• Culinary science and hospitality research
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• v.13 no.1 s.32
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• pp.119-128
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• 2007

Volatile flavor compounds of sauces made from shrimps, crabs or lobsters were analyzed by the combination of canister system, gas chromatography(GC) and mass selective detector(MSD). Of 72 total volatile compounds from 4 kinds of sauces, 45 compounds were identified from shrimp sauce(SS). Ten alkanes, 5 ketones, 3 aldehydes were obtained from SS. Especially, 3-methyl-2-butanone, 2-pentanamine, isobutane, 3-methyl-2-butanol, carbon disulfide and dimethyl sulfide were predominant compounds in SS. In crab sauce(CS), there were 18 compounds identified, including 4 alcohols, 4 alkanes, 3 aldehydes, 2 ketones, acid and amine. 2-Methoxy ethanol, trimethyloxirane and 3-buten-1-ol were special volatile compounds in CC. Volatile compounds from lobster head sauce(LHS) or lobster shell sauce(LSS) were 16 or 18 kinds respectively. The major volatile compounds of LHS were formic acid, 1-propanethiol, $\beta$-pinene and allyl sulfide, and those of LSS were acids, pentane, 3-methyl-1-butanol and 2,4-dimethyl-3-pentanone. It was thought that the volatile compounds identified from sauces as well as shrimps, crabs or lobsters might come from wine, onions, bay leaves or celery used as minor ingredients.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.3
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• pp.156-161
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• 2011

Objectives: Tetrahydrofuran (THF) is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. THF has been used as a solvent and a precursor for various syntheses of polymers. However, THF is known to irritate to the eyes, skin and mucus membranes. Overexposure by inhalation, ingestion or skin contact may produce nausea, dizziness, headaches, respiratory irritation and possible skin burns. The purpose of this study is to evaluate of the worker exposure and characteristics of workers in the workplaces that use or manufacture THF. Methods: Sixteen factories in Korea, which manufacture or use THF, were selected for this study and a total of 130 air samples including 104 time-weighted average (TWA) samples and 26 short-term exposure limit (STEL) samples, were collected. Air samples were collected with charcoal tube (100mg/50mg) and analyzed by gas chromatograph/flame ionization detector(GC/FID). Results: The TWA concentration of THF was 16.05ppm (GM) at PS script printing, 2.32ppm (GM) at PVC stabilizer, 1.03ppm (GM) at Lithium triethylborohydride, 0.63ppm (GM) at Polytetramethylene ether glycol(PTMEG), 0.42ppm (GM) at Manufacturing THF, 0.13ppm (GM) at Glue and 0.12ppm (GM) at synthetic rubber/resins. Two out of sampes for PS script printing exceeded 50ppm as 8-hour exposure limit of MOEL. The short term exposure to THF was 54.77ppm (GM) at PS script printing, 17.10ppm (GM) at PTMEG, 13.76ppm (GM) at Manufacturing THF, 2.86ppm (GM) at Lithium triethylborohydride, 0.87ppm (GM) at synthetic rubber/resins and 0.13ppm (GM) Glue. We found that the highest exposure process for both the TWA and STEL samples was PS script process. Two samples exceeded 100ppm as short term exposure limit of Ministry of Employment and Labor(MOEL). Conclusions: Characteristic of STEL concentration for THF is considerably different from TWA concentration in workplaces because workers could exposure high concentration of THF in a moment when they work irregularly schedule. So exposure controls for momentary works have to be prepared, and considered the skin absorption and inhale of THF.

• Journal of Environmental Health Sciences
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• v.37 no.6
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• pp.440-449
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• 2011

Objectives: This study was designed to determine the levels of polybrominated diphenyl ethers (PBDEs) in breast milk and to evaluate the relations with factors affecting these levels. Methods: The congener levels of PBDE in 22 samples of breast milk were analyzed using a high resolution gas chromatograph with a high resolution mass detector. In accordance with our standard operating procedures, the recoveries of internal standards had to range between 68% and 118%. Since the distribution of PBDE concentrations is close to log-normal, the data were logarithmically transformed before analysis. Test subjects were healthy primipara and multipara mothers with a mean age of 32 (SD = 2.7) in 2006. Results: Seven PBDE congeners (BDE-28, 47, 99, 100, 153, 154, and 183) were detected and identified in all of the pooled breast milk samples, indicating widespread contamination from PBDEs in the environment in Korea. Residue levels of total PBDEs (sum PBDEs from tri- to hepta-BDE) ranged from 0.84-13.1 ng/g lipid with median and geometric mean levels of 2.6 ng/g lipid and 2.74 ng/g lipid, respectively. PBDE congeners 47, 99 and 153 markedly predominated and accounted for about 75% of the amount of the PBDE congeners analyzed. BDE-47 was the dominant congener in most samples, whereas BDE-153 was predominant in a few (n = 7/22). BDE-47 was highly correlated with total PBDEs (r = 0.987, p < 0.01). In analyses of the differences of the means of log transformed breast milk PBDE levels for groups of potential covariates, only breast milk BDE-47 and BDE-99 levels were significantly associated with fish (p < 0.05) and meat consumption (p < 0.01). However, we did not find significant correlations between PBDE levels and maternal age, body mass index (BMI), parity, job presence and smoking status. Conclusions: Our findings are mainly limited due to the small sampling size and low doses of PBDEs exposure. Background and human exposure data of PBDEs is lacking, and longitudinal investigations into the environment and biota are encouraged to determine the health impact on future populations in Korea.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.391-398
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• 2004

Far-ultraviolet Imaging Spectrograph (FIMS) is the main payload of the Korea's first scientific micro satellite STSAT-1, which was launched at Sep. 27 2003 successfully. Major objective of FIMS is observing hot gas in the Galaxy in FUV bands to diagnose the energy flow models of the interstellar medium. Supernova remnants, molecular clouds, and Aurora emission in the geomagnetic pole regions are specific targets for pointing observation. Although the whole system was calibrated before launch, it is essential to perform on-orbit calibration for data analysis. For spectral calibration, we observed airglow lines in the atmosphere since they provide good spectral references. We identify and compare the observed airglow lines with model calculations, and correct the spectral distortion appeared in the detector system to improve the spectral resolution of the system.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.311-316
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• 2007

Trans fatty acid components separated and quantified using a SP-2560 capillary column in a gas chromatograph (GC) with flame ionization detector (FID). Trans fatty acid and total fatty acid contents were measured in 21 corn oils. Ranges of values for trans fatty acid (tFAs) contents of total fat (as g/100g fatty acids) were com oils $0.65{\pm}0.31$. Corn oils were heated at $175{\pm}5^{\circ}C$ for 5mins $(0{\sim}15\;times)$. The contents of tFAs (g/100) were increased from 0.292 (0 time) to 2.585 (15 times) in com oil. When frying oils (15 times) were incubated at $20{\pm}5^{\circ}C$ for 150 days, the contents of tFAs (g/100g) were increased from 2.585 to 3.683 in com oil. The amounts of tFAs (g) per serving size of frying oils (15 times) were increased from 0.01 to 0.18 in corn oil. The levels of the 18:1 trans isomers increased significantly the time of reusing of com oil.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.587-591
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• 2009

Volatiles in Artemisia princeps Pampan. cv. sajabal (sajabalssuk) and A. princeps Pampan. (ssuk) treated with different processing were analyzed using headspace-solid phase microextraction (HS-SPME)/gas chromatography- a mass selective detector (GC-MS). Sajabalssuk and ssuk were treated with steam distillation (SD) and freeze-dried/steam distillation (FD/SD) while controls were raw sajabalssuk and raw ssuk. Sajabalssuk had significantly more total volatiles than ssuk in control and FD/SD treated samples (p<0.05). Major volatiles in raw sajabalssuk were 2-hexenal, 1,8-cineol, trans-caryophyllene, and hexanal while those in raw ssuk were 1-hexanol, ${\beta}$-myrcene, limonene, and 2-hexenal, which implies that substantial lipid oxidation occurred in raw samples. Sajabalssuk with SD and FD/SD treatment had higher peak areas of 1,8-cineole, 4-terpineol, 1-octen-3-ol, and ${\alpha}$-terpineol while ssuk with SD and FD/SD treatment possessed 1,8-cineol, camphor, borneol, artemisia ketone, ${\alpha}$-thujone, and 1-octen-3-ol, which showed that steam distillation produced more volatiles from terpenoids than raw samples. Based on the results of HS-SPME/GC-MS, relative amounts of volatiles from lipid oxidation including 2-hexenal, hexanal, and 1-hexanol were reduced in sajabalssuk and ssuk with freeze-drying and/or steam distillation treatment.

• Analytical Science and Technology
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• v.23 no.1
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• pp.24-35
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• 2010

To learn more about the calibration properties of reduced sulfur compounds (RSCs) by the combination of gas chromatography(GC)-pulsed flame photometric detector (PFPD) and thermal desorption method, a series of calibration experiments were conducted on the basis of both internal and external calibration approaches. For these experiments, gaseous standards of 4 RSCs ($H_2S$, $CH_3SH$, DMS, and DMDS) were prepared at two different concentration levels of both low (10, 20, 50,and 100 ppb) and high ranges (100, 200, 500, and 1000 ppb) along with $CS_2$ as an internal standard. First, the external calibration results were compared between fixed standard volume (FSV) and fixed standard concentration (FSC) method. Secondly, FSV-based calibration results were compared between external and internal calibration results. As FSV method suffers from sensitivity variations less significantly than FSC, the former is recommended to maintain the consistency in GC-TD sensitivity for RSC analysis. In addition, when the calibration data were examined in terms of RSE between external and internal calibration data, the results were not consistent enough to show improvements in internal method. Hence, diverse efforts are desirable to optimize the reproducibility in terms of GC-TD sensitivity for RSC analysis.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.25-30
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• 2006

The female sex pheromone of the peach leafminer, Lyonetia clerkella Linne (Lepidoptera: Lyonetiidae), was analyzed by coupled gas chromatographic-electroantennographic detector (GC-EAD). GC-EAD analyses of pheromone gland extract revealed a single compound that elicited responses from male antennae. Retention time on DB-1 column of EAD-active compound was identical to that of synthetic (145)-14-Methyl-1-octadecene (14Sme-1-18Hy). In field tests, sticky traps baited with synthetic 14Sme-1-18Hy alone were highly attractive to male. Traps with 0.1 mg dose showed the lowest catches, but there were no significant difference in the numbers of moth caught in traps baited with doses of 0.5 and 1.0 mg. The results of the field assays for longevity of pheromone traps showed that effectiveness of lures maintained for at least 8 weeks under field condition. The attractiveness of 14Sme-1-18Hy was not affected by the addition of butylated hydroxytoluene (BHT) in lures as an antioxidant. Traps baited with 0.5 mg 14Sme-1-18Hy were successfully used to monitor L. clerkella male flights. Analysis of seasonal trap catches over two years showed that moth flight activity in peach orchards occurred over a period of seven months with six generations in Suwon.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.18-26
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• 2000

Since the regulation of MSDS (Material Safety Data Sheets) had started from July 1996, employers were required to furnish MSDS for the chemicals in use in their workplace. However, many MSDS did not contain upright information for the chemicals, and they were not updated regularly, and were not written in the standard format required by the Industrial Safety and Health Act (ISHA). The purposes of this study were 1) to examine the reliability of MSDS for mixed solvents, 2) to provide reliable MSDS to employers or employees, 3) to find out any difficulties in implementing MSDS after the initiation, and 4) to promote regular MSDS updating and to ensure the reliability of MSDS for chemical manufacturers. To check the reliability of MSDS of mixed chemicals, 21 samples of mostly degreasing solvents were collected along with their MSDS from the work place. The samples were analyzed by gas chromatography-mass selective detector(GC-MSD). Their components were classified as saturated hydrocarbon, cyclic hydrocarbon, aromatics, and halogen containing hydrocarbon, and the amount of each class were measured. Manufacture's MSDS were compared with the actual composition of the collected samples, and further examined the reliability by checking whether the chemicals analyzed were included in the MSDS correctly. Finally, each item of MSDS was evaluated whether the MSDS correspond to the regulation required by ISHA. The results were following: 1) most of the degreasing solvents in MSDS were incorrect in their composition and contents, 2) the information in the MSDS including hazard classification, exposure level, toxicity, regulatory information were incorrectly provided, and 3) some MSDS did not disclose carcinogens in their MSDS. Continuous monitoring of MSDS was required to ensure reliability of MSDS. The Chemicals containing hydrocarbons from C10-C15 need to be tested to provide toxicity data. In addition, governmental support for providing correct MSDS was recommended to ensure reliability of MSDS. The MSDS regulation relating to the confidential business information may need to be revised to ensure reliability of MSDS.

• Journal of Hydrogen and New Energy
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• v.26 no.1
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• pp.21-27
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• 2015

Hydrogen production from commercial diesel fuels is an attactive option for energy generation purpose due to the low cost and good availability of diesel fuels. However, in order to utilize commercial diesel fuels, the sulfur contents must be removed down to approximately 0.1 ppm level to protect the fuel cell catalysts from poisoning. Commercial catalysts $CoMo/Al_2O_3$ and $NiMo/Al_2O_3$ were tested for HDS (Hydrodesulfurization) of model diesel and commercial diesel. The experimental conditions were $250-400^{\circ}C$ and LHSV (Liquid Hourly Space Velocity) $0.27-2.12hr^{-1}$. $NiMo/Al_2O_3$ was found to be more effective than $CoMo/Al_2O_3$ in removing sulfur from model diesel. Based on the experimental results of model diesel, commercial diesel fuel purchased from a local petrol station was tested for HDS using $NiMo/Al_2O_3$. The GC-SCD (Gas Chromatography Sulfur Chemiluminescence Detector) results showed that the DMDBT (Dimethyldibenzothiophene) derivatives were fully removed from the commercial diesel fuel proving that HDS with $NiMo/Al_2O_3$ is technically feasible for industrial applications.