• Journal of Conservation Science
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• v.32 no.1
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• pp.21-32
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• 2016

Animal glue is a traditional material used extensively as adhesive and binder in mother-of-pearl, wooden structure, traditional painting, etc. Analysis of animal glue is usually performed with IR(infrared spectroscopy) based on the IR absorption of functional group. But, it has a limitation in confirming animal glue when a sample consists of several materials because of overlapping of the absorption band. Py/GC/MS(pyrolysis/gas chromatography/mass spectrometry) is a useful tool in analyzing the constituent of polymeric materials like animal glue by identifying their pyrolysate with very small amount of sample. In this study, confirmation of animal glue in a Dancheong sample was tried with this method. Characteristic pyrolytic compounds of animal glue and tung oil used in Dancheong were identified. Dancheong sample painted with Noerok as a coloring material, animal glue and tung oil was prepared and it was possible to find characteristic peaks of animal glue after thermal degradation and artificial weathering experiment. From this, we found that animal glue can be detected using py/GC/MS in cultural heritage samples consisting of several materials and in different condition. IR was also tried to analyze Dancheong sample and the results were compared with those of py/GC/MS for the detection of animal glue.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.293-298
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• 2017

BACKGROUND: Pyrethroids (PYRs) are a widely used insecticide in agriculture and household area. In mammals, PYRs such as deltamethrin is metabolized to 3-phenoxybenzoic acid (3-PBA) in liver that is mainly excreted in urine. This study is designed to single exposure of deltamethrin to rats in a dose-dependent manner and identify the correlation between deltamethrin exposure and its metabolite (3-PBA) in urine. METHODS AND RESULTS: Exposure levels of deltamethrin were control (0 mg/kg bw), low (0.0705 mg/kg bw), medium (0.705 mg/kg bw) and high (7.05 mg/kg bw) dose. Low concentration was derived by ussing Korea predictive operator exposure model (KoPOEM). Dermal exposure persisted for 6 h, and urine specimens were collected for 24 h. The urine matrix was removed after a series of procedures and 3-PBA was analyzed by gas chromatography/mass spectrometry. CONCLUSION: There was a strong correlation ($R^2=0.83$) between the amount of oral exposure to delta me thrin and urinary levelof3-PBAexcreted. In dermal exposure groups of deltamethrin except high-dose, also there was a good correlation between urinary 3-PBA and deltamethrin exposure, but not stronger than in oral deltamethrin exposure groups. Based on these results, therefore, the amount of 3-PBA in urine can be used as a good monitoring indicator that reflexing the exposure level of deltamethrin to human body.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.216-221
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• 2016

Level and distribution of fourteen polycyclic aromatic hydrocarbons (PAHs) in the agricultural water samples collected in the waterways located in Gyeonggi and Gangwon, Korea were determined for monitoring and risk assessment. A simplified, fast but effective extraction and clean-up methods combined with gas chromatography tandem mass spectrometry (GC-MS/MS) was employed to measure the concentration of the target compounds. The extraction of the analytes of interest in water sample (10 mL) was performed with acetonitrile (10 mL) and the salt. To purify the target PAHs, the clean-up procedure was employed with 2 mL tubes of dispersive solid phase extraction. The optimized method was validated with recoveries, method detection limit (MDL), accuracy and precision. Good recoveries for each PAHs at 10 and $25{\mu}g\;L^{-1}$ were achieved (60 to 110%, with RSD <20%) with linearity (>0.99). MDL for all the analytes was achieved with $0.2{\mu}g\;L^{-1}$. GC-MS/MS results showed that concentration of phenanthrene in the water samples from Gyeonggi (20 sites) ranged from 0.82 to $2.56{\mu}g\;L^{-1}$ and from Gangwon (15 sites) ranged from 0.83 to $1.62{\mu}g\;L^{-1}$. Other PAHs were not found in the water samples but the continuous monitoring for these areas were required.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.715-720
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• 2007

The levels of butyltin compounds in poly(vinyl chloride) (PVC) food packaging using gas chromatography/mass spectrometry (GC/MS) were monitored. The analytical method, involving the ethylation with sodium tetraethylborate, was found to be selective and sensitive for mono-n-butyltin (MBT), di-n-butyltin (DBT), and tri-n-butyltin (TBT), validated by a $0.005\;{\mu}g/mL$ limit of detection (LOD), an $R^2>0.999$ for linearity, and >90% of recovery, respectively. Finally, none of the commercial food wraps and gaskets showed detectable levels of butyltin compounds.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.271-276
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• 2011

Volatile profiles of beverages and encapsulated powders containing Artemisia princeps Pampan extracts were analyzed by solid-phase microextraction-gas chromatography/mass spectrometry during production and storage. Beverages containing 0.32 and 0.64% extracts were stored at room temperature for 8 weeks and $60^{\circ}C$ for 8 days, respectively. Encapsulated particles were stored at room temperature and $60^{\circ}C$ for 8 days. Total volatiles in beverages decreased significantly during storage, irrespective of storage condition (p<0.05). Terpenoids, including cymene, thujone, and ${\beta}$-myrcene, were major volatiles in beverages, and some volatiles including ethylfuran, vinylfuran, and 2-fufural increased in 60oC samples only. Total volatiles in microcapsules at room temperature were not significant different for 8 days (p>0.05), whereas those at $60^{\circ}C$ increased by 16.5 times. Limonene was the most detected volatile in microcapsules, and aldehydes such as hexanal, pentanal, and octanal, and furans such as 2-butylfuran and 2-pentylfuran increased in the $60^{\circ}C$ samples, which may have originated from oxidized lipids used in the microcapsules.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.348-360
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• 2011

To verify the volatile compounds contributing to coffee off-flavor, medium roasted Colombian, Sumatra, Ethiopian and light and dark roasted Colombian bean coffees were sequentially and studiously over extracted. Eight espresso samples and eight filter-dripped samples were analyzed by gas chromatography/mass spectrometry with the solidphase microextraction method and evaluated by sensory tests. In total, 67 compounds were detected, and desirable aroma decreased sharply, while off-flavors increased rapidly after 30 mL of espresso and 200 mL of drip coffee. Percent peak area of 4-ethylguaiacol revealed a linear increase during extraction and was highly correlated with increasing off-flavor, suggesting that it could be an indicator of over extraction. Considering the odor activity value, guaiacol and 4- vinylguaiacol were also contributory compounds to off-flavors.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.533-540
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• 2010

Effects of pH (1.8-10.2) and time (56 sec-15 min 4 sec) at high hydrostatic pressure (500 MPa) on the reduction of volatile compounds in garlic were studied. Volatile components of garlic were obtained from the headspace, analyzed, and identified by gas chromatography (GC)-mass spectrometry and an electronic nose. Nineteen sulfur compounds were identified as major compounds in garlic, and furan, aldehydes, alcohols, and ketones were also detected. Off-flavor compounds were more effectively reduced under strong acidic conditions. As the residence time at 500 MPa increased from 56 sec to 15 min 4 sec, the total amount of volatile compounds decreased significantly. The total amount of sulfur compounds decreased about 70% compared to those of raw garlic when the garlic was soaked in buffer (pH 6.0) and treated at 500 MPa for 15 min 4 sec. A principal component analysis showed that the off-flavors of garlic were reduced by the operating time of high hydrostatic pressure as well as pH treatment. The correlation coefficient of the results between GC and the electronic nose analysis was 0.9620. Therefore, pH and high hydrostatic pressure treatment could be used as an efficient method for reducing of garlic off-flavor.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.23-28
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• 2017

Pyrolysis characteristics of waste plastic films were investigated by using a thermogravimetric analysis and pyrolyzer-gas chromatography/mass spectrometry. Thermogravimetric analysis results revealed that the pyrolysis of waste plastic films can be divided into two distinct reactions; (1) the decomposition reaction of starch at between 200 and $370^{\circ}C$ and (2) that of other plastic polymers such as PS, PP, PE at between 370 and $510^{\circ}C$. The kinetic analysis results obtained by using the revised Ozawa method indicated that the apparent activation energy of the pyrolysis reaction of waste plastic films was also changed dramatically according to the different decomposition reactions of two major waste plastic film components. Py-GC/MS results also revealed that the typical pyrolyzates of each polymer in waste plastic films were levoglucosan (starch), terephthalic acid (PET), styrene monomer, dimer, and trimer (PS), methylated alkenes (PP), and triplet peaks (PE) composed of alkadiene/alkene/alkane. The phthalate, used as a polymer additive, was also detected on the pyrogram of waste plastic films mixture.

• Journal of Life Science
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• v.27 no.5
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• pp.561-566
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• 2017

Dendropanax morbifera Lev. is known in Korea for its golden sap and medicinal properties. The many biological activities of the leaf and stem extracts suggest that this tree could be a valuable source of medicinal compounds for the treatment of various ailments such as dermatitis, migraines, dysmenorrhea, muscle pain, and infectious diseases. However, there is little information on the composition and biological activity of the volatile fraction of D. morbifera. Therefore, in this study, the volatile compounds in leaves, stems, and sap of D. morbifera were isolated using solvent and supercritical fluid extraction (SFE), and analyzed by gas chromatography/mass spectrometry to reveal their chemical composition and identify potential compounds of interest. Fifteen compounds were identified in the leaf extracts, whereas 29 and 3 compounds were identified in the stem and sap extracts, respectively. The volatile profiles obtained using solvent and SFE differed. Esters and aromatic hydrocarbons predominated in the solvent extract of leaves and SFE extract of stems, whereas the solvent extract of stems and SFE extract of leaves contained terpenoids. Limonene, ${\alpha}$-pinene, and ${\beta}$-myrcene were identified in the volatile extract of sap, with limonene representing 96.30% of the total peak area. In addition, the antiproliferative effects of the solvent extracts of leaves and stems were evaluated, revealing that these solvent extracts were particularly effective in decreasing the proliferation of HepG2 cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.822-832
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• 2017

This study analyzed contents of organic acids, free sugars, and volatile flavor compounds by type of Jerusalem artichoke (Helianthus tuberosus L.). Organic acids in dried Jerusalem artichoke were mainly composed of malic acid, citric acid, and succinic acid. Sucrose, fructose, and glucose were the major sugar components of dried Jerusalem artichoke. Free sugars were more abundant in the white colored sample than in the purple colored sample. In contrast, purple colored sample contained more organic acids than the white colored one. Volatile compounds in Jerusalem artichoke were investigated using the solid-phase micro-extraction method of gas chromatography/mass spectrometry. A total of 117 volatile compounds were identified in Jerusalem artichoke, and chemical classification was as follows: 5 acids, 13 alcohols, 19 aldehydes, 12 hydrocarbons, 15 ketones, 8 miscellaneous, 27 pyrazines, and 18 terpenes in all samples. Terpene was the most abundant in Jerusalem artichoke, and ${\beta}$-bisabolene was the main component in terpenes. The second most common compound was aldehyde, and hexanal was the highest. Pyrazines were the most abundant in the roasted samples, and 2,5-dimethyl-3-ethylpyrazine was present at the highest level, followed by 2,5-dimethylpyrazine. Compared with purple samples, main compounds contained in white samples were aldehydes and hydrocarbons, whereas the major compounds in purple samples were terpenes and alcohols.