• 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.

• Analytical Science and Technology
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• v.17 no.1
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• pp.29-36
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• 2004

An analytical method of polybrominated diphenyl ethers in soil samples by isotope dilution method using gas chromatography/mass spectrometry (GC/MS)-selected ion monitoring (SIM) was described. PBDEs in soil were extracted with soxhlet extractor and then silica and florisil solid phase extraction (SPE) methods as purification of extract were compared. After clean-up, the extractions were analyzed by GC/MS with SIM mode. Quantitation was performed isotope dilution method using four $^{13}C$ isotopically labeled PBDEs as internal standards. This developed method was validated for eight congeners of PBDEs in the concentration range 0.04~4 ng/g in soil and the average recovery of the analytes ranged 30.8~110.8% for florisil and 44.4~110.7% for silica, respectively. The method detection limits of PBDEs were 0.04~0.3 ng/g.

• Analytical Science and Technology
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• v.13 no.4
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• pp.484-493
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• 2000

The simultaneous analysis of alkylphenols, chlorophenols and bisphenol A in biota samples was performed by gas chromatography-mass spectrometry-selected ion monitoring mode. The phenols were extracted from sample with organic solvent and Forisil and Silica columns for clean-up procedure were compared. Recovery studies were performed at 1-ppm level of phenols added to each biota sample. Their recoveries ranged between 83 and 116% with coefficient of variations of 2.4-11.9%. To improve the detection limits of phenols, trimethylsilyl (TMS) derivatization was applied. The gas chromatographic properties of free phenols and TMS derivatized phenols were also investigated.

• Analytical Science and Technology
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• v.14 no.5
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• pp.400-409
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• 2001

A method for the analysis of most common phthalate acid esters (9 secies) in biota samples by gas chromatography-mass spectrometry-selected ion monitoring mode is described. Phthalates in biota samples are extracted by organic solvent and purified by Florisil column. Phthalates are easily contaminated during extraction prodedure. Since the extraction and cleanup steps for biota samples generally are more complicate than those for water or sediment samples, we compared with contamination state of each sample work-up step. By applying this developed method, the overall recoveries ranged between 79 - 117% in biota sample which was spiked with standards. For phthalates used in this study, the quantitaive accuracy, elution pattern on Florisil column, and detection limits were also investigated.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.389-397
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• 1996

The volatile concentrate obtained from the edible Korean dureup plant (Aralia elata Seem.) by a distillation-extraction system was separated into hydrocarbon and oxygen-containing fractions, and the latter was further separated into nine subfractions by silica gel column chromatography. Gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) were utilized to identify 167 volatile compounds in the fractions. The volatile compounds included 72 hydrocarbons, 31 alcohols, 23 aldehydes, 16 esters, 10 acids, 6 ketons, 3 furans, 2 phenols, 1 indole, 1 oxide, 1 sulfide, and 1 lactone. ${\beta}-Caryopyllene$, a sesquiterpene hydrocarbon, was the most abundant volatile compound identified in Korean dureup (19.53%). Dureup oil was found to possess a woody or herbaceous aroma following sensory evaluation of each fraction and individual volatile component using a GC-sniff apparatus.

• Analytical Science and Technology
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• v.14 no.6
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• pp.499-503
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• 2001

A new simple, rapid and sensitive gas chromatographic technique for the determination of bisphenol-A in can materials, which is the major material of epoxy resin and polycarbonate polymer, is proposed. This method is characterised by derivatization of the bisphenol-A with a acylating reagent forming the acetate derivative to optimize the chromatographic property. The detection of bisphenol-A is performed based on GC/MS (gas chromatography/mass spectrometry). Several beverages were analyzed by the proposed method for the determination of bisphenol-A Bisphenol-A was assayed the range of $0.11{\sim}11.40{\mu}g/can$ from the can materials.

• Industry Promotion Research
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• v.9 no.1
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• pp.13-20
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• 2024

In this study, we conducted a compositional analysis of five darkening shampoos available in the South Korean market and evaluated their active ingredients and safety based on the analysis results. GC-MS analysis was employed to identify the main components of each shampoo, revealing discrepancies between the detected compounds and the ingredient lists provided by the manufacturers. These differences are interpreted as being due to the limitations of the GC-MS analysis and the volatility of certain compounds. Further investigations were carried out to explore compounds potentially contributing to hair darkening. However, it was not definitively concluded that these compounds are directly involved in the hair darkening process. It is speculated that they may enhance hair care product performance and offer additional benefits to hair, or improve product texture, stability, or preservation. Additionally, the GC-MS analysis identified several compounds with potential safety concerns, necessitating caution when used as cosmetic ingredients.

• Journal of the Korean Chemical Society
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• v.41 no.9
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• pp.471-482
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• 1997

GC/MS was used to find an optimum experimental condition for the screening of organic acids in urine. Urinary organic acids were isolated through the liquid-liquid extraction method (LLE) to examine the influence of pH and the effect of including the back extraction and oximation processes respectively on the extraction. When pH was adjusted to 0.5 during the extraction without oximation process, relatively higher recovery rate and the smallest relative standard deviations (0.3-12.4%) were obtained. By removing the interference, the addition of back extraction made possible surer identification of organic acids with retention time of 15-16 minutes. Under this condition, we obtained the content distribution of urinary organic acids in healthy Korean children (n=16) by establishing the calibration curves for 51 standard organic acids.

• Journal of the Korean Chemical Society
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• v.40 no.4
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• pp.235-242
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• 1996

A surfatron-type microwave induced plasma (MIP) cavity has been constructed, which can be easily interfaced with a gas chromatograph. Various plasma gases such as He, Ar and N2 were used to generate the MIP and small amounts of CO2 gases were injected through the MIP to obtain characteristic spectrum of each plasma gas and to study feasibility of the MIP as a soft ionization source. Since He and Ar plasmas have high metastable state energy, it was not possible to detect sample gas in molecular state. With N2 plasma, however, a strong emission of molecular ions could be detected owing to its low metastable state energy.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2000.12a
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• pp.43-43
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• 2000