• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.292-302
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• 2005

Condition of Ion-Trap gas chromatography-mass spectrometry (GC-MS) for rapid screening of 206-pesticides residues in agricultural foodstuffs was optimized. As applying a wide-bore column (10 m${\times}$0.53 mm, DF 0.25 um) connected with a fused silica restrictor (0.6 m${\times}$0.1 mm), a significant retention time reduction was obtained. Additionally, the shape of peaks was sharper and higher than classical GC's and GC-MS's, which allowed lower detection limits. To easily manage many spectral data, both of Electron Ionization(EI) and Chemical Ionization(CI) techniques were adopted in screening procedure. At the following steps, MS-MS technique were used to confirm screened analytes in complicated matrices.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.37-42
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• 2003

To elucidate chemical strvacture of Ramaria formosa(Fr.) Quel was extracted with methanol for 72 hours, and then filtered twice. The extractive compounds were analyzed by the Libaries Search method, using GC and GC-MS Spectrometry. As a result, the five different compounds were analyzed, such as (1) methyl-hexadecanoate, (2) methyl-9,12- octadecadienoate, (3) methyl-cis-9-octadecenoate, (4) methyl-octadecanoate, and (5) 4-hexyl-2,5-dihydro-2,5-dioxo-3-furanacetic acid. The large quantity of compound, 4-hexyl-2,5-dihydro-2,5-dioxo-3-furanacetic acid, is expected that through experiments on animals the compound will be a potential agent which can be developed as a health food to relieve constipation or a laxative medicine.

• Korean journal of food and cookery science
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• v.14 no.5
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• pp.541-546
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• 1998

Volatile flavor components in leaf and petiole of fresh Pleurospermum kamtschaticum H$\_$OFFM/ were extracted by SDE (simultaneous steam distillation and extraction) method using diethyl ether as solvent. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Identification of volatile flavor components was based on the Rl of GC and mass spectrum of GC-MS. A total of 31 components, including 15 hydrocarbons, 4 aldehydes, 1 ketone, 5 alcohols, 2 esters, 3 acids and 1 oxide were identified in the essential oils. (Z)-${\beta}$-Farnesene, (Z, E)-${\alpha}$-farnesene and farnesene were the major volatile flavor components in fresh Pleurospermum kamtschaticum. Volatile flavor patterns of Pleurospermum kamtschaticum were analyzed using electronic nose. Sensor T30/1 and PA2 that were sensitive to alcohols had the highest resistance for fresh Pleurospermum kamtschaticum. Resistance of six metal oxide sensors was decreased in dried sample compared with fresh one.

• Analytical Science and Technology
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• v.23 no.2
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• pp.179-186
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• 2010

The oxidative metabolism of ibuprofen in healthy male urine collected at 3, 6, 9, 12 and 15 h after oral administration of ibuprofen was studied by GC/MS assay. To detect conjugated metabolites of ibuprofen, urine sample was acid-hydrolyzed with 6 M HCl at $100^{\circ}C$ for 30 min. To effectively extract ibuprofen and its metabolites, liquid-liquid extraction (LLE) was conducted at pH 3, 5, and 7, respectively. As a result, LLE at pH 3 was shown to be the best extraction condition. For the determination of trace amounts of ibuprofen and its metabolites in extract, trimethylsilylation (TMS) with BSTFA was applied and followed by GC/MS analysis. In this study, main 5 metabolites including parent drug were detected and these metabolites were assigned as three hydroxylated forms and one carboxylated form. Each metabolite was tentatively identified by both interpretation of mass spectrum and comparison with previously reported results. In addition, time profile of urinary excretion rate for parent drugs and metabolites was studied. Finally, the metabolic pathways of ibuprofen were suggested on the basis of the structural elucidation of its metabolites and excretion profiles.

• Analytical Science and Technology
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• v.19 no.5
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• pp.441-448
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• 2006

11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THCCOOH) is the major metabolite of tetrahydrocannabinol (THC) which is the primary psychoactive component of marijuana. It is also the target analyte for the discrimination marijuana use. A method using solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) was developed for the determination of THCCOOH in human urine. Urine samples (3 mL) were extracted by SPE column with a cation exchange cartridge after basic hydrolysis. The eluents were then evaporated, derivatized, and injected into the GC/MS. The limits of detection (LOD) and quantitation (LOQ) were 0.4 and 1.2 ng/mL, respectively. The response was linear with a correlation coefficient of 0.999 within the concentration range of 1.2 (LLE 1.3)~50.0 ng/mL. The precision and accuracy were stable within 1.20% and the recovery was 83.6~90.7%. The recovery of SPE method was lower than that of liquid-liquid extraction (LLE), but there were no apparent differences in LOD, LOQ, precision and accuracy between the two methods. While SPE method is used as a very effective and rapid procedure for sample pretreatment, and clean extracts, LLE method was not suitable for the extraction procedure of THCCOOH in urine. The applicability of the method was proven by analyzing a urine samples from a marijuana abusers.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.176-183
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• 2015

To characterize the aroma properties of roasted bulgogi reaction flavor obtained by using a high-temperature reaction apparatus, the volatile flavor and aroma-active compounds were analyzed using simultaneous steam distillation and solvent extraction (SDE)-gas chromatography-mass spectrometry-olfactometry (GC-MS-O). One hundred five volatile compounds were detected in roasted bulgogi reaction flavor using GC-MS. Out of these compounds, furfural was the most abundant volatile compound, followed in order of abundance by 5-methyl furfural, phenylacetaldehyde, and nonanal. Of the volatile compounds identified in roasted bulgogi reaction flavor, 33 aroma-active compounds were detected using GC-O. 2,3-Butanedione and furfural were the most intense aroma-active compounds detected. Other relatively intense odorants included hexanal, octanal, nonanal, undecanal, phenylacetaldehyde, 5-methyl furfural, 2,6-dimethyl pyrazine, and dimethyl trisulfide. These were important aroma-active compounds that contributed to the aroma of roasted bulgogi reaction flavor because of their potency and aroma properties. The concentrations of the aroma-active compounds increased as the reaction temperature increased, whereas those of the sulfide compounds decreased.

• Journal of Food Hygiene and Safety
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• v.12 no.3
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• pp.210-216
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• 1997

The prevention of oxidative degradation in fats and oils is largely controlled by the use of synthetic phenolic antioxidants. Antioxidants, BHA: 2-&-3-tert-butyl-4-hydroxyanisol, BHT: 3,5-di-tert-butyl-4-hydroxytoluene, TBHQ: tert-butylhydroquinone, PG: propyl gallate, PTG: pentyl gallate, OG:octyl gallate, were extracted from fatty foods with hexane and from hexane layer to presaturated acetonitrile with hexane. The polar phenolic hydroxyl groups of antioxidants were silylated with MSTFA and injected to Gas Chromatography/Mass Spectrometry. The calibration plots were linear in the investigated range, 0.1~10.0 $\mu\textrm{g}$/g. The limit of detection for 6 phenolic antioxidants was 0.1 $\mu\textrm{g}$/g. Recoveries and reproducibilities from samples fortified at 1.0 $\mu\textrm{g}$/g were in the range of 70~90% and 0.5~13%, respectively. The simultaneous determination of phenolic antioxidants in fatty foods using GC/MS-SIM mode and macro program was described.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1693-1698
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• 2012

A headspace gas chromatographic mass spectrometric (GC-MS) assay method was developed for the simultaneous determination of methyl tertiary butyl ether (MTBE), $tert$-butyl alcohol (TBA) and benzene, toluene, ethyl benzene and xylene (BTEX) in soil contaminated with gasoline. 2 g of soil sample were placed in a 10 mL headspace vial filled with 5 mL of phosphoric acid solution (pH 3) saturated with NaCl, and the solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was heated in a heating block for 40 min at $80^{\circ}C$. The detection limits of the assay were 0.08-0.12 ${\mu}g$/kg for the analytes. For five independent determinations at 10 and 50 ${\mu}g$/kg, the relative standard deviations were less than 10%. The method was used to analyze fifty six soil samples collected from various regions contaminated with gasoline in Korea. The developed method may be valuable for the monitoring of the analytes in soil.

• Preventive Nutrition and Food Science
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• v.13 no.1
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• pp.33-39
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• 2008

The volatile flavor components of Zanthoxylum pipperitum A.P. DC. produced in Korea and China were isolated using a Clevenger-type apparatus by steam distillation extraction, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yields of oils from Korean and Chinese Z. pipperitum A.P. DC. were 2.0 and 1.2% (w/w), respectively. From the two Z. pipperitum A.P. DC. oils, sixty and fifty-four volatile flavor compounds were tentatively identified, and they constituted 94.78 and 87.34% of the total peak area, respectively. Piperitone(p-menth-1-en-3-one) (13.48%) was the most abundant compound in the Chinese Zanthoxylum pipperitum A.P. DC. oil, followed by $\beta$-phellandrene, sabinene, terpinen-4-ol and linalool (each >5%). Whereas, the most abundant compound in the Korean Zanthoxylum pipperitum A.P. DC. oil was limonene (18.04%), followed by geranyl acetate, cryptone, citronellal, cuminal and phellandral (each >5%).

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.147-151
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• 2010

The volatile aroma constituents of Atractylodes japonica rhizome were separated by steam distillation extraction method using a Clevenger-type apparatus, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of the essential oil from Atractylodes japonica was 1.0% (v/w), and its color was pale yellow. Forty-five volatile flavor compounds, which make up 93.86% of the total peak area, were tentatively identified in the rhizome oil. The oil contained 32 hydrocarbons (79.19%) with sesquiterpene hydrocarbon predominating, 3 esters (12.46%), 4 alcohols (0.11%), 1 ketone (0.01%), 2 aldehydes (0.02%), and 3 miscellaneous compounds (2.07%).