• Toxicological Research
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• v.31 no.3
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• pp.265-271
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• 2015

This study was carried out to investigate contents of 8 polycyclic aromatic hydrocarbons (PAHs) from frequently consumed seafood and dairy products and to evaluate their chemical analysis methods. Samples were collected from markets of 9 cities in Korea chosen as the population reference and evaluated. The methodology involved saponification, extraction with n-hexane, clean-up on Sep-Pak silica cartridges and gas chromatograph-mass spectrometry analysis. Validation proceeded on 2 matrices. Recoveries for 8 PAHs ranged from 86.87 to 103.57%. The limit of detection (LOD) 8 PAHs was $0.04{\sim}0.20{\mu}g/kg$, and limit of quantification (LOQ) of 8 PAHs was $0.12{\sim}0.60{\mu}g/kg$. The mean concentration of benzo[a]pyrene (BaP) was $0.34{\mu}g/kg$ from seafood and $0.34{\mu}g/kg$ from dairy products. The total PAHs concentration was $1.06{\mu}g/kg$ in seafood and $1.52{\mu}g/kg$ in dairy products.

• Journal of Environmental Science International
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• v.11 no.5
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• pp.455-461
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• 2002

Polycyclic aromatic hydrocarbons(PAHs) are ubiquitous contaminants in coastal marine environment. PAHs enter estuarine and nearshore marine environment via several routes such as combustion of fossil fuels, domestic and industrial effluents and oil spills. In August of 1997, mussels(Mytilus edulis) were collected at 6 sites near Kori nuclear power plant in order to analyze the PAH content by HPLC with uv/vis detection. Unfortunately, I could not find any living oysters in which I firstly intended to measure the PAH content in the study area. NPTHL and ANCPL were the major dominant PAH compounds in mussels living in the intertidal zone of Kori, Korea, and DahA, BbF, BaP were the next dominant PAH group in mussels in the study area. The mean concentrations of 15 PAH in mussels ranged from 3.2 to 1,680 ppb(mean 105$\pm$60.5 ppb). Compared with other studies world over, the concentrations of carcinogenic PAHs were relatively low in mussels in the study area, even though total PAH content was rather high. According to N/P(Naphthalene/Phenanthrene) ratio(147) and the ratio of 2∼3 ring to 3∼5 ring PAHs(58∼90 %) in mussels in the study area, I expect that the major source of PAHs in this study area is rather fresh petroleum-derived. This study presents preliminary data for the PAH levels in mussels from the intertidal zone of Kori, and the data will hopefully be utilized for the assessment of oil pollution in the East Sea, Korea.

• Journal of the Korean Chemical Society
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• v.6 no.1
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• pp.88-93
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• 1962

The telomerization of vinyl acetate with carbon tetrachloride, chloroform and monochlorobenzene were investigated with respect to the synthesis of those telomers, properties and molecular weights of the formed telomers, and reaction mechanisms. Vinyl acetate reacted with carbon tetrachloride and chloroform to form telomers at 70-90$^{\circ}C$ and 60-70$^{\circ}C$, respectively and it formed polymer with monochlorobenzene. As a chain transfer agent, carbon tetrachloride was more effective than chloroform. In the telomerization of vinyl acetate and carbon tetrachloride: 1) The average molecular weight of the telomer decreased as the mole ratio of carbon tetrachloride to vinyl acetate increased. The optimum conditions for the highest yield of the telomer were as follows: Mole ratio of carbon tetrachloride to vinyl acetate : 2.5 Reaction time : 20 hours. 2) As the reaction proceeded, the refractive index and average molecular weight of the telomer increased rapidly in the first 10 hours but the increase was slow through the next 10 hours, so that, the average recurring number(n) of taxogen in the final product reached an almost definite value, i.e., 3. The telomer formed in the telomerization of vinyl acetate with carbon tetrachloride and chloroform turned to brown color in the air due to decomposition or polymerization. The suggested telomerization mechanism was supported by the hexachloroethane detected in the course of reaction.

• Analytical Science and Technology
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• v.18 no.5
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• pp.403-409
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• 2005

Polycyclic Aromatic Hydrocarbons(PAHs) contamination arises from several sources including processing of food(smoking, direct drying, cooking) and environmental contamination of air, water, or soil, the later being considered as the most important. In this study, to establish the analytical method for some PAHs[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 fish, alkali digestion time, extraction solvents, elution volume of florisil cartridge for clean-up have been optimized. The methodology involved saponification and extraction with n-hexane, 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 90 to 106%.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.3
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• pp.77-87
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• 2001

Composting is a cost-effective and environmentally-sound technology to treat soils contaminated with hazardous organic pollutants. Pollutants to be treated are as follows: explosives, phenolic compounds, PAHs, petroleum hydrocarbons, pesticides, and etc. Composting systems are windrow, static pile, and in-vessel. Design and operational parameters of composting are aeration modes, temperature, moisture content, nutrient supplement, amendment added, and etc. Appropriate oxygen concentration of composting for contaminated soils are 5~15%, while some compounds are degraded well at the low $O_2$ concentration of 2~5%. The most diverse microorganisms live in the temperature of $25{\sim}40^{\circ}$. 50~90% of the soil field capacity is the moisture content not to make a problem in composting. Assuming a bacterial chemical equation is $C_{60}H_{87}O_{23}N_{12}P$, theoretical C : N : P from bacterial chemical portion is approximately 20 : 5 : 1. It should be noted that the ratio does not apply to the total organic carbon measured in a waste because not all carbon metabolized by bacteria is synthesized to new cellular material. Initial C/N ratio of 25~40 is optimum. It is more economical to recycle soils or composts than to add commercial microbes.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.162-168
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• 1998

The characteristics of demulsification of petroleum emulsion by Streptomyces sp. 8321 were investigated. Demulsification ability of Streptomyces sp. 8321 appeared to be confined within the spores. Spore surface hydrophobicity was increased with culture age stimulating the demulsification ability. Over $1.1{\times}10^8spores/ml$ completely demulsified kerosene-0.2% Triton X-100 (2:1) emulsion. Among the low viscosity hydrocarbons, hydrocarbons with longer chain such as n-hexadecane and diesel were more rapidly demulsified. However, only 20-30% of the emulsion with high viscosity hydrocarbons was demulsified after 24 hours. Oil-in-water emulsions made by Corexit, Finalsol and BP series surfactants were completely demulsified within one minute. Demulsification rate ($t_{1/2}$) of oil-in-water emulsions made by Corexit 7664, 8667, Triton X-100 and Tween 80 decreased as their concentration increased. In case of water-in-oil emulsion made by Seagreen, $t_{1/2}$ was over 24 hours. Therefore, demulsification ability of Streptomyces sp. 8321 was more effective on oil-in-water emulsions.

• Analytical Science and Technology
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• v.11 no.5
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• pp.321-331
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• 1998

The separation and sample extraction methods of 19 polycyclic aromatic hydrocarbons (PAHs) in water samples were investigated by gas chromatography/mass spectrometry (GC/MS) and some extraction methods involved liquid-liquid extraction, disk extraction and solid-phase extraction methods. The separation of 19 PAHs was possible by partial variation of oven temperature of GC/MS in temperature range $80{\sim}310^{\circ}C$. Extraction procedures of PAHs in water samples were somewhat modified and compared as extraction recoveries and the simplicity of methods. Extraction recoveries of PAHs were 71.3~109.5% by liquid-liquid extraction method. By using disk extraction, good extraction recoveries (80.7~94.9%) were obtained in case of $C_{18}$ disk extraction method by filtration. And extraction recoveries of PAHs by $C_{18}$ solid-phase were in the range of 51.8~77.9%. Method detection limits (S/N=5) of 19 PAHs were in the range of 0.25~6.25 ppb by liquid-liquid extraction and solid-phase extraction and 0.05~1.25 ppb by disk extraction methods.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.157-161
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• 2009

This paper proposes an analytical method for determining amounts of polycyclic aromatic hydrocarbons (PAHs; benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i] perylene) in coffees beans. Soxhlet extraction and liquid/liquid extraction were tested for the quantification of seven PAHs. Soxhlet extraction was followed by cyclohexane extraction and used a silica cartridge. Liquid/liquid extraction was followed by n-hexane extraction and utilized a florisil cartridge. The extracts were analyzed by HPLC-fluorescence detection (FLD) with a Supelcosil LC-PAH column. The PAH recoveries ranged from 78.68 to 96.28% for the liquid/liquid extraction, and from 67.47 to 84.60% for the Soxhlet extraction.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.641-647
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• 1997

Volatile flavor components in whole edible portion, stem and leaf of fresh angelica (Angelica keiskei Koidz) were extracted by SDE (simultaneous steam distillation and extraction) method using the mixture of n-pentane and diethylether (1:1, v/v) as an extract solvent and analyzed by GC-FID and GC/MS. Identification of the volatile flavor components in aroma concentrate was mostly based on the RI of GC and mass spectrum of GC/MS. Twenty five hydrocarbons, 15 alcohols, 3 aldehydes, 6 esters, 2 ketones and 1 acid were identified in the whole edible portion of angelica. Twenty hydrocarbons, 13 alcohols, 4 esters and 1 acid were identified in the stem sample of angelica. Nineteen hydrocarbons, 11 alcohols, 4 aldehydes, 6 esters, 2 ketones and 1 acid were identified in the leaf sample of angelica. ${\gamma}-Terpinene$, germacrene B, ${\delta}-3-carene$, cis-3-hexen-1-ol, ${\gamma}-muurolene$ and ${\gamma}-elemene$ were the main components in each edible portions of angelica. The terpenoid compounds in volatile flavor components identified from whole edible portion, stem and leaf samples were confirmed as 75.76%, 86.42% and 78.21%, respectively. These results suggest that terpenoid compounds have a great effect on the flavor characteristics of angelica.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.172-175
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• 1994

Xanthomonas campestris M12 carrying OCT plasmid which could dissimilate octane was able to utilize n-alkanes of eight to sixteen carbon atoms via the capacity of this plasmid. M12 strain could utilize terminal oxidation products of these primary, alkanes, alcohols, aldehydes and fatty acids but not hexanoic acid, adipic acid, pimelic acid and heptanal. This strain also biodegraded n-alkanes by monoterminal or diterminal oxdation of straight-chain fatty acids, and branched-chain alkane.