• Proceedings of the PSK Conference
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• 2003.04a
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• pp.120.2-121
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• 2003

The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) mode followed by two work-up methods for comparison; isoBOC derivatization method and TBDMS derivatization method. Eleven phenols in paper samples were extracted with acetonitrile. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.68.1-68.1
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• 2003

A method for determination 11 endocrine disrupting chemicals of phenols in various samples was deloped. The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) followed by two work-up methods for comparison; isobutoxycarbonyl (isoBOC) derivatization method and tert-butyldimethylsilyl (TBDMS) derivatization method. Eleven endocrine disrupting chemicals (EDCs) of phenols in biological samples were extracted with acetonitrile and then acetonitrile layer was refrigerated at -60$^{\circ}C$ for 2 hours (freezing filtration). (omitted)

• Analytical Science and Technology
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• v.21 no.6
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• pp.495-501
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• 2008

Agilent 5973 GC-MS instrument was modified so that the capillary direct interface was removed and that a silicone membrane was installed between GC and MS. Feasibility study of the membrane interface GC-MS has been carried out. Vacuum of the mass spectrometer was not affected by the carrier gas flow rate up to $4.7m{\ell}/min$. As the carrier flow rate was increased, peak tailing was reduced and chromatogram peaks appeared earlier. Chromatogram peaks showed better separation and higher sensitivity as the membrane thickness was reduced from $127{\mu}m$ to $75{\mu}m$, and also as the interface temperature was increased. However, the membrane interface GC-MS had drawbacks such as background ions at 73 and 147 m/z and poor peak separation due to peak tailing.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.206-211
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• 2001

This article describes identification and quantification of benzene in the casting process. Air samples around the casting process were taken by using personal air sampler attached charcoal tube and desorbed by carbon disulfide. The identification and quantitative analysis of benzene have been performed by GC-MS and GC-FID. Calibration range of standard solutions for benzene was prepared in range from 0.1 to 2 times of TLVs concentrations($1.4{\sim}28{\mu}g/1m{\ell}$ CS2) and the limit of detection was $0.11{\pm}0.002{\mu}g/1m{\ell}$ CS2. Benzene detected in airborne was ranged in 4.0ppb~104.7ppb.

• Analytical Science and Technology
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• v.15 no.1
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• pp.26-30
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• 2002

In order to determine the contents of ethyl carbamate in Korean traditional alcoholic beverages and general beverages, GC/MS-SIM method was used after extraction of beverages with dichloromethane. The contents of ethyl carbamate in Korean traditional alcoholic beverages, non-distilled alcohol, and whisky were detected in the range of $4.6-50.2{\mu}g/L$, $27.8-45.4{\mu}g/L$, and $24.8-55.1{\mu}g/L$, respectively. The recoveries were ranged from 83.3 to 104.8 %. The values of relative standard deviation were ranged from 1.8 to 14.8 % and the detection limit was $0.3{\mu}g/L$.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.25-28
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• 1992

The changes of amount in flavor components of chewing gum during storage of various relative humidity were studied by GC/MS. The volatile components in chewing gum were extracted by sample preperation and 15 volatile components were identified by NIST/NBS library searching. According to the period of storage, quantities of major volatile components extracted by tetrahydrofuran-methanol solutions were determined by using tetradecane as internal standard. Until 4 weeks, comparing with starting peak area ratio, the decrease of chewing gum flavor components were rapid at 33, 75 than 53 R.H(%). And after 16 weeks, amount of chewing gum flavor at all storage conditions similarly decreased to $45{\sim}49%$ of the initial amount.

• Analytical Science and Technology
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• v.7 no.4
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• pp.441-453
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• 1994

Two extraction methods, liquid-liquid extraction(LLE) and solid-phase extraction(SPE), coupled with GC/MS were compared as preconcentration procedures for priority pollutants in water. Among the semi-volatile priority pollutants, 11 acid and 44 base/neutral compounds were spiked in reagent water. With LLE, which is a modification of EPA Method 625, the overall mean recovery of the 54 compounds was 91% with a mean relative standard deviation(RSD) of 4.6%. With SPE, the overall mean recovery of the 52 compounds was 53% with a mean RSD of 8.9%. The detection limits of both methods were in the range of $1{\sim}5{\mu}g/l$.

• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.1-10
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• 2000

The purpose of this study is to establish the assessment techniques of hazardous chemicals by the development of analytical method of biological samples. In this study, we have developed an extraction method of nine pesticides used for rice paddy that resulted in high recovery from the spiked human urine by the liquid-liquid extraction with diethyl ether at pH 7.0. Calibration curve obtained from each pesticide standard using by gas chromatography/mass spectrometry/selected ion monitoring has shown good linearity and detection limits were the range of $0.4{\sim}2.0$ ng/mL in urine. As a biological monitoring, urine samples of local farmers exposed directly to nine pesticides in the field were collected and analyzed by GC/MS. Of the tested pesticides, metabolites of phenthoate assumed were identified by GC/MS analysis. No parent compound was detected.

• Analytical Science and Technology
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• v.10 no.1
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• pp.1-8
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• 1997

We identified nicotine, cotinine and toluene in high school volunteer's urine by using GC/NPD, GC/FID and GC/MS. To analyze of nicotine and cotinine, urine samples were extracted with diethylether and centrifuged on a benchtop centrifuge for 5 min. The upper organic layer was injected into a GC. The distributions of nicotine and cotinine were $4{\sim}630{\mu}g/L$ and $63{\sim}1,602{\mu}g/L$ in smoking-group, respectively. To analyze of toluene, head space vial was filled with 2mL sodium citrate solution and 1mL of urine. The vial was warmed in a water bath at $55^{\circ}C$ for 20min, and then $250{\mu}L$ of head space air was injected into a GC. The result show that toluene was not detected in all of the volunteers' samples. However, the range of toluene was 0.1~28.0mg/L in glue sniffer's urine samples(NISI data).

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.494-501
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• 1993

The volatile flavor components of traditional and commercial kochujang were collected by simultaneous steam distillation-extraction (SDE) method. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC/MS). Tested kochujang included Sunchang kochujang prepared with glutinous rice, Boeun kochujang prepared with barley, Sachun kochujang prepared with wheat and commercial kochujang. One hundred and twelve volatile flavor components which included 30 esters, 15 alcohols, 14 aldehydes, 13 acids, 9 ketones, 7 alkenes, 6 phenols, 3 alkanes, 3 pyrazines, 2 benzenes and 2 furans were identified. The major volatile compounds in traditional and commercial kochujang were 2-methyl propanal and ethanol, which represented $21{\sim}36%\;and\;2{\sim}44%$ of total GC peak area, respectively.