On the other hand, only the alkenes showed decreasing trends at the Joongheung site in Yeosu. Major sources of abundant species such as ethane, propane, n-butane, toluene were estimated by analyzing seasonal variations, correlation with other VOC species, and emission profiles. A major source of n-butane was identified as LPG cars, while major sources of toluene varied considerably from one site to another. The lower alkanes were composed of ethane and propane, both of which showed a strong seasonal variation, low in the summer and high in the winter, indicating that a major source might be the heating by gaseous fuels. Ozone formation potentials of VOC species were evaluated by applying MIR and POCP to the measured VOC species concentrations. Toluene contributed the most to total ozone forming potentials followed by m,p-xylene for all the type 2 and 3 PAMS sites except for two sites in Yeosu-Gwangyang. Ethylene and propylene were the first and second contributors to total ozone forming potentials at Joongheung site in Yeosu.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.747-757
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• 2014

Since the air contamination by air pollutants from indoor construction materials and daily supplies has been increased in recent decades, the public interest of using environmentally friendly products and improving indoor air quality also attracted much attention. As known as effects of phytoncide, it has been used in construction materials and daily supplies with various method. In this study, hinoki cypress (Chamaecyparis obtusa) was used because of its high contents of phytoncide. The leaves of hinoki cypress (C. obtusa), which generated by pruning, were extracted by steam distillation, and then used as humidification water source. Volatile organic compound (VOC) from C. obtusa were characterized by GC-MS (Gas chromatograph-Mass spectrophotometry) in order to evaluate effects and risks of using C. obtusa extracts. Total 86 types and 116 types of VOC were detected from distilled water (DI water) and C. obtusa extracts, respectively. Aromatic compounds (DI water: 13 types, 53%; C. obtusa extracts: 13 types, 38%) and terpenoids (DI water: 16 types, 23%; C. obtusa extracts: 23 types, 33%) were detected more diverse types and higher amount than other compound categories. No additional aromatic compounds were found from C. obtusa extracts, so C. obtusa extracts did not affect on aromatic compounds emission. However, in terpenoids, total amount of emission from C. obtusa extracts increased to 33% from 23% (DI water) and 7 more types of compounds were found from C. obtusa extracts. Especially, from C. obtusa extracts, terpinen-4-ol was emitted 71 times higher than DI water. During the humidification with C. obtusa extracts, emitted terpenoid compounds were well known for higher anti-bacterial, anti-insect, and anti-septic functions, but also these had anti-hypertensive and anti-cancer activities. Therefore, terpenoids from C. obtusa extracts can help to improve public health by using humidifier.

• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.61-67
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• 1970

The growth characteristics of Candida tropicalis KIST 359, isolated from soil samples collected at an oil depot in Korea, have been studied by cultivating batches under varying conditions. The conclusions of the study were: 1. The yeast easily assimilates hydrocarbons in a range of $C_{14}-C_{17}$, and the optimum cultivation temperature and pH are $30^{\circ}C$ and 5.5, respectively. 2. Using this strain of micro-organism, gas oil gives a higher cell yield than kerosine and with gas oil except urea all other nitrogen sources $(NH_4NO_3,\;NH_4Cl,\;(NH_4)_2SO_4\;and\;(NH_4)_2HPO_4)$ similarly support a satisfactory growth of the yeast. 3. The highest yield is obtained with a gas oil level of 10%(v/v), and concentrations of nitrogen source and $MgSO_4{\cdot}7H_2O$ of 0.5 and 0.05%(w/v), respectively. 4. The protein content of dried yeast cells is 59.8%. Its amino acid composition can be compared well with that of FAO provisional patterns, but with a low methionine and a high lysine content.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.54-61
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• 1998

Samjangs (Korean-style mixture of soybean paste) were prepared using magjang, traditional doenjang (Korean style soybean paste), and mixture of traditional doenjang and magjang (a kind of Korean style soybean paste) as a main composition. Charateristics including volatile compounds were investigated. Total sugar in samjang by using magjang was higher than that of other treatment while reducing sugar of the mixed treatment was high. Glutamic acid $(230.6{\sim}310.9\;mg/100\;g)$ was highest among free amino acids. Hunter color values of samjang with magjang was lower than those of others. Volatitle flavor components of smajang were identified with GC and GC-MSD. Fifty four components including 11 alcohols, 7 esters, 13 acids, 3 aldehydes, 4 alkanes, 4 phenols, 3 pyrazine and others were found in samjangs. Ethanol, acetic acid ethyl ester, 3-methyl butanoic acid, 2,4-hexadienoic acid and acetic acid might be major volatile components considering of high peak area. Pentanoic acid methyl ester and 4-methoxy-2-buten-1-ol were higher than other components in samjang with magjang while 2-methyl-1-propanol, butanoic acid and 3-methyl butanoic acid were in samjang with traditional doenjang and ethanol, acetic acid ethyl ester and 2,4-hexadienoic acid were in the mixed treatment.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.108-121
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• 1994

The retention indices of branched-chain alkane, benzene ring, alcohol, amine, ketone, aldehyde and cyclic compounds were measured at 150, 180 and $210^{\circ}C$ on OV-1701 and OV-1 capillary columns. The group retention factors (GRF) of the substituents and the st` ructure retention factors (SRF) of the molecular structure change are derived from the retention indices of reference compounds and series of homologues. The $GRF_f$ equation of `f'th substituent is $GRF_f\;=\;I_{obs}-(100Z + \sum\limits_{i{\neq}f}GRF_i$ + {\sum}$SRF_i$)and the SRFf equation of `f'th molecular structure group is $SRF_f\;=\;I_{obs}-(100Z + {\sum}GRFi + \sum\limits_{i{\neq}f}SRF_i$). The predicted retention indices for those compound were in agreement, within the error of $\pm2$ and $\pm3%$, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively. The $\Delta$ xi of the substituents and $\Delta$ yi of the molecular structure change according to temperature change are derived from the $\Delta'/^{\circ}C$ of reference compounds and series of homologues. The $\Delta$ xi equation of the `f'th substituent is ${\Delta}x_f = {$\Delta}'/^{\circ}C+ \sum\limits_{i{\neq}f}\Delta$ xi + {\sum}{\Delta}yi\;and\;{\Delta}yi$ equation of the `f'th molecular structure group is ${\Delta}y_f$ = {\Delta}'/^{\circ}C+{\sum}{\Delta}xi +\sum\limits_{i{\neq}f}{\Delta}yi$. The predicted $\Delta'/^{\circ}C$ for these compounds were in agreement, within the error of ${\pm}18%$ and 17%, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.721-730
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• 2006

The effects of compost amendment on the removal of petroleum hydrocarbons and the activities of microorganisms in soil ecosystem have been studied in bioremediation of diesel contaminated soil. The relation between biological activities and removal of petroleun hydrocarbon was determined by ATP(Adenisine Triphosphate), n-alkanes and TPH concentration analysis. After 80 days of bioremediation, the removal of TPH in soil amended with compost increased more than 10% compared with control soil which was tilled in the same condition without compost addition. The biodegradations of n-alkanes having 12 to 20 moles of carbon were distinctive. As the soil was contaminated with more diesel, the ATP has decreased rapidly. When the TPH amounted to 80,000 mg diesel/kg, the ATP decreased to 4 ng/g from initial concentration of 65 ng/g. While the ATP in the compost amended soil increased to 112 ng/g after tilling for 6 days, the ATP in the control increased to merely 36 ng/g after tilling for 14 days. Also while the control soil showed a lag time in ATP increase, the compost amended soil did not show that but showed a rapid ATP increase within a short time. The patterns of changes in ATP concentration were similar to those in daily removals of TPH with time difference of about 7 days.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.302-308
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• 2015

Isothermal vapor liquid equilibria for the binary system of 3-methylpentane with ethylene glycol monopropyl ether ($C_3E_1$) and ethylene glycol isopropyl ether ($iC_3E_1$) were measured at 303.15, 318.15, and 333.15K. In our previous work, phase equilibria for the binary system of $C_3E_1$ mixtures were investigated according to the chain length of alkane, alcohol or those isomer. But in this study, we discussed the different effect of $C_3E_1$ and its isomer, $iC_3E_1$, on the phase equilibria. The measured systems were correlated with a Peng-Robinson equation of state (PR EOS) combined with Wong-Sandler mixing rule for the vapor phase, and NRTL, UNIQUAC, and Wilson activity coefficient models for the liquid phase. All the measured systems showed good agreement with the correlation results. And it was found that the phase equilibria showed very little difference between the $iC_3E_1$ mixture system and the $C_3E_1$ mixture system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.20-30
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• 1993

Liquid Chromatographic behavior of Pd(II) in Isonitosoethylacetoacetate imine IEAA-NR: R=H, CH3, C2H5, n-C3H7, n-C4H9, C6H5-CH2) Chelates were investigated by reversed phase high performance 1iquid chromatography on Micropak MCH-5 Column using Methanol /water as mobile phase. The optimum condition for the separation of Pd-Isonitrosoethylacetoacetate imine chelates were examined with respect to the flow rate, mobile phase strength. It was found that Pd(IEAA-NR)2 chelates were eluted in an acceptable range of the capacity factor value (0 $\leq$ log k' $\leq$ 1), The dependence of the logarithm of capacity factor(k') on the volume fraction of water in mixture with in the binary mobile phase was examined. Also, the dependence of k'on the liquid-liquid extraction distribution constant in methanol-water / n-alkane extraction system was on system was invert tigated for Pd(IEAA-NR)2. Both kinds of dependence are linear, which suggests that the retention of the electroneutral metal chelates be largely due to the solvophobic effect.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1144-1150
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• 1997

Volatile flavor components of soybean koji kochujang made from a glutinuous rice by improved method were analyzed by using a purge and trap method during fermentation, and identified with GC-MSD. Fifty-six volatile flavor components including 16 alcohols, 15 esters, 7 acids, 4 aldehydes, 5 alkanes, 3 ketones, 1 benzene, 1 alkene, 2 phenol and 2 others were found in improved kochujang. The number of volatile flavor components detected immediately after making kochujang were 32 and increased to 46 components after 30 day of fermentation. The most number 55 of volatile flavor components were found after 90 day of fermentation. Thirty-one kinds of volatile flavor components were commonly found through the fermentation period 9 alcohols such as 2-methyl-1-propanol, ethanol, 3-methyl-1-butanol, 8 esters such as methyl acetate, ethyl acetate, 2-methylpropyl acetate, 3 aldehydes such as butanal, acetaldehyde, furfural and 11 othesrs. Although the various types of peak areas (%) of volatile flavor components were shown in kochujang during the fermentation days, ethanol. ethyl acetate, ethyl butanoate, 2-methylpropyl acetate, 2-methyl-1-propanol and 3-methyl-1-butanol were mainly detected during fermentation. Those might be the major volatile flavor components in kochujang made by improved method. Peak area of ethanol was the highest one among the volatile flavor components at immediately after mashing and 90 day while ethyl acetate showed the highest Peak area after $30{\sim}60$ day of fermentation and 3-methyl-1-butanol showed the highest peak area after $120{\sim}150$ day of fermentation.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.351-355
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• 2002

Volatile compounds of kimchi-flavored steak sauce were isolated using simultaneous steam distillation and solvent extraction methods and identified by matching mass spectrum and retention index (RI) with the reference data. Twenty-three compounds including five aldehydes, four alcohols, four acids, three sulfur-containing compounds, one ketone, and six others were identified, among which the most abundant compound was eugenol. Sulfides such as dimethyl dis- and trisulfides, and acids such as acetic and dodecanoic acids showed strong effects on the kimchi flavor. Aroma extract dilution analysis with three fold dilution factor shown in over the FD value 34 identified 2-butanal, 2-pentylfuran, methyl-2-propenyl disulfide, and 2-furanmethanol. Strong good aroma was detected in the RI range between 1030 and 1357, bad aroma in RI 1561, sweety aroma in RI 2057, clover aroma of eugenol in RI 2122, and rancid flavor in RI 2251.