• Asian Journal of Atmospheric Environment
• /
• v.5 no.3
• /
• pp.146-151
• /
• 2011

1-Nitropyrene (1-NP), 2-NP and 2-nitrofluoranthene (2-NFR) are useful markers for studying the atmospheric behaviors of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs). However, present methods for measuring trace levels of these compounds are lesssensitive and laborious. Here we describe several improvements to a previously reported high-performance liquid chromatography-chemiluminescence detection system that allows it to determine trace levels of 1-, 2-NPs and 2-NFR. The proposed system was equipped with a reducer column packed with Pt/Rh instead of zinc whose life-time was limited. The combination of Cosmosil MS-II (monomeric ODS) and AR-II (polymeric ODS) columns was used instead of polymeric ODS columns as the separator column to improve the separation. An ethanol mixture with acetate buffer (pH 5.5) was used in place of an acetonitrile mixture with the same buffer to activate the reducer column. The same ethanol mixture was used as the mobile phase for the clean-up column. The switching time of the column switching valve was optimized to concentrate the amino-derivatives of above NPAHs quantitatively on the concentrator column. The concentrations of bis(2,4,6-trichlorophenly) oxalate and hydrogen peroxide in the chemiluminescence reagent solution were optimized to 0.4 mM and 30 mM, respectively, to increase the sensitivity. Under the above conditions, the detection limits (S/N=3) of 1-, 2-NPs and 2-NFR were 1 fmol (0.25 pg), 10 fmol (2.5 pg) and 4 fmol (1 pg), respectively. The proposed system was effectively used to determine trace levels of 1-, 2-NPs and 2-NFR in airborne particulates collected at Noto Peninsula. The atmospheric concentrations of 1-, 2-NPs and 2-NFR were not more than sub pg $m^{-3}$ levels. They were higher in winter (January) than in summer (July). In both seasons, the concentrations were in decreasing order, [2-NFR]>[1-NP]>[2-NP].

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.36 no.2
• /
• pp.99-103
• /
• 2010

Waxes, or long-chain hydrocarbons, may be obtained naturally from animals, vegetables, and mineral waxes, or may be synthesized. The oil-wax gels are widely applied to lots of cosmetics such as lipsticks. For example, the lipstick texture is strongly dependent on the glossiness of the oil-wax gels. Extensive research has been carried out to investigate the lattice structure of wax mixture in pure solvents (hydrocarbons) and defined mixtures. However, only a limited amount of work has been published on the lattice structure of wax matrixes in undefined mixtures. The objective of this study was to investigate the relationship between the lattice structure of ceresin wax and different wax mixtures and the glossiness of oil-wax gels. Recently visual factors such as the glossiness of skin are generally known as the words to express the beauty. The mechanism of glossiness has been suggested to understand the changes that occur in the lattice structure of the wax matrixes when they are forming gels and also the effects of the nature of solvent. The present work investigates the lattice structure of the wax matrixes and glossiness of oil-wax gels obtained from ceresin and microcrystalline wax as well as of the gels formed by different waxes in solvent.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.28 no.3
• /
• pp.257-266
• /
• 2018

Objectives: The objective of this study was to evaluate asphalt fumes and PAHs exposure among asphalt road paving workers. Methods: Task-based personal air samplings(n=41) were carried out in 3 asphalt road paving construction sites using PTFE (polytetrafluorethylene) filters for asphalt fume and XAD-2 with glass fiber filters for PAHs. The concentration of fumes and PAHs were showed by four different job(paver finisher operator, paving laborer(raker), macadam roller operator and tire roller operator). Results: The geometric mean(GM) concentration of asphalt fumes as benzene soluble aerosol was highest at paving laborers($42.32{\mu}g/m^3$), followed by in order, paver finisher operators($41.57{\mu}g/m^3$), macadam roller operators($31.9{\mu}g/m^3$), and tire roller operators($30.31{\mu}g/m^3$). The GM of total PAHs concentration was highest at paver finisher operators($37.5{\mu}g/m^3$), followed by in order, paving laborers($20.13{\mu}g/m^3$), tire roller operators($8.66{\mu}g/m^3$), and macadam roller operators($6.23{\mu}g/m^3$). The results of the evaluation of 16 compounds of PAHs showed that the concentrations of naphthalene, achenaphthylene, achenaphthene, pyrene, fluorene and benz (a) anthracene was higher than those of other PAHs compounds and as the carcinogenic substances, benzo(a)pyrene, and debenz(a,h) anthracene were detected. The benzo(a)pyrene equivalent concentration(BaPeq) was $2.81{\mu}g/m^3$ at paver finisher operators, $2.07{\mu}g/m^3$ at paving laborers, $0.41{\mu}g/m^3$ at tire roller operators and $0.22{\mu}g/m^3$ at macadam roller operators. Asphalt road paving workers have higher benzo(a)pyrene equivalent(BaPeq) values even though at lower total PAHs concentration than workers in steel pipe coating and tar industry. Conclusions: Asphalt road paving workers were found to have risk of carcinogen exposure due to higher Benzo(a)pyrene equivalent concentration(BaPeq) than other PAHs exposure occupations. This study confirmed the carcinogenic hazards among asphalt paving workers.

• Korean Journal of Food Science and Technology
• /
• v.32 no.5
• /
• pp.1015-1021
• /
• 2000

Volatile flavor components (VFCs) in cooked black rices (Suwon-415 and Chindo) were studied. The major reactions during cooking, which result in aroma volatiles, are the Maillard reaction between amino acids and reducing sugars, and thermal degradation of lipid. Black rices washed with water were soaked in 1.5 folds water and heated at $110^{\circ}C$ in oil bath for 30min. VFCs in cooked black rices were extracted for three hours by SDE and were analyzed by GC and GC/MS. A total of 91, 82 volatiles were identified in Suwon-415 and Chindo black rice, respectively. Suwon-415 was composed of 26 alcohols, 10 aldehydes, 5 acids, 11 esters, 15 ketones, 9 hydrocarbons, 3 furans, 3 nitrogen containing compounds and 9 sulfur containing compounds. Chindo was composed of 28 alcohols, 9 aldehydes, 4 acids, 12 esters, 14 ketones, 5 hydrocarbons, 3 furans, 3 nitrogen containing compounds and 4 sulfur containing compounds.

• Analytical Science and Technology
• /
• v.19 no.5
• /
• pp.415-421
• /
• 2006

The following concentrations of some PAHs were investigated; [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno (1,2,3-c,d)pyrene] in vegetables(n=160) and fruits(n=50). The food samples were purchased at the local markets in Seoul, Chuncheon, Daejeon, Kwangju and Pusan. The samples were radish, onion, bean sprouts, welsh onion, chinese cabbage, spinach, young pumpkin, garlic, cucumber, carrot, lettuce, sesame leaf, tangerine, persimmon, apple, pear and banana. The methodology involved ultrasonic extraction with dichloromethane, clean-up on Sep-Pak florisil cartridges and determination by HPLC/FLD (High Performance Liquid Chromatography/Fluorescence Detector). Overall method recoveries for 8 PAHs spiked into these products ranged from 95 to 102%. The mean level of the following PAHs were determined; benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene and indeno(1,2,3-c,d)pyrene in vegetables and fruits was N.D., 0.014 ng/g, 0.031 ng/g, 0.016 ng/g, 0.019 ng/g, 0.091 ng/g, 0.016 ng/g and N.D., respectively.

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

• International Journal of Oral Biology
• /
• v.42 no.4
• /
• pp.175-181
• /
• 2017

The aim of this study was to provide a basis for the molecular mechanism underlying the pharmacological action of ethanol. We studied the effects of 1-propanol on the location of n-(9-anthroyloxy)palmitic acid or stearic acid (n-AS) within the phospholipids of synaptosomal plasma membrane vesicles (SPMV). The SPMV were isolated from the bovine cerebral cortex and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL). 1-Propanol increased the rotational mobility of inner hydrocarbons, while decreasing the mobility of membrane interface, in native and model membranes. The degree of rotational mobility varied with the number of carbon atoms at positions 16, 12, 9, 6 and 2 in the aliphatic chain of phospholipids in the neuronal and model membranes. The sensitivity of increasing or decreasing rotational mobility of hydrocarbon interior or surface by 1-propanol varied with the neuronal and model membranes in the following order: SPMV, SPMVPL and SPMVTL.

• Particle and aerosol research
• /
• v.10 no.2
• /
• pp.61-75
• /
• 2014

Five on-road measurements were made using a mobile laboratory (ML) to characterize spatial and temporal air pollutant distributions over roads around a day-care center in urban area on 30 August 2013. Fixed monitoring was also done near the day-care center using the ML during the periods between on-road measurements. On-road air pollution monitoring route was classified into seven sections and three zones to identify severe polluted roads among many roads having different traffic volumes and directions. Typical pollutants emitted from vehicles such as $NO_x$, black carbon, particle-bound polycyclic aromatic hydrocarbons, and submicron particles including nanoparticles were monitored using real-time instruments. Peak concentration episodes were frequently observed during the on-road measurements and most peaks were simultaneously monitored at four pollutants. Colored on-road air pollution map for each pollutant provides an insight on spatial air pollution distribution, showing heavily polluted roads and sections. Average on-road $NO_x$ concentration of each run was similar to that monitored at the nearest roadside air monitoring station.

• Publications of The Korean Astronomical Society
• /
• v.27 no.4
• /
• pp.195-200
• /
• 2012

We show how the rotation emission from isolated interstellar Polycyclic Aromatic Hydrocarbons (PAHs) can explain the so-called anomalous microwave emission (AME). AME has been discovered in the last decade as microwave interstellar emission (10 to 70 GHz) that is in excess compared to the classical emission processes: thermal dust, free-free and synchrotron. The PAHs are the interstellar planar nano-carbons responsible for the near infrared emission bands in the 3 to 15 micron range. Theoretical studies show that under the physical conditions of the interstellar medium (radiation and density) the PAHs adopt supra-thermal rotation velocities, and consequently they are responsible for emission in the microwave range. The first results from the PLANCK mission unexpectedly showed that the AME is not only emitted by specific galactic interstellar clouds, but it is present throughout the galactic plane, and is particularly strong in the cold molecular gas. The comparison of theory and observations shows that the measured emission is fully consistent with rotation emission from interstellar PAHs. We draw the main lines of our PLANCK-AKARI collaborative program which intends to progress on this question by direct comparison of the near infrared (AKARI) and microwave (PLANCK) emissions of the galactic plane.

• Publications of The Korean Astronomical Society
• /
• v.27 no.4
• /
• pp.117-122
• /
• 2012

The interstellar dust grains are formed and supplied to interstellar space from asymptotic giant branch (AGB) stars or supernova remnants, and become constituents of the star- and planet-formation processes that lead to the next generation of stars. Both a qualitative, and a compositional study of this cycle are essential to understanding the origin of the pre-solar grains, the missing sources of the interstellar material, and the chemical evolution of our Galaxy. The AKARI/MIR all-sky survey was performed with two mid-infrared photometric bands centered at 9 and $18{\mu}m$. These data have advantages in detecting carbonaceous and silicate circumstellar dust of AGB stars, and the interstellar polycyclic aromatic hydrocarbons separately from large grains of amorphous silicate. By using the AKARI/MIR All-Sky point source catalogue, we surveyed C-rich and O-rich AGB stars in our Galaxy, which are the dominant suppliers of carbonaceous and silicate grains, respectively. The C-rich stars are uniformly distributed across the Galactic disk, whereas O-rich stars are concentrated toward the Galactic center, following the metallicity gradient of the interstellar medium, and are presumably affected by the environment of their birth place. We will compare the distributions of the dust suppliers with the distributions of the interstellar grains themselves by using the AKARI/MIR All-Sky diffuse maps. To enable discussions on the faint diffuse interstellar radiation, we are developing an accurate AKARI/MIR All-Sky diffuse map by correcting artifacts such as the ionising radiation effects, scattered light from the moon, and stray light from bright sources.