• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.486-497
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• 2019

The non-isothermal and isothermal pyrolysis properties of H lignin and P lignin extracted from different biorefinery processes (such as supercritical water hydrolysis and fast pyrolysis) were studied using thermogravimetry analysis (TGA) and pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS). The lignins were characterized by ultimate/proximate analysis, FT-IR and GPC. Based on the thermogravimetry (TG) and derivative thermogravimetry (DTG) curves, the thermal decomposition stages were obtained and the pyrolysis products were analyzed at each thermal decomposition stage of non-isothermal pyrolysis. The isothermal pyrolysis of lignins was also carried out at 400, 500, and $600^{\circ}C$ to investigate the pyrolysis product distribution at each temperature. In non-isothermal pyrolysis, P lignin recovered from a fast pyrolysis process started to decompose and produced pyrolysis products at a lower temperature than H lignin recovered from a supercritical water hydrolysis process. In isothermal pyrolysis, guaiacyl and syringyl type were the major pyrolysis products at every temperature, while the amounts of p-hydroxyphenyl type and aromatic hydrocarbons increased with the pyrolysis temperature.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.2
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• pp.46-52
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• 2019

This research was conducted to analyze the effects of temperature on coking characteristics of kerosene. The kerosene was heated to 600 K, 700 K, and 800 K, and the cooled samples were collected. The used copper tubes were replaced according to the temperature conditions. The liquid and copper specimens were analyzed by gas chromatography-mass spectrometry and scanning electron microscopy equipped with an energy dispersive x-ray spectrometer, respectively. The results of the analysis confirmed that a carbon deposit was formed from the coking of fuel on the inner surface of the copper specimen at a relatively high temperature (800 K) of the copper tube.

• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.80-89
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• 2019

Pine barks are important biomass resources because they are utilised in the production of pine wood and rosins. However, no chemical study has been conducted on the hydrophilic status of pine barks in Indonesia. This aim of this study is to explore the hydrophilic extracts of the barks from six Pinus species (P. elliotii, P. caribeae, P. oocarpa, P. merkusii P. montezumae, and P. insularis). The hydrophilics of pine barks were analysed using gas chromatography-mass spectrometry. The presence of polyphenol contents in the ethanol extracts obtained from the barks of six Pinus species was determined using the tannin-formaldehyde method, Folin-Cioucalteu assay, and vanillin-HCl assay. The ethanol and hot water soluble extractives derived from inner barks were higher in quantity when compared to those derived from the outer bark samples. The polyphenol measurement showed that the highest value of total phenol content was derived from the outer bark of P. montezumae whereas those of the total phenol and tannin- formaldehyde contents were derived from the inner and outer barks of P. oocarpa. GC-MS analysis revealed that nitrogenous compounds are dominant constituents in the inner and outer barks of the six species, followed by sugars and monophenolics, respectively.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.264-269
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• 2020

The study aimed to characterize chemical composition and anticancer property of the n-hexane fraction derived from Asiasari Radix et Rhizoma. The anticancer activity was evaluated on a panel of cancer cell lines including HN22, HSC2, HSC3, and HSC4 cells (human oral cancer), HCC827 and HCC827GR cells (human lung cancer), and KYSE30 and KYSE450 (human esophageal cancer) by MTS assay. As a result, The least polar subfraction from n-hexane-soluble layer displayed notable cytotoxicity on the tumor cell lines with IC50 ranging from 1.20 to 17.0 ㎍/ml. The chemical composition of constituents in the active subfraction was determined by gas chromatography-mass spectrometry (GC-MS). The essential oils comprised of sesquiterpenes including β-gurjunene (7.45%), γ-amorphene (6.61%), guaia-6,9-diene (6.40%), δ-guaiene (5.21%) and a phenylpropanoid, safrole (0.49%) were mainly identified in addition to long-chain hydrocarbons including n-heptadecane (24.60%), 7-hexadecene (4.44%) and a diterpenoid, ent-kaur-16-ene (6.57%).

• The Korean Journal of Food & Health Convergence
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• v.9 no.4
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• pp.11-18
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• 2023

Oil was extracted from cashew nuts. The physicochemical parameters of the oil were determined. A chromatographic assay of the oil was carried out using Gas Chromatography-Mass Spectrometry. Seventeen compounds were detected: Phenol, Phenol 2-methyl-, Cyclohexene 4, 4-dimethyl-, m-Fluoro-2-diazoacetophenone 4-dimethyl-, Tetradecanoic acid, Phenol 4-octyl-, n-Hexadecanoic acid. Others are 9, 12-Octadecadienoic acid (Z, Z) - methyl ester, Hexadecanoic acid methyl ester, Methyl stearate, Dodecanoic acid methyl ester, 9, 12, 15-Octadecatrienoic acid methyl ester, 9, 12, 15-Octadecatrienoic acid (Z, Z, Z)-, Oleic acid, Octadecanoic acid, Tetracosanoic acid and 9-Octadecenoic acid methyl ester. Among the components are omega three and omega six essential free fatty acids. The rheological profiling and flow properties of cashew nut oil were determined using a Programmable Rheometer. Cashew nut oil exhibits slight dilatant behaviour at the low end of shear rate. The long chain and high molecular weight of its constituents controlled its rheology. Long-chained 9-Octadecenoic acid methyl ester, 9, 12-Octadecadienoic acid (Z, Z) - methyl ester, Tetracosanoic acid and methyl stearate, coupled with their high molecular weights are responsible for the shear thickening effect observed. Two models, Carreau-Yasuda and Ostwald-de Waele Power Law were employed to fit the rheological data. The Carreau-Yasuda model followed well the data.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.14-17
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• 2024

Objectives: This is a case of air exposure assessment conducted after researchers complained of headaches and odor due to residual substances from fire extinguishing agents spread throughout the laboratory due to a malfunction of the fire extinguishing facility. Methods: A component analysis was conducted on the residual substances of a fire extinguishing agent spread in a laboratory using Py-GC-MS (pyrolysis gas chromatography mass spectrometry) at the research institute's own central equipment research center. As a result of the component analysis, several types of substances were detected. Among these, five types of substances subject to work environment measurement in the aromatic hydrocarbon series, which can affect headaches and odor, were selected as substances subject to exposure assessment in the air, and the measurement and analysis methods of the target substances were conducted in accordance with the KOSHA Guide for each substance. Conclusions: The measurement results showed that all 5 types of substances were not detected at locations A, B, and C. This is believed to be the result of the residual substances in the fire extinguishing agent being measured when approximately two months had elapsed after being exposed to the test bench, and the substances already exposed had volatilized and disappeared. In this survey, it is believed that the measurement process is more important than the measurement results.

• Food Science and Preservation
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• v.30 no.3
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• pp.395-404
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• 2023

Essential oil (EO) was extracted from the peel of Citrus hystrix DC. originating from Tinh Bien, An Giang province (Vietnam), using steam distillation. The study aimed to determine some physicochemical properties of Citrus hystrix peel EO (ChpEO), including the acid value (AV), saponification value (SV), ester value (EV), density, specific gravity, and freezing point. The chemical composition was also analyzed by gas chromatography-mass spectrometry (GC-MS). Compounds like β-pinene (30.19%), D-limonene (22.15%), and sabinene (21.37%), with antioxidant and antibacterial properties, had a relatively high content. The EO was also capable of inhibiting the growth of both Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Salmonella typhimurium (ATCC 13311), and Bacillus cereus (ATCC 11778) specifically.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.5
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• pp.642-648
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• 2012

In the present study, yakju was developed added with 100~400 g of meoru (Vitis coignetiae). We analyzed the volatile flavor compounds and investigated the sensory properties of meoru yakju. The volatile flavor compounds were isolated from in fusions by Porapak Q column adsorption. The concentrated flavor extract was analyzed and identified by GC (gas chromatography) and GC-MS (gas chromatography-mass spectrometry) analyses. Thirty-five compounds, including five alcohols, nine esters, seven acids, four hydrocarbons, three ketones, and seven other compounds, were identified. The total number and content of volatile flavor compounds in control yakju were the highest, but they decreased as the amount of added meoru increased. On the other hand, yakju containing 200 g of meoru was characterized by the highest content of ester compounds, and it was the most preferred in terms of flavor, color, taste, and over all acceptability. Based on these results, addition of 200 g of meoru to 1,715 g of control yakju was determined to be the optimal condition for making meoru yakju.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.122-127
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• 2016

The objective of this study was to identify the volatile compounds and aroma-active compounds from acai berry (Euterpe oleracea). Volatiles were isolated by high vacuum distillation using solvent-assisted flavor evaporation (SAFE) and liquid-liquid continuous extraction (LLCE). To identify the characteristic aroma-active compounds of acai berry, gas chromatography-mass spectrometry-olfactometry was used. Aroma-active compounds were evaluated by aroma extract dilution analysis (AEDA). A total of 51 and 54 volatile compounds from acai berry were identified from SAFE and LLCE extracts, respectively. Alcohols were confirmed to be important volatile compounds in acai berry, as the major volatile compounds were 2-phenylethanol, (Z)-3-hexenol, and benzyl alcohol. ${\beta}-Damascenone$ (berry, rose), trans-linalool oxide (woody), (Z)-3-hexenol (grass), and 2-phenylethanol (rose, honey) were considered the aroma-active compounds in acai berry. The most intense aroma-active compound of acai berry was ${\beta}-damascenone$.

• Food Science and Preservation
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• v.6 no.2
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• pp.206-215
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• 1999

Volatile flavor components in five varieties, Bekdo, Chundo, Yumung, Daegubo and Hwangdo, of peach (Prunus persica L.) 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. Analysis of the concentrate by capillary gas chromatography and gas chromatography-mass spectrometry led to the identification of 83, 85, 70, 74 and 66 components in Bekdo, Chundo, Yumung, Daegubo and Hwangdo, respectively. Aroma patterns (29 alcohols, 27 ketones, 18 aldehydes, 9 esters, 5 ethers, 3 acids, 6 terpene and derivatives, and 26 miscellaneous) were identified and quantified in five cultivars. Ethyl acetate, hexanal, o-xylene, (E)-2-hexenal, hexanol, (E)-2-hexen-1-ol, benzaldehyde, r-decalactone and r-dodecalactone were the main components in each samples, though there were several differences in composition of volatile components. Beside C$\_$6/ compounds, a series of saturated and unsaturated r- and $\delta$-lactones ranging from chain length C$\_$6/ to C$\_$l2/, with concentration maxima for r-decalactone and r-dodecalactone, were a major class of constituents. Lactones and peroxidation products of unsaturated fatty acid (i.e. C$\_$6/ aldehydes and alcohols) were major constituents of the extract.